Industrial Radioisotope Economics

TECHNICAL REPORTS SERIES No. 40

00000517577 INDUSTRIAL RADIOISOTOPE ECONOMICS The following States are Members of the International Atomic Energy Agency:

AFGHANISTAN IVORY COAST ALBANIA JAPAN ALGERIA REPUBLIC OF KOREA ARGENTINA KUWAIT AUSTRALIA LEBANON AUSTRIA LIBERIA BELGIUM LIBYA BOLIVIA LUXEMBOURG BRAZIL MALI BULGARIA MEXICO BURMA MONACO BYELORUSSIAN SOVIET SOCIALIST MOROCCO REPUBLIC NETHERLANDS CAMBODIA NEW ZEALAND CAMEROUN NICARAGUA CANADA NIGERIA CEYLON NORWAY CHILE PAKISTAN CHINA PARAGUAY COLOMBIA , PERU CONGO (LÉOPOLDVILLE) PHILIPPINES CUBA POLAND CZECHOSLOVAK SOCIALIST REPUBLIC PORTUGAL DENMARK ROMANIA DOMINICAN REPUBLIC SAUDI ARABIA ECUADOR SENEGAL EL SALVADOR SOUTH AFRICA ETHIOPIA SPAIN FINLAND SUDAN FRANCE SWEDEN FEDERAL REPUBLIC OF GERMANY SWITZERLAND GABON SYRIA GHANA THAILAND GREECE TUNISIA GUATEMALA TURKEY HAITI UKRAINIAN SOVIET SOCIALIST REPUBLIC HOLY SEE UNION OF SOVIET SOCIALIST REPUBLICS HONDURAS UNITED ARAB REPUBLIC HUNGARY UNITED KINGDOM OF GREAT BRITAIN ICELAND AND NORTHERN IRELAND INDIA UNITED STATES OF AMERICA INDONESIA URUGUAY IRAN VENEZUELA IRAQ VIET-NAM ISRAEL YUGOSLAVIA ITALY The Agency's Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July 1957. The Headquarters of the Agency are situated in Vienna. Its principal objective is "to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world".

(C) IAEA, 1965 Permission to reproduce or translate the information contained in this publication m ay be obtained by writing to the International Atomic Energy Agency, Kärntner Ring 11, Vienna I, Austria.

Printed by the IAEA in Austria February 1965 TECHNICAL REPORTS SERIES No. 40

FINDINGS OF THE STUDY GROUP MEETING ON RADIOISOTOPE ECONOMICS HELD IN VIENNA, 16-20 MARCH 1964

INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 1965 International Atomic Energy Agency. Industrial radioisotope economics. Findings of the Study Group Meeting . . . held in Vienna, 16- 20 March 1964. 576 p. (IAEA, Technical reports series no. 40)

621.039.8.003

INDUSTRIAL RADIOISOTOPE ECONOMICS, IAEA, VIENNA, 1965 STI/DOC/10/40 FOREWORD

Within twenty years of the availability of radioisotopes in quantity the use of these as tracers has been widely applied in scientific research and in industrial process and product control. Industry spends millions of dollars on these new techniques. Since the overall attitude of industry is to favour methods that involve rapid financial returns the economic benefits must be considerable. In promoting the peaceful uses of atomic energy, the IAEA is actively interested in the international exchange of experience in all applications of radioisotopes. This has been demonstrated by a number of scientific conferences where new results of direct importance to the industrial use of radioisotopes have been presented. In 1963 the IAEA also published a literature survey on radioisotope applications described in the scientific literature up to 1960, classified according to industry. However, the available scientific literature was found insufficient to determine the extent of the use of radioisotopes and the economic benefits derived from it. Therefore, further fact-finding efforts were necessary. The IAEA thus decided to carry out an International Survey on the Use of Radioisotopes in Industry. In 1962 the IAEA's highly industrialized Member States~were invited to participate in the Survey; 25 declared their willingness to do so and in due course submitted their national reports. These included information on how radioisotopes were used by industry in each country and indicated the size and form of the economic advantages, primarily in terms of savings made by industry. The findings from the Survey were discussed at a Study Group Meeting on Radioisotope Economics, held in Vienna in March 1964. The officer-in-charge of the Survey was Hans G. Forsberg of the IAEA's Division of Research and Laboratories, who also acted as Scientific Secretary to the meeting. The valuable contributions of Member States, the authors of individual papers, and of the invited experts are gratefully acknowledged.

CONTENTS i. Background to the Survey 3 Administration and implementation of the International Survey on the Use of Radioisotopes in Industry 7 Basic economic and statistical considerations 13

II. NATIONAL REPORTS Argentina 21 Australia 31 Austria 49 Belgium 55 Canada 61 Czechoslovakia 71 Denmark 77 Finland 85 France 91 Germany, Federal Republic of 105 Israel 117 Italy •. 119 Japan . 123 Netherlands 133 Norway 141 Poland 155 Portugal 161 South Africa 163 Spain 171 Sweden 177 Switzerland 187 United Kingdom 193 United States of America 257 Venezuela 287 Yugoslavia 289 Information about non-participating countries 297

III. TECHNICAL AND ECONOMIC SUMMARIES The uses of radioisotope gauges in industry 303 J. F. Cameron (IAEA) Economic benefits of radioisotope gauging 329 The use of ionization methods in industry 359 C. G. Clayton (United Kingdom) Economic benefits of ionization methods 395 Gamma-radiography: A rough comparison with other non- destructive testing methods 401 J. Th. Bering (Netherlands) Economic benefits of industrial radiography 417 Emploi des sources importantes de rayonnement . . 429 P. Lévêque (France) Economie benefits of massive irradiation 437 The use of radioisotopes in industrial tracing 439 Knut Ljunggren (Sweden) The industrial use of analytical tracer methods 459 G. B. Cook (IAEA) Economic benefits of radioactive tracer methods 465 Miscellaneous industrial applications of radioisotopes 477 H. G. Forsberg (IAEA)

IV. PRESENT RESEARCH THAT MIGHT AFFECT THE USE OF RADIOISOTOPES IN THE FUTURE The United States Atomic Energy Commission programme on isotopes and radiation development and its industrial impact . . 485 E. E. Fowler (United States of America) Discussion 510

V. PANEL DISCUSSION Obstacles to an increased use of radioisotopes 519 (Chairman: L. G. Erwall; Panel Members: C. G, Clayton, R. Cornuet, E. E. Fowler, J. P. van Gansberghe and H. J. Marcinowski)

VI. RESULTS OF AND CONCLUSIONS FROM THE SURVEY 539

VII. APPENDICES Appendix I: Questionnaire 553 Appendix II: List and explanation of "Broad product groups" .... 569

List of Chairmen of Sessions and Secretariat 571 List of Participants 572 INTRODUCTION

BACKGROUND TO THE SURVEY

The history of industrial applications of radioisotopes is not long. With the exception of a few techniques, namely gamma radiography and tracer investigations of chemical reactions and piston-ring wear, it has all developed after the second World War. The interest in this field has been considerable. In the period 1951-1960 more than 1000 scientific papers were presented at 15 big national or international meetings. A recent literature survey, which by no means claimed to be exhaustive, recorded some 2500 original or survey papers published up to the end of 1960. The number of articles published later is not known, but all evidence shows that the trend is still positive, even though many applications are so well-established that nothing at all is published in those fields any more. This very rapid development might well be justified scientifically on the basis of the very interesting facts that have been revealed with the use of radioisotopes. But this is not the only factor. Quite soon it was realized that a still more important reason lay in the direct and indirect economic benefits industry was gaming by applying these radioisotope methods. It is known that industry's attitude towards scientific inventions may be summarized as: "Does it pay?" And, evidently radioisotope methods did pay, for the industrial demand for their introduction grew, even though in the early days radioisotopes were neither easily obtainable nor were the devices for detection of radiation very advanced or even reliable. In the middle 1950's, many scientists were of the opinion that after ten years of experimental work economic nuclear power would be just around the corner. They turned out to be somewhat over-optimistic; another decade had to pass before the enormous investments in nuclear power could start to pay off. However, it had already been argued that the greatest contribution to mankind and to the world economy would, in the foreseeable future, come not from the big installations of nuclear power but from the very small ones — the radioisotopes, obtained as by-products in nuclear research reactors. To support this view, some people started to collect information which would allow a calculation of the total benefits deriving from the industrial applications of radioisotopes to be made. In 1953, the United States Atomic Energy Commission published an estimate, based upon interviews with a small number of users and extrapolating to obtain a figure for industrial establishments in the United States of America, making use of radioisotope techniques. The result obtained was $ 122 million. This was up-dated in 1957 and its results became world famous when, at the UNESCO Radioisotope Conference in Paris that year, W. F. Libby, at that time a member of the United States Atomic Energy Commission, claimed that in 1957 industry in the United States would save about $ 400 from radioisotope use alone, and that this sum would have reached the figure of $ 2000 million in five years' time, i. e. in 1962. At the Second United Nations International Conference on the Peaceful Uses of Atomic Energy held in Geneva in 1958, a spokesman for the Soviet Union claimed that the industrial applications of radioisotopes yielded savings of 1700 million roubles in the USSR. Then, in 1959 a more detailed survey in the United States was published — the results of this survey gave a figure 4 INTRODUCTION

which was only a tenth of what Libby had stated. And, more recently the Chairman of the Atomic Energy Board of the Soviet Union presented figures for 1961 of 200 million roubles. Inspired by these surveys, several smaller ones were run, e. g. in the United Kingdom and in Sweden. These surveys indicated very considerable direct savings and much more important indirect and potential economic benefits. It is obvious that the approaches had differed from one survey to the other and it is very difficult to draw any definite conclusions from the published figures. Therefore, one needed an international survey which used the same techniques in all countries. On one hand it would be possible to make a comparison of the extents to which industry in the various countries had introduced this new technical method; on the other hand it would also be possible to determine the most appropriate way of estimating the economic benefits. Being an international organization, the International Atomic Energy Agency would clearly be the most appropriate body to administer such a survey. The IAEA Secretariat had for many years been interested in seeing whether such a project would be feasible with the international co-operation it required. However, there is no shortage of projects for the Agency, so it is possible that this one would have been postponed into the distant future had it not been for some additional factors that gave the necessary impetus to the project. The first and most important factor originates from the Agency's position in the United Nations family of international organizations in dealing with the problems of the industrialization of less-developed countries. Many of these countries have established their own national Atomic Authorities, which are the Agency1 s counterparts in these countries. Their main duty is, of course, to introduce nuclear energy. But it is quite clear that the introduction of nuclear power stations in these countries would, for the time being, be a waste of money and of useful scientific and technical manpower; conventional energy is still very competitive. But in every country on earth the introduction of nuclear power in its diminutive form, i. e. as radioisotopes, is worthwhile. All fields of radioisotope methods are included — medical, agricultural, hydrological and industrial. Here, then, is an excellent and very important playground for these authorities. The less-developed countries have many needs and it may not be so easy for a local atomic energy commission to convince the governmental administration of the importance of spending money on radioisotopes. However, the goal of all governmental activities today is industrialization — this is the only established pathway to economic development. With reliable figures on how radioisotope methods are used in the already industrialized countries and if these figures show the economic advantages accruing, the commissions' task of making their governments isotope-minded will be made much easier. Economics is something that every government understands for, whatever the political system in a country, decreased cost of industrial production means more money to the state, either as owner of industry or by taxes, and improved competitiveness on the world market. Provided that an international survey could give figures which show promise of future savings — BACKGROUND TO THE SURVEY 5

quite apart from the human considerations associated with the use of isotopes, e. g. in medicine — the commissions would obtain greater support to their devoting part of their activities to radioisotope work. There was also another means. No doubt the radioisotope methods are fairly well introduced in the industry of industrialized countries, but most scientists in this field have a strong conviction that the number of applications could be multiplied, on one hand by introducing established techniques in a greater number of industrial plants, and on the other hand by developing new methods. Radioisotope techniques, such as we know them today, are not likely to be the most refined ways of using nuclear radiations. There are many reasons why radioisotopes are not more frequently needed — fear, reluctance to adopt new methods, legislation, lack of knowledge and last, but not least, inability to see the economic advantages in any individual case. Results from an internationally guided survey would be the most likely to remove these and any other obstacles to an increasing use of radioisotope methods and to increased research for their improvement. Of course, for such a survey each country must achieve the necessary co-operation between industry and a suitable national body, which is prepared to devote its best forces to producing a useful and vital report. After some preliminary consultations, the Agency felt that it would be worthwhile and feasible to go ahead with such an international survey. The purpose of it had to be two-fold: it had to account for the actual applications of radioisotopes and also for the economic benefits derived. In choosing the timing of the survey, one further point had to be considered. In the early stages of introducing any new technique it is relatively easy to demonstrate how improved technical and economic results can be directly attributed to the particular technique. The longer the time after its introduction the more difficult is this task. The reason is that people forget, or cannot reconstruct, the situation existing before the introduction of the new method. All technological processes are subject to continuous change and, when a sufficient number of changes have taken place, it is no longer possible to determine with any validity what benefits should be credited to the one or other improvement. For example, there comes a time when the use of a particular technique, say the use of electricity, has been so universally accepted that it becomes impossible to think of an industrial process without it. Sooner or later the same thing, even if on a smaller scale, will be the case with radioisotopes. In the early I9601 s the methods, introduced in the 1950's and now in regular operation, were still at a stage where the economic advantages over using older processes could be assessed. In a few more years' time it will probably not be made with any accuracy. So, in the autumn of 1961, the Agency decided to put such a survey in its 1962 programme. This publication is the report on this undertaking, "The International Survey on the Use of Radioisotopes in Industry". It begins with a presentation of the methods used to administer and implement the Survey and some basic economic and statistical considerations. The second part contains the highlights of the individual national reports, submitted to the Agency by the participating Member States. The reports have been edited by the Agency's Secretariat in order to make their contents readily comparable. Each report 6 INTRODUCTION includes a short paragraph on the activities of the particular national Atomic Energy Authorities in the field of industrial applications of radioisotopes. Then follow reviews of the technical and economic aspects of certain radioisotope techniques contained in the national reports. The findings of the Survey were discussed at a Study Group Meeting on Radioisotope Economics held in Vienna from 16-20 March 1964. The points raised in the discussions at this meeting were also considered in the above- mentioned reviews. Also from this meeting are included the text of a lecture and the subsequent discussion devoted to present research that might affect the future use of radioisotopes, and the records of a panel discussion on obstacles to an increased use of radioisotopes. The results and the overall experience of the Survey are presented in a concluding chapter. ADMINISTRATION AND IMPLEMENTATION OF THE INTERNATIONAL SURVEY ON THE USE OF RADIOISOTOPES IN INDUSTRY

In 1960 the Agency contacted those bodies which were known to have made similar national surveys and asked for their views on international co-operation in this field. Although warned that the project would be large and would necessitate great efforts from both the Agency and the participating countries, the overall opinion was positive and the preparatory work was then started. In July 1961 a Consultants' Meeting was called to advise on the intended IAEA survey. The purpose of the Consultants' Meeting was to discuss the most practical approach to this problem by drawing on the experience of the consultants present, all of whom had been closely involved in earlier attempts of this kind. It was agreed that the purposes of the survey should be to outline the present applications of radioisotopes in industry, and to calculate their economic benefits. It was decided to consult a survey statistician for advice on the preparation of a questionnaire which was to be as simple as possible. This questionnaire was to be circulated and collected by national bodies nominated by governments, partly because the Agency did not have the necessary personnel and partly because the industrial firms concerned might not wish to give information to an international organization. If desired, the national bodies could add their own questions and use them for any national purpose. The reports forwarded to the Agency should, however, be prepared in a convenient standard manner. The experts recommended that the best way to implement the survey would be to ask all the industrialized member states of the Agency to undertake similar approaches to all industries actively using radioisotopes and that the results should be based mainly on the industries' attitudes to the savings pattern. Nevertheless, the Agency secretariat should provide the national bodies with the necessary information on how to estimate savings, so that they could assist individual users. Too detailed an instruction should, however, be avoided, as this might hamper the individual initiative of the national bodies, particularly as they might invent new and appropriate methods for estimating savings. It was already clear that only a limited number of firms would be in a position to give figures on savings. Nevertheless, it was recommended that the highest possible response rate should be aimed at to permit the most detailed technical review on how isotopes are used by industry. All the national surveys should, if possible, cover the same period. The experts also recommended that a scientific meeting should be arranged as soon as possible after the conclusion of the survey to compare the national reports and discuss overall results. On the basis of these recommendations, the questionnaire and the presentation of the survey were prepared by the Agency secretariat and Mr. W. Rudoe of the United Kingdom Board of Trade acted as survey statistician consultant. 8 INTRODUCTION

Early in this work it was found convenient to use one questionnaire form in order not to deter respondents from participating in the survey at the very beginning. Further, it was found practical to separate the questions relating to savings estimates from those relating to types and benefits of radioisotope techniques. "Savings" were defined as "a measurable difference in costs between the method used before introducing radioisotope techniques and the new radioisotope method. " According to this scheme, "direct savings" are defined as raw material savings, finished product scrap savings, labour savings etc., while "indirect savings" are defined as avoid- ance of shut-downs, better process control etc. "Customers' savings" and "intangible savings" should not be accounted for in the survey. In the second part of the questionnaire, a check list of radioisotope techniques and benefits were included in order to standardize and facilitate matters. The following six groups of radioisotope techniques were distinguished: radioisotope gauging, industrial radiography, ionization applications, tracer techniques, massive irradiation and miscellaneous applications. At an early stage in this work, economists objected to the broad scope of the survey which could lead mainly to indirect savings estimates, which are difficult to calculate. They felt that a more defined approach could be established by selecting radioisotope techniques according to their inherent power to create economic gains which could be calculated satisfactorily. This approach would certainly profit by more reliable figures, but would contribute less to the general understanding of the importance of radioisotopes to industry which was one of the main purposes of this survey. Realizing that these problems exist, the Agency tried to prepare and present the survey in such a way that difficulties would not seriously hamper its real aim, which was to make radioisotope applications more attractive to industry. On 25 April 1962, 37 of the Agency's most developed member states were invited to participate in the survey and to nominate bodies responsible for its implementation. In order to facilitate the decision of the member states, a provisional model of the questionnaire together with an addendum giving additional information was attached to the invitation. Asa quick response was hoped for, it was suggested that the national surveys should ask for data for a period of 12 months, preferably the calendar year 1961. When, by July 1962, 10 member states of the Agency responded posi- tively to the invitation and had replied to the effect they would perform national surveys, it was finally decided to start the project. Thus, in the middle of August, the first instructions were distributed to the national bodies together with the final version of the questionnaire the Agency suggested for use. These questionnaires were printed in the four working languages of the Agency and those countries which might use the forms were invited to request the number of copies necessary from the Agency. Countries requiring questionnaires in other languages were asked to arrange for printing themselves. The questionnaires are given in the Appendix. It was pointed out that those member states which found the questionnaire impractical for their purposes were allowed to prepare their own, but the hope was expressed that these should at least contain the minimum information requested in the Agency' s questionnaire. IMPLEMENTATION OF THE INTERNATIONAL SURVEY 9

Together with the questionnaire, suggestions as to how they should be completed were also distributed. It was pointed out that the national bodies had to make the final version of these instructions, dependent upon local conditions. Certain advice was also given to the national bodies concerning how the questionnaire should be used. Thus, it was pointed out that their first duty would be to make a list of all users of radioisotopes which,in most countries, are registered with the national health authorities. Secondary information might also be received from companies dealing in instruments, so that a cross-check could be made. As far as radiography and tracing were concerned, special firms have been established which assist industry in these fields. Co-operation with such firms would be most favourable for clarifying all applications of radioisotopes, so it was suggested that national surveys should be performed in close co-operation with these firms. In many cases the health authorities might not have details of the actual work performed by such firms, since they have a general licence for work with radioisotopes. It had to be considered whether it would be necessary to ask for detailed information from all companies making use of the services of these firms, or whether one should collect information through the servicing firms. The most qualified person to fill in the questionnaire would be the head of the works departments or any other responsible engineer. However, the initial letter and questionnaire would probably have to be sent to the director of the establishment. Thus, the circular letter must be in such a form that the addressee should refer it to the most appropriate person. Finally it turned out that 25 of the Agency's member states decided to participate in the survey. Of these, 18 have implemented complete surveys as suggested by the Agency; nine made use of the Agency's questionnaire; and nine designed questionnaires of their own. However, in most cases these were only translations of the questionnaire into the appropriate languages. Much more detailed questionnaires were developed only by the French and the UK national bodies. Of the remaining participating countries, two which had recently completed similar surveys replied to the effect that they would use the information then collected at that time and only bring it technically up to date. The remaining five countries have made other approaches to the project, or submitted limited reports only. In the invitation it was suggested that the survey should be limited to the manufacturing industry. At the request of a number of participating countries it was later decided to widen the scope of the survey to include the uses of radioisotopes in prospecting, mining and ore treatment, as well as in petroleum recovery. The industrial activities were, for the convenience of participating countries, split up into 12 broad product groups, mainly in accordance with the United Nations International Standard Classi- fication. The groups were as follows: "Food", "Tobacco", "Textiles and Footwear", "Wood and Paper", "Leather and Fur", "Rubber", "Chemicals and Plastics", "Cement, Glass and China", "Petroleum and Coal", "Basic Metals", "Machinery", and "Services". Further details of the groups are seen in the Appendix. 10 INTRODUCTION

A few applications of radioisotopes do not fit easily into any classification system, neither according to techniques nor to product group. A list of such applications, as well as suggestions concerning how they should be treated, was distributed by the Agency. As far as the economic details of the questionnaire were concerned, the opinion of industry was, in principle, to be accepted. From experience in earlier surveys of making direct approaches to industry, it was estimated that only a limited number of the reports would contain complete and treatable information. Therefore, it was suggested to the national bodies that they should perform follow-up actions so that all the necessary data would be obtained. As a basis for follow-up actions the filled-in questionnaires were to be used and thus it would be wise to allow the companies to keep a copy of their reply. Many companies are themselves not aware of the possible ways in which the benefits gained by using radioisotopes can be estimated. This might be the most common reason for lack of information on the forms returned. During follow-up actions it might therefore be advisable if the national bodies could give industrial people such guidance as would enable them to complete the forms accordingly. Detailed evaluation of the replies is also not possible if one has no definite scheme to follow. In the second part of the instructions issued in February 1963, national bodies were therefore given some notes on suitable methods for estimating radioisotope economics. By using these notes it was hoped that the national bodies would be able to prepare the economic contents of the national reports. However, more detailed treatment of data probably necessitates first- hand knowledge by the national bodies of such important facts as accuracy of nuclear and alternative gauges, operational experience of X-ray and radioisotope sources in radiography etc. This can only be obtained by making a few detailed case studies of routine applications. Such studies may also suggest other ways to treat the technical data, which in certain cases would be more relevant than those suggested by the Agency. For many reasons carefully made case studies would be more important than summaries of subjective information from industrial engineers for showing the economic benefits of radioisotope methods. Thus, in all correspondence with national bodies the Agency has underlined the value of such case studies. Also, the opportunity of examining the economics of more unusual or quite unique applications of radioisotopes, where the results would be of world-wide interest, is of equal value. The inclusion of such studies in the report to the Agency would require the permission of the company involved. However, it was felt that the publicity value for the company would be so great that active participation could be anticipated. In the second part of the instructions it was stated that final reports to the Agency were expected not later than 31 August 1963. In the part a suitable scheme for breaking down replies was suggested which would be particularly useful for countries with a wide range of industrial isotope applications. Further instructions were issued in June and October 1963. They dealt mainly with details concerning how the national reports should be submitted IMPLEMENTATION OF THE INTERNATIONAL SURVEY 11 to the Agency and informed the national bodies about the organization of a meeting to discuss the survey. By the official deadline date for the submission of reports, the Agency had received only nine contributions to the survey. At the end of 1963 the total number of reports had grown to 20 and, by the time of the study group meeting (see below), to 23. The remainder arrived in July 1964. Already, at an early stage of the preparatory work, it was felt that the findings of the survey should be discussed at a meeting of all the participating national bodies. It was finally decided that this should take the form of a Study Group Meeting on Radioisotope Economics and 16-20 March 1964 was the date chosen. The meeting was held at the Agency1 s headquarters in Vienna. All participating countries were asked to send participants to the meeting, while the rest of the Agency's Member States, as well as a number of international organizations, were asked to send observers. Well-known scientists were asked to review the various techniques included in the survey. Experts in statistics and economics, who assisted the Agency Secretariat in evaluating the reports, also attended the meeting. Forty participants from 22 countries were nominated for the Study Group Meeting. Seven non-participating Member States and three international organizations were represented by 23 observers. The programme of the meeting was divided into three parts, namely: I Experience of the International Survey on the Use of Radioisotopes in Industry II Present Use of Radioisotopes — technical and economic aspects III Summary of present and outlook for future use of radioisotopes in industry. Within the first part, four lectures were given concerning the background of the survey, its administration and the statistical and economic aspects involved. After the speeches, comments were made by various participants on the experience collected in their national surveys. The national reports, as well as a number of the working papers, were made available to the participants before the meeting started. The contents of the national reports were summarized by experts, each in his field, and presented to the audience. Three days were used for this mapping of present usage; the economic aspects were mainly covered by case studies, presented by participants. The last day was devoted to the third point on the Agenda and began with a summary of present research that might affect the future use of radioisotopes. Afterwards came two panel discussions, one on experience of obstacles to an increased use of radioisotopes, the other on the results of the survey and the meeting. These were prepared before and during the meeting by small working groups. The discussions at the Study group Meeting and the Supplementary information obtained from various countries have been used as a guidance for the Agency1 s Secretariat when preparing the text of this publication.

BASIC ECONOMIC AND STATISTICAL CONSIDERATIONS

A survey of this type is in the nature of a piece of market research and the methods applied for such purposes would, of course, also be relevant for this task. The trouble was, however, that few countries were expected to put the corresponding efforts and money into it — permitting visits, telephone interviews etc. In preparing the survey, the use of a questionnaire to be mailed to industry appeared to be the only practical approach. Then, the main problem is to secure a high response rate. All experience from national surveys on radioisotope use, as well as from other enquiries directed to industry showed that a questionnaire has to be as simple as possible, even at the loss of certain useful information. In drafting the Agency questionnaire this point was always kept in mind. At an early stage it was already clear to the Agency that the detailed information on economics would not be easy to obtain. In some cases companies may prefer not to divulge information because of their concern for security, but in most cases the reason is that sufficient technical data are lacking. Calculation of total savings from any particular technique in any category of industry would most likely need an up-scaling. The same, of course, applies to any attempt to assess the total benefits to a country. Only in the NICE Survey of 1958 was such a high response rate obtained that the results could be used and claimed to be the total benefits. These attempts might be made in various ways. When designing the questionnaire the experts prepared several possibilities for the national bodies. As radioisotope users are, in most countries, registered with the public health authorities or other official bodies, it is in practice possible for any national body to obtain complete lists of users. This is the necessary way to discover to whom the questionnaire should be mailed, but it can also be used for other purposes. Often the registers keep records of the number of sources, purpose of installations etc. With some effort it would then be possible for any national body to determine the response rate of any particular technique in addition to the over-all response rate when the forms are returned. It would also be possible to calculate the response rate, not only with regard to the number of users, but also to the number of devices of various kinds. In many cases this would be the most convenient way for any up-scaling work. The other way was to raise the question of isotope-assisted output. If this figure and the figure of total output of a particular firm is given, it can be compared with the total output figures of all firms employing a particular technique, or all the firms of that branch in a country. By using such data, a scaling-up of the economic content of forms returned from a proportion of the total industry would be meaningful, both to estimate the total savings from a particular technique and the potential savings if this technique would be applied to all industrial users. With this information on hand the savings reported could also be related to the value of the isotope-assisted output. It is most likely that this relation would be relatively constant for individual applications. The questionnaire suggested by the Agency is found as Appendix to this publication. The check-list in its Part II ought to be self-explanatory; it

13 14 INTRODUCTION includes indications of the type of application so that the national body would be able to make the necessary breakdown of techniques when presenting the national reports. The benefits to be indicated here were selected as the most likely ones under each heading. The savings, if any, were to be specified under Part I. There is no doubt that radioisotopes produce tangible benefits to industry; no other explanation can be given for the widespread and growing use of this technique. In a few cases research is done which will not pay yet, but should do so in the future. But most of the industrial uses today are found in manufacturing so the most important savings are probably found there. These manufacturing savings can be attributed to a limited number of cases, namely Savings in raw material; Savings of scrap; Savings of labour; Savings of other production factors (such as power); Savings, because of increased production (fewer shut-down decrease of adjustment time; and Savings because of lower capital and maintenance costs. To this list others may be added which are less easy to account for in direct savings. In the questionnaire the three last cases were grouped together to limit the number of points. The savings given by industry would in most cases be given "gross", i. e. without deduction of the costs. Where "net" savings are given, this must be specified. In Part I the various elements constituting the cost of radioisotope use were asked for. Any additions to the equipment and facilities installed or acquired in 1961 were to be listed separately. Figures were requested for installations (radioisotope, equipment, structures etc.) and for annual costs (maintenance and operation). Any meaningful economic analysis has to be a comparison of costs and revenues. The analysis of these factors is a science in itself. But to attain the objective of the survey "to calculate the economic benefits, the radioactive aids mean to industry", one must, in a broad survey of this kind, maintain the business man's viewpoint and keep the manipulation with data to a minimum. Consequently, a straightforward system of analysis was suggested that would present the facts in a simple but acceptable way. The costs are of two different types: installations, which have to be given a certain depreciation each year and annual costs, such as maintenance and operation. The possible way of presenting the economic results may be

Net annual savings; Investment — gross annual savings, minus other annual costs; and Total annual costs — gross annual savings.

The first figure might be the simplest to present, but it is a bit difficult to see its significance if one does not know the efforts made to reach this figure. A comparison of a net sum with any cost factor is scientifically incorrect and should therefore be avoided. BASIC ECONOMICAL AND STATISTICAL CONSIDERATIONS 15

A comparison of the investment with the measurable benefits (gross annual savings less maintenance or operation costs) is a very useful one for many purposes. It is very frequently used as a basis for decisions on a company's investment policy, because it illustrates the number of month's or years' operations that are necessary for an investment to pay off, i. e. the amortization period. The third way j.s to make the straightforward comparison between an annual cost and an annual benefit. This has the additional advantage already in the calculation of including a relevant depreciation period and considers the interest which, when expensive installations are made, is quite a considerable factor. When evaluating the national reports this method will be used as the most appropriate one: the results presented as the cost-benefit ratio, which can be formulated as

C:B

where C = annual cost and B= gross annual savings. The gross annual savings are normally provided for in the questionnaire. The annual cost is best accounted for using the formula

C = M + I(l/t+ r/200)

where M = annual maintenance and operation costs, I =total investment, t = depreciation period, yr, r= interest (cost of money to the company), in %. As depreciation periods the following seem to be appropriate: For equipment 5 yr, for constructions 5-30 yr and for buildings 30-90 yr. The rate of interest differs from country to country, but for the survey period and in the participating countries 6-10% seems to be a generally accepted level. Whether the cost of isotope (3i) should be accounted for in the depreciation scheme, or as part of the maintenance costs, depends on the nature 60 3 of the source. Such nuclides as Co , Cs* ? and Sr90 t which have a long half-life, are most likely to be added to the equipment costs and given a five year's depreciation. Rather short-lived nuclides such as Ir192 and substances used as tracers should be considered as part of the annual maintenance costs. For sources with an intermediate life-span, such as those containing Te204 or Pm147 and certain brems Strahlung sources, some appropriate depreciation period should be chosen. However, in most industrial - applications, the source costs are of limited importance and the way they are dealt with will not considerably affect the total result of the annual cost estimate. Using the approach, a cost-benefit ratio of 1:1 or higher indicates that if the tangible savings do not motivate the use of this method if it is still applied, the company is either .operating at a. loss or there are intangible savings that outweigh the direct disadvantages. As the later figure in the ratio increases, the manufacturing becomes more and more beneficial. 16 INTRODUCTION

TABLE I

ECONOMIC INFORMATION CONCERNING COUNTRIES PARTICIPATING IN THE IAEA INTERNATIONAL SURVEY ON THE USE OF RADIOISOTOPES IN INDUSTRY (Values for 1961)

Output value Percentage Factor costv of Exchange Output gross Population Country Currency rate for per capita national (Million) US$ Local Million product (US$) currency US$

Argentina pesos 140 246 X 1Û9 1760 29 21.0 85 Australia A.£ 0.45 2.7 Xl09a 6000 (36) 10.5 560 Austria A.S. 26 80 xlu9 3100 55 7.1 435 Belgium B. Fr. 50 231 X109 4600 49 9.2 500 Canada Can. S 1.05 13.0 Xlu9 12400 39 18.2 680 CSSR Information not available Denmark D. Kr. 7 17.7 X109 2600 39 4.7 550 Finland F. M. 3.3 5.9 X109 1 800 42 4.5 400 France N. F. 5 154 XIO9"3 30800 46 46.0 660 Germany, Fed. Rep. of DM 4 145 X109

Source: UN STATISTICAL YEARBOOKS and "The Growth of World Industry" 1938-1961 * Includes Mining, Manufacturing, Construction and Utilities (ISIC 1-5).

1 July 1961-30 June 1962. Gross domestic product at market prices. Excludes wine production but includes fishing. ' Includes the Saar and West Berlin. Net domestic product at factor cost. ' Includes transportation, storage and communication. Net material product. ; 1960. Assumption made by the Agency. Gross material product. BASIC ECONOMICAL AND STATISTICAL CONSIDERATIONS 17

When a representative case is calculated, with t = 5 yr, interest at 6%, and M = 0. 02 I, one arrives at annual cost C of 0. 25 I. With a C:B equal to 1:4, the equipment represented by I will be amortized in one year: the amortization period is 12 months. Increasing C:B ratios give correspondingly longer amortization periods. To permit a comparison of the extent to which various countries make use of radioisotopes, information about the industrial output is needed. Such is given in Table I; the information contained in it is mainly quoted from UN Statistical Publications. It has also been checked and completed by the UN Statistics Office.

NATIONAL REPORTS

ARGENTINA

The survey in Argentina was performed under the auspices of the Na- tional Atomic Energy Commission and was conducted by Mr. A. C. Castagnet and Mr. J. J. Di Gregoro. It covers the conditions valid in the period from middle 1961 to middle 1962. The full text of the report will be found in an information publication, with the title "Aplicacion de Radioisotopos en la Industria Argentina", issued by the Commission (CNEA). The Agency questionnaires were used for the survey. By using the replies information could be obtained concerning 133 various users which should cover all applications in Argentina at that time. As background information it should be mentioned that, according to national statistics, the output value of the Argentine industry in 1961 was 246 000 million pesos, which corresponds to US$ 1760 millions. This corresponds to 29% of the gross national product of the country.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

The industrial use of radioisotopes was introduced in Argentina by CNEA in 1958, through what was then the Radioisotopes Department. It started with the construction of the first gammagraphy installations and the training of staff in tracer techniques and in the calculation and design of monitoring equipment. Almost simultaneously, the same Department launched a promotion and information programme consisting of courses on radioisotopes, lectures, symposia, exhibitions and so on. Once the need had been created for staff to work with radioactive materials and for the services they could provide, CNEA offered technical assistance directly to interested firms. The growth of a market for the industrial applications of radioisotopes led to the creation of the first private companies for the construction of nuclear monitoring equipment and the provision of radiography and tracer services. CNEA supported private enterprise in this field from the start, by applying two well-defined principles - free distribution of plans and specifications for the equipment constructed in its workshops and laboratories to all persons interested and non-competition with the new private industry in the sale of equipment or services which, having due regard to technical, economic and public-safety factors, could normally be provided by private firms. As a result of this policy, which in its general outlines is still followed, Argentine industry is now producing and using radioisotope equipment and applying techniques which have led to reduced production costs and improved quality and have provided solutions to technological problems connected with production processes. In addition, universities and other institutions have begun to offer courses on the industrial applications of radioisotopes, thus satisfying the growing interest in the subject shown by students, professional circles and technicians.

21 22 NATIONAL REPORTS

Under its Applications Programme, which includes provision of basic and specialized courses on radioisotopes, CNEA is continuing its research on, and the development of, new nuclear equipment and techniques.

CONTENTS OF THE REPORTS

In Table I a summary is given concerning the use of radioisotopes by the Argentine industry during the period of investigation (mid 1961 to mid 1962). Details about savings in money are given only by very few users, but full information is given about investments and, in several cases, about maintenance and operation costs.

Gauging

All available information on how thickness gauging, level gauging and oil-well logging is performed in Argentina is shown by Table II. Further details are revealed in the national reports about the plans for introducing new gauges, e. g. in paper, sandpaper and plastics manufacturing. Six gauges are ordered, five of which are of domestic origin. These were installed in 1963 and early 1964. Three applications not included in the survey are also mentioned in the report — thickness measurement of the cladding of nuclear fuel elements using the beta radiation from the natural uranium contained in the elements, a device for measurement of snow depths in remote areas and soil-moisture gauging of road compaction characteristics. Particularly detailed information is given on oil-well logging and it is reproduced here in extenso: "The introduction of radioactive logging in the Argentine oil industry has represented a great improvement over the techniques used before 1959. The obvious saving derives from the improved information obtainable concerning wells, which one of the firms consulted summarized as follows: (1) Great accuracy in the choice of drilling sites, so that the oil- bearing stratum can be located to within a few centimetres in wells several thousands of metres deep where a single error could lead to the abandonment of a potentially rich well; (2) Clear differentiation, before drilling, between oil and gas in wells already encased. This helps avoid problems connected with pressurized con- creting and sealing of gas strata, which can then be held in reserve for future repair work on the well (applications of multi-spaced logging); (3) Determination of the porosity of ground formation, using neutron and density logging; (4) Localization of cement plugs and determination of the approximate amount of cement beyond the piping; (5) Determination of ground formation densities (densilog cross- sections). Used in conjunction with cross-sections obtained by conventional neutron measurement, these enable engineers to make quantitative and qualitative analyses of formations in order to establish porosity. (6) Estimation of volumes of liquids in ground formations from the effect of chlorine atoms on slow neutrons; 'TABLE I

SUMMARY OF RADIOISOTOPE USE IN ARGENTINE INDUSTRY IN 1961-62

Total Gauging Radiography lonization Tracing M. I.* Misc. Broad No. of No. of No. of No. of No. of No. of No. of No. of users No. of No. of product group users users gauges users sources users devices Res. Prod. users users

1. Food 2. Tobacco 3. Textiles 2 2 2 4. Wood, paper 2 2 3 5. Leather, fur ms 6. Rubber Z 7. Chemicals, 2 1 1 1 1 plastics 8. Cement etc. 1 1 1 9. Petroleum 15 15 20 2 5 2 and coal 10. Basic metals 6 4 5 2 2 11. Machinery 2 1 1 1 12. Services 14 1 1 9 18 4 Not identified Total; 44 26 33 15 27 6 1

Remarks: To the number of users reported here should be added 92, who make use of gamma radiography services provided by certain firms listed under "users of radiography" * Massive irradiation. TABLE II

THE USE OF RADIOISOTOPE GAUGING IN ARGENTINA 1962

Thickness gauging

No. of No. of Investment Broad product group Application Benefits users devices (US $)

Textiles and footwear Vinyl fabrics 2 2 9000 Better quality reduction of rejects'1, savings of raw material, adjustment of machinery. Wood and paper Paper grammage 2 3 20000 Better quality, higher output, reduction of rejects. Chemicals and plastics Cellophane film 1 1 5500 Better quality, higher output, reduction of rejects. Basic metals Rolling 3 4 25000 Better quality, improved output0, reduction of rejects. g Construction and Pipe walls 1 1 2500 Savings of labour building

TOTALS 9 lla 61500

Level gauging

Cement.glass and china Clinker level 1 1 4500 Continuous control of process Basic metals Load level in electrothermic kiln 1 d 500 Better control of process

TOTALS 2 1 5000 TABLE II (cont. )

Well logging

No. of No. of Investment Broad product group Application Benefits users devices (US$)

Petroleum and coal Surveying of underground strata 15 20e f Savings due to better information about boreholes s

TOTALS 15 20

Four of these units were constructed in Argentina by private industry One firm estimated savings of US $12 000 during the survey period. The cost of equipment was US $4000. Another firm reported savings of US $13 000 annually. The cost of the gauge was US $3000. Experimental use Control units estimated. Four companies in Argentina provide radioactivity logging services for the petroleum industry. One firm, owning ten mobile control units, estimated its investments at US $217 000 of which $55 000 were spent during the survey period. Annual maintenance costs were $25 000. 26 NATIONAL REPORTS

(7) Structural correlations to establish the lithology of ground formations. It should be noted that radioactive logging can provide information on wells which have already been encased in steel. Electric, induction, sonic and other types of logging in a well which has not been lined can provide valuable information on the areas to be drilled, but the exact location of individual strata once the well has been encased can be determined accurately only by using the correlation obtained from radioactive logging. The sources used generally consist of 300 me of Ra-Be. The results of the survey show that four firms in the country are engaged in bore-hole logging with radioisotopes, which work is done on behalf of about 15 oil companies. It has not been possible to indicate the amount of equipment used and the corresponding outlay for all companies. Only one of the firms consulted stated the cost of its radioisotopes and associated equipment: this amounted to US $217 000, of which $50000 was invested dur ing the survey period. The annual maintenance costs over the same period were estimated at US $25 000. One firm estimated its savings from the use of radioactive logging in terms of reduced drilling. It stated, as an example, that on the southern flank of the Comodoro Rivadavia (Santa Cruz deposit), where 32 000 wells were drilled and completed between 1959 and 1963, the number of drillings per well, which had formerly varied between five and six, had been reduced to an average of not more than two. As each separate drilling costs about US $650, the saving under this heading alone is obvious. These figures are of course only approximate, as allowance has to be made for other factors which have also contributed to the improvement in methods. The high percentage of drillings that turned out to be productive is further proof of the advantages of using modern methods and advanced techniques of all kinds, and the use of radioisotopes for gauging is one such method. It is quite possible .that it was owing to inadequate information that many wells were abandoned as unproductive in the past. Each well represents a cost ranging between US $20 000 and $100 000. "

Radiography

Less than four years after the first work carried out by CNEA, the use of radiography has become widespread throughout Argentine industry, so that, in terms of the number of users, it now heads the list of industrial applications of radioisotopes. The full details on the distribution of gamma radiography over the various industries are shown in Table III, taken directly from the national report. The Table shows that, during the survey period, there were about 100 firms in the country making routine or periodic use of gamma-ray radiography in the inspection of materials, welds and installations. Eight of them possess a total of 12 radiography units of their own to a value of US $17 500. The remainder use the services of seven specialized firms with 15 units valued at US $25 000, for whose services a sum of approximately US $12 200 was paid out during the 12 months of the survey. One of the firms Broad product group No. of No. of Investment Application Benefits users sources (US«) Number Name

7 Chemicals and plastics Materials, pipes 6 1 2600 Plant safety and industrial equipment

9 Petroleum and coal Pipes and 2 5 10000 Plant safety industrial equipment gtn 10 Basic metals Castings 20 2 4700 Quality control

11 Machinery Pipe welds 1 200 Prevention of breakdowns Naval construction 9 1 3000 Safety Manufactured 37 5400 Quality control and articles savings

12 Construction and Buildings 2 250 Better technical information building Boilers and pipes 12 3 2200 Prevention of accidents Welds 11 1350 Prevention of breakdowns

TOTALS 100a 12b 29 700C

Only eight companies possess their own equipment, the rest use the services of seven specialized companies The 15 units belonging to service companies have not been included ; they cost US $25 000 This comprises US $17500 for equipment and US $12200 for services paid by users 28 NATIONAL REPORTS consulted, owning four units worth US $8000, estimated its maintenance costs at US $1 000. Publication of the technical data on the equipment built by CNEA sti- mulated the founding of private companies for the manufacture of industrial radiographie equipment. There are now four such companies and their activities include the supply of services. Twenty-three of the 27 units reported for the survey period were entirely constructed m Argentina by private firms or by CNEA.Nuclides in regular use are Cs137, Co60 and Ir192. A few unusual applications deserve special mention: (1) Complete inspection of a reinforced concrete structure which it was proposed to extend but for which the original plans were not available. Using 5 c of Co60 as source, the number, diameter and location of the re- inforcement rods could be easily determined. (2) Radiography (using only 10 c of Co60) of a sternpost approximately 30 cm thick in which it was believed that a cavity was present. The film, obtained with a sensitivity of more than 10%, confirmed the existence of the flaw which was then repaired. (3) The radiography of solid rocket propellant, using brems Strahlung from an Sr90 source of 500 me and a natural r uranium target. (4) Radiography of rolled fuel-elements for reactors,!. 3 mm total thickness using beta particles from an Sr90 source of 500 me. This method, used by CNEA to check the fuel elements of its own manufacture, offers high sensitivity (better than 2%) and definition with an exposure of five minutes. lonization

Trials have been carried out to eliminate static charges from spun plastic articles, in the mounting of bifocal lenses (to prevent the attraction of ambient dust) and in the milling of plastic materials. In the latter case, the static charges, probably generated in the course of milling, caused agglomeration and adhesion of the powdered plastic on the grid of the sieve, thus blocking it and reducing output. lonization of the air over the route followed by the powder from the hopper to the sieve, using a beta source, appears to have improved working conditions considerably. However, the presence of moisture also contributed to agglomeration of the plastic of the method. The ionization applications have, however, not yet passed the experimental stage.

Tracing

The experience so far collected in industrial tracing in Argentine is not overwhelming, but a few methods have been introduced and can be considered established. These are: Location of cross connections in a gas-pipe system, using CHaBr82; Location of obstructions in oil pipe-lines, using intact radioactive sources; Leak detection on a long-distance telephone cable, using radioactive gases; Flow-rate measurements of open streams with the "total count" method; Investigation of sand movement along the sea-shore, using sand particles labelled with Ag110m . ARGENTINA 29

Miscellaneous applications

The manufacture of self-activating luminous paints by the incorporation of radioisotopes in the luminescent pigments was undertaken in this country by a private firm during the survey period. The nuclides used were Pm147 and Ra228. The paints were used on instrument dials.

SUMMARY OF ECONOMICS

Although only a few companies give full details about the economics of the radioisotope applications, a short summary of the situation can be given (in US $):

Investment Annual cost Gross savings Net savings

Gauging 300000 100000 not known not known Radiography 50000 not known not known not known Tracing 10000 not known not known not known 360000

The only two cases which estimate savings in gauging represent cost- benefit ratios of 1-10 or higher. The highest investment and annual costs concern logging, where economic details for various reasons are not easily obtainable, but it was stated above that this technique is very highly thought of. The potential range of applications in Argentine industry is very considerable. It is the belief of the national body, performing the survey, that the savings will in a few years time reach values many times higher than in the period of the survey.

AUSTRALIA

(TheSurvey in Australia was conducted by the Atomic Energy Commission. Mr. D.C.L. Dalziel was responsible for the report)

The questionnaire designed by the Agency was distributed to 148 companies, which were licensed to use radioisotopes. Out of these, 126 replied; however, only 52 covering 57 plants were relevant to the scope of the survey. It is, nevertheless, believed that these represent all the major users of radioisotopes. Table I shows how the replies were distributed over the various states, and the positive ones over the various product groups. In 1961 the total industrial output value measured at factor cost was to the order of £A 2700 million, i.e. US$6000 million. This corresponded roughly to 36% of the gross national product.

Activities of the national Atomic Energy Authority

The Australian Atomic Energy Commission (AAEC) has taken a very direct interest in the promotion of industrial applications of radioisotopes. In early 1960 it established an Industrial Advisory and Consulting Service. At the end of 1960, the Commission started producing radioisotopes on its own, which was a further encouragement to a wider use of radioisotopes. Figure 1 shows the number of projects handled by this group up to the end of June 1963, as well as the revenue to the Commission from these projects. Figure 2 shows the geographical distribution of the projects handled up to the end of June 1963. The concentration in the Sydney area reflects the proximity of the AAEC Research Establishment. Figure 3 shows the number of shipments of radioisotopes supplied each quarter year by the AAEC. Some of the shipments supplied from local production would have been used for medical purposes, but the imports were all for non-medical purposes. The absence of figures for importations during the first two quarters of 1961 is due to the fact that it was not until 1st July 1961 that the AAEC became responsible for all impo rtation of radioisotopes for non-medical application.

Contents of the report

Table II shows how industry made use of radioisotopes in Australia in 1961. The figures are based upon these replies to the Agency's questionnaire which contained useful information.

Gauging

Radioisotope gauging is the most widely used application of radioisotopes in Australia. The comments returned from firms which use such gauges showed also a decided satisfaction with this method.

31 TABLE I

NUMBER OF FIRMS USING RADIOISOTOPES IN 1961

Number of circularized Breakdown by industry of positive answers firms which use radioisotopes (Broad product groups)

State Total Number which gave Total Food Tobacco Textiles Wood Chemicals Cement, Petro- Basic Machinery Services Research and and and glass leum metals NO I Negative Positive footwear paper plastics and and answers china coal

Victoria 61 9 27 25 27 1 2 2 2 6 1 3 4 3 2 1

New South 66 11 35 20 22 - 1 1 1 - - 4 6 7 2 Wales -

Queens- S 4 1 2 ------2 • land - - - -

South 5 - 4 1 1 ------1 - - - Australia H Crt Western 5 2 2 1 1 - - - - - 1 Australia - - - - -

Tasmania 6 - 2 4 4 - - - 2 - - - - 1 1 -

Total 148 22 74* 52 57 1 2 3 5 7 1 5 9 10 11 3

100 15 50 35 *

* Of the 74 negative replies, 67 were not applicable to 1961, no relevant information being available on the remainder. AUSTRALIA 33

100 - 20 000 1

90 / // 80

0 70 bJ i O at (L i U. 60 O /' et bml .''' t | so l // bl / > / ULATIV E REVENU

3 O i 3 O C / / <^ *° O X , I> o / z / 3 / ° 30 4/ Vl'/ r/[/ i

0 auARTER MAR JNE SEP DEC MAR JNE SEP DEC MAR ONE SEP DEC MAR JNE SEP DE Et

Fig. 1 Extent of advisory service provided by the A. A. E. C. Industrial Advisory and Consulting Service

Table III shows how the various types of gauges were applied. Thickness gauging is seen to be applied in most types of industries where it would normally be accounted for, i.e. in textiles, paper, plastics and the metal industry. Density gauging is, on one hand, applied to cigarettes; on the other hand, it is also applied to liquids and slurries in the food, chemical and cement industries (one case each). Level gauging is applied frequently in the chemical and petroleum industries and, in a few cases, in the metal fields. As specific examples of this technique, package monitoring and the automatic charging of coke pre-heaters were mentioned. In the first case, the considerable advantages in completely preventing under-filled packages from leaving the plant and reaching a customer were stressed. In the second case, the gauge operates as a level detector of the coke in the pre-heater 34 NATIONAL REPORTS

Fig-2 Location of customers for whom work has been carried out by the Advisory and Consulting Service up to 3.6.63 AUSTRALIA 35

SYDNEY AREA

1 (F) Sydney - Source of oil contamination 32 (L) Chippendale - Thickness of bimetallic strips 2 (F) Sydney - Source of oil contamination 33 (F) Hacking River - Flow measurement demonstration 3 (W) Camperdown - lonization of gases 34 (W) Botany - Gas-flow rates 4 (W) Sydney - Mixing test 35 (W) Garden Island - Boiler performance 5 (W) Redfern - Thickness measurement 36 (F) Mortlake - Gas-flow measurement 6 (W) Camperdown - lonization of gasej 37 (F) Bondi - Gas-leak detection 7 (W) Camperdown - lonization of gases 38 (W) Bankstown - Radome thickness measurement 8 (W) Sydney - Leak test 39 (W) Clyde - Oil interface measurement 9 (W) Alexandria - Tracer test at glassworks 40 (W) Alexandria - Mixing test 10 (W) Pyrmont - Tracer test for leaks in ovens 41 (W) Silverwater - Leak detection 11 (W) Newtown - Mixing test 42 (W) Botany - Mixing test 12 (W) Waterloo - Mixing tests 43 (W) Botany - Mixing test 13 (W) Pagewood - Ring main survey 44 (W) Silverwater - Leak test 14 (W) MatraviUe - Location of blockage in drain 82 (W) Silverwater - Leak detection 15 (W) Bankstown - Radome thickness gauging 84 (L) Sydney - Manufacture of Pu239 sources 16 (W) Sydney - Measurement of sewage flow 85 (W) Matraville - Static elimination 17 (L) Waterloo - Wall-thickness measurement of bottles 86 (W) Alexandria - Mixing test 18 (W) Bankstown - Radome thickness gauging 90 (W) Bankstown - Radome thickness measurements 19 (W) Granville - Mixing test 91 (W) Bankstown - Radome thickness measurements 20 (W) Bankstown - Radome thickness gauging 92 (W) Silverwater - Leak detection 21 (F) Villawood - Leak test demonstration 93 (L) Sydney * Thickness measurements on glass tubes 22 (W) Sydney - Sewage flow 94 (F) Camellia - Drain location 23 (F) Sydney - Flow measurement 95 (W) Sydney - Leak test 24 (L) Sydney - Activation analysis 96 (W) Sydney - Flow measurement 25 (L) St. Leonards - Activation analysis 97 (W) Bankstown - Radome thickness measurements 26 (W) Bankstown - Radome thickness gauging 99 (W) Gore Bay - Interface detection 27 (W) Rydalmere - Location of drain blockage 101 (W) Lidcombe - Leak testing 28 (F) Bilgola - Bore-hole location 104 (W) Bankstown - Radome thickness measurements 29 (L) Sydney - Thickness measurement of railway overhead wires 105 (W) Clyde - Location of blockage in pipe 30 (L) Leichhardt - Labelling cement additives 106 (L) Punchbowl - Flow patterns in dies 31 (L) Waterloo - Thickness of plastic bottles 107 (W) Clyde - Location of baffles

STATE PROJECTS

45 (W) St. Marys (N.S. W.) Radiography of filled shells 68 (L) Southport (Qld.) - Monazite in sand 46 (F) Coalcliff (N.S. W.) Crack detection in coal mine 69 (F) Singleton (N.S. W.) - Bore-hole logging 47 (W) Port Kembla (N. S. W.) Thickness gauge maintenance 70 (F) Maitland(N. S. W. ) - Cooling water tracing 48 (W) Port Kembla (N. S.W.) Measuring steel volume in furnace 71 (F) Williamtown (N.S. W.) - Leak testing 49 (F) Gundagai(N.S.W.)-Riverflowmeasurementdemonstration 72 (F) Newcastle (N. S. W.)- Silt tracing 50 (L&F) Yallourn (Vic. ) - Coal density and moisture gauging 73 (F) Hexham (N.S. W.) - Silt tracing 51 (L) Sherbrooke (Vie. ) - Tritiation of two organic compounds 74 (F) Cockle Creek (N.S. W.) - Effluent tracing 52 (L) Melbourne (Vic.) - Tritiation of "Endoxan" 75 (F) Swansea (N. S.W.)- Ash tracing 53 (W) Altona (Vic.) - Cooling water losses and flow rate 7f> (F) Adelaide (S.A.) - Water movement studies 54 (W) Melbourne (Vic.) Level gauging of liquid ammonia 77 (F) Ascot Vale (Vic. )-Plut, plating of steel discs 55 (W) Broadmeadow (Vic.) - Location of leaks in motor vehicles 78 (W) Woomera (S. A. ) - Oil break-through in separation plant 56 (W) Melbourne (Vic.) - Gas-flow measurements 79 (F) Cessnock (N. S.W.)- Mine ventilation studies 57 (W) Hobart (Tas.) - Static elimination , 80 ( W) Woomera (S. A. ) - Oil break-through in separation plant 58 (F) Port Huon (Tas. ) Effluent disposal investigation 81 (W) Woomera (S.A.)-Oil break-through in separation plant 59 (F) Swan Hill (Vic. ) - Leak testing 83 (F) Melbourne (Vic.) - Leak detection 60 (F) Renmark (S.A.) - Ground-water tracing 87 (W) Port Kembla (N.S. W. ) - Measuring steel volume in furnaces 61 (W) Coogee (W.A.) - Flow patterns in cement kiln 88 (W) Port Kembla (N.S. W.)- Measuring steel volume in furnaces 62 (F) Fremantle (W. A. ) - Leak test 89 (W) Mackay (Qld.) - Flow patterns in vacuum pans 63 (L) Perth (W. A.)-Activation analysis 98 (F) Cooma (N.S. W.) - Stream gauging 64 (F) Perth (W.A.) - Tracing sewage effluent 100 (L) Adelaide (S. A. ) - Density reading measurements 65 (W) Mackay (Qld) - Flow patterns in vacuum pan 102 (W) Coalcliff (N.S. W. ) - Detection of cracks in new roof 66 (W) Bundaberg (Qld. ) - Residence time in sugar subsider 103 (F & L) Latrobe Valley (Vic.) - Advice in "sink-hole" tracing 67 (W) Southport (Qld.) - Static elimination

F - field project W - works project L - laboratory project 36 NATIONAL REPORTS

400

360

320 IPMENT S S 200 ü. o ce 160 ÏÏÏT UJ 0> i 120 z

80 im [l

0 1961 1962 1963

Fig. 3

Shipments of radioisotopes supplied by the A. A.E.G. Research Establishment

ill Radioisotopes manufactured at the Research Establishment

I I Radioisotopes supplied by import from overseas

shaft and it keeps the coke level always above a certain height; charging starts automatically when the top coke surpasses a minimum level. The monetary savings are thought to be very high in this case. The other gauges which are accounted for in the national report are portable neutron and back-scatter gauges for surface and sub-surface measurement in oil prospecting and civil engineering and, in one case, a portable back-scatter gauge for corrosion control. As an example of the application of density and moisture determinations, measurements on an earth-and-rock-filled dam were mentioned. During the compaction, the radioisotope technique enabled the period of testing to be cut from the normal 24 hours to one hour only. The advantages of gauging, in the industry's view, is presented in Tables IV and V. The first Table contains a total of 72 positive indications; the second, a total of 83. The radioisotopes used and the economic benefits are included in Table VI, and Tables VII and VIII, respectively.

Radiography

TableII showed the number of users as well as the number of sources applied. Details about the nuclides used will be found in Table VI. TAB1E U SUMMARY OF RADIOISOTOPE USE IN AUSTRALIAN INDUSTRY IN 1961

Gauging Radiography lonization Tracing Broad Total M.I.* Misc. product No. of No. of No. of No. of No. of No. of No. of No. of Users No. of No. of group usera users gauges users sources users devices Res. Prod. users users

1. Food 1 1 1 2. Tobacco 2 2 32 3. Textiles 3 3 3 1 4. Wood, paper 5 5 12 1 5. Leather, fur - H 6. Rubber - ? 7. Chemicals, 7 6 30 1 2 1 1 E plastics 8. Cement etc. 1 1 I 1 9. Petroleum 5 3 33 1 1 1 and coal 10. Basic metals 9 2 6 6 12 1 11. Machinery 10 3 3 4 7 1 12. Services 11 2 4 7 30 3 Not identified 3 1 2

Total 57 28 125 18 50 2 12 2 1

* Massive irradiation 38 NATIONAL REPORTS

TABLE III

THE USE OF RADIOISOTOPE GAUGES IN AUSTRALIAN INDUSTRY IN 1961

Number of devices

Broad No. of Thickness Density Level Other product Total users gauges gauges gauges gauges group

Food 1 1 1 Tobacco 2 32 32 Textiles 3 3 3 Paper 5 12 12 Chemicals, 6 20 1 9 30 plastics Cement etc. 1 1 1 Petroleum 3 30 3 33 and coal Basic metals 2 2 4 6 Machinery 3 2 1 3 Services 2 2 2 4

Total 28 39 35 45 6 125

The advantages of gamma radiography given by industry in reply to the Survey are shown in Tables IX and X. The economics are contained in Tables VII and VIII. lonization

The replies contain a very low number of ionization applications. It is believed that the actual number is somewhat higher. The types of applications used in Australia cover ionization sources in electron tubes, elimination of static charges, and fire-alarm systems.

Tracing

Cases of industrial tracing were reported from the period under survey. It was not possible to make any actual distinction between research and process control, so this has been left out. Among the investigations performed, the following may be mentioned. At very low concentrations of antimony in lead (<0.01%) the rate of oxide formation on molten lead is a function of the antimony content. Oxidation rates of molten lead were established for antimony concentrations between 10-6% and 10-2% by using Sb124 under standard conditions. The results have TABLE IV

ADVANTAGES OF GAUGING APPLICATIONS

Number of cases where used in: Textiles Wood Chemicals Cement, Petroleum Basic Type of advantage Food Tobacco and and and glass and Machinery Services Research Total metals footwear paper plastics and china coal

Product of better 1 1 1 3 5 1 - 1 1 14 quality - -

Closer control - 1 2 4 4 - 2 1 2 - within tolerances - 16

Saving of raw material - - 2 2 5 ------9 E Reduction of rejects - - 1 2 4 - - 1 - - - 8 >

Saving of scrap - 1 2 2 5 - - 1 - - - 11

Saving of labour - - 1 1 2 - 3 1 3 2 13

Others ------1 1

Total 1 3 9 14 25 1 5 5 5 3 1 72 TABLE V NUMBER OF CASES WHERE BENEFITS OBTAINED BY MEANS OF GAUGING

Number of cases where benefits obtained as a result of:

Closer control Saving Application Product of Reduction Saving Saving within of raw Other Total better quality of rejects of scrap of labour tolerance material O 2 Thickness 8 12 7 7 7 9 - 50

Density 6 4 2 2 3 2 - 19 o Level 2 4 2 1 1 4 - 14 ?o H C/5 Component analysis ------

Others ------

Total 16 20 11 10 11 15 - 83

Gauge Usage: Regular 81% Occasional TABLE VI

NUMBER AND QUANTITY (IN CURIES) OF RADIATION SOURCES USED

Co«»* Cs»37 jrisz XJ2M Sr90 Others Application Number Activity Number Activity Number Activity Number Activity Number Activity Number Activity of of of of of of sources (c) sources (c) sources (c) sources (c) sources (c) sources (c) H Gauging 14 0.230 2 0.30 - - 30 0.411 48 1.885 31 1.818 Z r Radiography 19 11.95 14 57.5 17 89.7 ------

Total 33 12. 180 16 57.80 17 89.7 30 0.411 48 1.885 31 1.818

* In addition one source of 500 000 c for massive irradiation. In addition one source of 1000 c for massive irradiation, also used in speculative research. TABLE VII COSTS OF ALL RADIOISOTOPES USED IN 1961 AND THE NECESSARY ACCESSORY INSTALLATIONS AND EQUIPMENT

Cost of (in £A) Maintenance costs (£A) Total (not in respect of equipment Isotopes Equipment including Radiation Constructions Investment Broad product group including radiation where sepa- (e.g. gauge maintenance safety and Others during safety measures rated from counters and invest- equipment installations 1961 equipment etc.) ment during 1961)

Food 10 100 15250 NIL NIL NIL NIL 15350 Tobacco 400 200 22200 NIL NIL NIL 1700 22400 Textiles and footwear 100 420 5680 300 1770 NIL 4400 8170 Wood and paper 480 2040 22490 600 6403 NIL 6300 31533 Chemicals and plastics 1980 4510 25840 NIL 4840 200 7300 35390 "0 g Cement, glass, china 100 240 1200 NIL 440 1850 NIL 3730 H en Petroleum and coal 110 1840 8880 30 1030 NIL 680 11780 Basic metals 230 1530 58560 355 16020 500 20050 76965 Machinery 70 820 4040 940 3790 NIL 220 9590 Services 380 3771 8184 970 2478 525 3025 15928 Research (Note 1) NIL 1000 5000 400 NIL NIL 1000 6400

Total 3860 16471 177 324 3595 36771 3075 44675 237236

Note 1. Although radioisotopes have been used in 3 research projects, figures shown refer to only one application. Savings (in £A) resulting from the use of radioisotopes Total -Radioisotope assisted Rejects Broad product group turnover turnover Raw Labour Others Total material and (£A) (£A) Cft scrap

Food 326 000 99000 30 NIL NIL NIL NIL NIL Tobacco 3750400 3375300 90 7000 7000 6000 NIL 20000 Textiles and footwear 3 510 000 2500900 71 25000 5000 750 NIL 30750 Wood and paper 42371110 17 025 700 40 62555 52000 6000 2000 122 555 Chemicals and plastics 15 929 000 6 518 122 41 4200 2000 10600 3000 19800 H Cement, glass, china 1 078 000 1 034 100 96 NIL NIL NIL NIL NIL $ E Petroleum and coal 34199000 5877000 17 NIL NIL 10000 1500 11500 Basic metals 38 273 900 30 593 200 80 NIL 31000 12000 9000 52000 Machinery 62519500 888 550 1.4 NIL NIL 1200 20000 21200 Services 2 572 900 87300 0.3 NIL NIL 1740 10000 12640 Research NIL NIL NIL NIL NIL NIL NIL NIL

Total 203 298 700 67259472 98 755 97000 48290 46400 290445

Percentage 34 33 17 16 100

The savings (in £A) were achieved by the use of - Gauges 258 379 Radiography 30 875 Other applications 1191 Total 290 445 TABLE DC ADVANTAGES OF RADIOGRAPHIC APPLICATIONS

Number of cases where used in:

Cement, Type of benefit Wood Chemicals Petroleum Textiles glass Basic and and and Machinery Services Research Total Food Tobacco and and metals paper plastics coal footwear china

Better control of raw 1 - - 1 1 1 - 4 material - - - -

Better control of B 1 ------6 3 6 - 16 T3 products g H Reduced time of V) - - - - - 1 4 2 5 - 12 inspection -

Others ------

Total 2 - - - - - 1 11 6 12 - 32 AUSTRALIA 45

TABLE X NUMBER OF CASES WHERE BENEFITS OBTAINED BY MEANS OF RADIOGRAPHY

Number of cases where benefits obtained as a result of:

Application Better control Better control Reduced time Others Total of raw materials of products of inspection

Control and inspection of:

Welds 2 11 11 2 26

Castings 3 13 11 1 28

Materials to 2 5 5 1 13 be machined

Others - - - - -

Total 7 29 27 4 67

Radiography Usage: Regular 59% Occasional been used in establishing a routine analytical procedure for determining antimony concentrations below the range normally covered by the emission spectrograph. Cr51 and P32 have been used as tracers to study the relative movements of the various charge components in a lead blast furnace. Experimental results were incomplete due to temporary discontinuance of the project. However, it is considered that radioisotopes offer the only means of assessing rates of descent in the charge columns. The AAEC carried out tracer tests, using Au198, to ascertain the tidal movement in a river estuary. The tests were undertaken on behalf of a company who wished to establish that effluent being discharged into the river would be satisfactorily dispersed even during the worst tidal conditions. The results enabled the company to choose the correct site for the outfall. "Methoxone", 2, 4-dichlorophenoxyacetic acid, was labelled with C1* and this product was used for several purposes, such as the study of its translocation in plants, using a combination of quantitative chromatography and autoradiography. The labelled compound was also used for routine isotope dilution determinations. Tritiated monomers were used to study polymerization processes and the diffusion of hydrogen in polymers. Further examples of work performed in 1961 or later may be seen from the legend to Fig. 2, although the description of the projects is made very brief. A few surveying articles on industrial tracing in Australia may also be referred to here [1, 2]. 46 NATIONAL REPORTS

Massive irradiation

Two cases of massive irradiation were reported. One was in chemical research where a 1000-c source of Co60 was applied. The other, more important, was a plant equipped with 500000 c of Co60, the main purpose of which was to sterilize animalic fibres such as sheep or goat hair. Australian regulations require that imported animal fibres should be sterilized (particularly against anthrax). Normally formaldehyde is used for this purpose but penetrating radiation has the advantage that the fibre bales do not have to be opened. This method eliminates all risks of infection due to anthrax. The plant was built for the textile industry; still, it has found other uses such as in the sterilization of pharmaceutical products. Details about irradiation economics are not available; however, the bare existence of such a plant indicates the presence of certain technical and economic advantages. The plant has been described in the literature [3J .

Miscellaneous applications

Only one application in this group is reported: the use of Po210 in the study of surface reactions in chemical research. Further details were not available.

Sources used

Information on the nuclides and the source strengths used in the applications described above is summarized in Tables VI and XI.

TABLE XI

RADIOISOTOPES USED IN SPECULATIVE RESEARCH, TRACING, IONIZATION AND MISCELLANEOUS APPLICATIONS

Isotope Number of applications

Ra222 16 p32 2 Na24 2 Ba/La 1 Au198 3 Sbm 1 Cr" 1 Br82 1 c" 1 H« 7 Pm"7 1 Hg203 1 1131 1 Po210 1

Total 14 39 AUSTRALIA 47

Economic considerations

Tables VII and VIII give summaries of the companies' replies to the economic questions of the questionnaire. Most of this information was obtained through very laborious follow-up actions.- The firms replying report their total turnover to be£A203 million. Thus they represent about 8% of total Australian industry. The isotope-assisted output is, of course, much less: £A 67 million, i.e. a third of the output of the companies, i.e. around 3% of the total industrial output. A very high percentage is shown by the isotope-assisted output in the tobacco industry (density gauging), cement (gauging and tracing), and in basic metals (gauging, radiography and tracing). Average cost-benefit ratios can be calculated for a few applications. For density gauging in the tobacco industry it is 1 - 2. 5 (assuming three years' depreciation period); for thickness gauging in the textile industry 1-15; for thickness gauging in the paper industry 1-15.5, etc. The remaining group is more complicated in cost structure so cost-benefit ratios will not be too meaningful; however, the investment made by the machinery industry seems to be paying off very well.

REFERENCES

[1] GREGORY, J. N., Radioisotopes in the Physical Sciences and Industry Jl, IAEA, Vienna (1962) 415. [2] WATT, J.S., Production and Use of Short-lived Radioisotopes from Reactors 1, IAEA, Vienna (1963) 343. [3] MURRAY, G.S., Nucleonics 20 12 (1962) 50.

AUSTRIA

The Austrian survey was conducted by the Federal Ministry of Trade and Reconstruction and Mr. R. Renner was responsible for it. The survey covers the situation in 1961. A questionnaire was distributed to 46 users who were registered with the authorities. As a basis for the report 43 returned forms were used. Further, a number of visits and other follow-up actions were undertaken. In 1961 the industrial output value reached 80000 million Schillings, i.e. US$3100 million. This sum represents 55% of the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

As there is no central official Atomic Energy Authority in Austria, the duties are distributed over a number of official and semi-official bodies. For the industrial applications of radioisotopes the most important organizations are the Ministry of Trade and Reconstruction which sponsors certain, research and development activities mentioned below and the Österreichische Studiengesellschaft für Atomenergie which has a group directly devoted to industrial service. This is a continuation of the earlier activities of the Radiuminstitut. As these later activities are not accounted for in the report, they will be briefly reviewed here. They include amongst others tracer investigations in industry concerning mixing and retention time s etc., the construction and installation of miscellaneous devices, such as warning signs to ensure that two loading cranes do not come too closely together. Corrosion inside pipes is studied by radiography using a liquid inside the pipes as a radiation source [1] . Food preservation and other applications of massive irradiation is on the programme of other groups within this body. Activation analysis for industrial firms is undertaken both by this body and by university institutes.

CONTENTS OF THE REPORT

In Table I are listed the main industrial applications in Austria in 1961, as presented from the national report. Certain figures have been based on additional information received. The list does not, however, cover the services given by various central institutes in radiography and industrial tracing.

Gauging

The distribution of 34 gauges over the various industries is shown in Table II. The main use of gauging is in the wood and paper industry. Ten users possess 16 area weight gauges of which 15 are for in-line production control. These gauges represent, however, the greater part of Austria's paper production — in fact they checked 53.5% of it.

49 TABLE I SUMMARY OF RADIOISOTOPE USE IN AUSTRIAN INDUSTRY IN 1961

Gauging Radiography lonization Tracing M.I.* Misc. Broad Total product No. of group users No. of No. of No. of No. of No. of No. of No. of users No. of No. of users gauges users sources users devices Res. Prod. users users

1. Food 2. Tobacco 3. Textiles H 4. Wood, paper 10 10 16 O 5. Leather, fur 6. Rubber 1 1 5 7. Chemicals, 6 5 8 2 1 plastics g H 8. Cement etc. 9. Petroleum 2 2 3 1 and coal 10. Basic metals 14 1 2 14 30 11. Machinery 12. Services 1 1 1 Not identified

Total 34 19 34 14 30 - T 3 2 1 -

* Massive irradiation AUSTRIA 51

Number of devices Number Broad product group of Thickness Density Level Logging Total users gauges gauges gauges devices

Wood, paper 10 16 16 Rubber 1 5 5 Chemicals, plastics 5 7 1 8 Petroleum and coal 2 3 3 Basic metals 1 2 2

Total 19 30 1 3 34

Thickness gauges are also applied to the fabrication of tire cords, plastic sheets and laminated plastic sheets and laminated plastic products, and to the cold rolling of metal; level gauging is applied to package monitoring. Logging of bore-holes is made by the state-owned oil manufacturing company and by a private prospecting firm. As far as economy is concerned, details are available for paper and rubber industries. For paper this summary is given:

Total investment AS 1 300 000 Annual cost (including depreciation and maintenance) 305 000 Estimated annual gross savings 1 400000 Net savings, approx. 1100000 The cost-benefit ratio so obtained is 1 - 4.6.

The annual paper production is 577 000 t; and the isotope assisted output is 310000 t. The gross savings correspond to approximately 0.1% of the output value. In the rubber industry no economic details are given, but only technical information. This indicates, however, quite substantial figures for savings in raw material and scrap: approximately 1. 25% and 0.75% respectively, in the production of 8000 t/yr of rubber-coated tire cords. Investment for this account's for some AS 770000. Using standard prices of raw material and products, the gross savings represent at least AS 2000000. With the assumption that operation and maintenance costs are low, a cost-benefit ratio of 1-10 is calculated. No details of importance are available on the other uses except investments which amount to AS 440000 in the plastic industry and to AS 140 000 in cold rolling. Logging is used in the prospecting for oil using both gammabackscatter and neutron devices. These methods are, however, considered only as 52 NATIONAL REPORTS

complementary to other methods in regular use as the measurement of resistibility, self-potential and normal radioactivity. Only a low number of the holes drilled each year are logged by nuclear devices.

Radiography

A total of 14 companies were licensed to use gamma radiography; six of them used this technique for testing castings and eleven for testing tubes, vessels and other structures. Although considerable advantages were reported for the use of gamma radiography, no assumptions of the magnitude of the benefits were made. The investment in equipment amounted to AS 1 400000. Further, the existence of two central institutes which specialize in gamma radiography, among other things, should be mentioned; these are the Schweisstechnische Zentralanstalt and the Technische Versuchs- und Forschungsanstalt. According to information provided directly from these bodies, their activities in gamma radiography are quite considerable. The former employs 3-4 sources of Co60 and Ir192 for testing welds in pipe-lines and high-pressure process units for the chemical and petroleum industry. Since much of these investigations are done in the field or at spots where operation of X-ray tubes is not popular, gamma sources are very much preferred. The second institute concentrates on testing steel constructions used in hydro-electric power plants. Other constructional details in steel or steel-products are also regularly examined. Another important field for inspection is cable-car wire. Even here 4-5 sources of Co60 and Iri92 are used; those in the field have a very high utilization. Both institutes are frequently consulted by various branches in the metal industry for the inspection of welds and castings. By education, welders, they also apply gamma radiography for control purposes.

Tracing

Two chemical firms reported the use of tracers for research and one of them also made use of analytical methods. No' economic details were given. Full-scale applications were reported from three sources. One of them— the oil manufacturing company — applies these tracer methods for several purposes. The two most frequent uses are the tagging of cement to study the effects of cementation in bore-holes and the addition of labelled resins to study the infiltration of gas or water into a producing well. Several other methods are also used, although less frequently [2] . An annual saving was reported in 1961 from lower labour and measuring costs in the determination of cement bonds using the radioisotope method instead of an ultrasonic one, shown by the following details:

Annual cost by radioisotope method AS 400 000 (including depreciation of equipment and research costs) AUSTRIA 53

Annual cost by ultrasonic method 500000 (labour only) Net savings, at least 100000 Cost benefit ratio is 1 - 1.2.

However, as a result of tracer studies performed in 1961, considerable benefits were achieved through an increased oil output of two wells. The gross savings reached the value of AS 1 100 000 in 1962 and will continue to flow in for a number of years. The total costs of the reconstructions etc. were low and accordingly the cost-benefit ratio must be very high. The industrial testing and research institute is marking use of tracer techniques for two purposes: the determination of the direction and flow- rate of ground-water [3] and the determination of leaks in railway cars in a testing chamber [4] . Direct economic savings are achieved in determining flow direction, as the measurements could be made using one bore hole instead of, as before, one central and several concentrically placed holes where sampling was made. The gross saving for each measuring point is the cost of boring 2-4 holes at AS 6000 each. The cost of a tracer experiment was assumed to be AS 4000. Such investigations are now made at several places around the Neusiedlersee in Burgenland and in the vicinity of Vienna, aiming at regulating the level of the lake and establishing a new water supply for the capital. Both these projects are of considerable importance and tracer methods do indirectly result in very substantial although so far intangible savings. The testing of railway cars is speeded up quite considerably by the use of tracers, from five days to four hours, according to the user. The results

TABLE III ECONOMIC SUMMARY OF SAVINGS ACHIEVED IN 1961

Cost Gross Annual Net benefit saving cost saving ratio

Thickness gauging Paper 1400000 305000 1100000 1 - 4 Rubber (2 000 000) 200000 (800000) 1-10 Plastic 100000 Metals 35000 Radiography 450 000 Tracing, research 300 000 Tracing, production 500 000 400000 100000 1-1.2

(3 900 000) 1800000* (3000000)

Figures given in brackets are incomplete or assumptions. * Of which AS 900 000 corresponds to such uses where savings estimates were made. 54 NATIONAL REPORTS

are also more precise than before. Gross savings are achieved by lower labour cost and better use of the facilities. Net savings are given as AS 90 000 for each tested car. The number of individual tracer experiments made each year by the two users is rather high, more than twenty a year in the oil-field operation and several tens a year in both hydrology and in rail way-car testing.

Summary

Using the companies' replies, the main Austrian savings in 1961 have been summarized in Table III.

REFERENCES

[11 CLESS-BERNERT. T. . DUFTSCHMID. K. and GETOFF. N. . 3rd UN Int. Conf. PUAE A/CONF/p.862 (1964). [2] DOLAK, E. , Erdoel Z. (1963) 86. [3] MAIRHOFER, H., Atompraxis 9 (1963) 2. [4] LEIDNEGG, M. , PUTZ, L. and SCHAUSBERGER, H. , Kältetechnik 14 (1962) 206. BELGIUM

Various bodies were responsible for preparing the Belgian survey, but the project was finally implemented with the joint co-operation of the "As- sociation Belge pour le développement pacifique de l'énergie atomique" and thé "Bureau Belge des radioisotopes". Mr.L. Leboutte, Administrative Director of the former and Mr. J.-P. van Gansberghe, Director of the latter organization, were responsible for it. The Agency's questionnaire was used for the survey. It was circulated to those 75 industrial establishments which were known to make use of radioisotopes in research and production. However, certain users were excluded: those who only made use of simple ionization devices in lightning conductors and in smoke detectors and those who possessed only calibration sources. Forty-six users supplied useful information, the response rate thus being around 60%. The period chosen for the investigation was 1962, as it was considered easier to obtain reliable data for this year than for the previous one. That year the industrial output measured at factor cost, is given as 231 000 million Belgian Francs, i.e. US$4600 million. The industrial output is estimated to represent 49% of the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

During the last ten years radioisotope methods have slowly been introduced into Belgian industry mainly as a result of the efforts of the equipment sales agent. The organizations which were devoted to the development of nuclear energy took little or no initiative in widening the application of radioisotope methods. The production of radioisotopes was started at "Centre d'études de l'énergie nucléaire" at Mol. In 1961 a working group was formed which consisted of representatives of the Atomic Energy Commission, other governmental bodies, universities and independent research groups, as well as of industry itself, with the aim of promoting the industrial applications of radioisotopes. In 1962 this group decided to create a special organization for this purpose: the "Bureau Beige des radioisotopes". The Agency's survey coincided very well with this new organization's desire to establish the actual use of radioisotopes in Belgian industry at this time. To draft any programme for the activities of this organization it was necessary to know the present use and to compare it with the international situation of established industrial application of radioisotopes.

CONTENTS OF THE REPORT

In Table I is given a Summary on the total Belgian use of radioisotopes in 1962.

55 Gauging Radiography lonization Tracing M.I* Misc. Broad Total product No. of group users No. of No. of No. of No. of No. of No. of No. of users No. of No. of users gauges users sources users devices Res. Prod. users users

1. Food 3 3 4 2 . Tobacco 2 2 4 3. Textiles 1 1 2 4. Wood, paper 18 18 47 2 2 5. Leather, fur 6. Rubber 1 1 1 7. Chemicals, 14 13 19 1 1 4 1 plastics 8.- Cement etc. 3 3 6 9. Petroleum 9 7 29 1 1 and coal 10. Basic metals 15 9 29 3 17 2 11. Machinery 3 3 13 12. Services 6 3 3 3 20 Not identified

Total: 75 57 144 10 50 3 3 6 1

Remarks: Some 125 firms making use of gamma radiography services, provided by service firms, are not included. * Massive irradiation BELGIUM 57

Gauging

In 1962, 57 users possessed 144 nuclear gauging devices, which were distributed throughout industry as shown in Table II. The most frequent

TABLE II

THE USE OF RADIOISOTOPE GAUGES IN BELGIAN INDUSTRY

Number of devices Number Broad product of group users Thickness Density Level Logging Total gauges gauges gauges devices

Food 3 4 4

Tobbacco 2 4 4

Textiles 1 2 2

Wood, paper 18 42 5 47

Rubber 1 1 1

Chemicals, plastics 13 9 10 19

Cement, etc. 3 6 6

Petroleum, coal 7 1 1 26 1 29

Basic metals 9 9 20 29

Services 3 3 3

Total! 57 64 5 74 1 144 application of gauging is thickness gauging in the paper industry. The 42 gauges check 76% of the total paper output. The exact contents of the replies were not released in the Belgian report, but its author has estimated that, with standard assumptions of depreciation period and rate of interest, the net savings represent 0.7-0.8% of the isotope-assisted output. The most important economic factor given by the replying companies was increased quality of product; secondly, closer control within given limits, and thirdly, decrease of the amount of scrap. In the tobacco industry the density gauging is applied to the manufacturing of cigarettes. According to the report the gauges save an amount of 1% of the assisted output of raw tobacco, which is worth more than 100 million Belgian Francs. The investment for this application reaches 140000 Belgian Francs. The cost-benefit ratio which can be accounted from this is considerable: 1-20, even if a very short depreciation period of, say, three years is chosen. No details are given on the exact purpose of the other gauging installations or on their economic significance. This is mainly explained by the 58 NATIONAL REPORTS fact that these installations represent a certain technical improvement, but do not replace any earlier method. The companies applying, for example, level gauging are then not ready to attribute any savings to the use of such devices.

Ra diography

Seven industrial users possess, as shown in Table I, apart from their own equipment, some 30 sources. Further, one can find in Belgium three firms which provide radiography services for others. These firms have 20 sources, but represent a higher number of exposures per year than all the other firms together. About 125 firms, mainly in the metals industry, are served by these three firms. As an example the report quotes information given by an important firm producing industrial tubes and other items made of copper. Gamma radiography control is applied to 70% of the output. With appropriate depreciation time the annual costs represent 0. 7% of the output value. The main costs are radioactive sources, radio-protection equipment and photographic material.

lonization

lonization methods are used in printing to eliminate static electricity charges. Elimination is claimed to be very effective. In one case it is applied to a monthly journal with 60 pages in four-colour print. Because of static charges on the paper, certain irregularities in the feeding of paper appeared and this caused displacements of the various colours relative to each other on the pages. For this reason more than 30% of the prints had to be rejected. Static elimination by the use of radioactive sources reduced this to a normal and very low percentage (3-4%).

Tracing

Radioactive tracers are used in chemical and metallurgical research by some firms, but detailed information was not available.

Radioisotopes used

In Table III, reproduced from the national report, are shown the amounts of radioisotopes used in the various applications of gauging, radiography and ionization, described above.

CONCLUSIONS

Although the results of the survey give a somewhat incomplete picture both from the technical and economic point of view, there is no doubt that the importance of radioisotope methods is considerable. TABLE III

DISTRIBUTION OF THE PRINCIPAL SOURCES (NUCLIDES AND ACTIVITIES) FOR EACH BROAD PRODUCT GROUP

Broad product 85 90 137 147 Co«« Kr Sr Cs Pm Ir192 T1zo* Totals group

1. Food 160 160 2. Tobacco 5 5 3. Textiles 5 5 4. Wood, paper 10 150 6 357 523 5. Leather, fur 0 CO M 6. Rubber 6 6 § 7. Chemicals, plastics 680 1000 53 12 1 1746 a 8. Cement etc. 240 240 9. Petroleum, coal 364 5 2650 3019 10. Basic metals 13355 900 12750 27005 11. Machinery 10930 1250 86400 98580 12. Services 80 80 13. Various 15 15

Total each nuclide 25819 1150 980 16650 12 86400 373 131384 me

Note: (1) All the activities are given in millicuries and at their nominal values. (2) For the nuclides with relatively short half-life such as Ir192 it is considered that they are substituted at regular intervals. 60 NATIONAL REPORTS

The author of the report has looked into the potentials of the radioisotope applications. In a diagram, which is reproduced here (Fig. 1) he shows the number of radioisotope users in 1962 and the total number of firms in

180-

170-

U) 160- CL ill X ce 150- o S UO- o o 130 V) u z < 120- E x a t- 110 - o UJ X et o o 100 o o 0 90 o 5 o >• It o 80 0.

UJ 70- in z 60 u 2 50- UJ _l œ 40 o < o o 30- Ul < CD u. 0 0 20- d Z 10-

0 •bBBI

Fig.l

Radioisotope users in 1962 from firms employing over 200 workers the corresponding branches of industry which employ more than 200 workers. From this it seems that radioisotope methods should be of great potential value to Belgian industry. However, he concludes, there are many problems to overcome. These originate in a fear of, or reluctance to use radioisotopes and also in legislation and insurance policy. National efforts and international co-operation are needed to meet these obstacles. The "Bureau Belge des radioisotopes" has already taken the necessary steps, and is also examining the problems of applying recent research results to industrial practice. CANADA

The Canadian Survey was undertaken by the Atomic Energy of Canada, Ltd., and Mr. R. J. Moffett was the officer responsible for it. The survey covered the situation in 1961. However, complete statistics were provided concerning the more important applications for the year 1963. In 1963 about 500 industrial users of radioisotopes were registered with the health authorities. Information for 1961 was obtained from 132 companies with the use of the Agency1 s questionnaire. The pattern of radioisotope use in Canada is not the standard one, but includes all known applications. The report covers them well. Tracer methods are not accounted for in the report. Fortunately, this use has been reviewed in an article [1] to which reference will be made, although it was not found in the report itself. In 1961 the output of the Canadian industry was 13000 million Canadian dollars. This corresponds to US$12400 million and to 39% of the gross national product.

ACTIVITIES OF NATIONAL ATOMIC ENERGY AUTHORITIES

The main activities in the industrial radioisotope field of the Atomic Energy of Canada, Ltd., has been concerned with the production of radioisotopes and the development of large radiation sources. There are, however, small groups within it working on the development of both gauging and tracer methods. The response of the Canadian industry to these later activities has not been very high.

CONTENTS OF THE REPORT

A summary of the use of radioisotopes at the end of 1963 is shown in Table I.

Gauging

The number of gauges in the various categories of industry, as shown by the national report, is given in Table II. There might be minor discrepancies in the definition of thickness, density and level, in comparison with the standard terminology of the survey. The Canadians have also reported how the gauges are distributed over the various categories of industry, with regard to the individual nuclides used as sources and their total nominal activity. As the Tables demonstra- ting this are very illustrative, they are reproduced here (Tables III-V) for the cases of thickness, density and level gauging. The application of component analysis is the determination of beryllium by a nuclear reaction analysis based upon the emission of neutrons when beryllium is exposed to high-energy gamma rays. The instruments are

61 TABLE I

SUMMARY OF RADIOISOTOPE USE IN CANADIAN INDUSTRY IN 1963

Total Gau in Radiojraphy lonis;ation Tra<:ing M.I* Misc. Broad g g No. of No. of No. of No. of No. of No. of No. of No.oi users No. of No. of product group users . users gauges users sources users devices Res. Prod. users users

1. Food 12 12 24 2. Tobacco 10 10 464 3. Textiles 1 1 1 4. Wood, 49 49 193 Paper 5. Leather, - Fur I 6. Rubber 8 8 8 7. Chemicals, 36 36 118 Plastics 8. Cement, 11 11 21 etc. 9. Petroleum 26 21 222 5 5 &Coal 10. Basic 70 55 200 15 60 metals 11. Machinery 78 41 82 19 45 18 12. Services 48 38 61 10 35 Not identified 124 97 3836 27 Total: 473 282 1394 49 145 97 3836 27 18

* Massive irradiation. CANADA 63

TABLE II

THE USE OF RADIOISOTOPE GAUGES IN CANADIAN INDUSTRY 1963

Number of devices No. of Broad product group Component Total users Thickness Density Level Logging analysis gauges gauges gauges devices gauges

Food 12 1 13 10 - - 24

Tobacco 10 - 464 - - - 464

Textiles 1 1 - - - - 1

Wood, paper 49 165 16 12 - - 193

Rubber 8 8 - - - - 8

Chemicals, plastics 36 17 16 85 - - 118

Cement, etc. 11 1 11 9 - - 21

Petroleum, coal 21 9 4 6 - 203 222

Basic metals 55 17 135 12 36 - 200

Machinery 41 43 9 30 - - 82

Services 38 22 35 4 - - 61

Total: 282 284 703 168 36 203 1394

referred to as berylometers. The gamma-emitting nuclide is Sb124 and the total nominal activity is 35 140 me. The main use is in mining and accordingly all the instruments are classified into the basic metals group, although some might belong to the chemical industry. In oil-well logging there are 203 units licensed in Canada. Of these 59 use radium (total some 83 g) and the other 144 use isotopes as shown by Table VI. The three first are used in neutron logging devices; the others in gamma backscatter devices. Economic information is revealed for a few applications and the reported data are given below. In the food industry information was obtained from a few companies employing 10 level and density gauges. They represented an investment of $480000 and the advantages were described as keeping closer control within tolerances and the reduction of the number of rejects. However, no direct manufacturing savings were obtained; on the contrary, increased costs in maintenance and servicing were reported, but obviously they were compensated for by the intangible savings inherent in the technical advantages. The first installations were made in 1959. TABLE III

NUMBER AND ACTIVITY OF THICKNESS GAUGES IN CANADIAN INDUSTRY 1963

Radioisotopes and activities Total Number (me) activity Category

192 37 60 90 106 85 y ß Ir Cs' Co Tmno Sr T1204 Ru Kr y ß

Food i - 2000 ------2000 -

Tobacco - -

Textiles - 1 - - - - - 30 - - - 30

Rubber - 8 - - - - 380 - - - - 380

Paper 5 160 22000 625 50 - 710 1180 - 19000 22675 20790 -o O Chemicals - 17 - - - - 1750 40 40 10320 - 12150

Cement - 1 - - - - 20 - - - - 20

Machinery 25 18 4000 3530 9030 1000 445 540 500 2770 16560 5255

Basic metals 2 15 10000 50 - - 2330 30 70 - 10050 2430

Petroleum 9 - - 850 75 - - - - - 925 -

Services 12 10 - 100 59700 - 230 - - 200 59800 430

Totals 54 230 38000 5155 68855 1000 5865 1820 610 32290 112010 41485 Radioisotopes and activities Total Number (me) activitiy Category 5 9 44 y 6 CS137 Co so Kr« Sr ° Ce i T1204 y ß

Food 8 5 930 - 16000 100 - - 930 16100

Tobacco - 464 _ - 11900 11565 - 680 - 24145

Textiles - -

Rubber ------O

Paper 9 7 1745 1000 235 80 - - 2745 315

Chemicals 12 4 5810 1300 - 25 5 40 7110 70

Cement 10 1 6700 - - 40 - - 6700 40

Machinery 7 2 590 - 250 25 - - 590 275

Basic metal 128 7 36620 5415 - 825 - - 42 035 825

Petroleum 2 2 9050 - - 110 - - 9050 110

Services 28 7 2165 1460 - 1225 - 40 3625 1265

Totals 204 499 63610 9175 28385 13995 5 760 72785 43145 Radioisotopes and activities Total activity Number (me) Category y ß C$i" Ra Co60 Sr90 Kr85 r 3 Ra

Food 7 3 80 - 20 800 - 100 800 -

Tobacco - -

Textiles - - O Rubber - - 2

Paper 12 - 7465 - 550 - - 8015 - - Chemicals 84 1 15895 25 270 2 - 16165 - 25 •8 H Cement 9 - - - 80 - - 80 - - en

Machinery 28 2 10850 - 6300 25 10 17150 35 -

Basic metal 12 - 2700 . 495 - - 3195 - -

Petroleum 6 - 125 - 550 - 675 - -

Services 4 - 580 - 2 - - 582 - -

Totals 162 6 37695 25 8267 827 10 45962 837 25 CANADA 67

TABLE VI

ISOTOPES USED IN OIL-WELL LOGGING

Nominal Nuclide No. total activity (me)

PU239 6 30000

Am241 16 455 000

Po210 35 530 000

Cs137 60 41000

Co60 15 2000

Others 12 14500

Total: 144 approx. 1 070 000

In .the tobacco industry information was obtained for about 400 gauges. The total installation was given as $1 200 000 and yearly maintenance as $30000. No details on the economic benefits were given, but positive indication was given as far as both manufacturing savings and overall quality were concerned. The equipment has been in use since 1955. As was shown in Table I, thickness gauging is applied to a considerable extent in the paper industry. Economic information is available from a number of companies using 70 gauges (40% response). These gauges are applied to an output of US $133 million, i. e. some 20% of the total output of paper. Provided that those who replied to the questionnaire are representative of the Canadian paper industry as a whole, one would assume that the isotope-assisted output would be at least half the total. This order is also indicated by the relationship of isotope-assisted output to total output by the replying companies. The installation cost of these gauges reached the total of $325 000. Al- though the application dates as far back as 1951 more than 20% of the investments were made in 1961. Savings were given as $116 000 which, if it is accounted net, corresponds to a cost-benefit ratio of about 1:2.8. The value given corresponds roughly to 0. 1% of the assisted output value. For the other gauging applications, sufficient information on purpose and economy is lacking. There are numerous installations in the chemical and plastics industry for level gauging and in the metallurgical and machinery industry for level and density control.

Radiography

A considerable number of gamma radiography installations are in use in Canadian industry, the numbers being shown in Table I. 145 sources of 68 NATIONAL REPORTS

Co60 and Ir192 were reported and their nominal activity was over 3000 c. The replies from industry contain several examples of gamma radiography from the various industrial sectors. However, no useful economic data were given. lonization

Two types of applications are reported: the use of fire detectors and static eliminators. Both devices make use of radium and thus fall outside the economic scope of the survey. Of the fire detector (referred to as Pyre- a-larms) one would find 2814 units in Canadian industry; the source is 40 ng of Ra226. The static eliminators have sources averaging 60 /ug of Ra226. The printing trades, particularly in the production of newspapers, and some rubber and textile plants, especially where static electricity is a nuisance, most frequently use 1022 units.

Tracing

The use of radioactive tracers have not been subject to the survey. How- ever, there are some fairly active groups in Canada employing radioisotope tracing to the better understanding of industrial processes. They are found in the paper industry and in mining. Atomic Energy of Canada Ltd. has also, as was mentioned previously, a small group devoted to such work. The following summary was received from the national body: "Radioactive isotopes have been used in both industrial and research investigations by members of the Department of Mines and Technical Surveys, Ottawa, Canada, Industrial applications have involved the use of Ag110, Co60, Aui?8 and Cu64 to investigate such processes as the residence times of charges in furnaces and kilns used in metallurgical processes, the wear rate of grinding balls in large ball mills, the flow of ore particles in extraction metallurgy, and the study of copper smelting [1, 2]. The factors effecting the flotation of hematite and cassiterite have been investigated on a laboratory scale using oleic acid tagged with C14. Radioactive tracers have also been used to examine the mechanisms of rare-earth extractions [3]. Research studies have included the investigation of the behaviour of dilute binary alloys during solidification employing Ag110, Au198, Sb124, Tl204, Sn113 and Zn65 as tracers. Diffusion studies in semiconducting compounds using the tracer technique have also been undertaken [4]. " The feasibility of analytical procedures, such as in-linea-activation analysis, are being studied extensively, although the promising results have not so far been taken up by industry. Full-scale tracer investigations in the pulp and paper industry have been made for a long time, e. g. concerning the fibre distribution on paper machines. Other recent applications of the tracing technique have been in determining a nitrogen leak in an underground high voltage distribution cable, the circulation of chips in digesters for the paper industry, and in investigating the variation of density in oil refinery equipment. CANADA 69

Wear measurements have been made in industrial processing such as grinding or machining, and also of rails under the severe winter conditions in northern Canada [5].

Massive irradiation

A total of 30 irradiators are in use in Canada for research and development and they vary from 75 c cobalt-60 to 17 500 c cobalt-60. The total installed amount of cobalt-60 is 100 000 c. The distribution of these irradiators is as follows:

Agriculture 3 Universities 9 Fisheries Research 1 Research Laboratories 10 Industrial Laboratories 3 AECL Development Labs. 3 AECL Mobile _1 30

Of these self-contained irradiators 13 have been designed to suit the particular requirements of research laboratories and universities. Further information on the research and applications of large radiation sources may be found in the publications from Atomic Energy of Canada Ltd. [6].

Miscellaneous applications

There are 45 facilities within 18 firms for the application of luminescent compounds to instruments and time pieces etc. It has not been possible to establish with any accuracy the consumption of the activity for these purposes, and licences cover only the maximum permissible stock to be held at any one time.

CONCLUSIONS

In using the material submitted it is not possible to draw any conclusion concerning the total economic benefits of radioisotopes to the Canadian industrial economy. However, there is no doubt that they are very substantial, particularly those benefits which derive from the gauging of industrial processes and from the testing of industrial products.

REFERENCES

[1] EICHHOLZ, G. G., Nucleonics 18 10 (1960) 116. [2] HORWOOD, J. L. and DIBBS, H. P., Mines Branch Technical Bulletin TB 52, Department of Mines and Technical Surveys (1963). 70 NATIONAL REPORTS

[3] MANNING, P. G. , Canadian J. Cherti. 40 (1962) 1684. [4] BETTS, R. H. and DA VIES, J. A., 1964 Annual Conf. C. N. A. , May 25-27 (1964). [5] O'RILEY, L. J. , TOLMIE, R. W., LILLIE, A.B., 1962 Annual Conf. C. N. A., May 28-30 (1962) [6] ATOMIC ENERGY OF CANADA, Ltd., Gamma Irradiation in Canada, 1-3(1962-64). CZECHOSLOVAKIA

The survey in Czechoslovakia was performed by the Atomic Energy Commission. No details of the method or response are given in the national report. Statistics on industrial output or national product are not available from Czechoslovakia. In order to interpret the economic figures in the report it should be noted that the official exchange rate is $14 for 100 Czechoslovak Crowns, (i.e. approx. 7 Crowns = $1.)

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITY

For the distribution of radioisotopes for research and practical industrial applications, a specialized Institute for Research, Production and Appli- cation of Radioisotopes has been established. This co-operates with the Institute of Nuclear Research of the Czechoslovak Academy of Science. The Institutes also work closely together with several other institutions of various sectors of Czechoslovak industry. In addition to the above-mentioned Institutes, the Gamma Defectoscopy Centre is engaged in activities related to radiography with gamma radiation and the increasing application to various industrial fields of non-destructive testing methods. All of these activities concerned with practical application and utilization of radioisotopes are co- ordinated by the Czechoslovak Atomic Energy Commission.

CONTENTS OF THE REPORT

In Table I is given a summary of the reported use of radioisotopes. It does not cover the applications of radioisotopes entirely, but accounts for most of the activities.

Gauging

According to the report 115 gauges were installed in Czechoslovak industry in 1962. .They were distributed throughout the various industries as shown in Table II. In the food industry nuclear gauging devices are installed to measure the density of milk of lime in one sugar refinery and the level in a lime oven in another sugar refinery. Research work is being done on the use of gauging to determine the dry-matter contents of canned foods; however, this application was not accounted for in Table II. In the textile industry thickness gauges are used for measurement on textile fabrics. In the paper industry a number of thickness gauges are used for measuring the area weight of paper. A special device has been constructed by making use of reflected beta particles for this purpose and, in the future, this instrument will be installed as part of regulating mechanisms. Thickness gauges are applied in measuring rubber layers on cord fabrics in the rubber industry.

71 TABLE I SUMMARY OF RADIOISOTOPE USE IN CZECHOSLOVAK INDUSTRY IN 1962

Broad Total Gauging Radiography lonization Tracing M.I.* Misc. product No. of No. of No. of No.of No. of No.of No.of No. of users No. of No. of group users users gauges users sources users devices Res. Prod. users users

1. Food 2 2 2 2. Tobacco 3. Textiles 2 2 2 2 3 4. Wood, 2 1 5 1 paper H 5. Leather, O fur 6. Rubber 2 2 3 2 3 7. Chemicals, 15 5 23 6 3 3 "U plastics O 8. Cement etc. 5 4 11 3 8 4 9. Petroleum 5 2 2 6 4 and coal 10. Basic 14 8 60 4 12 2 6 metals 11. Machinery 30 3 2 24 138 4 2 12. Services 8 3 5 5 10 3 Not identified Total 85 32 115 36 168 16 16 22

* Massive irradiation CZECHOSLOVAKIA 73

TABLE II

THE USE OF RADIOISOTOPE GAUGES IN CZECHOSLOVAK INDUSTRY

Number of devices No. Broad product of group Total users Thickness Density Level gauges gauges gauges

Food 2 1 1 2 T extiles 2 2 2 Wood, paper 1 5 5 Rubber 2 3 3 Chemicals, plastics 5 8 15 23 Cement etc. 4 6 5 11 Petroleum and coal 2 2 2 Basic metals 8 58 2 60 Machinery 3 2 2 Services 3 5 5

Total 32 81 9 25 115

In the chemical and plastics industry level gauges are used for various purposes, thickness gauges for plastic foils and for laminated or varnished materials and density gauges for various powders or liquids. In the cement industry density gauges are found for measuring cement slurries and level gauges for limestone level in storage bins. Component analysis gauges are used in the petroleum and coal industry for determining the ash content of coal. Various gamma-ray logging probes are also in use. The basic metals industry shows the greatest number of installed gauges in any particular category of industry. Thickness gauges are used for measurements on rolled sheet metal such as strips and foils, on tin coatings and to determine the wall thickness of tubes. The weight per unit length of manufactured tubes is also subject to control by radioisotope gauging. In machinery industry level gauges are installed to control the levels in cupola furnaces. In the category, referred to as services, several types of gauges are found, such as those for measuring volume weight and the humidity of structural materials, volume weight and compaction in road construction, and the homogeneity of pre-stressed concrete details. The economic considerations will be given at the end of this summary. 74 NATIONAL REPORTS

Radiography

Gamma radiography has a very long history in Czechoslovakia. It was already applied in about 1938 in a few cases. The extent of gamma radiography is shown in Table I, where 168 sources are accounted for. This list does not deal with the entire activity of the Gamma Defectoscopy Centre, referred to in the introduction. The use of gamma radiography for testing welds is reported by several industries. Inspection with gamma rays is performed extensively determining the homogeneity of concrete structures as well as for locating rein- forcement bars. Radiography is most widely used in the basic metals and machinery groups. It is stated that industry applies gamma radiography as a complement to X-ray machinery and betatrons. lonization

Table I accounts for relatively few ionization devices in industry. Ac- cording to the text of the report, the use is much more widespread. Static charge eliminators are applied in the textile industry, wood and paper industry, rubber industry and in the plastics industry. Fire alarms with radioactive ionization sources may also be found in the textile industry. Gas chromatography ionization detectors are used in the chemical industry.

Tracing

Industrial tracing is widely used in Czechoslovakia. No less than 38 users in research and/or production have been accounted for in the report. Below are mentioned some of the rather interesting tracing applications which are used. Important results were reported in the field of tracing techniques from textile industries where practical applications were primarily focused upon improvements in washing, dyeing and drying technology. Through the application of radioactive tracing techniques it was claimed that more than 2000000 Crowns were saved in 1962. In rubber technology radioactive tracers have been applied in order to determine the degree of rubber vulcanization, the homogeneity of rubber compounds and for basic studies of the vulcanization process. Further, the process of cord fabric impregnation and tire wear has been studied with tracer techniques. Tracer methods have also been adopted for a number of process studies in chemical engineering, leak detection, wear and corrosion studies etc. In the cement industry the material transport through rotary kilns has been studied. In the petroleum and coal industry tracer techniques have been used in bore-hole inspection, coal transportation and in dust control in plant atmosphere. In the field of metallurgy the most relevant activities were concerned with identifying the origin of non-metallic inclusions, the objective being to determine suitable cheap refractory materials. Another objective was to study the conditions which govern the transition of sulphur from fuels into CZECHOSLOVAKIA 75 metallic baths and slags in SM-type furnaces, this being an important oc- currence where liquid fuels with a high sulphur content are used. Other problems solved by tracer techniques werç the choice of material for lining ball mills, the source of contamination of carbon-free ferro-chromium by phosphorus, the influence of sulphur concentration and of deoxidizing elements on the deoxidation kinetics of iron and certain problems related to welding techniques and flotation. Applications of tracing methods in the machinery group are largely confined to research institutes where the processes of diffusion, the protection of materials against corrosion and the wear of machine elements are investigated. Methods of studying those processes, which take place during machining operations by means of isotopes, are established standard techniques; the same can be said about measuring the wear'of drop-hanger bearings of large-sized hydraulic turbines and of gear boxes, as well as about certain corrosion studies.

Massive irradiation

Although not included in Table I, research on the use of large radiation sources for industrial processing is frequently mentioned in the report. In the food industry the interest is concentrated on the preservation of foodstuffs which normally have a short life-span. The commercial sterilization of sanitary materials by irradiation is studied and this work has recently advanced to a semi-operational stage. The radiation vulcanization of rubber is studied and so are the radiation-induced modification of plastic material, polymerization and chemical reactions.

ECONOMIC CONSIDERATIONS

The report makes the following considerations concerning the industrial use of radioisotopes: "It was not possible to evaluate all the savings which are obtained in Czechoslovak industries as a result of the adoption of radioisotopes. The firms approached by us on this point often claim, instead of submitting concrete figures concerning the economies obtained, the merits of these methods for the introduction of automatic operation, improved working safety, the establishment of more exact sequences of operations, the location of material waste, for obtaining more accurate material balances, the savings of materials, more efficient control of manufacturing procedures etc. From informative analytical studies it can be seen that each of the instruments incorporated directly in a manufacturing process can be claimed to save something in the region of hundred thousand Czechoslovak Crowns per year, the savings resulting from the use of inspection instruments amounting to some fifty thousand Crowns per year in each case. It is not possible to make a similar evaluation for tracer methods as each application must be calculated separately. For example, when the sources of non-metallic inclusions in steel were located, it was possible to replace fire-clay bricks by semi-acid ones, the prime cost of which 76 is about 50% lower. In the Orlîk hydroelectric power station the wear of a drop-hanger turbine bearing was measured; thus, a seizure of this bearing, which would have involved an expense of 12 million Crowns, was prevented. One research institute engaged in this type of activity claims a saving of five million Czechoslovak Crowns from the quality improvement of research work, which has become faster and more exact, the necessary data being obtained for more efficient anti-corrosive actions, such as a reduction of aggressive action of hot water in power-engineering equipment, an increased efficiency of preserving agents and the efficiency determination of corrosion inhibitors in equipment for transportation and processing of oil. A more important advantage, not evaluated by statistical data, consists in extending the service life of the equipment. A gammagraphic investigation undertaken on an iron concrete headframe during the operation of a mine resulted in a saving equivalent to three months' production of the mine, while the investment required by this investigation amounted to about 12 thousand Crowns. The economy obtained through adopting radioisotopes in this field has not yet been evaluated in a complex form, only isolated cases having been so far calculated. Most firms have not submitted numeri- cal values concerning the application of gammagraphy, but they claim that, since the defectoscopic check-up was introduced into manufacturing processes, complaints due to hidden defects have ceased. Other similar cases of evident savings have been ascertained; thus, there is every reason to suppose that, thanks to the adoption of radioisotopes in Czechoslovak industry, savings amounting to 50 million Crowns were obtained in 1962. Ac- tually, the definite sum amounts, according to evidence, to more than 50 million Crowns. " DENMARK

For several reasons it was not p'ossible for Denmark to implement a national survey on the use of radioisotopes and their economic implications by using the normal approach to industry. Instead, the Danish Government entrusted Mr.E.Somer, Director of the Danish Isotope Centre, to prepare a report covering as many aspects as possible of the use of radioisotopes. The information is entirely technical, but the picture of the wide-spread Danish application of radioisotopes is very clear. The output value of the Danish Industry in 1961 reached DKr. 17 700 million, i.e. US$2600 million. This represents 39% of the gross national product of the country.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITY

The Danish Atomic Energy Commission have only limited activities in this field. Its main interests are concentrated on the application of massive irradiation and a service is offered to Danish industry. So far, however, only accelerators are used. Reactor irradiations are also made for producing radioisotopes in the commission's research reactors. For the rest, the initiative is left to private enterprises and semi-official institutions. Important organizations in this field are the Danish Welding Centre and the Danish Isotope Centre which have dominating positions in radiography and other applications, respectively. The activities of these centres will be reviewed below.

CONTENTS OF THE REPORT

Table I gives a summary of the industrial use of radioisotopes, but the work of the two Centres is not included.

Gauging

According to Table I, 50 users possessed 174 gauges in 1963. They were distributed throughout industry as shown in Table II. The gauging is applied as follows: Food industry: thickness of chocolate slabs; Tobacco industry: density of cigarettes; Textile industry: automatic weighing in packaging of cotton wool; Wood and paper industry: thickness of paper; Rubber industry: thickness of calendered rubber; Chemical and plastics industry: thickness of laminates, level in containers; Cement industry: density of slurries; Petroleum industry: density and level in the petrochemical industry and refineries, sulphur contents of petroleum;

77 TABLE I

SUMMARY OF RADIOISOTOPE USE IN DANISH INDUSTRY IN 1963

Broad Total Gauging Radiography lonization Tracing M.I* Misc. product No. of group users No. of No. of No. of No. of No. of No. of No. cf users No. of No. of users gauges users sources users devices Res. Prod. users users

1. Food 3 2 3 1 2. Tobacco 3 3 72 3. Textiles 5 2 6 3 41 1 4. Wood, paper 13 13 56 1 O 5. Leather, fur - 2 6. Rubber 2 1 2 1 7. Chemicals, 17 10 11 2 4 3 5 -So plastics O 8. Cement etc. 2 2 2 1 9. Petroleum 7 7 and coal 8 10. Basic metals 5 4 7 1 1 1 1 . Machinery 6 1 2 2 3 12. Services 5 5 5 Not identified

Total: 68 50 174 1 1 5 45 4 10 4 Remarks: The activities of the Danish Isotope Centre and the Danish Welding Centre are not included. * Massive irradiation DENMARK 79

TABLE II

THE USE OF RADIOISOTOPE GAUGES IN DANISH INDUSTRY, 1963

Number od devices Number Broad product of group Component users Thickness Density Level analysis Total gauges gauges gauges gauges

Food 2 3 3 Tobacco 3 72 72 Textiles 2 6 6 Wood, paper 13 56 56 Rubber 1 2 2 Chemicals, plastics 10 5 6 11

Cement etc. 2 2 2 Petroleum and coal 7 1 6 1 8

Basic metals 4 1 6 7 Machinery 1 2 2

Services 5 5 5

Total 50 67 85 25 1 174

Basic metals industry: level of charge material in cupola furnace, thickness of light metal sheet; Machinery industry: level in furnaces; Services: level gauging in steam boilers and in gas production. Special comments are made in the report on a few items. In the case of tobacco it is stated that, although most machines are equipped with gauges, no considerable financial savings are obtained as raw tobacco is a relatively cheap material and the taxation of cigarettes is entirely based upon the number of cigarettes produced. In other countries high savings may be obtained if taxation is based on the consumption of raw tobacco, but the report deems it highly questionable if savings deriving from decreased taxes should be accounted for in a survey like this. An important gauging application, not listed in Table II, as it is arranged for by the Danish Isotope Centre, is the checking for porosities in cast alumina bricks for the lining of window glass furnaces. By measuring gamma-ray transmission through the bricks they can be classified according to the size and position of the porosities. When a furnace is relined, only first-class bricks are put at the most critical positions and, in doing this, long working periods of the furnace can be achieved in between the relinings. This has a very high economic importance in the increased yearly output of the furnace and in decreased cost for repairs and lining material. 80 NATIONAL REPORTS

Another similar application, which is also developed and used by the Danish Isotope Centre, is the radiometric checking of the reinforced concrete to determine presence, position and size of the reinforcing bars. A device for locating obstructions in high-pressure tubes in steam boilers has also been developed by the Centre [1]. The testing of nuclear reactor shielding is made by similar techniques [2]. An unusual application of thickness gauging which was installed more recently is in the control of the production of rock-wool sheets. Over a period of 500 s, 1000 individual measurements are made, and every 10 min the plant controller receives information on the mean density and deviations during the past period. This information is used for regulating belt speed, air supply and the amount of binding material [3].

Radiography

Table I includes only one individual user of gamma radiography. To complete the picture, the activities of the Danish Welding Centre must be included. This institute has, since 1940, given industry advice on non- destructive testing methods and made radiographie investigations. In 1962, the most recent year for which statistics were available, the Centre made 52 000 exposures, 8000 of which were with gamma sources and the rest with X-rays. The number of sources was 20 and 15, respectively.

lonization

Five companies in the textile, chemical and plastics group make use of 45 static elimination devices. No further information is revealed.

Tracing

Tracing is very widespread in Danish industry. A few firms make use of radioactive tracers in their own research and process control. However, a great number make use of the services of the Danish Isotope Centre. The report gives some details of its activities in 1961 and for the period from its beginning in 1957 up to mid-1963. This is reproduced here (Table III). Among the tracer investigations performed by industry itself or by the Centre, those below may be mentioned. Activation analysis is applied in the food industry for determining residues of pesticides in food-stuff and beverages. Mixing and sedimentation studies are carried out in the wood and paper industry by using neutron- activated china clay as a tracer. The chemical industry reports an interesting routine analytical application — the determination of weed-killing agents by isotope dilution [4], Activation analysis is applied to various research problems and straight tracing is used for many research and process control purposes such as the determination of detergent efficiency, the studies of mixing and flow characteristics of process units. Similar investigations have been made in the cement industry. In petroleum refining many investigations have been made with tracer methods, such as the establishment of water balances and the fate of waste water. DENMARK 81

TABLE III

INVESTIGATIONS PERFORMED BY THE DANISH ISOTOPE CENTRE

1961 1957 to July 1st 1963

X 1 Q. 2 (4 $ •fo •o 3 Tracer s Miscellaneou s Tota l lonizatio n Tracer s Miscellaneou s £ lonizatio n £ &

1. Food i 2 11 14

2. Tobacco 2 2 2 12 14

3. Textiles and foot-wear 1 1 1 1

4, Wood and paper 1 2 3

5. Leather and fur 0

6. Rubber 2 2 2 10 12

7 . Chemicals and plastics 1 2 3 1 2 12 15

8. Cement, glass and china 1 1 7 1 2 10

9. Petroleum and coal 1 3 4 1 1 5 7

10, Basic metals 1 1 15 3 4 22

11. Machinery 1 12 1 14 17 64 11 92

12. Services 2 18 20 11 122 133

Total 2 0 17 29 48 41 3 88 191 323

Tracers are used in the basic metals industry for studying non-metallic inclusions in steel. Air pollution studies in the foundry industry have been carried out by the use of inactive tracer methods combined with neutron activation analysis. Autoradiography of neutron-activated polished specimens cut out of large industrial iron castings is used to determine the distribution of segregations. Various applications are reported from the machinery industry. The corrosion of contacts for telephone relays is studied by means of tracers. Leak detection of hermetically sealed components is carried out using Kr^s as a tracer. The corrosion of cooling water-pipe lines on ships has been 82 NATIONAL REPORTS

stopped through the establishment of critical-velocities of cooling water by means of tracers. Prediction of pollution dispersion in coastal waters is carried out by means of tracers and this, economically speaking, is a most important tracer application. The pollution of bathing beaches and fishing waters through industrial and municipal waste waters is dealt with by means of expensive purification plants and outlet tubes leading into the sea. Tracer investigations reveal the most economical combination of purification factor and outlet-tube length [5]. Dredging costs have been cut considerably at different harbour approaches thanks to better knowledge of littoral drift problems obtained by means of tracer investigations. Leak detection in buried piping systems of all kinds is carried out regularly by means of tracers. Tracers are also used to locate faults in compressed air-protected, long-distance telephone cables. The flow conditions in new types of high-pressure boilers for power stations have been evaluated by means of tracer studies.

Miscellaneous applications

Beta radiography is applied to the study of laundry wear [6]. A few instrument companies possess radioactive sources for checking equipment.

CONCLUSIONS

The report contains no economic details, but makes it clear that, in many cases, there are strong economic reasons for installing radioactive devices or making tracer investigations. The attitude is also expressed concerning the philosophy of industrial radioisotope applications as "three levels of isotope applications". This is reproduced here. A market analysis carried out by the Isotope Centre some years ago showed clearly that isotope applications can be divided into three groups and it is worth while dealing with the need of promoting these and the situation concerning the uses for each of these groups separately. (1) Applications which are carried out by means of commercially available instrumentation which is delivered and installed by the manufacturer. The user needs no special know-how in these cases. Most thickness, density and level gauges fall into this group as well as smaller gamma radiographie units, source arrangements for the elimination of static electricity, etc. (2) Tracer and radiometric methods, mainly for analytical applications, which are used constantly in the works laboratory. (3) Tracer and radiometric methods, mainly for process investigations, which are only carried out once or a few times in each individual enterprise. In these cases it very rarely pays for the user to buy his own equipment and to get specially trained staff. Most statistics on the use of radioisotopes in industry and the accompanying savings deal mainly with the first category of applications. How- DENMARK 83 ever, to-day the promotion, production, sale and service of instruments belonging to this group of applications is fully commercialized. There is no more justification for the public compilation of reports on savings in this group than there is for savings due to any other commercial type of instrumentation used by industry to-day. A one-sided promotion of one of several types of industrial instrumentation may even cause a less-balanced industrial development. This cannot be of public interest and may in the long run even prove disadvantageous for the use of radioisotopes. As already mentioned the first category of applications depends mainly on commercial promotion. Only in exceptional circumstances does the industrial user need the service of a specialized institute, as in cases where the customer service of the instrument manufacturer is not able to deal with applications falling outside the normal use of instruments. A specialized institute can also assist the local instrument manufacturers in the development of instrumentation. In the second type of applications a specialized institute has the task of developing new methods and assisting the running in of the applications in the work until the regular staff can carry on alone with the method. For the third type of applications the existence of a specialized institute is most important. There are very few industrial enterprises which can afford to run specialized isotope laboratories with highly trained staff.

REFERENCES

[1] SOMER, E., Atomwirtschaft £(1963) 96. [2] SOMER, E., Atomwirtschaft 5 (1960) 63. [3] New Scientist No. 323 (Jan. 1963) 182. [4] SÖRENSEN, P., Anal. Chem. 28(1956) 1318. [5] BERG, O. and SOMER, E., Production and Use of Short-lived Radioisotopes," Reactors _I_, IAEA, Vienna (1963) 405. [6] JENSEN, J., Symposium on Radioisotopes in the Textile Industry, Lindau (1964), in press.

FINLAND

The survey in Finland was performed by EKONO, the Association for Power and Fuel Economy, on behalf of the Atomic Energy Commission within the Ministry of Commerce and Industry. The responsible officers were Mr. E. Rotkirch and Mr. I. Mäkipentti. For the survey a questionnaire corresponding to that suggested by the Agency was used. This was distributed to all firms licensed by the Govern- mental Institute of Radiation Physics to work with radioisotopes. These numbered 67, out of which 49 reported use of radioisotopes and one reported sporadic use of tracer techniques. The answers were neither complete nor uniform, so they had to be supplemented by personal contacts. Figures of total output were drawn from the Central Statistical Office of Finland. In 1961, the period to which the Survey was devoted, Finnish industry produced goods at a value of 5900 million Finnish Marks, measured at factor cost. This corresponded to US $1800 million and to 42% of the gross national product of Finland.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITY

The Commission has as such taken no direct initiative for promoting radioisotope work in Finnish industry, but it sponsors general radioisotope research and has had, from 1963, the possibility of producing radioisotopes in its research reactor.

Contents of the report

The industrial use of radioisotopes, as revealed by the replies to the survey is shown in Table I. It contains information about all important applications realized in 1961 by 47 users. They should in principle account for all applications within the scope of the survey.

Gauging

There are 37 users of gauging employing 69 gauging devices. Their distribution over the various categories of industry is shown in Table II. The most important gauging application is the thickness gauging in the paper industry. Eighteen replies account for 31 installations, all for continuous measurements. All except two of the replies report that the savings are considerable, but only two of these had studied the situation so carefully that they could assess the savings on actual figures for decreasing raw material use, reduction of scrap and increased production. The level gauging in the paper industry is frequently connected to a general process control system and the savings are due to decreased need of manpower and to improved uniformity in quality. The first can be calculated easily, while the latter is very difficult to assess. The economic data are presented in Table III, together with those from all the other applications.

85 TABLE I

SUMMARY OF RADIOISOTOPE USE IN FINNISH INDUSTRY IN 1961

Gauging Radiography lonization Tracing Total M.I.* Misc. Broad product group No. of No. of No. of No. of No. of No. of No. of No. of users No. of No. of users users gauges users sources users devices Res. Prod. users users

1. Food 2. Tobacco 3. Textiles 2 1 2 1 7 4. Wood, paper 26 25 48 1 1 5. Leather, fur 6. Rubber 1 1 1 1 -o 7. Chemicals, plastics 3 3 8 O :» 8. Cement etc. 2 1 1 1 H CO 9. Petroleum and coal 1 1 4 10. Basic metals 7 4 4 3 4 11. Machinery 2 1 1 1 12. Services 3 1 1 2 3 Not identified . Total: 47 37 69 6 8 4 8 1

Massive irradiation. FINLAND 8.7

TABLE D

THE USE OF RADIOISOTOPE GAUGES IN FINNISH INDUSTRY

Number of devices Broad product group Number of Total users Thickness Density Level gauges gauges gauges

Textiles 1 2 2 Wood, paper 25 31 17 48 Rubber 1 1 1 Chemicals, plastics 3 . 3 5 8 Cement 1 1 1 Petroleum and coal 1 4 4 Basic metals 4 2 2 4 Services 1 1 1

Total : 37 38 3 28 69

The use of thickness gauges was also reported from other industries. From the rubber industry is quoted a further example, where savings are estimated in the same way as for paper (see Table III). The only further information available concerns the petroleum industry, where use is made of level gauges. The company concerned claims to obtain savings in raw material and in labour reaching a value corresponding to 0.01% of the isotope-assisted output. Details of cost for all applications are given in Table III.

Radiography

Except for the statistics given in Table I, very little information is provided about the purpose of testing. In the metal sector (groups 10 and 11) it obviously concerns ingots and welded seams. In the service group it also concerns concrete constructions. lonization

lonization devices are not very much in use in Finnish industry. A company in the textile trade makes use of seven installations for the elimination of static electricity. Several further installations, although the number is not precisely known, may be found in the paper, rubber and machinery industries. The general advantage of these devices is that they decrease fire hazard and overcome other inconveniences caused by static charges. TABLE HI

Production Costs • Savings

Broad product Grand total Total for Isotope Investment Annual (US$) Isotope Savings mainly due to group No. for broad answering assisted among (US«) (USS) assisted product group group answering production (US S million) (US $ million) group (%) (US $ miUion)

1 937 2 24 3 327 4.2 1.1 8600 159 570 0.35 Less fire hazards, reduction of scrap 4 1225 333. 0 176.0 135000 7300 750000 0.6 Reduction of scrap, saving of labour 5 18 6 29 11.7 1. 1 5000 75 Saving of raw material 7 187 1.6 0.5 2886 45 Saving of raw material 8 103 9 37 37 18.0 6900 90 2250 0.01 Saving of raw material, saving of labour 10 233 14.1 4.9 6705 210 Saving of labour 11 699 12.4 2.6 1530 600 Saving of raw material 12 293 39.0 6750 90 Saving of labour

4112 453.0 204.2 173371 8569 752820 0.5 TABLE IV

PIN-POINTED REASONS FOR SAVINGS AND LIST OF ADVANTAGES

Advantages because of: Les s fir e hazar d Ra w materia l Prod , scra p Labou r Les s fir e hazar d Broa d produc t N o saving s Prod , o f ra w materia l Reductio n o f scra p Savin g of labou r Les s energ y grou p Othe r bette r qualit y Savin g o f Reductio n o f reject s easie r Saf e runnin g Shorte r tes t N o Close r contro l consumptio n Qualit y chang e understandin g proces s oper . Improve d plan t efficienc y advantage s Close r Contro l o f

1 2 3 2 2 1 1 1 1 1 1 4 4 9 11 9 3 12 18 4 2 7 9 1 2 1 2 1 5 « o 6 1 1 1 1 7 1 1 1 1 1 1 1 8 1 1 9 1 1 10 2 1 1 1 2 1 2 1 11 1 1 1 12 1 2 1 1 1 2

11 11 18 1 12 4 15 24 • 8 2 7 13 1 1 2 1 2 2 4 2 1 90 NATIONAL REPORTS

Tracing

The survey does not mention tracing. This is because in Finland tracing investigations are normally not made by the corresponding industries themselves but by branch laboratories or other bodies such as EKONO. The latter organization has already published some of its investigations [1] , It has also been possible to obtain information about the number of tracer experiments on a fully technical scale which have been carried out by Finnish industry up to 1961. There were 17 experiments, out of which six concerned the paper industry, five the cement industry, and two each the basic metals, the machinery and services groups. The retention time of process units such as digesters or bleaching towers have been investigated in the paper industry. The mixing characteristics of cement slurry basins have been studied with short-lived tracers in the cement industry. The behaviour of potassium in a rotary kiln and the flow pattern in glass furnaces was also studied. In the metal industry the lining wear in furnaces was measured by mounting weak cobalt sources in the lining and then measuring from outside, whether or not the source was intact. In machinery industry the mixing of scrap during melting in a cupola furnace and the mixing of binding material in foundry sand was studied.

Economic summary

Table III shows the economic details reported. The cases where savings are reported concern only gauging applications. Table IV gives a summary of companies' views on the reasons for savings and the advantages of radioisotope methods. The cost-benefit ratios of these are 1:15 for paper gauging and 1 : 1.3 for petroleum refinery gauging. In the case of textiles the costs are higher than the tangible savings; this indicates that this application has also certain intangible advantages.

REFERENCES

[1] LUOTO, U.A. and ROTKIRCH, E.G., Proc. 2nd UN Int. Conf. PUAE 19 (1958)28. FRANCE

In 1961, before the Agency had invited its Member States to participate in the international survey, the French authorities decided that they wanted to carry out a national survey with a scope almost identical with that of the Agency's. By close co-operation between the Agency and various French officials information about the preparatory work and the first steps was ex- changed, so that the final report could be handed to the Agency as the French contribution to its survey. The French survey was implemented by "L'atome industriel" under contract with the "Commissariat a l'énergie atomique". Mr. M. Robin was responsible for the survey. A complete 106-page report was issued in French [1] . The questionnaire used in the French survey differed slightly from the one suggested by the Agency but asked for all the information wanted by the Agency. Table I shows the response within the various groups of establish-

TABLE I

RESPONSE TO QUESTIONNAIRE

Number of Number of Number of No response Type of forms positive negative or forms enterprise distributed replies replies returned blank

Official 119 63 24 32 establishments Private industrial 941 537 208 196 establishments Laboratories 183 58 33 92

TOTAL 1243 658 265 320

ments to which the questionnaire was circulated. The addressees were those official bodies, private companies and research laboratories which were known to use radioisotopes. Further addressees were those establishments which had consulted the section for radioisotope applications within the Commissariat. The overall response rate was 74%, of which 53% (of the total) was positive and 21% negative. It was believed that, of the remaining 26%, most were not using radioisotopes, although the lack of response may have been in part due to the fact that several questionnaires were possibly sent to various departments of the same firm, while the complete answers were given on one form. It was claimed that at least 80% of the actual users contributed to the survey. Table I gives details of the response. As the response to the economic details was relatively weak a considerable number of follow-up visits were made. No less than 68 plants or laboratories were visited during this action.

91 92 NATIONAL REPORTS

According to UN statistics the value of the industrial output in 1961 was Ffr 154 000 million, i.e. US$30800 million. The French industry contributed 46% to the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITY

The "Commissariat a l'énergie atomique" has since the early 1950's supported the industrial applications of isotopes. Already in 1955 it was reported [2] that more than 110 problems of an industrial nature had been subject to consideration by a special group at its Saclay centre. Sixty-four investigations had been performed - these included both the design of radioisotope gauges for particular industrial problems and the performance of tracer or radiochemistry studies. In addition, from outside the Commission, much early industrial work could be reported [3] . However, towards the end of the 1950's the Commission felt that most applications had reached the stage where industry did not need any further assistance and this was accentuated by the fact that a highly competent instrument industry was rather active [4, 5] . Thus, its research work was concentrated on a limited number of fields, such as applied radiation chemistry, analytical methods employing radioisotopes and environmental tracing. The results of these efforts are clearly visible, both in this survey and in the programme of various international conferences. The direct industrial consultations have mostly been taken over by other organizations, e.g. "L'atome industriel", a private firm that was formed in 1961, and which also has its own research and development programme. One recent joint effort was the decision by the Commission to ask the firm to undertake the French survey, the results of which were supposed to increase industry's willingness to accept these techniques should any reluctance based on technical or economic considerations still exist.

Contents of the report

The report is very voluminous; thus, only part of the information in it can be reproduced here. In Table II, a summary of the French industry's use of radioisotopes in 1961 is given. Unfortunately, the report does not include information about the number of users of each technique, but instead the number of "applications", which means that a firm is double-counted if it makes use of more than one technique (even various types of gauging). So the number of applications is given as 1054, even if the total number of users does not exceed 656. Double-counting appears most frequently in the chemical industry, in machinery and in the non-identified group. There are certain discrepancies about the number of applications in the various Tables in the original report, so Table II does not correspond everywhere exactly to the figures given in the text below. It should be mentioned that the figures concerning tracer applications either analytical or otherwise, not only cover the number of firms using this technique in 1961, but are the integrated numbers since the beginning of this technique. In fact 65 of the applications were made before 1960 and 45 after TABLE II

SUMMARY OF RADIOISOTOPE USE IN FRENCH INDUSTRY IN 1961

Total Gauging Radiography lonization Broad Tracing M.I.* Misc. No. of No. of No. of No. of No. of No. of No. of No. of appl. No. of product group No. of appl. appl. gauges appl. sources appl. devices Anal. Others appl. appl.

1. Food 12 4 7 (7) 1 2. Tobacco 4 1 1 3

3. Textiles 48 37 87 3 1 6 (1) 4. Wood, paper 118 115 178 2 1 5. Leather, fur - 6. Rubber 30 21 35 1 2 1 (4) 1 7. Chemicals, 135 63 163 11 4 11 27 plastics 1+(12) 6

8. Cement etc. 21 11 43 1 1 6 (1) 1 9. Petroleum 107 53 237 19 10 23 and coal 1+(1)

10. Basic metals 80 29 182 34 5 10 (1) 1 11. Machinery 245 48 161 134 8 4 24 (4) 33 12. Services 75 31 306 18 3 16 (2) 5 Not identified 179 51 66 28 7 12 45 2-K15) 19 Total: 1054 464 1465 236 500 24 49 161 4-K48) 68

* Massive irradiation Note: The numbers concern applications instead of, as usual, firms. They were 656. Figures in the column for massive irradiation refer to straight applications. 94 NATIONAL REPORTS

1960 while the rest did not give information about when the tracer techniques were actually used. Further, in the massive irradiation group, it should be noted that most reported applications were for pure research purposes. Only four units intended for industrial processing were reported, one of them being the "Commissariat a l'énergie atomique" itself. The economic information will be discussed separately after the following technical summary.

Gauging

Table III gives the details of the number of applications and the number of gauges in various industries. Thickness gauging was widely applied in French industry in 1961. Two hundred and twenty one users employed 374 gauges. Further, the report shows that 197 of these used beta sources, 23 gamma sources and 13 alpha sources. Practically all these were used in process or product control; more than 80% operated continuously. There were also a number of applications of density gauging in 1961. There were 48 devices installed in 34 plants and the main uses were in the chemical and petroleum industries. Level gauging was the main one which was the most frequently used. The individual application most in use was in electricity production (level gauging in steam boilers) with 258 installed devices, but almost as many were found in mining (99 in coal mines and 108 in other mines). Quite high figures were also reported from the chemical industry (various process units) and the metal sectors (cupola furnaces). The dominating type of the remaining 185 devices was the portable density-moisture gauge used in prospecting for coal and oil and in civil engineering tests. Together these accounted for some 140 gauges. The rest consisted of a very inhomogeneous group including portable devices for corrosion control, moisture gauges for foundry sand etc. Eleven devices were used for chemical analysis: in petroleum industry for determining the C/H-ratio and sulphur contents of petroleum fractions and in the metallurgical industry for determining alloy composition by X-ray fluorescence. A few source-detector combinations for the position determination of cars in coking process etc. were also reported. One question, which the French body asked industry, was "Is this a measurement, which would be impossible without radioisotopes; was not practised before radioisotope methods were taken into use; or, does the radioisotope supersede an earlier method?'.1 Table IV shows the replies to this question for the various types of radioisotope gauging. It is quite obvious from the contents of the Table that, in the majority of cases, radioisotope methods compete with other gauging principles, but offer certain advantages. It is, however, also quite clear that many measurements can be made with radioisotope methods that were unlikely to have been made without them. TABLE in

THE USE OF RADIOISOTOPE GAUGING IN FRENCH INDUSTRY 1961

Number of applications Number of devices Broad Total number product of Thickness Density Level Thickness Density Level group applications Others Others Total gauging gauging gauging gauging gauging gauging

Food 4 - - 4 - - .- 7 - 7 Tobacco 1 - 1 - - - * - - * Textiles 37 35 1 1 - 81 * 6 - 87 Wood and paper 115 108 2 4 1 166 * 11 1 178 Rubber 21 21 - - - 35 - - - 35 Chemicals and 363 20 8 30 5 38 15 102 8 163 plastics

Cement etc. 11 2 1 7 1 2 * 40 1 43 Petroleum and 53 5 7 36 - 8 104 coal . 10 125 237

Basic metals 29 7 2 20 - 16 2 164 - 182 Machinery 48 16 5 24 3 20 7 119 15 161 Services 31 - - 20 11 - - 279 27 306 Not identified 51 12 7 5 27 16 16 5 29 66

TOTAL 464 221 34 151 58 374 48 858 185 1465

* Number of devices included under "not identified" 96 NATIONAL REPORTS

TABLE IV

INDUSTRY'S ATTITUDE TO RADIOISOTOPE GAUGING

Answer Thickness Density Level Others

Impossible without 55 4 28 6 radioisotopes No method used before 30 1 26 4 radioisotopes Radioisotopes supersede 108 24 74 - earlier methods No answer 33 15 24 7

TOTAL 226 44 152 17

Radiography

Table I shows no less than 236 applications of industrial gamma radiography. The main points of these are, of course, in the metallic sector, but several applications were also reported from the services group (civil and power engineering) and from the petroleum and chemical industries. Among those companies listed under "not identified" one would find 11 establishments that make gamma-radiographie investigations as a service to other companies. These companies exposed about 20% of all films used in radiography. Thus, the real number of firms benefiting from this technique was much higher than 236. However, it was not possible to establish any reliable figure on the number. The number of radiography sources in use and their distribution over various applicable nuclides was not reported. However, it was estimated at around 500. In the big group "Machinery", 59 applications were reported from foundries, 14 from the production of electrical and 25 from other machinery, 12 from shipyards and 14 from factories for aircraft and road vehicles. Table V gives a number of other details supplied by the companies concerning the use of gamma radiography.

lonization

In 1961 the applications of radioisotopes as sources for the ionization of air or other gases had only achieved a limited popularity in France. Only 24 users were found and their distribution over the various broad product groups is shown in Table I. The most frequent application was the stabilization of electrical discharges through the addition of small quantities of radioactive material in solid or gaseous form into tubes etc. Eleven applications of this technique were reported. FRANCE 97

TABLE V

FURTHER USE CONCERNING GAMMA RADIOGRAPHY

Inspection Inspection of of Others Total welds castings

Total number of applications 116 87 35 238 Material examined : Iron and steel 105 74 9 188 Non-ferrous metals 16 13 - 29 Other materials 2 1 4 7 No information provided 9 8 18 35

TOTAL 132 96 31 259

Radionuclides used : 60 Co 29 35 5 69 137 Cs 19 17 4 40 m Ir 46 12 3 61 Others 2 - - 2 No information provided 46 32 23 101

TOTAL 142 86 35 263

Industry's attitude: Impossible without 30 36 4 70 radioisotopes No method used before 20 16 4 40 radioisotopes Radioisotope supersedes 39 17 6 62 earlier method No answer 27 18 19 64

TOTAL 116 87 33 236

Ten applications of static discharge elimination were contained in the companies' replies; however, four of these had been abandoned in 1961. The installations in use contained alpha-emitting sources, such as radium or polonium and their use was heavily criticized from the health point of view. Seven various installations were also reported, some for gas chromatography and some for smoke and fire detection. One firm had installed more than 100 such detectors.

Tracing

The French report mentions 176 applications of radioactive tracers, 161 of which fall within the scope of the Agency survey. The distribution 98 NATIONAL REPORTS over the various product groups is shown in Table II. The reports reveal the following details about the various types of applications. Fifteen applications concerned wear and material transfer. Most frequent was the use of tracer for measuring the wear of mechanical parts, say piston rings or gears (nine cases). Also quite widespread was the use of small sources to study the wear of linings in furnaces (six cases). Seven research applications in the field of corrosion were reported. The flow-rate measurement of gases or liquids was reported in six cases. Tagging of go-devils in pipe-line operation etc. was reported from 17 users. Various types of radioisotope applications to leak detection were reported. Several companies made use of gaseous tracers to test leakage in pressurized telephone cables. Also, in detecting leakage from gas and water mains, radioactive tracer methods have been introduced. Another similar application is for studying the tightness of electronic components such as tubes and transistors. The components are kept for a certain period in a container with a radioactive rare gas under high pressure and if the tubes are not well sealed some radioactivity will enter. This can easily be detected afterwards. The total number of applications of the various leak testing methods was 16. Several investigations in geology, hydrology and hydraulics were reported. They concerned the movement of surface and underground water, the flow-rate of rivers and the movement of solid materials (sand or pebbles) in rivers or at coast lines. Ten such applications were accounted for. Sixteen various research applications concerning chemical reaction mechanisms or rates were mentioned in the returned forms. In various process industries physical tracing has been applied to the study of the material transport and mixing characteristics of various units. For example, the movement of glass in glass vans, of raw material in cement furnaces and of fibres in textile processing etc. Similarly, segregation in ingots was studied by tracers. This group includes in total 17 reported applications. The French pharmaceutical and food industries reported a frequent use of tracers to study the biological effects of various drugs or foods. No less than 30 such applications were reported. A final group included 32 miscellaneous applications which were not possible to classify into any of the previously mentioned nine groups of applications. To this belonged, among others, studies of the behaviour of bio- cides and fertilizers in nature.

Analytical applications

The French report distinguishes the analytical techniques as a group of its own. The report accounts for 49 such applications. Of these, however, several were in-line radiometric analysis classified by the Agency under gauging. Of the remainder, 16 cases concern activation analysis and 10 the use of radioactive indicators and précipitants or isotope dilution. In most cases activation analysis is done using reactor irradiation; in only one case was the use of an accelerator reported. Five applications were reported from the metal industry, eight from the chemical industry, FRANCE 99

one from machinery (semi-conductor production) and one from the paper industry. However, in all cases, the use of activation analysis is exceptional, or used in research only. No routine application was accounted for. The same is the case for the straight tracer methods in analytical applications. They were all reported to be used in research and in checking standard chemical procedures.

Massive irradiation

In 1961 in France a small number of irradiation facilities were installed. They were found at the "Commissariat a l'énergie atomique" and at various university institutions, but also three industrial enterprises possessed irradiation facilities. One of these was a private laboratory specializing in radiation chemistry studies, equipped with several cobalt sources and with accelerators, another was a joint laboratory of 12 big industrial firms having a 900000-c Co60-source, and a third was an oil company which had installed a source within its own research laboratory. Further information about the actual work of these laboratories and their progress after 1961 may be found in the scientific literature 16J . The reports mention 54 applications. Table VI shows their distribution over the various fields of activity.

Miscellaneous applications

Six users of luminescent paints were accounted for in the survey. One research laboratory reported work on the direct conversion of isotope power to electricity. Fifty industrial enterprises and research laboratories possessed weak radioactive sources for calibration purposes. Eleven further users did not reveal sufficient information to permit classification into any of the preceding groups.

ECONOMIC CONTENTS OF THE REPORT

Although the response to the technical questions was quite considerable, the economic questions were, in most cases, ignored. A summary of the response is given in Table VII. As is seen in the Table only 7% of the companies were able or willing to report savings. However, a much higher number indicated that such savings did exist by ticking the boxes in the questionnaire. Table VIII shows the overall response to these indications. It should be pointed out that, in the Table, a considerable number of "no answers" has to be interpreted as absence of benefit. The' total number of firms which did not give any indication at all was not given in the report. Using certain figures submitted by the individual companies and the results of the follow-up studies described above, the French body reached certain average figures of cost and savings. Using these figures up-scaled to the total French production, one reached a total value for the savings obtained in 1961. 100 NATIONAL REPORTS

TABLE VI

APPLICATIONS OF MASSIVE IRRADIATION IN 1961

Application Number

Sterilization of medical and pharmaceutical products 2

Chemical : Polymerization 6 Grafting of polymers 6 Modification of plastic materials (cross- linking etc.) 11 Other chemical effects 5 Study of irradiation effects on materials 9 Food irradiation 9 Other applications 6

TOTAL 54

No. (*)

Positive replies 656 100 Firms giving output 139 21 Firms giving details 315 47 Firms giving details on 182 27 costs for installations made in 1961 Firms giving details on 158 24 maintenance and operation costs Firms giving details on 153 24 investments planned for 1962 Firms giving details on 105 16 investments planned for 1963-65 Firms giving estimates of 44 7 economic benefits

For thickness gauging one found an average cost of Ffr 20 000. The yearly maintenance cost averaged Ffr 200. Charging 6% interest it was found that the average amortization period was six months, i.e. gross annual FRANCE 101

TABLE VIII

INDICATION CONCERNING EXISTENCE OF SAVINGS

Type of benefit Yes No No answer

Labour 66 97 493 Raw material savings 59 81 516 Lower maintenance costs 25 101 530 Savings of scrap or rejects 120 59 477 Other benefits 50 75 531 Increased production 26 83 547

TABLE IX

TOTAL SAVINGS OBTAINED IN 1961

Gross annual Net annual Applications Uncertainty savings savings

Gauging 20000000 16000000 -20%to + 20% Radiography 40000000 20000000 -50% to + 100% Tracing 2000000 2000000 -50% to + 100%

TOTAL 62000000 380000000 savings were around Ffr 40000. If a depreciation period of five years is chosen as a reasonable time, these figures can be used to find that the average annual cost would have-been Ffr 6600; the cost-benefit ratio obtained is quite high, 1:6. From this the total gross annual savings were estimated as Ffr 16 million, while the net savings amounted to Ffr 13.3 million. Similarly, the report estimates annual savings to the French industry from other types of gauges. For level gauging the figures were found to be Ffr 2.7 million gross and Ffr 1.8 million net. For density gauging the corresponding figures were Ffr 1 and 0.7 million respectively, for logging Ffr 300 000 both gross and net. Cost-benefit ratios for the first two types of applications are both calculated at around 1:3. For the last one it is obviously much higher. Reverting to gamma radiography the report says that its benefits are much more complicated to estimate, as averages are not reached as easily as in the case of radioisotope gauging. The author of the report makes two approaches to the problem. In the first he compares the cost of gamma-radiation equipment with that of X-rays, ultrasonics etc., provided that the same control programme TABLE X

SAVINGS IN VARIOUS CATEGORIES OF INDUSTRY IN 1961

Broad Number Number Output Net savings product French report group of of in 1961 estimated (%) group firms applications (Ffr million) (Ffr thousand)

3 Textile see below 4 Wood, paper Paper 1690 114 5950 6400 1.1 6 Rubber Rubber and plastics, textiles 9303 85 25550 6000 0. 24 7 Chemicals, Chemicals and fats 4539 126 24700 1400 0.06 plastics 8 Cement etc. Glass, 837 18 1870 200 0.11 refractories and construction materials 3214 8 4680 - -

9 Petroleum Petrol and natural gas 203 82 13300 1150 0.09 g H 10 Basic metals Mining and drilling, 184 40 5340 850 0. 16 CO metallurgy 748 75 22600 1900 0.08 11 Machinery Mechanical construction 25849 166 67500 5000 0.07 electrical construction 3570 84 9600 1100 0.11 12 Services Electricity 234 28 6050 6700 1.1 Gas 32 10 1800 - 6000 3.3 Building and public works 11722 20 34700 400 0.01

TOTAL (average) 62125 856 223650 37100 0. 2 FRANCE 103 would be carried out. The price difference is estimated at Ffr 1.8 million/yr. Further, he considers that the better efficiency of manpower that is obtained by applying panorama exposures with, for example, Co60 sources, represents a saving of around Ffr 2.5 million/yr. In the second approach attempts are made to calculate the cost of gamma radiography via the number of exposures performed each year. And this, he estimates, is at least 500000. So the total cost will be approximately Ffr 20 million/yr and, as very likely the gross benefits will be of the same order as the cost (e.g. assuming a cost-benefit ratio of 1-2), the gross savings are found to be Ffr 40 million/yr. For the other applications, particularly tracing, the annual gross savings are estimated at Ffr 2 million/yr. The figures for gauging are given as relatively certain (± 20%), whilst the figures for radiography and tracing could easily be increased or reduced by a factor of two. The report summarizes the probable benefits from the industrial use of radioisotopes in France as in Table IX. However, another approach was also made by the author to try to split these savings between the various categories of industry. It is given here in a slightly revised form as Table X to fit into the Agency's scheme of broad product groups. It should be noted that the output figures used represent the sales of the firms in the respective groups and, because of this, the total far exceeds the industrial output measured at factor cost. Goods purchased by a firm for further processing will be accounted twice when sales figures are used. • The report also contains figures for individual applications within various industries. A number of these "case studies" will be reproduced and discussed in the economic summaries of this publication.

REFERENCES

[1] ROBIN, M., Bull. Inf. Scient. Tech. No. 74 (July 1963) 3. [2] FISHER, C., Proc. UN Int. Conf. PUAE 14 (1956) 21. [3] GUERON, M. J.. Proc. UN Int. Conf. PUAE 14 (1956) 24. [4] LEVEQUE, P. et al., Proc. 2nd UN Int. Conf. PUAE 19 (1958) 42. [5] FISHER, C. and CASSIN, L., Proc. 2nd UN Int. Conf. PUAE 19 (1958) 42. [6] LEVEQUE, P., Proc. Int. Conf. Radiation Research, Natick, Mass. (January 1963) 104.

FEDERAL REPUBLIC OF GERMANY

The Federal German Survey was made by the Federal Ministry for Scientific Research together with the Federation of German Industries. A questionnaire, in general identical with that suggested by the Agency, was used and information was asked concerning the year 1961. The response was not very high, although the replies contain very interesting pieces of information. Therefore, further action was taken by the Ministry to obtain a more valid picture of the total use. For practical reasons this concerned the end of 1963. The federal status hampered this action somewhat as the response to it differs from state to state. However, the picture obtained shows a very widespread and differentiated use of radioisotopes in industry. It should be mentioned that, for the Federal Republic of Germany in 1961, the industrial output value measured at factor cost and including the Saar and Western Berlin was DM 145000 million. This corresponds to US $36 400 million and represents 52% of the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITY

In general it should be said that, although they are very interested in the industrial applications of radioisotopes, the Federal authorities do not work very actively for their promotion, but this is left to the parties directly concerned. However, research on radioisotope use is sponsored through a contractual system, and some of the results so far obtained are of direct industrial importance. Through the country's membership in the European Community, Federal German industry also receives research contracts from the Euratom organization.

CONTENTS OF THE REPORT

The questionnaire was distributed to the users of radioisotopes in each state through the authorities responsible for issuing licences for work with radioisotppes. The survey, covering the situation at the end of 1961, was conducted from 20 April to 30 September 1963 and produced the following results:

Total number of establishments approached 978 Number from which positive replies were received 300 (30. 7%) Number from which negative replies were received 78 (8%) Number from which no replies were received 600 (61. 3%)

Some of the negative answers were from firms which had not started to use radioisotopes until 1962-63 and had therefore acquired no experience. Another group of firms, including a number of large chemical industries, did not complete the questionnaire but sent in short reports from which only very scattered and often scanty data could be extracted.

105 106 NATIONAL REPORTS

The 300 positive answers showed that: Radioisotopes were used 283 times for gauging (1065 gauges) Radioisotopes were used 48 times in radiography (75 sources) Radioisotopes were used 11 times as tracers.

As the inquiry was carried out on a voluntary basis, it was to be foreseen that only a few answers would be received and that the figures for savings and turnover given in those answers would be far from complete; this was in fact the case. Of the 300 firms which answered, 88 (26%) gave figures for savings and 221 (67%) mentioned investments, while 116 firms (38. 1%) mentioned turnover. There were gaps in these data also. The replies were distributed over the various States as shown in Table I. A complete picture of the Federal German use of radioisotopes was sought in a later approach by the Federal Ministry of Scientific Research which contacted the various local authorities of the Federal German States

TABLE I

NUMBER OF FIRMS USING RADIOISOTOPES

Number of firms which use radioisotopes to which questionnaire was distributed No Number giving Number giving STATE Total answers negative answers positive answers

Schleswig- . Holstein 13 2 5 6 Hamburg 27 12 12 3 Lower Saxony 80 40 5 35 Bremen 6 - - 6 Nordrhein- Westfalen 500 395 - 105 Hessen 67 27 15 25 Rhineland- Pfalz 41 15 8 18 Baden- Württemberg 120 42 20 58 Bavaria 60 22 10 28 Saar 50 44 1 5 Berlin 14 1 2 11

Total 978 600 78 300

Percentage 100.0 61.3 8.0 30.7 FEDERAL REPUBLIC OF GERMANY 107 and asked for information about all users of radioisotopes registered. The results of this approach are shown in Table II; it should, however, be kept in mind that in some cases the classification of the individual user might not be the most appropriate one. Limited permission to possess radioisotopes (e. g. of natural uranium for preparation of enamels) fall beyond the scope of the survey. In most States these were selected before the information was forwarded to the Agency. This also applied to firms producing nuclear and other equipment and dealing with closed sources. The total figure obtained (712) is considerably lower than the number of users registered and to whom questionnaires were distributed (978). Further, it should be pointed out that in some of the States, sources of the ionization applications were not accounted for, so that the figures on this technique will be misleading. The Table gives no figures of the total number of gauges, sources, devices etc. Unfortunately it was impossible to obtain these. In the case of gauging there was, however, additional information available from the Federal German manufacturers of gauges. On ionization detailed figures are available from only a few of the States. The case of Baden-Wurtemberg is an illustration. Here, 45 users have installed no less than 5500 fire detectors.

Gauging

As was envisaged earlier the survey received 283 replies dealing with gauging. These replies were distributed over the twelve broad product groups in the way Table III shows. For comparison this Table also gives the total number of users as obtained from a later inquiry made to the States. The percentage of response is given. The average response rate is good, particularly as it is accounted against the total use two years later when a considerable increase in the use of gauges has taken place. Two-thirds of the firms in the three important groups of wood and paper, chemicals and plastics, and rubber have replied. The high response rate in basic metals and the low one in machinery are probably due to the fact that many firms have been classified into one group using the one approach and into the second by the other. That such things happen is obvious from the figures for the service group. Out of the 283 replies, 158 concern thickness, 17 density, and 99 level gauging. Sixteen cases concern other types or are not indicated clearly enough. As far as the replies show the distribution over the various categories this is shown in Table IV. The various isotopes applied in the 283 cases were:

622 sources of Co60 with a nominal total activity of some 13 000 /uc, 43 sources of Cs137 with a nominal total activity of some 6 000 me, 248 sources of Tl204 with a nominal total activity of some 1 100 me, 102 sources of Sr90 with a nominal total activity of some 5 500 me, 19 sources of Pm147 with anominal total activity of some 1 500 me, 18 sources of Kr85 with a nominal total activity of some 500 me, and 13 various sources (Ra226, Ruioe, Tmi70 etc. ) of totally some 300 me. TABLE II

USE OF RADIOISOTOPES IN FEDERAL GERMAN INDUSTRY IN 1963

Total Gauging Radiography lonization Tracing M.I.* Misc. Broad product group No. of No. of No. of No. of No. of No. of No. of No. c f users No. of No. of users users gauges users sources users devices Res. Prod. users users

1 . Food 16 5 13 1 2. Tobacco 4 4 1 3. Textiles 24 21 7 1 4. Wood, paper 108 108 1 20 5. Leather, fur i 6. Rubber 18 12 12

7. Chemicals, plastics 112 100 7 18 7 7 1 11 "O O 8. Cement etc. 65 42 10 5 2 1 10 9. Petroleum and coal 51 42 4 24- 5 2 10. Basic metals 101 55 23 32 12 12 2 11. Machinery 204 72 109 71 11 5 39 12. Services 33 6 19 16 1 5 Not identified 32 32

Total: .768 467 173 251 38 27 1 69

* Massive Irradiation FEDERAL REPUBLIC OF GERMANY 109

TABLE III

RESPONSE FOR GAUGING

No. of No. of Response Broad product positive users rate group replies (1963) (%)

1 . Food 4 5 80 2. Tobacco - 4 0 3. Textiles , 10 21 48 4. Wood, paper 80 108 74 5. Leather, fur - - - 6. Rubber 7 12 59 7. Chemicals, plastics 63 100 63 8. Cement etc. 19 42 45 9. Petroleum and coal 16 42 38 10. Basic metals 48 55 89 11. Machinery 20 72 28 12. Services 11 6 183 Not identified 3 - -

Total 283 467 58

The total number of sources (gauges) was 1065. The report further indicated the industry's attitude concerning the benefits, indicated by ticking the appropriate boxes in the questionnaire. A total of 494 positive indications were given from 274 replies. These are listed in Table V. As far as the economic details are concerned, specific information on gauging was not available; data were grouped according to industry. The economic information will therefore be reviewed after the various techniques have been surveyed. According to the firm Frieseke and Hoepfner, FederalGermany's leading manufacturer of gauges, the following number of their thickness gauges Were installed in late 1963:

Paper industry (paper, coated paper and paper board) 382 Chemical industry (artificial leather and oilcloth) 186 Plastics industry 241 Rubber industry (tyre cord and others) 69 Textile industry 18 Cement industry (abrasive paper) 86 Metal industry (cold rolling) 198 Machinery industry (photographic industry) 15 110 NATIONAL REPORTS

TABLE IV

THE USE OF GAUGING IN 1961

Total Number of replies Broad product No. of Thickness Density Level group replies gauging gauging gauging

1. Food 4 1 1 2 2. Tobacco - - - - 3. Textiles 10 10 - - 4. Wood, paper 80 69 5 5 5. Leather, fur - - - - 6. Rubber 7 6 1 - 7. Chemicals, plastics 63 34 5 22 8. Cement etc. 19 3 - 16 9. Petroleum and coal 16 3 2 7 10. Basic metals 48 16 1 20 11. Machinery 20 12 1 20 12. Services 11 2 i 7 Not identified 3 2 - -

Total 283 158 17 99

TABLE V

BENEFITS OF GAUGING INDICATED BY INDUSTRY

Thickness Density Level Total

Product of better quality 60 9 17 86 Closer control within tolerances 114 10 16 140 Saving of raw material 42 3 3 48 Reduction of rejects 72 8 10 90 Saving of scrap 25 6 12 43 Saving of labour 10 2 57 69 Others - - 13 18

Total 328 38 128 494 FEDERAL REPUBLIC OF GERMANY 111

The total is almost 1200 and they were sold to over 300 firms. Bearing these figures in mind one would assume the total number of gauges (all kinds) in Federal German industry in 1963 to be of the order of 2000. Of these 60 to 70% should have been thickness gauges, 20to30% level gauges and the rest density or other gauges.

Radiography

As previously listed 48 replies contained information on radiography. They were distributed over the broad product groups as shown in Table VI.

TABLE VI

RESPONSE FOR RADIOGRAPHY

No. of Response Broad product No. of positive rate group users replies (%)

1. Food - - - 2. Tobacco - - - 3. Textiles - - - 4. Wood, paper 1 1 100 5. Leather, fur - - - 6. Rubber - - - 7. Chemicals, plastics 4 7 57 8. Cement etc. - 10 0 9. Petroleum and coal 4 4 100 10. Basic metals 12 23 52 11. Machinery 20 109 18 12. Services 7 19 37 Not identified

Total 48 183 26

In the same Table are shown the number of users, given by the local Authori- ties in reply to the later approach. The response rate is much lower than in the case of gauging, but is still of a reasonable magnitude. The 48 replies gave 98 positive indications concerning b'enefits shown in Table VII. As in the case of gauging the economic details have been presented in such a way that it is impossible to draw any conclusions. The 48 replying companies in 1961 used 75 sources of which 16 contained Co60, nominal total activity 30 c; 9 contained Cs137, nominal total activity 9 c; and 50 contained Ir1^ nominal total activity 180 c. 112 NATIONAL REPORTS

TABLE VII

BENEFITS OF RADIOGRAPHY INDICATED BY INDUSTRY

No, of cases where benefits obtained as a result of: Better Better Reduced Product No. of control control time for tested replies Others Total of raw of inspection materials products

Welds 11 20 15 1 47 Castings 7 21 11 1 40 Materials to be machined 1 4 4 2 11 Others - - - - -

Total 48 19 45 30 4 98 lonization

In the survey 45 positive replies were obtained, containing information on ionization applications. However, they represent only a small fraction of the total number of users. Table II, which is known to be incomplete, shows more than 250 users. These applications are very widespread and the total number of devices must run into tens of thousands. As further information is lacking it is of little value to use the information from the repliers, particularly as they in no case account for savings from the use of radioisotopes.

Tracing

In the survey positive replies were obtained from 11 firms using radiotracer methods. However, other sources indicate that in the Federal Republic of Germany about 50 firms make use of these means, most of them in laboratory research but many also in full-scale process studies. A list of typical Federal German tracer applications was provided by the national body and is shown in Table VIII. The reports contain neither technical details nor economic data for these applications. Firstly, it cannot be expected that the users publish the advantages brought about by application of those means; secondly, in most cases it was not possible to calculate the profit, since there are no possibilities for comparison with conventional methods.

Massive irradiation

Research on the potentialities of the radiation processing of various goods is very active in the Federal Republic of Germany and is performed at universities, research centres and at industrial laboratories. However, most of this work has developed since 1961 and reference is made to such FEDERAL REPUBLIC OF GERMANY 113

TABLE VIII TYPICAL FEDERAL GERMAN TRACER APPLICATIONS

Field of application Tracer studies

Pharmaceutics Investigation of the distribution of remedies in the body, of their metabolism and excretion

Plastics Estimation of the degree of polymerization, of the molecular weight Estimation of the activity of catalysts Estimation of the contents of catalysts in high polymers Estimation of the loss of plasticizers and stabilizers from plastics Analytical chemistry Determination of the efficiency of separation methods Application Estimation of bonding and penetration of leather and textile additives Estimation of the thickness of protective films (waxes, dyes, varnish, cleaners) Estimation of the stability of emulsions and suspensions during the application on surfaces Investigation of diffusion rates

Chemical engineering Determination of the residence time of chemicals in continuous processes Determination of amounts of liquids in complicated apparatus Estimation of the time for mixing operations, of the efficiency of mixing devices, of absorption apparatus Investigation on separation of phases, on the flow- rate, transportation of chemicals in closed apparatus Patents etc. Investigation of the course of a chemical reaction Labelling of chemical products with inactive tracers, identification by activation analysis work in only one of the returned forms, where a 5000-c Co60 source is used for research purposes by only a chemical firm.

Miscellaneous applications

Of such applications which fall outside the normal groups, the only widespread one in Federal German industry is the use of luminescent paints. Turnover [ in 1 000 DM] Net Savings [in 1000 DM] resulting from the use of radioisotopes (116 replies) (88 replies) Broad product group Total of which radioisotopes are used for: Raw material Rejects Labour Other Total (1000 DM) (%) and scrap

3. Textiles 43.8 13.9 31.7 - - - - -

4. Wood and paper 023. G 512.0 82.2 230.1 68.9 10.0 42.0 351.0

C. Rubber 296. 5 2G3.7 88.9 502.0 5.0 - - 507.0

7. Chemicals and plastics 2029403.5 5941.1 834.7 1402.2 47.2 55.3 2339.4 8. Cement, glass, china 20.4 12.7 48.1 - 67.0 10.0 - 77.0 8 9. Petroleum and coal 1 594.0 14.3 9.0 - 70.0 2.0 40.0 112.0

10. Basic metals 1195.9 748,0 62.5 - 15.0 100.2 - 115.2

11. Machinery 314.1 122.4 39.0 - 22.0 55.5 - 77.5

12. Services 54.0 12.7 23.5 - - - - -

Total 2033611.8 7641.4 1566.8 1650.1 224.9 137.3 3579.1 43.8 46.1 6.3 3.8 100.0% TABLE X

COST OF ALL RADIOISOTOPES USED IN 1961 AND THE NECESSARY ACCESSORY INSTALLATIONS AND EQUIPMENT (221 replies)

Maintenance costs Cost (in 1000 DM) of: (in 1000 DM) in Constructions to Total (less Equipment Radiation respect of equipment, contain radio- Staff maintenance Broad product group Isotopes (e.g. gauges, safety Others 0 including radiation isotopes, including costs costs from tn tracers, etc.) equipment safety measures cost of installation Col. 1)

3. Textiles 13.6 17.4 24.2 5.0 1.5 - 1.0 49.1 cT) 4. Wood and paper 89.7 97.8 731.6 11.2 32.1 26.9 1.7 901.3 03 6. Rubber 1.1 4.9 7.3 0.8 0.3 0.2 - 13.5 B O 7. Chemicals and plastics 164.2 244.4 2681.0 143.6 506.8 69.0 12.3 3657.1 •n O 8. Cement, glass, china 6.8 17.5 90.6 21.6 12.6 6.9 - 149.2 m 9. Petroleum and coal 9.2 90.1 159.5 23.3 59.5 31.0 - 363.4 10. Basic metals 33.5 92.4 331.0 115.5 835.0 270.1 31.4 1 675.4 11. Machinery 45.4 49.7 381.0 81.8 738.1 382.2 19.8 1652.6 12. Services 41.7 24.8 124.9 109.0 54.9 105.6 0.1 419.3

Total 405.2 639.0 4 531 . 1 511.8 2240.8 891.9 66.3 8880.9 116 NATIONAL REPORTS

Although information might be incomplete, there are at least 50 in the chemicals, plastics and the machinery industries. Details on the amount of radioisotopes used is not available.

ECONOMIC SUMMARY

In Tables IX and X are reproduced the data from such firms which have given data on turnover, investment or savings. Of the savings reported DM 3 510000 originated from gauging, DM48000 from radiography and DM 20600 from other applications. This information assumes that almost all the reported figures on savings concern gauging. Unfortunately no analysis has been made of the costs and output figures for those establishments reporting savings. Still, it is possible to use the material contained in Tables IX and X and to draw certain conclusions concerning the economics of certain gauging applications. It is thus clear that the most important benefits are found in the chemicals and plastics industries. Here the savings in scrap and in raw material dominate. However, it is clear that there is no correspondence between isotope-assisted output and the figures of costs and net savings. The annual costs reach a figure of three millions, the net savings 2. 3 million, while the isotope assisted output is only six millions. The figure of total turnover is quite high: the replies cover, obviously, a considerable part of Federal Germany's chemical industry and it is quite clear that, although there are many gauging applications realized in this field, they concern only a very small fraction of the total output of chemical production. The group second, and third in importance, are the rubber, wood and paper industries, where Table IV shows that thickness gauging is the predominating application. Here the highest savings are reported in raw materials. The rate of isotope-assisted output is very high in both cases. The other groups report also savings, but here a comparison would be more uncertain, as radiography and gauging are both frequently used in the metal sector (groups 10 and 11). A very rough up-scaling for the year of 1963 would give an estimate of annual costs of about 30 million DM and annual net savings of about 40 million. However, this estimate must be considered as very uncertain; both figures can be wrong by a factor of 2 or even more. ISRAEL

In 1961 all activities in the industrial radioisotope field were adminis- trated by the National Atomic Energy Authorities, who also compiled a report on items which were of interest to the survey. It is known that after that date further development has taken place, but detailed information on the extent to which radioisotopes are used is not available. For comparison it should be quoted that the industrial output in Israel reached the value of 1.4 billion Israel pounds in 1961. This corresponds to US $470 million and represents 42% of the net domestic product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

The Israel Atomic Energy Commission has created an Industrial Appli- cations Group with the definite task of assisting in the diffusion of the use of radioisotopes and radiation in the country. This group is, however, still in the first stages of work. The work programme consists mainly of the following points: (1) Use of apparatus based on radiation sources; (2) Use of radioisotopes for tracing; (3) Use of the reactor services in activation analysis.

In the beginning the work of the group was directed towards potential users in addition to the work which had already been done in previous years.

I. The work on point (1) consists mainly in offering the service of gauges and other apparatuses to potential users on a lease basis inclusive of technician service. The main idea is that these apparatuses are costly ones, their functioning requires particular knowledge and the user needs the apparatus only sporadically — with planned organization it is hoped to put a wide variety of apparatuses at the service of potential users. One important contract concerns the uses of gauges and neutron gauges for density and chlorine determination in a project of research on the measurement of gradient concentration of salts in solar ponds, conducted jointly by the national Council of Research and Development and the In- dustrial Application Group of the IAEC.

II. The use of radioisotopes for tracing is the subject of the following projects which are all at their initial stage.

(a) The use of Co60 in tracing the underground flow of water. The work is done by the Radioisotopes Training Center Laboratories as sub- contractor of the IAEA for Israel Water Planning Ltd. (b) The use of Cl38 in a joint project of the Department of Chemistry of the Bar Ilan University and the Industrial Application Group of the IAEC to study the mechanism of dissociation of Mg C122H2O in the Aman process.

117 118 NATIONAL REPORTS

(c) The use of Na2^ in the leak detection of underground water pipes of the Water Department of the Tel-Aviv Municipality.

III. The use of the reactor for services in activation analysis is still at the organization stage. A research programme has been agreed upon between the Industrial Application Group of the IAEC and the Israel Police Scientific Department on an extensive research on human hair identification by the aid of activation analysis, for forensic and medical purposes. Still under discussion are the applications of activation analysis to other problems in the field of cri- minalistics. The use of activation analysis in hydrology research is also being discussed. ITALY

The Italian survey was made by the National Atomic Energy Commission in co-operation with the Society SORIN. Mr. C. Bertoni of the former and Mr. G. Lee of the latter were responsible for the Italian report. The survey primarily covered those users who applied radioisotopes in 1961 — statistics have, however, also been given on all applications realized up to the end of 1963. Of the total 152 users in the latter period 51 were contacted and asked to furnish the national body with appropriate information, using a questionnaire almost identical to that of the Agency. Only 12 replies were obtained. No follow-up action was taken. The output value of Italian industry, measured at factor cost, was in 1961 8.5X 1012 lire, i.e. US$13400 million. This figure corresponds to 45% of the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITY

Interviews with officials of the Atomic Energy Commission make clear that the industrial applications of radioisotopes have so far not received any direct support. Various private bodies and research centres do, however, partly devote themselves to this task.

CONTENTS OF THE REPORT

Table I summarizes the industrial use of radioisotopes in 1963. Un- fortunately, the statistics for 1963 do not give the number of devices, sources etc.

Gauging

There are 41 users of radioisotope gauging devices distributed throughout almost all of the broad product groups. Of these, thickness gauges are applied by 18, density gauges by 4, and level gauges by 19. Thickness gauges are applied to a considerable extent in the paper, the plastic and the metal industries. Individual companies in other sectors such as textiles and rubber also possess such devices. One company in the basic metals group, which gave a positive reply, had no less than 11 thickness gauges. Density gauging is applied to cigarettes in the tobacco industry, to cement slurries in the cement irïdustry and to gas mixtures in the nuclear power industry. Level gauging is used at a number of firms primarily in the chemical industry, but also in the cement and the machinery industries and also in other categories.

119 TABLE I SUMMARY OF RADIOISOTOPE USE IN ITALIAN INDUSTRY IN 1963

Broad Total Gauging Radiography - lonization Tracing M.I.* Misc. product No. of group users No. of No. of No. of No. of No. of No. of No. of users No. of No.of users gauges users sources users devices Res. Prod. users users

1. Food 2 . Tobacco 1 1 3. Textiles 5 3 1 1 4. Wood, 10 9 paper 1 5. Leather, fur O 6. Rubber 3 2 1 Z 7. Chemicals, 45 11 plastics 7 4 14 9 8. Cement etc. 5 5 9. Petroleum 5 1 2 and coal 1 1 10. Basic 21 1 14 metals 1 3 2

11. Machinery 41 7 19 2 1 12 12. Services 5 - 2 1 2 Not identified 11 1 1 2 5 2 Total: 152 41 - 45 10 28 12 16

* Massive Irradiation ITALY 121

Radiography

Table I shows no fewer than 45 users of radiographie techniques, which are mainly found in the metal field. Five companies in the basic metal group have provided certain economic information concerning their use of gamma radiography for welding control, for testing castings and machined parts and for corrosion control. They are presented as follows:

Lire US$ Total output 8700 million 12. 8 million Isotope-assisted output 1300 million 2 . 1 million Cost of radioisotopes 4. 3 million 6800 Cost of equipment 3 . 8 million 6800 Cost of health physics equipment 10.4 million 16400 Cost of constructions 32.0 million 51 000 Various costs 33. 6 million 53000 Total cost 74.1 million 118000

The total investment corresponds to 5. 8% of the value of the isotope- assisted output. No savings were given, but the main advantages were listed to be Better control of products; Decreased number of rejects; and Increased quality of products; The sources used contained Co60, Iri92, and Cs137.

lonization

lonization devices are used by 13 firms, mainly for static elimination purposes.

Tracing

Table I reveals that the use of tracers is rather widespread throughout the Italian industry, with 28 users in research and 12 in production. How- ever, no details are provided.

Miscellaneous applications

Among the miscellaneous applications listed are the use of luminescent paints in the metallurgical industry and the holding of standard sources for calibration purposes.

JAPAN

In early 1962, the Atomic Energy Bureau of the Japan Science and Tech- nics Agency decided to undertake a survey on the industrial use of radioisotopes. This survey was already well in progress when the Agency sent out its invitation for the International Survey. It was then decided that the material collected would be used as a Japanese contribution to the Agency's survey. Fortunately, practically all information asked for by thé Agency was included in the Japanese questionnaire. A report was issued in April 1963 [1,2] and its contents were also forwarded to the Agency. Mr.T. Shimamura was responsible for the contacts with the Agency. The survey covered a twelve months' period, ending on 31 March 1962. According to official statistics, the net material product measured at factor cost of Japanese industry was 6.7X1Q12 Yen, i.e.US $18600 million. This corresponds to 48% of the net national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

The Governmental organizations in the Atomic Energy field have given the use of radioisotopes considerable support over the years. In 1962 the Japan Atomic Energy Research Institute started to produce radioisotopes for domestic use. Up to this time all material was imported. In 1961 the import of radioisotopes reached a value of 323 million Yen, most of this going into research or clinical use. The widespread use of radioisotope methods is revealed by the great number of scientific papers published at the Japan Radioisotope Conference, which is held every second year, and elsewhere. For the time being, two of the main fields which are receiving support are the technical application of massive irradiation and the construction of radioisotope equipment for which the Japanese industry, with its long and successful experience in fine mechanics, ought to be very well suited.

CONTENTS OF THE REPORT

Of 360 industrial firms approached 202 replied to the effect that they were using radioisotopes in 318 establishments. It was supposed that these firms covered all industrial applications of radioisotopes. In Table I a summary is given on the distribution of these applications over the various techniques and broad product groups. As the question of ownership is irrelevant it would have be-en most convenient to consider the 318 establishments as "users" in the Table, but as the report gives all figures for the firms, they have been accepted and will be used throughout this summary. It should, however, be kept in mind that this gives a somewhat unfavourable position to Japan when compared with other countries participating in the survey. Of the 13 firms not classified two belong to food industry, three to basic metals and eight to services. Further details were not available.

123 TABLE I SUMMARY OF RADIOISOTOPE USE IN JAPANESE INDUSTRY IN 1961

Broad Total No. of Gauging Radiography lonization Tracing M.I* Misc. product No. of establish- group users ments No. of No. of No. of No. of No. of No. of No. of No. of No. of users gauges users sources users devices users users users

1. Food 2. Tobacco 3. Textiles 10 22 6 48 1 1 6 8 4. Wood, 19 24 17 49 2 1 paper 5. Leather, fur 6. Rubber 6 7 5 11 1 7. Chemicals, 34 42 15 77 5 8 12 7 plastics 8. Cement etc. 7 7 5 10 3 1 9. Petroleum 5 5 2 10 3 1 1 and coal

10. Basic 39 74 16 65 23 39 12 14 2 6 metals 11. Machinery 55 98 20 30 31 112 22 15 7 26 12. Services 14 22 9 27 2 2 3 4 6 Not identified 13 17 9 14 2 4 1 2 Total: 212 318 104 341 64 170 34 58 32 42

* Massive irradiation JAPAN 125

The Japanese survey also gives the correlation of radioisotope users to the capital of the firm concerned. It was found that: 62 firms (31%) had a capital higher than 5 billion Yen (US $14 million) 109 firms (54%) had a capital between 100 million and 5 billion Yen (US $0.3-14 million) 30 firms (15%) had a capital below 100 million Yen. The report states that, because of heavy investment of radioisotope techniques, small industry does not have the opportunity of introducing this technique. On the other hand, statistics also reveal that a very high number of Japanese firms do not make use of radioisotopes.

TABLE II

THE USE OF RADIOISOTOPE GAUGES IN JAPANESE INDUSTRY 1961

Number of devices No. Broad product of group firms Thickness Density Level Other Total gauges gauges gauges gauges

Textiles 6 6 42 48 Wood, paper 17 20 26 3 49

Rubber 5 11 11 Chemicals, plastics 15 13 2 56 6 77

Cement etc. 5 8 1 1 10 Petroleum and coal 2 1 2 7 10 Basic metals 16 46 7 9 3 65 Machinery 20 14 4 10 2 30 Services 9 5 9 2 11 27 Not classified 9 3 6 1 4 14

Total: 104 127 31 154 29 341

Gauging

Gauging is the most widespread radioisotope application in Japanese industry. According to the report, 104 users had in 1961 installed 341 gauges. These were distributed as shown by Table II. In the basic metals industry thickness gauging is applied to the measuring of thickness of rolled steel, of light metal sheets and of coatings, in the plastic, rubber and textile industries etc., to sheets of high polymers. Level gauges play an important part in Japan. These devices are most frequently found in the textile and chemical industries for the control of reaction vessels, and in paper mills for measuring the contents of chip or pulp 126 NATIONAL. REPORTS

in containers. Density gauging is applied to the measuring of mud in pipelines from dredging boats and coal powder in coal mining etc. The 29 other gauges represent various source-detector combinations. Seventeen of these are portable soil moisture/density gauges used in civil engineering tests, two are component analysis gauges determining individual elements by preferential absorption and six are density gauges measuring the thickness of snow layers. The rest are individual constructions such as one flow gauge, two inner-defect detectors (probably portable back-scattering gauges) and one static eliminator (thus belonging to the ionization group).

Radiography

As shown in Table I, there are 64 users of gamma radiography who apply 170 radiography cameras charged with Co6° or Csi3?. The most frequent user is the steel industry, followed by machinery, electrical machinery and ship-building (the three last sub-groups of "machinery"). It is briefly reported that the use of direct-image amplifying from X-ray screens has been introduced into routine operation in several works. This avoids the long exposure times the use of X-ray films required. lonization

Except for the one installation for the elimination of static electricity, the only ionization application reported was a 'vacuum gauge'. Twelve such devices were installed to measure the pressure in vacuum melting furnaces in the basic metal group and 22 to measure that in vacuum tubes in fabrication of precision machinery.

Tracing

The scope of radioisotope tracer work in Japanese industry is notable. The national report mentions that 58 firms make use of these means; 54 of these have their own tracer laboratories. Among the most frequent targets for tracer use the following may be mentioned: Investigations of chemical reactions and metabolism studies of drugs and foods; Investigation of wear and material transfer under operating conditions; Activation analysis of industrial products; and Leak detection.

Massive irradiation

The industrial applications of radiation chemistry are given very much consideration in Japan. No less than 32 companies, mainly in the textile, plastics and machinery groups, report research on such lines; 31 possess their own irradiation facilities, either radioisotope sources or accelerators. Up to 1962, however, no commercial production, including the use of large radiation sources, was reported. A report from 1963 shows that a few high- polymer products modified by irradiation were marketed [3], JAPAN 127

Present radiation chemistry research which might have an impact on production processes in the future concern.soil-state polymerization, radiation grafting and polymerization in solutions [4, 5].

Miscellaneous applications

Table I shows 42 users of radioisotope techniques other than the five described so far. These include, according to later information from the national body, the use of luminescent paints and calibration sources, and a few analytical applications, the use of ion-sources in vacuum tubes (normally classified as an ionization application), the leak detection of transistors and electron tubes (probably a tracer method) etc.

Additional information

At the Japan Conferences on Radioisotopes, numerous scientific communications have been made regarding the industrial use of radioisotopes. The number of papers included in the programmes of the various conferences are given in Table III. The details about the 5th Conference, held in 1963, were not complete. These numbers indicated, however, to a certain extent, the very central position of radiation chemistry in recent studies. The rapid increase in Japanese radioisotope use is shown by Fig. 1. The number of firms licensed to use radioisotopes has increased from 35 in 1954 to 202 in March 1962. In 1963 247 firms were reported to be continuing or to be taking up radioisotope work.

ECONOMIC INFORMATION

Like national reports, the Japanese one refers to the limited information on economic matters in industry's replies to the questionnaire. Information about the investment in radioisotope work (equipment, laboratories for tracer and radiochemistry work etc.) was received from 130 out of the 202 firms which made use of radioisotopes during the investigation period. Table IV shows the investment in various categories of industry. Sub-divisions under the Broad Product Group scheme have been made in accordance with the grouping of the Japanese statistics. The Table also shows the number of irradiation facilities, tracer laboratories and other installations (gauges, radiography source etc.). The investment is considerable, even if the figure of 4 million in nuclear industry is deducted as it probably means radioisotope production and basic radioisotope research, which is normally not accounted for in the national surveys. The figures for electrical machinery probably include a certain amount of money invested in equipment production. It is easy to find that a high number of irradiation facilities and tracer laboratories correspond to high investments in research. High investment in production is reported from, among others, the chemical industry, the iron and steel industry and the ship-building industry. The benefits were still more difficult to arrive at as only a very low number of firms were able to estimate them in monetary terms. Asa first 128 NATIONAL REPORTS

TABLE III

NUMBER OF PAPERS PRESENTED AT JAPAN CONFERENCES ON RADIOISOTOPES

1st Conf . 2nd Conf. 3rd Conf. 4th Conf. 5th Conf. (1956) (1958) (1959) (1961) (1963)

Massive irradiation and chemistry 3 6 43 45 54 Gauging 5 7 11 15 14 Radiography 5 6 7 6 ? Industrial tracing 10 7 16 9 18 Physics and 17 10 41 37 ? chemistry research Other industrial 2 2 7 2 ? papers

1SO

1954 195S 1956 1957 1958 1959 1960 1961 1962 March

Fig.l Number of Japanese firms using radioisotopes JAPAN 129

TABLE IV

INVESTMENT IN RADIOISOTOPE WORK (US$ thousands)

No. No. No. Investment for radioisotope use Broad product of of of group users replies I II III Research Production Total

Textile 10 8 10 5 49 1077 264 1341 Wood , paper 19 7 - 1 49 19 128 147 Rubber 6 - - 11 48 1 49 Chemicals, 34 13 4 12 85 1073 1212 2285 plastics

Cement etc. 7 X - 1 10 137 - 137 Petroleum, 5 X - 3 10 9 20 29 coal Basic metals: Iron 28 16 - 8 98 220 554 764 Non-ferrous 11 9 2 7 18 470 53 523 Machinery: General 13 9 48 82 112 194 Electrical 23 21 5 9 69 2575 1890 4465 Precision 7 4 2 2 18 98 24 122 Shipbuilding 8 7 1 33 552 318 870 Other 4 X . 4 9 5 14 Services: Electric power 8 7 22 72 45 117 Nuclear 6 5 7 4 7 4090 4090

Other 13 X 1 1 18 251 316 567

* Total: 202 131 31 54 545 10782 4932 15714

I = irradiation facilities, II = tracer laboratories, III = other installations * This figure includes data for 25 of the 35 firms indicated by x approach the reasons given by the companies for applying radioisotopes were summarized in Table V. In order to estimate the total economic benefits to Japanese industry, many case studies were'made. Savings were estimated using the formula:

D = C-(A-B).

A = the annual cost which is composed of depreciation of capital costs of the equipment, operation costs and the annual maintenance cost for gauging, radiography, tracer or irradiation. 130 NATIONAL REPORTS

TABLE V

REASONS FOR UTILIZING RADIOISOTOPES FOR INDUSTRIAL PURPOSES

Gauging Tracer Radiography Others Total

(a) No alternative method ,. 50 37 36 24 to radioisotopes 146

(b) For technical merits in improvement of quality 62 9 29 5 105 and process controls

(c) Trial use for research 19 10 14 67 purposes

(d) For economy of labour 28 7 7 3 45

(e) Attached to equipment - - 1 7 procured

(f) Others 4 6 4 7 21

B = the annual cost for substitute method. C = benefits achieved from savings of raw materials, decrease of product scraps, increase of products, amelioration and saving of labour cost and other latent benefits. Gauging is effective for saving raw materials, decreasing product scraps, ameliorating and saving labour cost. The estimates of the annual saving of gauging are made as follows. Information was collected for 39 thickness gauges. According to this information the factors in the formula vary within the following limits for each gauge.

US $ 3000- 15 000 1 000- 10000 13000-20000 Savings of raw material 8000- 13000 Decrease of product scraps 4000- 5000 Savings of labour cost 400- 600 Latent benefits 1200- 1600 D = 11 000-17000

The annual gross savings for the whole industry would amount to $1.4 million-$2. 2 million. JAPAN . 131

TABLE VI RADIOISOTOPE SAVINGS IN JAPANESE INDUSTRY 1961

Annual savings (US$)

Thickness gauges 1400000-2200000 Level gauges 560000- 820000 Radiography 820000-1100000 Tracers 280000- 560000 Others 190000- 280000

Total: 3300000-5000000

According to information on 71 level gauges, the corresponding factors range: US $ A = 700-1000 B = 700-2000 C = 3000-4200 Savings of raw material = 400- 500 Decrease of product scraps - 800-1300 Savings of labour cost = 100- 150 Latent benefits = 1700-2300 D =3600-5300

In a firm of pulp industry, the annual savings of $67 000 were reported. The annual gross savings are estimated at $560000-820000. Gamma radiography has made the non-destructive testing of products much easier in cases where X-ray machines cannot be used and is useful for decreasing the number of products of inferior quality and increasing the latent benefits. But labour cost seems to increase in general. According to 17 case studies, US $ 10000- 12000 5000- 8000 9000-10000 Savings of raw material 450- 470 Amelioration 1 500- 2000 Savings of labour cost - 100 Latent benefits 7000- 7 500 D = 4800- 6500.

The annual gross savings are estimated to range between $850000 and $1 500000. 132 NATIONAL REPORTS

Tracer techniques have been applied chiefly for research and process studies, but not continuously in process. It was therefore difficult to estimate its economics. From some information received the savings ranged from an annual benefit of $15 000 to a loss of $280. In conclusion, the savings arising from the use of radioisotopes in industry are shown in Table VI.

REFERENCES

[1] Atoms in Japan ]_ 6(1963) 8. [2] Atoms in Japan, Special 1963 issue, 18pp. [3] HENLEY. E.J., Nucleonics 21 9(1963) 78. [4] Atoms in Japan _4 5 (1960) 24. [5] Atoms in Japan 5 3 (1961) 14. NETHERLANDS

A study of the economic advantages from the use of radioisotopes in industry in the Netherlands was made by the Reactor Centrum Nederland and submitted to the Agency as the Dutch contribution to the International Survey. Responsible for the survey were Mr.E.K. Hoekstra and Mr. A. J. Verbiest. The concept of the Netherlands study was in general identical to the approach suggested by the Agency. A complete report on it was published [1]. The number of licenses for the industrial applications of radioisotopes given by the authorities from 1958 to the end of 1963 was 143, out of which 18 were classified as laboratory activities. A questionnaire, based upon the one suggested by the Agency, was distributed to all the licensed firms. One hundred replies were obtained; thus, the response rate was around 10°/o. A number of the replying firms were visited during follow-up actions and the economic benefits were discussed in detail during these visits. For 1961, the value of the Netherlands industrial output was given as H.F1 16900 million, i.e. US $4700 million. Industry contributed 41% to the gross national product.

The activities of the Netherlands Atomic Energy Authorities are mainly concentrated on the nuclear power development. However, several of its actions are of direct industrial importance, such as the production of radioisotopes in its reactor, general research on radioisotope methods which are performed at its establishments and active participation in certain projects. The official support of radioisotope methods in general, however, goes through other channels, such as the Central Laboratory Organization, TNO, and other institutes operating at universities and private laboratories.

CONTENTS OF THE REPORT

Table I shows how the Netherlands companies responding to the survey made use of the radioisotope techniques in 1962, the year selected for the survey. It should be noted that the figures for the groups 'chemicals' and 'services' are included in other groups under the heading of miscellaneous.

Gauging

The number of gauges in various categories of industry is shown in Table II. Thickness gauges are frequently found in the paper trade, in the production of high-polymer materials and in the rolling of metals. The use of thickness gauges has become economically important, for example in the production of laminated or impregnated materials. The gauges have permitted the plants to make a product with much smaller variation in total weight per unit area and also to work much closer to a given mini-

133 TABLE I

USE OF RADIOISOTOPES IN NETHERLANDS INDUSTRY IN 1962

lonization Tracing Broad Total Gauging Radiography product No. of M.I. * Misc. group users No. of No. of No. of No. of No. of No. of Res. Prod. users gauges users sources users devices

1. Food 2. Tobacco 6 6 59 3. Textiles H 4. Wood, paper 35 35 63 4 O 5. Leather, fur 6. Rubber 10 16 16 7. Chemicals, 14 12 plastics H 8. Cement etc. 6 6 9 CO

9. Petroleum 10 10 128 3 8 and coal 10. Basic metals 5 6 17 11. Machinery 12 127 12. Services 15 15 15 Not identified Total : 105 93 304 15 135 16

* Massive irradiation NETHERLANDS 135

TABLE II

THE USE OF RADIOISOTOPE GAUGES IN THE NETHERLANDS INDUSTRY

Number of devices Number Broad product of Total group users Thickness Density Level gauges gauges gauges

Tobacco 6 59 59 Wood, paper 35 63 63

Rubber, chemicals 16 21 3 24 and plastics

Cement etc. 6 9 9 Petroleum 10 128* 128

Basic metals • 5 5 1 6 Services 15 7 8 15

Total 93 89 66 149 304

* This figure does not only concern level gauges but also includes a proportion of other types. mum weight. Two companies impregnating a material with PVC report that they use on the average 25-50 g less PVC per square metre of ready-made material. This represents considerable savings in the consumption of raw material. The situation in paper production is similar, although the savings in raw material are not considered as important as the increased speed in adjusting the basic weight of paper or paper board. Several companies reported that the period of adjustment after radioisotope gauges had been installed decreased from 15 to 20 min to a few minutes. Also a considerable amount of shut-downs could be avoided as the gauge indicated early if the web started to get too thin. Density gauges are applied to cigarette production and this gives, according to the tobacco companies, quite positive economic results. These are derived from a somewhat increased production, constant filling of the cigarettes and a lower consumption of raw tobacco. In the services, density gauging was reported to be in use for the continuous determination of the solid contents of material dredged from navigation channels and sucked in pipe-lines. The density of the mud-water mixture is a function of the soils contents. Cs137 is used as a source and the results were reported to be very accurate and useful. In 1962 level gauging was a technique that was only recently introduced in the Netherlands industry. However, quite a number of installations were 136 NATIONAL REPORTS

TABLE III

GAUGING ECONOMICS IN THE NETHERLANDS INDUSTRY

Purpose of Annual Cost- Broad product Type of gauging Investment net benefit gauging (No. of group (H. Fl) savings gauges) ratio*** (H.F1)

Tobacco Density Cigarettes (59) 800000 500000 1-2.7

Wood, paper Thickness Paper and paper board (63) 1000000 1300000 1-6.-2

Chemicals, Thickness Laminated and plastics impregnated 120000 365000 1-16 products (11) Level Misc. (3) 4500 20000 1-21

Rubber Thickness Laminated and calendered 200000 230000 1-5.6 products (10)

Cement Level Glass vans 120000 small -

Petroleum Density Various (128) high* high* - and coal Level

Basic metals Thickness Metal sheets (5) 35000* 20000* 1-3.5 Level ? (1) 3400 10000 1-11

Services Level ? (8) 25000 20000 1-4.3 Density Dredging (7) not known high* -

Total 169## 2300000* 2600000* (1-4.8)

* Economic information was given only by a fraction of the firms. ** Figure concerns only applications where details on both investment and savings were given. *** Cost-benefit estimated, assuming 3 yr depreciation period in tobacco industry and 5 yr for the rest. found, as Table III shows. The predominant users are found in the petroleum and coal industries; among other functions, the determination of levels in coal sieves was mentioned in the report. In the chemicals and plastics industries several applications were reported; e.g. for the level control of boiling and corrosive liquids at elevated temperatures. Another application is in the glass industry where the level of the glass melt is gauged. Further technical details on level gauging were not given in the report. NETHERLANDS 137

Radiography

In the Netherlands, gamma radiography has found its most frequent use in the basic metal and machinery industries. It is used as a non-destructive testing method for welds, castings and material in production. Gamma radiography is also used to check the condition of installations, i. e. to locate corrosion or cracks. There are a few companies which use their own radiographical services, but one big consulting firm has a dominating position, serving no less than 300 industrial customers. The advantages of gamma radiography are appreciated in the national report as follows: "The average price for an exposure with gamma rays is about half the price for an X-ray exposure. Radioactive sources are independent of electric supply. The small size of a gamma source permits the testing application to pieces where X-ray sources could not be introduced. The weight of a radioactive source is normally smaller than that of an X-ray device; hence, it is more easily transported to remote areas. The construction of gamma radiographie equipment is more solid than X-ray devices." On the other hand, the report accounts for certain disadvantages, such as: "The exposure period for a gamma exposure must normally be longer than the period when X-rays are employed; also the quality of the image may be less satisfactory. Further, there is always a contamination hazard from radioisotope sources, so that the Netherlands Government calls for certain licences and increased insurance premiums are needed." A comparison of the two techniques shows, however, that in each case the most efficient method is always chosen; it is reported that the number of "unit hours" for X-ray and gamma-ray is of a ratio of 1. 7 to 1. For a total investment in gamma radiography of H.F1. 480 000 the net annual savings are reported as H. F1. 2425000. The number of sources in use is given as 135. lonization

Most accepted applications of ionization methods are to a higher or lesser degree found in Netherlands industry. For example the report mentions about 760 installations of lightning conductors equipped with ionization sources. Such sources have also been in frequent use for static elimination, but legislative and insurance problems have resulted in their almost complete abandonment. Detectors with ionization sources are also in use for smoke and fire detecting. However, the national report does not include any details on lightning conductors and fire detectors. Instead, it covers a few replies concerning static elimination and gas chromatography detectors. The details on these uses, although incomplete, are shown in Table IV. 138 NATIONAL REPORTS

TABLE IV

APPLICATION OF IONIZATION METHODS

Number Broad product Investment Application of Source Savings group (H. Fl) devices

Wood, paper Elimination 3 Not known 1400 doubtful

gas chromatography 1 Ra 22000 considerable, but not estimated

Chemicals, plastics Elimination 1 Ra 3000 doubtful gas chromatography 11 Sr'° 235000 considerable

Tracing

The radioactive tracer methods are reported to be a standard technique in industrial research. However, the number of users is not stated. Nu- merous examples of application are cited, such as Flow-rate measurement of flow in pipes; Tracing of underground water flow; Tracing of sand movement in channels, harbours and along shores; Location of jammed "go-devils" in pipe-lines; Leak detection of water pipes; Mapping the position of underground tubes; and Ventilation studies in mines. The last example is reported to be of utmost importance also in the protective measures against silicosis. However, no further details were given. The replies from the companies have given no hint as to the evaluation of the savings or other economic benefits of radiotracer methods.

ECONOMIC SUMMARY

As already shown, the report accounted for an annual net savings of H Fl. 2. 6 million and 2.4 million from gauging and radiography respectively. Making certain estimates, a total of H. Fl. 5. 9 million is reached. Table V shows how they are distributed over various industries. However, the system does not correspond directly to the "broad product groups'1 suggested by the Agency. According to national statistics, the total capital value of Dutch industry is H. Fl. 40000 million. Hence, the investment in radioisotope equipment shown in Table V is somewhat less than 0. 01%. When compared with the total output value, the annual net savings represent 0. 035%. NETHERLANDS 139

TABLE V

RADIOISOTOPE INVESTMENT AND SAVINGS IN THE NETHERLANDS INDUSTRY

Investment Net annual savings Category of industry (H. Fl) (H.F1)

Tobacco 800 000 500000 Rubber 320000 600000 Paper 1 023 000 1300000 Mining 400000 500000 Petroleum 360000 400 000 Metal 550000 2380000 Glass 166000 doubtful Chemistry 262500 218500 Various 110500 considerable

Total 3 992 000 5898500

REFERENCE

[1] VERBIEST, A.J.. Atoomenergie &_ (1964) 164.

NORWAY

The Ministry of Industry and Handicraft was nominated to implement the survey in Norway. In the preparation of the report it was assisted by the Institute of Atomic Energy. In the survey a translation of the IAEA questionnaire was used together with some additional questions of national interest. It was also found useful to include the year 1962 in the census in order to study any trends in the use of radioisotopes in Norwegian industries. The results from both years are included in this report. Before being circulated to companies the modified questionnaire was tested on a few industrial firms. The response to the survey was, as expected, neither complete nor uniform and had to be supplemented by telephone calls. This was particularly the case for the economic considerations. The total number of companies registered as users of radioisotopes at the end of 1962 was found to be 91. Of these establishments 87 were invited to supply information to the survey and useful replies were obtained from 74 (85%). Thirty-nine companies supplied economic figures for 1961 (53%) and 41 for 1962 (55%). Almost complete information was obtained for both years concerning the value of production and the value of investments. The corresponding figures of savings estimates were found to be about 35% for both years. Further details about response are shown in Table I. The output of Norwegian industry, measured at factor cost was NKr 12000 million in 1961,'i.e. US$1700 million. This represents 38% of the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITY

In 1952 Norway's first nuclear reactor went into operation and a regular production of radioisotopes started. From then onwards an advisory service was created which also performed tracer investigations requested by industry. Since 1959 another service group has been working at the Central Institute for Industrial Research. Radiography service for industry is offered by an independent organization, the Röntgen Control Board.

CONTENTS OF THE REPORT

Table II shows the situation of the use of radioisotopes in Norway in 1961. The additional use in 1962 was not considerable: the total number of users increased from 74 to 76 and the total number of installations from 96 to 101.

Gauging

Table III shows the distribution of gauging devices throughout the various categories of industry. The characteristics of the different uses are shown in Table IV.

141 TABLE I SUMMARY OF RESPONSE FOR 1961 (62)

Number of establishments consulted Number of establishments giving information on No. of Applying Total establ. Value Cost of Estimates Applying Applying Total number Broad isotopes number giving of equipment of product isotopes of establ. No. isotopes as tracers of useful output etc. savings 1962 1961(62) group 1961 before 1961 establ. replies 1961(62) 1961(62) 1961(62)

1 Food 2 Tobacco 3 3 3 3 2(2) 2(2) 2(2) 2(2) 3 Textiles 4 4 1 5 4 2(2) 2(2) 1(1) 2(2) 4 Wood, paper 29 29 1 30 27 18(18) 19(20) 8(8) 19(20) 5 Leather -o 6 Rubber 3 3 3 2 2(2) 2(2) 2(2) 7 Chemicals 3 4 2 6 5 1(1) 1(1) S CO 8 Cement, glass 1 1 1 9 Petroleum, coal 1 1 1 1 1(1) 1(1) 10 Basic metals 8 10 3 13 9 4(5) 5(6) 2(2) 6(6) 11 Machinery 16 16 2 18 16 4(4) 6(7) 1(1) 6(7) 12 Services 6 6 1 7 6

Total 73 76 11 87 74 32(33) 38(41) 14(14) 39(41) TABLE II

SUMMARY OF RADIOISOTOPE USE IN NORWEGIAN INDUSTRY IN 1961

Gauging Radiography lonization Tracing M.L* Misc. Broad Total product No. of No. of No. of No. of No. of No. of No. of No. of users No. of No. of group users users gauges users sources users devices Res. Prod. users users

1. Food 2. Tobacco 3 3 3 3. Textiles 4 4 5 4. Wood, 29 57 1 1 1 paper 28 2 5. Leather, fur - O 50 6. Rubber 3 3 4 2 2 7. Chemicals, 3 1 6 1 1 1 1 plastics

8. Cement etc. - 9. Petroleum 1 1 and coal 1

10. Basic 1 1 1 metals 8 6 6 11. Machinery 16 3 3 12 13 1 2 12. Services 6 1 1 1 4 Not identified Total 74 48 84 15 16 4 4 2 3 - 7

* Massive irradiation TABLE m

Number of devices Number of Broad product group Thickness Density Level Total users gauges gauges gauges

Tobacco 3 3 3 Textiles 4 5 5 Wood, paper 28 48 9 57 T) Rubber 3 4 4 O Chemicals, plastics 1 6 6 Basic metals 6 2 1 3 6 Machinery 3 1 2 3

Total 48 65 5 14 84 TABLE IV CHARACTERISTICS OF RADIOISOTOPE TECHNIQUES - GAUGING

Type of gauge used Frequency of use, times mentioned Benefits - number of times mentioned Number Product Closer Saving Broad Number Reduction Saving Saving of Material of control of product of Thickness Density Level Regular Occasional Exceptional of of of No. users gauged better within raw group replies rejects scraps labour (1961) quality tolerances material

2 Tobacco 3 3 Cigarette tobacco X 3 3 3

3 Textiles 4 3 Coated fabrics X 3 3 1

4 Wood, o paper 28 15 Uncoated paper X 14 1 4 11 5 5 4 4 6 Wood chips X 6 6 2 1 2 1

6 Rubber 3 2 Coated fabrics X 2 2 2 2

7 Chemicals 1 0

10 Basic-metals 6 2 Rolled metals X 2 2 1 1 Ore slurry X 1 1 1 Storage bunkers X 1 1

11 : Machinery 3 1 Steel plates X 1 1 1 Explosives X 1 1 1 1 1 Storage bunkers X 1 1

Total 48 36 33 3 15 24 11 5 6 9 146 NATIONAL REPORTS

Radiography

Gamma radiography is applied to non-destructive testing in manyplaces.. From Table II it can be seen that 15 firms do their own radiography testing, eight of the installations in use being owned by the firm in question and eight being hired from other organizations. Further, the Röntgen Control Board makes its own investigations as a consultant to industry. The characteristics of the various uses are shown in Table V. lonization

There are only two types of ionization applications used in Norwegian industry. One is for eliminating static charges in the rubber industry; the second is the use of ionization detectors in gas chromatography. One application of this is reported from paper industry and the other from the chemical industry.

Tracing

For the survey an attempt was made to collect information about all industrial use of tracers, whether before 1962 or during this year. A summary of the replies to this approach is given in Table VI.

Sources

The various radioisotopes used and their nominal activities are given in Table VII.

ECONOMIC SUMMARY

A summary of information is listed in Table VIII, some comments can be made on the various product groups. The figures in brackets are those for 1962.

Tobacco industry

Density gauges have proved to be useful instruments in the high-speed production of cigarettes. Nine per cent ( 12% in 1962) of the grand total production value of tobacco was isotope assisted in 1961. The corresponding investments in equipment etc. were reported to be NKr 34000(41000), which represent 0.1 (0.1)% of the total isotope assisted production value. These savings were realized through reducing the amounts of raw material because it was possible to run the production within closer tolerances.

Textile industry

The economic benefits realized by this industrial group were mainly due to the use of thickness gauges during the production of plastic foils and TABLE V

CHARACTERISTICS OF RADIOISOTOPE TECHNIQUES - RADIOGRAPHY

Frequency of use Field of inspection Benefits Times mentioned Number of times mentioned

Better Number Better Reduced Broad Number Materials control of control time No. product of Welds Castings tobe Others Regular Occasional Exceptional of Others users of group replies machined raw of (1961) products material inspection Zo Petroleum , 9 1 1 X 1 1 I coal

Basic 10 1 1 X 1 1 metals

11 Machinery 12 4 X X 2 1 1 1 3 1 2

12 Service 1 1 X 1 1

Total 15 7 2 4 1 1 5 2 2 TABLE VI CHARACTERISTICS OF RADIOISOTOPE TECHNIQUES - TRACER APPLICATIONS

Fields of application Frequency of use Benefits Number of experiments Times mentioned Number of times mentioned

Number Better of Clearer Wear control Broad users Number Process Chemical under- Better Lower Improved and Leak Chemical Occa- of No. product (before of plant reaction Others Regular Exceptional standing control cost plant Others corro- detection analysis sional process group 1961, replies studies studies of of of efficiency sion oper- 1961 processes product analysis and 1962)

3 Textiles 1 1 1 1 1

Wood, 4 2 2 2 2 1 1 paper O 7 Chemicals 5 5 5 2 1 1 7 5 50 H Crt Cement, 8 1 1 1 1 1 glass

Basic 9 4 4 1 1 2 2 1 5 1 1 metals — 11 Machinery 3 3 1 2 3 1 2

12 Services 3 3 1 2 3 3

Total 19 19 2 14 1 4 3 2 22 13 1 3 TABLE Vu RADIOISOTOPES USED IN 1961 (1962)

Isotopes used

Broad product 192 No. Co«> Sr*> CS«7 Ir T?04 Other group (me) (me) (me) (me) (me) (me)

2 Tobacco 90(120) 3 Textiles 5(5) (5) 50(50) g 4 Wood, paper 30(30) 20(20) 50(50) 640(650) 10(10) 6 Rubber 120(120) 7 Chemicals 180(180) 8 Cement, glass , 9 Petroleum, coal 5(5) 10 Basic metals 4300(4300) 20(20) 260(260) 10(10) 11 Machinery 6400(6400) 12 Services 10(10)

Total 4345(4345) 250(285) 310(310) 6400(6400) 880(890) 15(15) 150 NATIONAL REPORTS

TABLE VIII

ECONOMICS OF RADIOISOTOPE TECHNIQUES IN 1961(62)

Production (million NKr) Cost (NKr. 1000) Tota l isotop e assiste d productio n Tota l cos t o f equipmen etc . 1961(62 ) Tota l cos t o f hire d equipmen Percen t o f gran d tota l Percen t o f answerin g grou p i n us e befor 1961(62 ) installe d 1961(62 ) Tota l cos t o f equipmen etc . Tota l productio n valu e Percen t o f gran d tota l valu e amon g answerin grou p Tota l cos t o f equipment , etc . an d consultant s 1961(62 ) Gran d tota l productio n valu e fo r broa d produc t grou p fo r answerin g grou p

457 272 60 43 9 16 46 46 2 Tobacco (465) (271) (58) (54) (12) (20) (46) (26) (72)

870 19 2 7 1 37 23 31 54 3 Textiles (927) (39) (4) (7) (1) (18) (54) (52) (106)

Wood, 2486 541 22 321 13 59 634 60 704 3 4 paper (2413) (554) (23) (340) (14) (61) (704) (64) (768) (2)

167 93 56 9 5 10 101 101 6 Rubber (175) (101) (58) (9) (5) (9) (101) (45) (146)

2132(0 11 n(0 7 Chemicals (2235) (11) (ii)

Petroleum , 404(0 30 9 coal (523) (25)

Basic 2506 109 4 34 1 31 92 20 112 2 10 metals (2515) (184) (7) (101) (4) (55) (112) (37) (149) (10)

791(0 267(0 34 33(0 4 12 52 6 58(0 U Machinery (867) (320) (37) (37) (4) (12) (58) (13) (71)

6486 1034 16 414 6 46 959 117 1017 35 Total (6495) (1149) (18) (511) (8) (45) (1086) (237) (1241) (37)

(Increase 23% 22% 1961/62) NORWAY 151

TABLE VIII (cont'd)

Mainte- nance Savings (NKr 1000) (NKr 1000)

Savings Saving s estimate o f tota l o f isotop e assiste d prod , valu Percen t o f tota l isotop e assiste d prod , valu e Maintenanc e o f equipment , etc . establishment s Correspondin g isotop e assiste d productio n valu e Saving s estimate referre d t o Percen t o f tota l estimate d an d cos t o f healt h precaution s saving s mainly due to

2 34 43000 34 0.1 1.6 Density (41) (54000) (41) (0.1) (1.8) gauging

2 15 2000 53 0.8 2.5 Thickness 3 (3) (15) (2000) (53) (0.8) (2.3) gauging

13 715 122000 1881 0.6 88 Thickness 4 (14) (725) (121 000) (2037) (0,6) (88) gauging

1 145 9000 145 1.6 6.8 Thickness 6 (1) (145) (9000) (145) (1.6) (6.3) gauging

30« 9 Radiography (25)

1 13 28000 16 0.1 . 0.8 Thickness.density JL\Jirt (2) (13) (31000) (42) (0.1) (1.8) and level gauging

10 2« 11 (12) (2)

27 922 204000 2129 0.51 100 (32) 939 (217000) (2318) (0.45) (100)

W Figures not included in total of the column. 152 NATIONAL REPORTS

the coating of textiles. Of the grand total production value 1 (1)% was isotope assisted. The usefulness of nuclear gauges is indicated by the doubling of the investment in 1962. For the establishments concerned the total savings estimate was found to be NKr 53000 (53000) or 0.8 (0.8)% of the total isotope assisted production value.

Wood and paper industry

The major part of the investments in nuclear gauges and also the major part of the reported savings obtained by Norwegian companies have been realized by this group of industry. Of the grand total production value 13 (14)% was isotope assisted in 1961 (62), corresponding to a total investment in equipment etc. of NKr 704000 (768000). The total savings estimate was found to be NKr 1 881 000 (2037 000) or 0.6 (0.6)% of the isotope assisted production value. The savings obtained account for nearly 90% of the total reported savings estimate.

Rubber industry

Savings were realized by the rubber industry by using thickness gauges during the calendering of rubber products. In 1961 (62) 5 (5)% of the grand total production value was isotope assisted, and the total investment in equipment etc. amounted to NKr 101 000 (146 000). The corresponding savings were estimated to be NKr 145 000 for both years or 1.6% of the total isotope assisted production value, which is the highest value reported.

Basic metals industry

For this industrial group 1 (4)% of the grand total production value was isotope assisted in 1961 (62) and NKr 112000 (149000) were invested inequip- mentetc. The corresponding savings were estimated to be NKr 16 000 (42 000) or 0.1 (0.1)% of the total isotope assisted production value. The savings were realized by the use of thickness, density and level gauges. The estimates summarized above are based on figures related to the use of nuclear gauges. This \~fpe of radioisotope application has proved to be useful, especially in the wood and paper industries, which account for about 60% of the total investments and about 90% of the total savings. The total investments figures in equipment etc. indicate that the use of nuclear gauges has not yet reached saturation level. During 1961-62 the total investments increased by 22%, resulting in a corresponding increase of 23% in the isotope assisted production value. During the same period the savings estimate total increased by 9%. The percentage of savings to the total isotope assisted production value decreased from 0.51 to 0.45. Due to the lack of statistics in the savings figures it is difficult, on this basis, to make any conclusions concerning the trends of savings. In conclusion it can be stated that five broad product groups (tobacco, textiles, wood and paper, rubber and basic metals) have supplied sufficient information to allow a total savings estimate of more than NKr 2000000/yr NORWAY 153 to be calculated. This savings estimate refers to 7(8)% of the grand total production value for the product groups concerned. Three broad product groups (chemicals, petroleum and coal, and machinery) did not supply sufficient information to make savings estimates. The total savings estimate mentioned refers mainly to direct economic benefits like labour savings, raw materials savings such as higher production speed, better products etc. These benefits are of great importance to industry, but it has proved difficult to estimate these benefits in terms of economic figures.

POLAND

The Polish contribution to the Agency's survey was issued by the De- partment of Isotope Development, within the Office of the Commissioner of the Government for the Use of Atomic Energy. The information concerns the period 1 July 1961-30 June 1962. It was based upon data reported periodically from branch centres dealing with the industrial use of radioisotopes, namely: Bureau of Nuclear Equipment; Institute of Nuclear Science; Institute of Basic Technical Problems (Dept. of Isotope Research); Institute of Electrical Engineering, (Dept. of Industrial Radiology); Institute of Mining. (Isotope Laboratory); Institute of Industrial Chemistry (Isotope Laboratory); and Academy of Mining and Metallurgy (Institute of Nuclear Techniques). In the above-mentioned institutions are concentrated all the activities in the field of radioisotope applications, i.e. the design and supply of industrial gauges and laboratory equipment, the design of their installation, the planning of process control applications and the carrying out of investigations in industrial plants. It is unlikely that any plant was supplied with gauges or carried out investigation with the use of radioisotopes without the assistance of some of the above-named institutions, so that the information should be complete as far as the technical details are concerned. The evaluation of economic benefits from the use of radioisotopes was carried out by officials of the Commissioner of the Government for the Use of Atomic Energy. They visited individual plants, collected the necessary data, discussed them and calculated the savings. Most of the plants were not able to supply this kind of information themselves. According to official statistics the net material product of Polish industry was Zl 234 000 million, measured at factor cost. This corresponded to 62% of the gross national product, and based on the official exchange rate it reached the value of US $ 9800 million.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

Radioisotopes were first used in the Polish industry in 1954, although already much earlier some research work had been carried out in the field of nuclear geophysics. A more lively interest in the industrial application of radioisotopes was created by the papers read at the International Con- ference on Peaceful Uses of Atomic Energy held at Geneva in 1955. Initially the progress in this field was slow because of the lack of skilled personnel, and lack of isotopes and equipment. The training of the first cadre for industry started in 1956-57. The Isotope Commission of the State Council for Peaceful Uses of Atomic Energy and the Department of Isotope Development in the Office of the Com- missioner for the Use of Atomic Energy were created in 1958. They have contributed to a widespread application of radioisotopes in the most important branches of industry. These bodies have supported research on radioisotope methods and on the development of nuclear equipment. The fruits of these efforts are now beginning to be harvested by industry. In

155 156 NATIONAL REPORTS the period of the survey the number of applications was not very great. How- ever, the report believes that this was a period of the "demonstration- programme" and a rapid growth was expected from 1963 onwards.

CONTENTS OF THE REPORT

Table I gives a summary of how the various isotope techniques were applied in the various categories of industry.

Gauging

Gauging is the predominant technique of radioisotope applications in Polish industry. In 1962, 140 out of 166 users used it. Table II shows how the 219 gauges were distributed over the categories of industry. Thickness gauging was applied to paper, calendered rubber and (most frequently) to hot-rolled and cold-rolled steel plates. Density gauging was applied in two cases only: to concentrated sul- phate solutions in the chemical industry, and to a mixture of oil and water in pipelines for crude petroleum. Level gauging was the most accepted application in Polish industry: it accounted for 188 out of 219 installations. It was applied by three industrial plants to measure the level of liquid ammonia in separators at 300 atm pressure. Several other applications in the chemical industry were also reported. Level gauging was also applied to glass furnaces in six establishments. In the petroleum and coal industry various level gauging installations may be mentioned, including the measurement of coal level in hoppers and skips, of fine coal in hoppers, and the use of a source detector combination as an interlock of coke-batteries. In the basic metals industry level gauging was applied to the level of iron in cupola furnaces. In the services group the report mentions a large number of level gauging devices applied to liquids and liquid gases in containers and bottles of various kinds. The remaining applications of the gauging principle refer mainly to the use of density and moisture gauges in oil well logging (seven devices). One device was used in coal logging and one in potassium prospecting. One unusual application of a radioisotope gauge is a portable device for determining the metal contents of ores by radiation-induced X-ray fluorescence.

Radiography

The national report covers 22 establishments using gamma radiography for non-destructive testing. Of these cases, six concern the radiography of castings, nine the radiography of tube welds in steam boilers, and two the radiography of ship welding. In the services group, five applications to welding are reported, e.g. for control of pipeline welds. TABLE I SUMMARY OF RADIOISOTOPE, USE IN POLISH INDUSTRY IN 1962

Gauging Radiography lonization Tracing M.I. Misc. Broad product Total No. No. of No. of group of users No. of No. of No. of No. of No. of No. of No. of users users users users gauges users sources users devices Res. Prod.

1. Food 2. Tobacco 3. Textiles 4. Wood, 5 5 5 paper 5. Leather, fur 6. Rubber 4 4 4 1 18 7. Chemicals, 19 19 45 2 plastics 8. Cement, etc. 7 7 11 2 9. Petroleum 32 32 44 1 and coal 10. Basic metals 9 6 12 9 11. Machinery 17 17 12. Services 73 67 98 5 1 Not identified

Total: 166 140 219 22 80 1 18 15 158 NATIONAL REPORTS

TABLE H

THE USE OF RADIOISOTOPE GAUGES IN POLISH INDUSTRY IN 1962

Number of devices

Broad product group Number of users Total Thickness Density Level Other gauges gauges gauges gauges

Wood and paper 5 5 5 Rubber 4 4 4 Chemicals, plastics 19 1 44 45 Cement, etc. 7 10 1 11 Petroleum and coal 32 3 33 8 44 Basic metals 6 8 3 1 12

Services 67 98 98

Total: 140 17 4 188 10 219

lonization

Only one ionization application was reported. This is the elimination of static electricity on rubber coating machines. To this problem some 80 ionization sources were applied.

Tracing

No research applications of tracers were reported. In industrial process control several companies employed radioactive tracer methods. Among these the following may be mentioned: Determination of retention time of various materials in rotary kilns and furnaces (cement, chemical and basic metals industry); study of mixing of solids (basic metals industry); investigation of sources of non-metallic inclusions in steel; determination of wear of blast furnaces; weighing of liquid aluminium in electrolytic cells by isotope dilution; localization of leaks in pipelines; control of oil well operations; determination of wear of wire-drawing dies; and investigation of scaling of ingots.

ECONOMIC INFORMATION

The total costs of radioisotope gauges differ for individual applications. The average overall cost of gauges plus installation are as follows: POLAND 159 •

Beta thickness gauges ca. Zl 100 000 Density gauges Zl 100-150 000 Level gauges Zl 30- 50 000 Gamma relays Zl 10-15 000

The cost of the radioisotopes is in most cases low when compared with the total costs, so that they are not accounted for separately. The amortization periods for radioisotope gauges are very short, rarely exceeding 12 months. A chemical company that installed level gauges on liquid ammonia separators regained its investment in four months. A metallurgical company that installed thickness gauges on cold rolling mills regained its investment in three months. The investment for tracer applications in process control is difficult to calculate because such investigations are carried out by specialized isotope laboratories in the institutes, which work on the state budget, and the costs of structures, buildings and health physics equipment do not concern a particular investigation in the industry but a general research programme. Using the method referred to before, the economic benefits from the application of radioisotopes in industry were for the reported period estimated as follows:

Gauging ca. Zl 70 000 000 Radiography ca. Zl 20 000 000 Tracers and other "ca. Zl 10 000 000

Total £a. Zl 100 OOP OOP

These estimates concern mainly the application of isotope gauges and radiography. Savings from most applications of tracers to process control were not included because they do not come directly from the investigations carried out in the reported period, but are obtained after the period of time necessary for undertaking changes in technology and in reconstruction of manufacturing equipment.

PORTUGAL

The survey in Portugal was implemented by Junta de Energia Nuclear, Laboratorio de Fisica e Engenharia Nucleares. Mr.C.Cächo was responsible for it...... As Portugal is not yet highly industrialized, radioisotopes have found only limited numbers of applications in this country. Industry accounts for an output value of only Esc 28 000 million, i. e. US $950 million. This is 41% of gross national product.

CONTENTS OF THE REPORT

Table I gives the industrial uses of radioisotopes in Portugal in 1962.

Gauging

Radioisotope gauging is the most widely used technique. Three firms in the wood and paper industry regularly apply thickness gauges (equipped with Tl204-sources). One firm in the chemical industry uses portable backscatter gauges for corrosion control. One petroleum refining firm uses one level gauging installation on catalysts in reaction vessels and has, besides, one portable device for corrosion control. One technical laboratory (reported in the service category) applies radioisotope soil moisture and density gauges in civil engineering tests. No economic details were given.

Radiography

Seven industrial establishments in the basic metals and machinery industries (not separated in the national report) apply gamma radiography to the testing of castings and welds. The number of sources and the nuclides applied were not reported. Several advantages of gamma radiography are mentioned: better control of products, reduction in labour cost and inspection time, lower costs than alternative methods for testing very thick materials, ability to test parts where X-ray machines cannot be used.

Tracing

The refinery company referred to above is using "go-devils" equipped with radioactive sources to inspect pipe-lines. The technical laboratory, also mentioned above, has applied radioactive tracer methods to several civil engineering problems, such as literal drift and silt transport in rivers.

161 TABLE I

SUMMARY OF RADIOISOTOPE USE IN PORTUGUESE INDUSTRY IN 1962

Gauging Radiography lonization Tracing M.I.* Misc. Broad Total product No. of No. of No. of group users No. of No. of No. of No. of No. of No. of No. of users users users users gauges users sources users devices Res. Prod.

1. Food 2. Tobacco 3. Textiles 4. Wood, paper 3 3 3 O 5. Leather, fur Z 6. Rubber 7. Chemicals, 1 1 1 ID plastics O 70 8. Cement, etc. H 9. Petroleum 1 1 2 1 and coal 10. Basic metals 11. Machinery 7 7 12. Services 1 1 2 1 Not identified

Total 13 6 8 7 2

* Massive irradiation SOUTH AFRICA

The survey in the Republic of South Africa was handled by its Atomic Energy Board. Mr. J.K. Basson, of its Isotopes and Radiation Division, was responsible for its implementation. At the end of 1961, 100 non-medical users of radioisotopes were registered with the Atomic Energy Board. Of these, 72 were industrial organizations, 18 universities and basic research institutes, and 10 public institutions. The total number of users who responded to the national inquiry, which made use of the Agency's questionnaire, was 33, representing virtually all industrial firms making appreciable use of radioisotopes. Some of the remaining cases were outside the scope of the survey, or, although licensed, made no use of radioisotope methods during 1961. Additional information has been submitted concerning the activities of 23 further users, so that Table I contains details on 56 users. In 1961, the net value of the output of South African industry was R910 million, i.e. US $2700 million. Industry accounted for 39% of the net national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

South Africa is rather remotely situated, and this has created certain difficulties in obtaining radioactive material for practical use. This situation may have partly hampered the development of radioisotope methods, but it should be noted that nevertheless about 700 consignments, including 33 various radionuclides, were imported in 1962. Most of these shipments were by air, some by sea. Limited amounts of radioisotopes were produced in a cyclotron. In 1964, the first South African reactor will be in a position to meet demands, particularly for short-lived radioisotopes. The Atomic Energy Board controls the use of radioisotopes. Moreover it supports radioisotope training and has arranged courses of its own. Re- search with radioisotopes performed or assisted by the Board is considerable. At a scientific meeting held in Pretoria in 1963, 53 research papers were read, and a survey of the industrial applications was also given [1],

CONTENTS OF THE REPORT

Table I shows how the 56 users of radioisotopes in 1961 were distributed over the product group and techniques.

Gauging

Table I shows that gauging was applied by 32 users possessing 112 devices. TableII gives details of the purpose of these devices. Thickness gauges were found in the paper and the plastic industry. Among the applications in the paper industry was one of laboratory design for checking the variations across the web; the rest were for measuring in

163 Gauging Radiography lonization Tracing M.I.* Misc. Broad Total product No. of No. of No. of No. of No. of No. of No. of No. of users No. of No. of group users users gauges users sources users devices Res. Prod. users users

1. Food 1 1 1 2. Tobacco 3 3 59 3. Textiles 4. Wood, 4 4 10 paper O 5. Leather, fur 6. Rubber 7. Chemicals, 2 2 12 1 1 1 plastics 8. Cement, etc. 2 2 3 9. Petroleum - and coal 10. Basic metals 14 9 16 2 2 2 6 11. Machinery 4 4 14 12. Services 3 2 3 1 31 Not identified 23 10 10 10 3

Total: 56 32 113 8 48 11 1 3 6 3

* Massive irradiation SOUTH AFRICA 165

TABLE II

THE USE OF RADIOISOTOPE GAUGES IN SOUTH AFRICAN INDUSTRY IN 1961

Number of devices Number Broad product of group users Thickness Density Level Other Total gauges gauges gauges gauges

Tobacco 3 59 59 Wood, paper 4 10 10 Chemicals, plastics 2 11 1 12 Cement etc. 2 2 1 3 Basic metals 9 12 2 2 16 Services 2 3 3 Not classified 10 10 10

Total: 32 21 72 4 16 113 line. Density gauges were found in the tobacco industry to determine the filling of cigarettes. In fact, all the cigarette production in the country is now gauged by radioisotope devices. Within the basic metals group six gold producers made use of density gauges in ore treatment. One density gauge was also reported by a big chemical firm, but no details were given. Level gauges were found in a few cases in the cement industry and in the basic metals industry. No details were given. Most of the remaining gauges consisted of portable devices for density- moisture determination of solids. They were used mainly in civil engineering but were also applied in the basic metal and other industries. Included in the cement group, among the "other" gauges, was the scanning of refractory blocks used in relining glass furnaces. This is an important application from the economic point of view and its economic implications will be discussed below. Finally, in the basic metals group is a source-detector combination for use on coke oven doors. According to the user, this is the safest and simplest method to ensure that the doors on both sides of an oven that is being pushed are open.

Radiography

Gamma radiography was reported from seven industrial firms and one enterprise in the services group (the South African Bureau of Standards). From the seven firms, there were six reports of applications to welds and three to castings. ^ The South African Bureau of Standards possesses by far the largest number of sources for gamma radiography (31 out of 48). It is working as 166 NATIONAL REPORTS

an independent consultant for a large number of companies (exact figure is not known). Since the later part of 1961, it has been receiving competition from a private firm that has gamma radiography on its programme, but the activities of this firm were not included in the survey. lonization

The replies to the survey cover only one application of ionization methods: a gas chromatography detector used occasionally in the food industry. A small number of firms in various other categories use similar devices, as well as static eliminators, etc. Because of the limited economic value of these applications they were not covered by the survey but have been included in Table I for the sake of completeness.

Tracing

Several interesting applications of tracer methods are reviewed in the report. Three firms use radioisotopes in research, six in process control. Among the research applications is a chemical company studying and developing methods of analysis with the aid of tracers, such as P32 and Mo". Activation analysis has been applied in gold processing. Process. studies with radioisotopes have been applied over the years by various process industries, e.g. for leak detection, mixing studies and retention time determination. In 1961, however, only firms in the basic metals group gave replies regarding such uses. In the processing of diamond deposits the occasional use of this technique was reported for studying the extraction of diamond from the ground material. This method has been described. [2], One gold miner undertook process studies with Au198. One further company studied the wear of furnace lining with installed Co60 sources.

Massive irradiation

Recently research has begun in South Africa on the preservation of foodstuffs. For the period of investigation, however, no work was reported.

Miscellaneous applications

Among the applications not covered by the five previous techniques, only the use of luminescent paints was reported, and only a few companies were involved.

Other information

From the report details are available of the imports to South Africa of radioisotopes in 1961 and 1962 (Table III), and of the nominal amounts of radioisotopes used by industry (Table IV). Table IV includes only gauging and radiography. For tracing purposes mainly P32, AU198, Zn65 and Aul98 were reported. SOUTH AFRICA 167

TABLE ffl

IMPORTS OF RADIONUCLIDES (IN MILLICURIES) TO SOUTH AFRICA IN 1961 AND 1962

Radionuclide Imports 1961 Imports 1962

Industry Research Industry Research

_ H3 . 36000 12000 14 c - 14 - 49 p32 3700 15400 290 263 ss s - - - 6 Ca45 - - - 11 Sc46 - - - 4 Cr51 - 3 - 8 Fe55 - - - 10 Co58 - - - 2 60 Co 325 22010 2035 2000 Zn85 - 81 - 2 ' Kr85 , - - 3000 5r9' - - 395 4 Nb95 - - - 3 Agiiom - - - 2 Sb124 - - 400 100 ,131 - 5000 - 5 Cs137 2500 6 5050 62 Ce144 - 5 - 1 l92 Ir 46850 5 18615 18000 Au198 - 850 1 10600

Hg203 - 2 1 250 Tl204 - - 485 6

Po210 - 1050 4 4 Ra226 420 - - 4 Ra/Be - - 515 20

Total * 53800 80400 27800 46100

* including minor activities of other nuclides; total figures rounded off. 1961 from national report, 1962 from [1], Quantities below 1 mc/yr excluded. The imports for medical purposes amounted to 20500 me in 1961 and 27 200 me in 1962. 168

TOTAL NOMINAL ACTIVITIES (IN MILLICURIES) IN USE IN SOUTH AFRICAN INDUSTRY IN 1961 (Data from main 33 users)

Gauging Radiography

Co60 650 17000

Cs137 600 26000

Ir192 400 34000 Sr90 1100 - Tl204 350 - Ra/Be 32 -

ECONOMIC INFORMATION

Although most firms gave unusually positive and detailed technical information, the information on economic details was much less satisfactory. Twenty seven gave details of costs, and 10 of savings. Nearly every firm, however, reported benefits from a quantitative point of view. Table V shows the benefits derived from the various applications as indicated by the answers to questionnaires. The most important benefit in gauging is obviously the closer control within tolerances. Savings in labour and better product quality take second place, raw material and scrap being less frequently mentioned. In radio-' graphy the main advantage comes from the higher reliability of the tested product. Other important reasons are savings in labour and decreased testing time. For tracing, the six replies indicate that the most important economic factor was improved plant efficiency and clearer understanding of the process. Examples on savings estimates may be quoted from the tobacco industry. Two firms, with an isotope-assisted output of R38 million/yr report an annual cost of R29 000. The net savings are R37 000/yr, corresponding to a gross annual saving of R66 000. The cost-benefit ratio is 1:2.3. The gross savings correspond to 0. 17% of the output value. An example from the plastics industry concerns a thickness gauging installation for R700 000 production value. Annual cost is R387, and the savings is estimated at R3750/yr. The cost-benefit ratio is high: 1:10 approximately. Six density gauges in gold mining companies have also been subject to savings estimates." The net savings are given at an average of R800 per gauge. The average cost-benefit ratio is about 1:3. The scanning of refractory blocks, referred to above, has been subject to a thorough economic analysis. The source-detector combination indicates SOUTH AFRICA 169

TABLE V ADVANTAGES OF VARIOUS TECHNIQUES (Number of times indication given)

Gauging Radiography Tracer Total replies 23 13 6

Product of better quality 10 8 - Closer control within 19 1 - tolerances Saving of raw material 7 1 - Saving of labour 10 5 - Reduction of rejects 5 1 - Saving of scrap 5 1 - Saving of time - 3 - Other 6 1 6

Total: 62 20 6

TABLE VI

SUMMARY OF ECONOMIC INFORMATION

Isotope - Total Annual Total Broad product Technique assisted investment cost output group applied * output (Rand) (Rand) (Rand) (Rand)

Tobacco Density gauging 144000 36000 55.4 106 45 106 Wood, paper Thickness gauging 8600 2400 11.7 106 7.2 106 Chemicals, plastics Gauging, radio- 30400 8500 3.1 106 2.1 106 graphy, tracing Basic metals Gauging, radio- 52 00 16250 - - graphy, tracing Machinery Radiography 15000 3500 - - Services Radiography 16000 3000 " " gauging

Total: 266000 69600

* Not including applications where sufficient information was lacking 170 NATIONAL REPORTS

.which blocks are porous or defective, and these are returned to the producer for replacement. Blocks with a higher density than the average are selected for lining at the most vital parts. Using this method together with certain other improvements in technique the firm states that the life-spans of the furnace linings has been increased by 20-25%. A fifth of this is attributed to the isotope technique, representing a saving of R17 500-20 000/yr. The costs are not given but they must be fairly low. One company using gauging, radiography and tracing reports a total saving of R7000- 14 000/yr. However, the multiplicity of techniques makes an analysis impossible. One interesting case is reported on radiography of castings. At a capital cost of only R657 savings of about RIO 000 on a production valued at R640 000 is reported. The savings arise from better product control, less labour and better use of raw material, and they reach 1. 5% of the production value. The cost-benefit ratio would be 1:15; however, it is not clear whether operation costs were properly accounted for. Table VI summarizes the economic information available.

REFERENCES

[1] BASSON, J.K., Application of isotopes and radiation, Nat. Conf. Nucl. Energy (Pretoria. April 3-8, 1963) 559. [2] NESBITT, A.C., Application of isotopes and radiation, Nat. Conf. Nucl. Energy (Pretoria, April 3-8, 1963) 99. SPAIN

The survey in Spain was conducted by the Spanish Atomic Energy Board, and the contacts with the International Atomic Energy Agency were maintained by Mr. J.M. Gamboa, Head of the Board's isotope section. In mid-1963 there were in Spain 43 users of radioisotopes for industrial purposes. The report submitted to the Agency contains technical information about 37 of these users. The overall response to the economic questions was poor, so follow-up action was necessary. Even then only a few cases submitted sufficient information to establish the economic benefits of radioisotope use. In 1960, the latest year for which information was available, the industrial output in Spain reached Pta 187 000 million, i.e. US $100 million. This corresponded to 33% of the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITY

Before 1957 no industrial applications of radioisotopes could be accounted for in Spain. In 1957 the Isotope Section of the Atomic Energy Board was organized, and this body has devoted itself to the promotion of radioisotope methods. It was also responsible for drawing up the rules to govern the use of these methods, and is registering all applications. In addition, it has taken up research methods which may become useful in the future, such as food preservation and industrial tracing. It has also performed tracer experiments and other investigations under direct contract for individual firms.

CONTENTS OF THE REPORT

Table I shows how Spanish industry made use of radioisotope methods in mid-1963. Table II shows how these methods were introduced in the period 1958-63. The six "other activities" in Table II are those not included in Table I.

Gauging

Radioisotope gauging is used in various processes. Table III shows how the 41 gauges are operated. As this Table shows, thickness gauging, is the predominant technique, being applied to paper, calendered rubber, plastic sheet and rolled products. Density gauging is applied only to cigarette manufacture. Level gauging is used in one case for modern plastic material. Of the other gauges, two in the services group are applied to sand and concrete to determine their density by backscattering. No details were released of the third gauge.

171 Gauging Radiography lonization Tracing M.I.* Misc. Broad Total product No. of No. of No. of group users No. of No. of No. of No. of No. of No. of No. of users users users users gauges users sources users devices Res. Prod.

1. Food 2. Tobacco 1 1 2 3. Textiles 4. Wood, paper 2 2 4 5. Leather, fur 6. Rubber 1 1 6 O 7. Chemicals, TO 8 5 14 2 9 1 H plastics co 8. Cement, etc. 9. Petroleum and coal 10. Basic metals 8 7 12 1 1 11. Machinery 13 12 16 2 12. Services 3 1 2 2 49 1 Not identified 1 1 1 Total 37 18 41 13 17 4 58 2 2 * Massive irradiation SPAIN 173

TABLE II

INDUSTRIAL APPLICATIONS OF RADIOISOTOPES IN SPAIN (Industrial users who had received or applied for licences by 15 June 1963)

Other Techniques employed activities S A E *« 3 *~^ D .c C fl) •a Year 2* o ^ M 00 w Si ° .2 o .2 S S « a g •o ö <~* T 3 s g es '-' S G ** (U

e O x ut 2 58 o f

BO « 1w ÄO •: s *« "" C *Ü u «0 S S *^* M *0 «i M .2 (O ce o r i i li i l < Annua l c i Trainin g öS S H 2 2 Commerci a

A B C D E F

1958 1 .... - 1 1

1959 1 1 2

1960 1 ... 1 2 1 5 7

1961 1 3-2 - 1 7 14

1962 1 5 2 - - 8 22

1963 (l) 15 3 2 - 1 21 43

Total 17 13 4 2 1 4 2 43

(1) First six months only (2) Firms importing, selling and advising on the installation of industrial radioisotope equipment for other users (3) Training centres, other than the Board's Isotope Section, providing engineering students with technical instruction in the industrial uses of radioisotopes

Radiography

Table I shows how the 13 users were distributed over the various product groups. In 18 cases, radiography was applied to welding; in seven to castings. Five of the welding cases referred to transport equipment, and the remainder were distributed over various objects to be inspected. lonization

Two applications of ionization methods were reported: one in the chemical industry, where ionization is applied to the elimination of static charges; the other in the use of lightning conductors. The number of devices is nine and 49 respectively. 174 NATIONAL REPORTS

TABLE III

THE USE 0F RADIOISOTOPE GAUGING IN SPANISH INDUSTRY IN 1963

Number of devices Number : Broad product of group Level Other users Thickness Density Total gauges gauges gauges gauges

Tobacco 1 2 2 Wood and paper 2 4 4 Rubber 1 6 6 Chemicals, plastics 5 12 2 14 Basic metals 7 12 12 Services 1 2 2 Not identified 1 1 1 •

Total 18 34 2 2 3 41

Tracing

Two applications of tracers were reported, both in process and product control. Further details were not given.

Miscellaneous applications

Two applications of luminescent compounds were reported in instrument- making firms belonging to the machinery broad product group.

ECONOMIC INFORMATION

The economic information provided is presented in the form of case studies, the contents of which are quoted directly translated from the report:

User No. 6

This user has been regularly using two thickness gauges for control of plastics manufacture since 1959. Total annual production is worth Pta 146 million and all products are monitored by the two gauges. According to the manufacturer, the advantages of the method are improved quality, more stringent controls within the tolerances laid down, and a considerable saving in raw materials and fabrication wastes. The manufacturer estimates that, depending on whether the radioisotope gauges are used or not, there is a 5% difference in the fineness of the toler- SPAIN 175

ances to which it is possible to work. On the basis of a raw-material cost of Pta 50000/t and a production of 1500 t/yr, this yields an annual gross saving of Pta 4. 75 million on raw materials. It is also estimated that use of the gauges reduces the quantity of manufacturing rejects by 15 t/yr. Since such rejects are sold at Pta 50000/t cheaper than high-grade products, this involves an annual saving of Pta 750000. Adding this total to the previous figure, the overall saving is Pta 5. 5 million/yr. The cost of the equipment, including radioisotopes, is Pta 375000. Maintenance costs are Pta 20000/yr. On this basis, the total annual investment required (allowing for maintenance, amortization and interest) is Pta 108125.

User No. 16 In this case, equipment is used for measuring the density and moisture of the ground during road building. According to the user, considerable savings are possible with the density-gauging technique (radioactive method — Pta 7 per determination; conventional method — Pta 15 per determination). Moreover, about 70 determinations can be made daily with the radioactive method compared with about 20 with the conventional. The net benefit per 70 determinations can thus be estimated at 20(15-7) + (70-20)15 = Pta 910. As the user carries out about 4000 determinations/yr on a non-continuous basis, the total saving can be estimated at 4000/70X910 = Pta 52000/yr. Really big savings can be achieved by means of the isotopic moisture- gauging technique. While there is apparently no substantial difference in cost as between individual determinations by conventional and by radioactive methods, the great speed with which radioactive determinations can be made (contrasting with a time-lag of 24 h in the case of the desiccation method) means that very considerable savings can be achieved. An engineer using the radioactive technique does not have to wait for a new layer of earth to be laid during the work of compacting. While it is very difficult to make an accurate assessment, the saving obtainable ranges probably from 5% to 15% of the total cost of compacting. In the case in point, where the annual sum spent under this heading amounts to Pta 20 million, the saving can be put at an average level of Pta 2 million/yr. At a total cost of Pta 508 000 the moisture-and density-gauging equipment can be considered to have paid for itself after a period of about three months. Allowing for maintenance, amortization and interest, the total annual investment required is Pta 119380.

User No. 19

This user carries out radiographie inspections on a commercial basis on behalf of other firms that request his services. He is the largest consumer of radioisotopes (mainly Ir192) for this purpose in Spain, isotopes being used for approximately 90% of all the radiographs he makes. Firms pay about Pta 200 per radiograph, which means that the user, who gives a figure of Pta 90-100 for his costs, can make a profit of about Pta 105. 176 NATIONAL REPORTS

Because of a complete absence of data it is impossible to calculate how much the firms benefit. It can be reasonably assumed, however,, that a firm willing to pay Pta 200 for a radiograph will make at least assmuch profit as the contractor. On this basis the net saving (as between contractor and firm) will be about Pta 200 per radiograph. In the case under review, where a total of 12 000 radiographs were made in 1961, the net saving would amount to 12 000X200 = Pta 2.4 million. The cost of the equipment was Pta 411 070, the annual cost of the radioisotopes Pta 123780, and maintenance amounts to 32270 pesetas. This corresponds to an annual investment of Pta 252 651.

User No. 34

This manufacturer installs lightning conductors, fitted with radioactive heads, which are imported from elsewhere in Europe. Having investigated what his customers would have had to pay for conventional lightning conductors, he supplied the following data:

No. of installations fitted 56 Total cost Pta 2 939 207 Total cost if conventional lightning conductors had been installed Pta 6 561000 Net saving Pta 3 621 793

User No. 26

This user employs a 5-c Cs137 source to make radiographie inspections of penstocks and discharge pipes, and also of high-speed rings and scroll cases of water turbines. He makes 1000 radiographs/yr. Assuming a profit similar to user No. 19, the net annual saving would be Pta 200 000. The cost of the equipment and the annual cost of the isotopes are Pta-82 000 and Pta 27 000 respectively. This corresponds to an annual investment of Pta 44 270.

User No. 18

This user employs two level gauges for molten plastics, each of which costs Pta 42 5000 to install. Previously, equipment was used based on electric contacts, which was subject to frequent breakdowns and caused hold-ups in production. This does not happen with the new equipment. The user has not supplied sufficient data to enable the economic benefit of the new technique to be estimated. SWEDEN

In 1960 a survey on the economic benefits obtained from the industrial use of radioisotopes was undertaken in Sweden. When the Agency invited Sweden to take part in the international survey, the Swedish authorities decided that it would not be advisable to trouble industry with a new approach. Instead, the results of the 1960 survey were submitted as the Swedish contribution [1], As considerable technical developments had taken place since 1960, it was decided, however, that an up-dating should be made by collecting statistics on the increased use of radioisotopes. This task was entrusted to Mr.L.G. Erwall, Head of the Isotope Techniques Laboratory. In the 1960 survey it was found that 231 firms were licensed to work with radioisotopes. A questionnaire was distributed to all users of gauging and radiography, and the users of other techniques were approached by phone or personal visits. The average response rate to the questionnaire was about 60%. The gross product value of Swedish industry is not reported in the United Nations Statistics. An assumption, based on Swedish domestic statistics, gives for 1961 a total output value at factor cost of SKr 28000 million, i.e. US $5400 million.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

The activities of the Atomic Energy Company are concentrated on nuclear reactors and power production; the Company's main contribution to isotope development work has been the production of radioisotopes for use as sources or tracers. Governmental support of isotope development work was expressed in other ways. In 1937, a group for non-destructive testing was created within the Royal Swedish Academy of Engineering Sciences; in 1941, this group was reorganized within the Tekniska Röntgencentralen AB (TRC), a company owned by private firms that is now the predominant user of gamma radiography. Similarly, in 195.3 a research group was created at the Royal Institute of Technology in Stockholm. This group was supported by the government through the Atomic and the Technical Research Council, and worked on tracer research and on activation analysis. It began also tracer investigation in industrial plants. In 1960 this group was reorganized into the Iso- tope Techniques Laboratory, an independent laboratory receiving support from both government and industry for research and development in the field of isotope techniques, and also performing work for industry on a consul- tation basis.

CONTENTS OF THE REPORT

Table I gives a summary of the various applications of radioisotopes in Swedish industry in 1960.

177 TABLE I

SUMMARY OF RADIOISOTOPE USE IN SWEDISH INDUSTRY IN 1960

Gauging Radiography lonization Tracing M.I.* Misc. Bioad Total product No. of No. of No. of No. of No. of No. of users group users No. of No. of No. of No. of users users users gauges users sources users devices Res. Prod.

1. Food 3 3 3 2. Tobacco 1 1 5 3. Textiles 4. Wood, paper 48 45 120 2 5 5. Leather, fur 6. Rubber 3 3 10 T3 7. Chemicals, 30 28 64 4 2 g plastics H 8. Cement, etc. 3 2 5 1 9. Petroleum and coal 10. Basic metals 15 2 3 8 10 1 7 11. Machinery 26 14 21 14 20 1 2 12. Services 6 2 50 3 Not identified 40 30 44 10 Total 175 128 275 24 80 10 8 20

* Massive irradiation SWEDEN 179

TABLE II

THE USE OF RADIOISOTOPE GAUGES IN SWEDISH INDUSTRY IN 1960

Number of devices Number Broad product of group users Thickness Density Level Total gauges gauges gauges

Food 3 3 3 Tobacco 1 5 5

Wood, paper 45 80 40 120 Rubber 3 10 10 Chemicals, plastics 28 55 9 64 Cement, etc. 2 5 5

Basic metals 2 3 3 Machinery 14 10 11 21

Total 98 160 5 66 231

Gauging

Table II shows the distribution of gauges over the various categories of industry in 1960. A total of 44 level gauges applied as steam boiler guards are not included as their distribution was not known in detail. In 1960 the predominant use of gauges was for thickness measurements in paper and in the plastics industry. Other users were found in the rubber industry, the cement industry (abrasive coatings) and the metals industry (cold rolling). Density gauges were limited to the State monopoly tobacco company. Level gauges had only recently been introduced, but they were already distributed over a great number of industries. Among the level gauges were two package control units. All but a few of the gauges installed in the paper trade were on paper machines. A small number of laboratory instruments were, however, registered. According to the replies, the main advantages of the gauges were a decreased amount of scrap, faster adjust- ments of area weight, and a smaller number of operational breakdowns due to breaks of the paper web. A few case studies were made in plants producing 10000-40000 t/yr of newsprint paper. The amount of scrap saved annually was about 0. 2% of the value added in production (the scrap going back in the process). Sixty-three of the gauges were used to produce paper of various qualities. As the number of paper machines in Sweden in 1959 was 210, this means that only 38% were equipped with gauges. However, many of these machines are small, with limited capacity. Using the statistics available, 180 NATIONAL REPORTS it was found that 1. 15 million t of paper were regularly gauged. This corresponds to almost 75% of the Swedish paper production. The smallest machine equipped with a radioisotope gauge had a production of about 4000 t/yr. The corresponding figures for paper board are 11 isotope-gauged machines in a total of 90. But here it is also evident that mainly the bigger units have been equipped. The 11 gauges watch 105 000 t/yr of paper board (45% of the total production). Finally, it should be mentioned that six gauges were installed on pulp machinery, the main reason being to avoid break in the pulp web. In the plastics industry and the rubber industry there were 65 installations working on various sheet materials, laminates, tyre cords, etc. Here considerable savings in raw material and scrap were reported, varying from 1 to 7% of the total production in the replying sample. In the machinery industry only one firm could evaluate savings, but here both labour and scrap were mentioned. The benefits were about 1% of annual production. Level gauging was used considerably. Such gauges were mainly in the wood and paper industry, the machinery industry, mining and the chemical process industry. In the wood and paper industry level gauges were applied to various containers and to process units such as the pre-treatment chamber in the production of fibre board. In the machinery industry they were frequently applied to cupola furnaces. In the chemical industry such gauges were applied in various high-pressure plants. In the food industry they were applied in sugar beet storage. An interesting application, marketed since 1959, is a complete steam boiler guard including a radioisotope level gauge. In 1960 more than 40 had been installed, mainly on boilers producing less than 5 t/h of steam. Boilers with higher output have.to be under human control to prevent dry boiling, but below 5 t/h human supervision may be limited provided acceptable mechanical guards are installed. There were of these guards only two, one of which was the radioisotope device. Such installations are therefore rather attractive for many small industrial units such as laundries, abattoirs and space heating stations. The number of installed gauges has been counted and published several times during the last 12 y. The results are shown in Table III. The number of installations has increased considerably since 1960, and at the end of 1963 480 gauging installations could be accounted for, even if the steam boiler guards were not included. Table IV shows the distribution of devices based upon information from producers and importers of gauges. This has not been double-checked, but will give a general picture. The comparison with 1960 is rather interesting. A considerable increase in the number of thickness gauges is recorded, even in the paper industry. Quite a proportion of these are, however, laboratory instruments for determination of the cross-section profile of the paper. Thickness gauges have entered the textile industry, although the numbers have increased much less in most of the other categories. The number of density gauges in the tobacco industry has increased fourfold. Density gauges for liquids and slurries have slowly begun to be SWEDEN 181

TABLE III

THE NUMBER OF RADIOISOTOPE GAUGES IN SWEDISH INDUSTRY

a 1952 1955 b 1960C 1963

Thickness gauges 5 70 160 270

Density gauges - - 5 25

Level gauges (of which steam 1 1 no 340 boiler guards) (44) (155)

Total 6 71 275 635

Westermark, T. [2]

Westermark, T. [3]

Forsberg, H.G. [1]

TABLE IV

DISTRIBUTION OF RADIOISOTOPE GAUGES IN SWEDISH INDUSTRY IN 1963

Number of devices

group Thickness Density Level Total gauges gauges gauges

Food 10 10 Tobacco 20 20 Textiles 20 20 Wood, paper 140 1 110 250 Rubber 10 10 Chemicals, plastics 75 30 105 Cement etc. 10 4 14 Petroleum and coal 5 5 Basic metals 10 10 Machinery 15 20 35

Total 270 25 185 479 182 NATIONAL REPORTS installed in the paper and cement industries, and probably also in ore dressing. The greatest increase has been in level gauging. Radioisotope level gauges have become more and more popular over a widening industrial field, interesting newcomers being the petroleum refining and various chemical process industries. In addition a number of odd applications of gauges are known, such as the use of gamma sources to prevent the opening of furnace doors unless trucks are waiting for the contents, and to give warning of the breach in cold rolling breaks. Portable neutron and density gauges are used by a few companies in civil engineering tests.

Radiography.

Radiography with gamma rays is performed by the TRC company, referred to before, and by a number of private firms in the metal branches. In 1958-59 the TRC reported some 150000 exposures, 8% of which were performed with gamma sources and the rest with X-ray sources. The number of sources was 50 and 60 respectively. In 1963 the proportion had changed to the advantage of X-ray sources (91 X-ray and 25 radioisotope sources). Only Co60 and Ir192 were used. Other methods of non-destructive testing had also increased at the expense of radiography. In 1960 the companies, working with their own equipment, possessed some 30 sources. They made about 10000 exposures with gamma rays, which is somewhat less than TRC made. No later information about the scope of their radiography testing is available. lonization

The number of ionization installations in 1960 was relatively low. Es- tablished applications were static eliminators in the textile industry, smoke detectors in such plants with very inflammable production, and the addition of radioactive gases to stabilize the discharge in cold cathode tubes.

Tracing

In 1960 21 Swedish industries were licensed to work with radioactive tracers in laboratory research or in its production. However, an investigation showed that only a minority of these used these tracers in the daily routine. A considerable part of the efforts in this field is made by the Isotope Techniques Laboratory (ITL) [4, 5]. In research eight companies were using the technique. Three of them in the drug and pharmaceutical industry used labelled substances to study the metabolism of various drugs. Two companies in the wood and paper industry were making laboratory tests with radioisotopes. Further, one firm in the basic metals group used tracing to study flotation and for chemical analysis; one firm in the machinery group performed wear tests. Using their own personnel and equipment, or employing ITL on a con- sultation basis, 20 firms applied radioactive tracers in process control. SWEDEN 183

In 1962, statistics were published giving the integrated number of tracer investigations in full industrial scale as 195, each of which might include a considerable number of tracer injections under various conditions. The development of this technique is shown in Table V. These investigations

TABLE V

.TRACER INVESTIGATIONS IN SWEDISH INDUSTRY 1954-61

1954 or before 0

1955 2

1956 8

1957 16

1958 24

1959 34

1960 56

1961 55

Total 195

The rate after 1961 is estimated at 50 or more/yr.

TABLE VI

TRACER INVESTIGATIONS IN SWEDISH INDUSTRY 1954-61 CLASSIFIED ACCORDING TO INDUSTRY

Basic metals and machinery industry 65 Cement industry etc. 13 Wood and paper industry 73 Food industry 4 Chemical industry 9 Services, including building 31

Total 195 were distributed over various categories as shown in Table VI. Standard leak detection with radioisotopes (see below) was not included in this list. Among the applications of tracers in process and product control, the following may be worth mentioning. 184 NATIONAL REPORTS

TABLE VII

ESTIMATED NET SAVINGS IN SWEDISH INDUSTRY In 1960

Direct Indirect Application savings savings (million SKr/yr) (million SKr/yr)

Thickness gauging

Paper 1.0 1-10

Pulp and paperboard 0.1 0.1-1 Plastics 2.0 0.5-5 Metallurgical products 0.2 ? Sub-total 3.3 2-16

Level gauging

Dry-boiling guards 0.2 - High-pressure processes 0.2 - Other 0.3 - Sub-total 0.7 ?

Radiography 0.5 ?

Tracing

Laboratory applications 0.2 0.5 Full-scale studies 0.1 0^5 Sub-total 0.3 1.0

Total 4.8 3-17

In the food industry: Determination of retention time in process units in sugar refining; In the chemical industry: Studies of chemical unit processes, flow rate measurements, leak detection in heat exchangers; In the wood and paper Studies of retention time in digesters, bleaching industry: towers, mixing units, etc.; In the cement industry: Studies of transport through rotary kilns, mixing studies of solid and liquid components; In the basic metals Studies of the origin of non-metallic inclusions, industry: studies of the distribution of alloying elements, 185

weighing of slag amounts in furnaces, determination of wear of refractories in furnaces; tagging for identification purposes; In services: Studies of behaviour of water purification plants, leak detection in underground pipes, studies on dilution of industrial and community sewage in open receivers, flow rate measurements. Leak detection with radioactive tracers was, in 1960, performed also by two private enterprises as a complement to other methods of localizing leaks in water mains. In 1960 radioactive tracers were applied to about 20 cases out of a few hundred investigations performed by these firms. Analytical applications of radioisotopes (mainly activation analysis) were used, although not very frequently in industrial applications, e.g. determinations of metals in wood pulp, poisonous metals in crops and food- stuff, and rare earths in metals.

ECONOMIC SUMMARY

In the 1960 survey the economic benefits of radioisotopes to industry were classified in two categories: direct and indirect. The direct benefits correspond to the term of savings in a general meaning, i. e. manufacturing savings in terms of labour, raw material and scrap. The indirect benefits concern both tangible benefits, such as increased output of production from the same amount of raw material, and increased price, and intangible benefits such as increased quality in general, better market situation, and fewer complaints. The results were extrapolated from the sample of industries submitting useful replies to the whole Swedish industry using a particular technique, the figures of output being used as scaling-up factor. Applying the Agency's definition of savings, all the direct and the lower estimate of the indirect ones, reported in Tables VII and VIII, would be included.

TABLE VIII

ESTIMATED NET SAVINGS IN SWEDISH INDUSTRY IN 1963

Direct Indirect Application savings savings (million SKr/yr) (million SKr/yr)

Gauging 8 4-30

Radiography 0.5 ?

Tracing 0.5 2

Total 9 6-32 186 NATIONAL REPORTS

REFERENCES

[1] FORSBERG. H.G., FKO-medd. 38 (1960) . [2] WESTERMARK. T., Tekn. Tidskr. 82(1952) 596. [3] WESTERMARK, T.. IVA _27 (1956) 203. [4] ERWALL, L.G. and LJUNGGREN, K., Proc. 2nd UN Int. Conf. PUAE 1£(1958) [5] ERWALL. L.G., FORSBERG, H.G., LJUNGGREN, K., Production and Use of Short-lived Radioisotopes from Reactors I, IAEA Vienna (1963) 229. SWITZERLAND

The Federal Council Delegate for Atomic Affairs which is the responsible body for national atomic energy questions, was nominated by the Swiss Government to implement the survey in Switzerland. Since, at that time, no central records of radioisotope users existed in Switzerland, it was difficult to trace the actual users. The Agency questionnaire was distributed to 62 major Swiss firms. Thirty forms were returned blank, indicating that no use was made of radioisotopes and nine contained information about applications. They were, however, believed to cover all important applications in use in Switzerland, with the exception of the application of luminescent dyes in the instrument and watch industry. Three additional firms made certain statements concerning their use of radioisotopes.

CONTENTS OF THE REPORT

Table I summarizes the contents of the nine replies as far as the techniques are concerned.

Gauging The use of radioisotope gauging was reported from five companies. Ab- sorption thickness gauges were applied to PVC sheets (two sources of Tl204) and to metal sheets and plates (two sources of Cs137). The use of gauging resulted in a product of better quality within close tolerances and also the saving of raw material and rejects. Level gauging was reported from one firm (two sources of Co60). Cer- tain savings in labour and raw material were attributed to this, but no assumption of their magnitude was made. Several unconventional applications of radioisotopes for gauging purposes were mentioned by some firms. One measured the play within parts of mechanical structures after assembly by means of gamma absorption. The same company employed the backscattering of beta radiation for inspection of rectified metal surfaces. It also applied beta backscattering to test the homogeneity of mixing. In all cases it is claimed that the results of these methods are unique and could not be obtained by using any conventional methods. Another company reported the occasional use of component analysis gauging, but no details were revealed.

Ra di ography As far as the companies' reports reflect the use of radioisotopes in Swiss industry, gamma radiography is the most widespread application — five of the replying companies used about 20 sources for inspecting all kinds of materials, welds, castings etc. The sources used were Ra, Co60, Cs137 , Ir192 and Tm170 . In all cases they were reported to be used as a complement to X-ray, the choice in each case being made more on technical than on economic grounds.

187 TABLE I

SUMMARY OF RADIOISOTOPE USE IN SWISS INDUSTRY IN 1962

1. Food 2. Tobacco 3. Textiles H 4. Wood, paper O 5. Leather, fur 6. Rubber 7. Chemicals, 1 1 2 plastics 8. Cement, etc. 9. Petroleum and coal 10. Basic metals 2 1 2 1 2 1 11. Machinery 5 2 5 4 18 1 1 1 12. Services Not identified 1 1 1 1 1 1 Total: 9 5 10 5 20 1 3 1 1 1

Massive irradiation SWITZERLAND 189 lonization

One firm reported the use of an ionization chamber with a radioactive source to detect fires in the initial stage. The same firm also used radium and tritium to ascertain the response time of cold-cathode electron tubes. The results were in both cases satisfactory, but no economic details could be provided. Among the additional replies referred to above, two concerned ionization applications. The following statement was made by an instrument producer: "In our output the use of radioisotopes is not linked with the concept of economy. We use radioactive sources purely to improve the quality of our products. We eliminate electrostatic charges in our balance by this means." Another producer states: "The use of polonium by us is limited strictly to the manufacture of antistatic brushes sold mainly to watch manufacturers and to gramaphone record collectors for purposes of dusting. No actual saving can therefore be established. "

Tracing

Several tracer applications were reported. The uniformity in the mixing of various products was studied by one company by adding tracers and autoradiographic detection. Two firms reported the occasional use of tracers in chemical analysis. In one case the purpose was to study the determination of trace elements, such as zinc, in high-purity metals. Zn65 was used for studying losses of zinc in the various steps of the standard analytical procedure. One firm also applied tracers in studying chemical reaction mechanisms. However, no direct savings were reported from tracer use.

Massive irradiation

One firm reported the use of large radiation sources in research.

TABLE II

SWISS IMPORT OF RADIOISOTOPES FOR PREPARATION OF LUMINESCENT DYES

Nuclide imports/ yr 1961 1962 1963 (c)

Tritium (H3) 500 16000 17250 C14 0.2 0.15 n.a* Pm147 - 52 n.a. Ra 0.7 0.95 1.22

* n.a. - not available TABLE HI

ECONOMIC INFORMATION PROVIDED BY SWISS FIRMS PARTICIPATING IN THE SURVEY

Broad product Chemicals, Machinery Not Basic metals Basic metals Machinery group plastics (4 firms) classified

Gauging, Gauging Gauging. Application Gauging Tracing lonization radiography and radiography Var. research

Year when radioisotopes 1952 1953 1961 1941 1962 were first used 1956 and 1948

Total output 70 million - - - 7 million (S.Fr.) -

Isotope assisted output - - - 4. 5 million (S.Fr.) - -

Investment (total) 25000 45000 16000 580000 6000 (S.Fr.) 45000

Investment made in 1961 - - 16000 6000 - - (S.Fr.)

Operation and maintenance costs - - - - 200000 - (S.Fr.) SWITZERLAND 191

Miscellaneous applications

One firm also reported studies on the direct conversion of beta radiation energy to electrical energy. Although not discussed in great detail in the report, radioisotopes are very frequently used in self-luminescent dyes by Swiss firms producing watches and other fine mechanical details. Table II gives details of the import of radioisotopes for this purpose. The figures in Table II show that this import is considerable; in 1963 its value was almost one million Swiss Francs. The economic importance of these dyes is certainly considerable. It is qiy.te clear that radium, the natural substance, is still considerably used despite its long half-life and high toxicity. On this problem one user states: "Some isotopes offer advantages over conventionally used radium, mainly as regards radiological safety in the production, application and use of the self-luminous materials. Some isotopes are cheaper, some more expensive than the equivalent amount of radium. The advantages cannot be expressed in figures."

ECONOMIC INFORMATION

None of the companies approached provided estimates of savings. Some of them gave details of total output, isotope assisted output and investment. Table III gives an extract from the replies.

UNITED KINGDOM

A survey on the direct advantages from the industrial applications of radioisotopes in the United Kingdom was performed by J. L. Putman and N. W. Jollyman in 1958 [1], The methods used in that survey and its results were very valuable to the International Atomic Energy Agency when preparing the international survey. On being invited by the Agency to participate in this survey, the United Kingdom authorities were a little hesitant as they realized the huge task of performing a full national survey. Nevertheless, it was finally decided to participate in the Agency's scheme and, in October 1962, the Ministry of Science asked the Government Social Survey to carry out an enquiry into the present use of radioisotopes in UK industry and the economic benefits deriving from them. The report of this enquiry is a very voluminous document that is at present in press [2]. A summary of it has also been presented to the general public [3]. Consequently, this presentation will be brief and only a limited number of tables of the report can be reproduced. Further details can be found in the more complete versions. The approach and methods used in the UK survey are of a very general interest, as the problems to be overcome were of quite a different order of magnitude from those in most of the other countries which contributed to the international survey. Therefore, these will be dealt with in some detail here. In 1961 the value, measured at factor cost, of the total output of UK industry was placed at £ 11 300 million, or US $32 000 million; this is 48% of the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES The United Kingdom, like several other countries, became interested in the industrial applications of radioisotopes at an early date. The first international conference devoted to these fields was held under the auspices of the United Kingdom Atomic Energy Authority [4]. By the middle 1950's the U. K. A.E. A. 's subdivision devoted to the research and promotion of industrial radioisotope methods had developed many of the techniques which benefit industry today. For example, the very substantial contributions from this group to the UN Conferences on the Peaceful Uses of Atomic Energy may be quoted [5-9]. The production and marketing of radioactive material from United King- dom reactors started early and contributed to the early introduction of radioisotopes in that country. The Radiochemical Centre at Amersham is still one of the world's leading isotope producers, both of short-lived radioisotopes and labelled compounds. In the 1960's the tendency has been to concentrate on research activities. One rather important direction has been the study of the practical applications of large radiation sources. Several plants have been erected for this purpose [10] . The development of advanced measuring devices, such as component analysis gauges, is still going on. The U.K.A.E.A. also has an

193 194 NATIONAL REPORTS

advisory group at the Wantage Research Laboratories which offers its services for industrial investigations, e.g. with tracer methods.

Methods used in the survey

The Government Social Survey, the body nominated to implement the UK survey, is normally concerned with the collection of facts about people and their circumstances — for example, housing, old age problems, occu- pational mobility, juvenile delinquency etc. Thus, it is very well equipped for treating large series of data and has solid experience of various kinds of enquiries. At an early stage the Agency questionnaire was considered to be too general and vague for use in the United Kingdom and it was consequently modified in various ways: (a) To produce the information in a form which could readily be processed; (b) To a form, which with regard to local conditions would produce the highest rate of response; and (c) To provide more sharply differentiated categories. A first modified draft of the new questionnaire was tested by visits to a few establishments to ask for their views on whether the necessary information could be supplied in the form asked and for any suggestions they could give which might eliminate any ambiguity in the questions. It was decided to conduct the survey in two stages. In the first stage, a preliminary questionnaire was sent to all the establishments having had connections with radioisotope work (see below), asking

(a) Whether the establishment had used radioisotopes during the relevant year (1961); (b) If the establishment had stopped using radioisotopes by 1961 and the reasons for their ceasing to use them; (c) If they had used radioisotopes during 1961. and whether they were willing to co-operate in the survey; (d) The main type of activity carried on at the establishment, (i.e. whether it was mainly engaged in manufacturing, processing, or research etc. ); (e) The radioisotope technique used and the industry of the establishment; and (f) The name and telephone number of the official to whom the main questionnaire should be sent.

In those cases where it was known in advance that the establishment was a head office, permission was asked to approach their branches and/or subsidiaries. Accompanying each questionnaire or request was a personal letter from the Minister for Science stressing the importance of the inquiry and asking for their co-operation. From the information received at this preliminary stage it was possible to determine which establishments were eligible for inclusion in the main part of the inquiry. For the second stage of the inquiry, a different questionnaire was designed for each of the six techniques. Each questionnaire comprised three UNITED KINGDOM 195 parts; Part I related to the technique used in the establishment, Part II to the economic side of the inquiry and Part III asked for general comments. For each technique used, Parts I and II of the relevant questionnaire were sent to the establishment. In those cases where more than one industry was served by the establishment and radioisotopes were used in each, separate questionnaires were sent for each industry. (For example, this meant that if an establishment served two industries at the one address, and both used gauging techniques, that establishment would receive two copies of Parts I and II of the gauging questionnaire. Each establishment received one copy only of Part III, irrespective of the number of techniques employed or industries served. In addition, a duplicate set of questionnaires was sent to the establishment for their own records. Figure 1 shows a diagram of the procedure applied. Because there was no single comprehensive list of isotope-user establishments in the United Kingdom at the time this inquiry was initiated (1962), use had to be made of the lists kept by the Atomic Energy Authority and the Ministry of Housing and Local Government. Under the new regulations, however, which came into force on 1 December 1963, all users of radioisotopes are required to register with the Ministry of Housing and Local Government. While these lists were not fully comprehensive, most of the evidence suggests that they covered the vast majority of industrial establishments using their own equipment. A total of 1416 establishments was initially involved in the survey but, of these, many were found to be ineligible, and a decision was made to exclude 600 for various reasons, namely:

(a) Establishments which, although shown on the lists as having been users, had, in fact, merely obtained technical literature at some stage or enquired for information, but this fact had not been recorded on the lists. (b) Establishments which, although using isotopes, were not users during the relevant period of the survey, i.e. 1961. This was the second largest group, 160 in total. (c) All non-industrial users — i.e. hospitals and medical research, universities and technical colleges, agricultural research and manufacturing undertakings (in so far as they could be distinguished from firms manufacturing fertilizers for example), government departments and research establishments (such as the Royal Air craft Estab- lishment at Farnborough), the Armed Forces and Civil Defence (but not ordnance factories), branches of the Atomic Energy Authority (including their experimental power stations), pure research establishments not linked with an industrial firm or an industry, whole- sale or retail distributors and private individuals (25 cases). (d) Users of radioisotopes outside the United Kingdom — this affected a few oil and mining companies (11 cases). (e) Manufacturers of nucleonic or associated equipment, or of machinery embodying nucleonic gauges; providing they were not using isotopes to control their own output, or incorporating isotopes in discharge tubes or neutron generating tubes (46 cases). 196 NATIONAL REPORTS

NON-USER HEAD OFFICES ONLY Pré- Questionnaire (1) Minister's letter Minister's letter /Expia natory letter Letter asking permission to contact branches and subsidiaries 1 NO R ÏPLY REPLY

1 2 weeks Returned Riafusal Ineligible Eligible \r by Post (2) 1st reminder Office A 2-3 weeks / \ V 1 / \ 2nd reminder Abandoned Abandoned (5) Letter stating Head Rest New documents ineligibility Offices / (asat(l)) ./-^ I /

later Subsidiaries ar ^ if userls/ x / branches con tacted 1 3rd reminder New documents Main Questionnaires (asat(l)) Explanatory letter 1 Abandoned NO REPLY QUESTIONNAIRES RETURNED N 3 weeks (11) Letter of thanks (7) 1st reminder

(later) ^, (12) Queries (telephone)

(8) 2nd reminder (telephone)

1 month before closure

(9) 3rd reminder (letter)

(10) 4th reminder

Abandoned

Fig. 1

Procedure and time-table for contacting isotope users UNITED KINGDOM 197

(f) Establishments in receipt of a gamma radiography service only (32 cases). (g) Those who only used radioisotopes to calibrate nucleonic or other equipment, including the testing of monitoring equipment for detecting radioactivity in water supplies, food or air (53 cases). (h) Users of naturally radioactive materials etc. (24 cases).

The decision to exclude those establishments using a radiography service only was based on three criteria:

(1) That, generally speaking, this type of user is not usually registered as an isotope user abroad and would therefore have been excluded from the surveys of other participating countries; (2) The difficulty of obtaining a complete list of establishments using such a service (as not all firms giving this service would be willing to disclose names and addresses of their customers); (3) The difficulty that the users of an inspection service would have in assessing any economic benefits gained from the service. The So- cial Survey did, however, ask the service firms for this information in a summarized form in order to estimate the costs of the service and the number of customers involved (including some technical data). These returns show a total of some 450 firms availing themselves of the service (the true figure is, of course, larger than this). Information on the clearly important economic gains of the firms who use this service is unfortunately missing.

TABLE I RESPONSE OF ELIGIBLE USERS

No. of RESPONSE BY ELIGIBLE USERS establishments (*)

Completed schedules returned by eligible establishments (includes 33 cases in which information for more than one establishment was given by parent establishments) 695 85.2

Information supplied by U. K. A. E. A. (19 users of bulk or cell irradiation service, 7 users of tracer service) 26 3.2

No reply to preliminary (25) or main questionnaire (21) 46 5.6

Refused 36 4.4

Untraceable 13 1.6

TOTAL ELIGIBLE ESTABLISHMENTS 816 100 198 NATIONAL REPORTS

At the request of the U.K. A. E. A., however, firms who had availed themselves of their bulk irradiation service during 1961 were included, as, at this particular time, the U.K. A. E. A. was responsible for practically the whole of this type of service. The economic advantages obtained from this particular technique were in most cases rather small at this time, due mainly to its experimental nature. The U.K. A. E. A. also requested that users of their tracer service be included in the survey. While it is true that naturally radioactive isotopes should be excluded from the survey, it was in fact difficult to do so. However, they are analysed separately, and the 10 establishments — all luminizers — excluded at the beginning for this reason, are later re-grouped with similar establishments in the analysis of miscellaneous applications. Table I shows the response of the remaining 816 eligible users. It can be seen from Table I information was obtained for 721 cases. A total of 880 forms were returned. They contained information from 688 establishments, 33 of which were dealt with by their parent establishment. The overall response rate then was 88%, based on the number of eligible users. As some of the firms which never replied probably do not make use of radioisotope methods, it is fair to estimate that at least 90% of all firms using radioisotopes in 1961 contributed to the survey.

Contents of the report

Table II summarizes how industry used radioisotopes in 1961 according to the forms returned. In order to obtain a better perspective, it should be pointed out that the UK body decided to subdivide broad product groups 11 and 12 into two sub-groups each. This method of presentation will be followed in the Tables below. Table III gives a rather interesting picture of the replies to the question of when radioisotopes were first introduced. It is rather surprising that, even in a country which is considered to be very advanced in radioisotope usage, the rate of firms introducing even well-established techniques such as gauging and tracing is not decreasing. On the other hand, the number of firms entering the field of gamma radiography does seem to slow down with time. This has, however, been complicated by the fact that the number of companies which have their products tested by gamma radiography is much higher than the figures given in Tables II and III. Twenty-four organizations which offer such services to industry have roughly 500 customers. The decision whether to make use of these services or to install one's own gamma sources is subject to so many factors that even here the decreasing number does not necessarily reflect a decreasing trend in the introduction of gamma radiography. The technical contents of the report will be presented first and the economic implications will then be reviewed in some detail.

Gauging

The survey covers 2037 gauging devices for 446 applications in308firms. Table IV gives a summary of how UK industry used radioisotope gauges in 1961. TABLE n

USE OF RADIOISOTOPES IN UNITED KINGDOM INDUSTRY IN 1961 ACCORDING TO COMPLETED SURVEY FORMS

Total Gau; n Radiography lonLzation Tracing M.I.* Broad product P & Misc. No. of No. of No. of No. of No. of No. of No. of No. of No. of group No. of users users users gauges users sources users devices users users 1. Food 22 13 19 - 5 15 5 3 2. Tobacco 12 11 897 - 1 6 3. Textiles 20 16 72 - 4 58 1 1 4. Wood, 363 5 12 2 2 paper 96 91 - 2 5. Leather, - - - - fur X 6. Rubber 15 12 41 - - 1 5 (—zI 7. Chemicals, 110 41 258 8 14 42 223 41 19 o plastics 1 0 8. Cement, etc. 28 21 54 3 4 2 4 3 3 i 9. Petroleum 27 16 51 8 10 12 69 9 4 and coal 10. Basic 94 31 141 62 147 1 1 14 metals 11. Machinery 223 37 95 124 364 34 46. 25 26 14 12. Services 74 20 46 38 , . 167 12 38 25 3 1 Not identified Res. Prod. Total 721 308 2037 235 706 . 118 475 107 35 66 17

* Massive irradiation TABLE HI

THE YEAR DM WHICH RADIOISOTOPES WERE FIRST USED, ANALYSED BY TECHNIQUE

Technique

Massive All uses Gauging Radiography Tracers lonization Miscellaneous Year Irradiation

Number (%) Number (%) Number (<#>) Number (.%) Number (%) Number (%) Number (<7o)

1950 or before 12 4 30 12 10 8 8 7 - - 8 44 68 8 1951 to 1955 71 23 96 40 22 18 18 15 3 6 2 11 212 25 1956 27 9 19 8 4 3 6 5 3 6 1 6 60 7 1957 32 10 14 6 13 10 5 4 4 9 1 6 69 8 1958 41 13 18 7 19 15 17 14 - - 1 6 96 11 1959 34 11 15 6 10 8 19 16 5 11 1 5 84 10 32 10 12 5 14 11 16 14 4 8 3 17 81 9 H 1960 V) 1961 33 11 7 3 23 18 19 16 14 30 - - 96 11 No Answer 27 9 32 13 11 9 10 9 14 30 1 5 95b 11

Total 309 100 243 100 126 100 118 100 47 100 18 100 861 100

Total number of establishments 699a> b

Some establishments use more than one technique Excludes 19 users of the U. K. A. E. A. Bulk Irradiation Facilities who were not sent questionnaires TABLE IV

THE USE OF RADIOISOTOPE GAUGING IN UK INDUSTRY IN 1961

Number of devices Total number Number of Thickness Density Broad product group Subgroup of users applications Level Other gauges gauges gauges Total _ 1 Food 13 15 1 2 16 19 2 Tobacco 11 20 897 897 3 Textiles 16 20 72 72 4 Wood and paper 91 124 357 3 2 1 363 5 Leather and fur - - - c 12 14 41 41 6 Rubber zI— < 7 Chemicals and 41 75 71 25 161 1 258 H Plastics tn 0 8 Cement 21 24 17 2 34 1 54 9 Petroleum and coal 16 32 4 8 20 19 51 10 Basic metals 31 57 93 - 45 3 141 Q 11 Machinery a Metal products 9 11 7 2 18 27 o Engineering and electrical goods 19 31 33 1 2 6 42 Vehicles and shipbuilding 5 8 4 8 3 15 Misc. manufacturing 4 7 7 4 11 Construction 2 4 - 2 9 11 Gas, water, electricity 8 9 2 5 3 2 12 Technical services and research 10 15 9 4 7 3 23

Total 308 466 718 957 317 45 2037 202 NATIONAL REPORTS

Gauging is by far the most common application of radioisotopes, accounting for almost 35% of all schedules. The use of isotope gauges is particularly widespread in the tobacco, paper, chemicals and basic metals industries, as shown in Table IV; the tobacco industry alone accounts for 44% of all gauges, with a mean of 82 gauges per establishment. The term"number of applications" here refers either to the material gauged, or it means number of different gauges: differences can arise out of the type of gauge (thickness, level etc. ), or the isotope used, or the strength of the isotope. Thus a thickness gauge with a 25-mc thallium-204 source used to gauge PVC sheeting would be counted as one application, while an identical source used on paper, or a source of a different strength, or one using another isotope, would be counted as a different application. A still clearer picture of the use is given by the detailed presentation of the purpose of gauging reproduced in Table V. It should be noted that the concept of density given is a somewhat wider meaning here than normal in evaluating the national reports. In Table IV a few cases were therefore transferred to "others" in order to permit the most appropriate international comparison. Information on radioisotopes used as sources is provided in Table VI. Table VII shows the regularity of use, and Table VIII industry's attitude towards the advantages of the introduction of radioisotope gauges. The first column of Table VII shows those cases where isotope gauges are used continuously on the production line of the whole output of a plant; the second shows cases where they are used only on one of several production lines in the same plant. Two things can be said in general about gauging. First, practically all applications are used for continuous process control (1779 out of 2037). Secondly, UK industry's experience of gauges is almost unanimously positive — only in four cases was it stated that no advantage existed or the device worked unsatisfactorily. This attitude is a very strong argument for the installation of gauges, wherever possible. The figures on the economics of gauging support this view even more (see below).

Radi ography

Table IX shows how uses of radiography are spread out over the various industries distinguished in the UK survey. The unit selected for recording on the forms was exposure containers; this might, however, contain more than one source. A distinction has .been made between establishments using radiography primarily to provide a service to others and those using such equipment for inspecting their own manufactures. The former were sent a slightly modified version of Part I of the radiography questionnaire. Table X shows which radioisotopes were used. Ir192 is seen to be the predominant one followed by Co6° and Csi37. Only a few Tmi^o sources were found in addition to the three mainly used nuclides. One can see from both Tables that, on an average, the service companies possess many more sources than the other users. This is rather natural, when one considers that work by a service firm must be carried out in several phases at the same time since the customer does not want TABLE V

TABLE SHOWING NUMBER OF GAUGES USED BY EACH INDUSTRY, BY TYPE OF GAUGE AND MATERIAL USED

Type of gauge Broad product group Material gauged No. of (and total No. of each) gauges

1 Food Level (16) Contents of cans and bottles 6 Limestone and coke in lime kilns for sugar refining 7 Sugar 2 Chemicals 1 Density (2) Liquid foods, ice cream 2 Thickness (1) Dough 1 19 o 2 Tobacco Density (897) Cigarette tobacco 897 z 3 Textiles Thickness (72) Coated fabrics 56 o Uncoated fabrics 6 0 Plastic sheet, tapes, etc. 7 Textile flooring and felt material 3 § 72

4 Wood and paper Thickness (357) Uncoated paper, board 319 Coated or laminated paper 38 Density (3) Timber, straw building board 3 Level (2) Wood pulp 2 Component analysis (1) Preservative treated timber 1 363 TABLE V (cont. )

Type of gauge No. of Material gauged Broad product group (and total No. of each) gauges 6 Rubber Thickness (41) Coated fabrics 30 Rubber goods 11 41 7 Chemicals and plastics Level (144) Chemical solutions and slurries 67 Contents of bottles, tubes and packets 52 Solid chemicals, bulk products 21 Lime, cement etc. slurries 4 Thickness (71) Plastic sheet, tapes, film etc. 68 2 Yarns 1 > H Coated metal 1 Vessel walls 1 I Density (42) Contents of bottles, tubes and packets 17 Ammunition, explosives 18 Chemical solutions, slurries and solids 7 Component analysis (1) Wood and board 1 258 8 Cément etc. Level (34) Glass in furnaces 30 Lime, sand, and cement slurries 3 Plaster 1 Thickness (17) Coated glass and abrasives 13 Glass fibre mat, asbestos felt 2 Plastic sheet, tapes, cellophane etc. 2 Density (2) Coated glass, glass and asbestos fibre 2 Component analysis (1) Coated glass and abrasives 1 54 TABLE V (cont. )

Type of gauge No. of Broad product group Material gauged (and total No. of each) gauges

9 Petroleum and coal Level (20) Water in boilers or pipes 5 Coal and coke 9 Petroleum and petroleum fractions 3 Liquids and catalysts 1 Alignment of machines in coal and coke production 2 Density (8) Petroleum and petroleum fractions 4 Building felt 4 Thickness (4) Coal, coke 2 c Metals 2 z Component analysis (17) Petroleum and petroleum fractions 8 Sulphur in oil 8 a Coal and coke 1 Bore-hole logging (2) Oj.1 and rock 2 a 51 a 10 Basic metals Thickness (93) Rolled and laminated metals 86 8 Coated metal 5 Cylinders and boilers .2 Level (45) Ore powder, slurry, charged material in blast furnaces 14 Cement clinkers 14 Liquid metals in blast furnaces 5 Dust level on electrostatic percipitators 6 Coal and coke 2 Tar pressure vessels 2 Sinter in bunkers 2 Density (1) Ore, powder, slurry, charged material 1

to o TABLE V(com.)

No. of Broad product group Type of gauge Material gauged (and total No. of each) gauges

Moisture (2) Ore powder, slurry, charged material 2 141

11 a Metal products Level ( 18) Chemical solutions and slurries 17 Sodium in tubes 1 Thickness (7) Rolled and laminated metals 3 Coated metal products 3 Laminated plastics 1 Density (2) Plastics 1 Storage bunkers (coal) 1 27 g lib Engineering and Thickness (33) Coated paper 6 electrical goods Plastic sheet, tapes, film etc. 6 Paint, resins 7 Rolled or laminated metals 4 Steel pipes and tubes 4 Coated abrasives and glass 2 Uncoated paper 1 Rubber goods 1 Coal, coke 1 Ice (aircraft instruments) 1 Level (2) Water in boilers or pipes 1 Storage bunkers (coal) 1 Density (1) Rubber Latex 1 TABLE V (com. )

Type of gauge No. of Broad product group Material gauged (and total No. of each) gauges

Components analysis (2) Rubber 1 Coal and coke 1 Scintillation counter scanning (4) Metal castings 4 42 lie Vehicles and ship-building Density. (8) 8 Cable c Thickness (4) Metal (coated and uncoated) 2 z Rotor blades and undercarriages 2 Level (3) Chemical solutions and slurries 2 Fuel and lubricants in engines 1 15 oO lid Miscellaneous Level (4) Chemical solutions and slurries 4 manufactures Thickness (7) Film base 3 i Coated or laminated paper 2 Coated fabrics 1 Record matrix 1 11

12a Construction Density (5) Cement clinkers, solid sand and concrete 5 Level (2) Lime, sand, cement slurries 2 Moisture (4) Cement clinkers, - solid sand and concrete 4 11 TABLE V (cont, )

Type of gauge No. of Broad product group Material gauged (and total No. of each) gauges

12b Gas, water, electricity Level (3) Chemical solutions and slurries 2 Storage bunkers (coal) 1 Density (5) Chemical solutions ans slurries .2 Dust/water in pipelines 2 Coal, coke 1 Thickness (2) Steel pipes and tubes 2 Component analysis (2) Nuclear fuel and reactor materials 2 12 O z 12c Transport - -

12d Technical services, Density ( 6) Coated metal products 3 and research Cement clinkers, solid sand and concrete 2 Yarns 1 Level (7) Coal and coke 5 Water in boilers or pipes 2 Thickness (9) Tobacco 1 Uncoated paper, felt, board 6 Textile flooring 1 Coated metal 1 Scintillation counter Steel sections 1 scanning (1) 23

Total gauges 2037 TABLE VI

ISOTOPES USED IN GAUGING ANALYSED BY THE NUMBER OF GAUGES OF DIFFERENT TYPES

Type of gauge

Thickness gauge Level gauge Density gauge Moisture gauge Component analysis OtheKa) All applications Isotope No. of gauges No. of gauges No. of gauges No. of gauges No. of gauges No. of gauges No. of gauges _ _ Cobalt- 60 7 189 5 5 206 Iridium- 192 - 1 - _- _- - 1 _ G Caesium-137 6 40 18 _ _ 64 Strontium- 90 172 51 934 5 1162 Promethium- 147 27 - - - 1 - 28 i Polonium-210 - - - 1 - 1 2 Cerium- 144 4 4 18 - - - 26 Lead-210 - - - - 5 - 5 Ruthenium- 106 3 - ' - - - 3 ' Caesium- 134 - - 1 - - 1 Isotope unknown 14 - - - 3 - . 17

Total no. of gauges 718 300 982 6 24 7 2037

(a) Scintillation counter scanning and bore-hole logging. (b) Incl. 4 Combinations with other Isotopes (Tm, Kr, Tl. H3) (c) Incl. 1 Combination with other isotopes (Pb210). tss O CD TABLE VII

INDUSTRY OF GAUGE USERS ANALYSED BY THE REGULARITY WITH WHICH GAUGES ARE USED

Regularity of use Total Used for number Number of Used on total Used on part of spot checks of Research, of establishments output at that output at that Research and Broad product group plant operation experimental, No answer gauges stage of stage of production or sampling prototypes production production of products No. of gauges No. of gauges No. of gauges No. of gauges No. of gauges No. of gauges 1 Food 11 4 1 3 - - 19 13 2 Tobacco 208 689 - - - - 897 11 3 Textiles 66 3 - 3 - - 72 16 4 Wood and paper 285 38 22 7 11 - 363 91 8 6 Rubber 26 14 - 1 - - 41 12 7 Chemicals and plastics 141 36 9 16 54 2 258 41 8 Cement etc. 40 11 - 3 - - 54 21 9 Petroleum and coal 23 4 16 6 - 2 51 16 10 Basic metals 88 40 2 7 - 4 141- 31 lia Metal products 3 • 17 7 - - 27 9 lib Engineering and electrical ' goods !6 8 6 11 - 1 42 19 lie Vehicles and shipbuilding 9 - 3 3 - - 15 5 lid Miscellaneous manufactures 8 2 - - - 1 11 4 12a Construction 2 - - - 9 - 11 8 12b Gas. water, electricity 4 - 4 4 - - 12 2 12c Transport ~ ------12d Technical services and research - - 2 12 9 - 23 10 Total 930 849 82 83 83 10 2037 309* * One establishment appears in two industries and some establishments give more than one answer to Regularity of Use. UNITED KINGDOM 211

TABLE VIII

ADVANTAGES OF USING RADIOISOTOPE GAUGES

Number of establishments mentioning each advantage Advantages ,

No. (*)

Product of better quality or greater uniformity 185 60 Closer control within tolerances 213 69 Saving of raw material 107 35 Reduced scrap or rejects 121 39 Lower labour costs (e. g. because less inspection) 66 21 Reduced shutdown time (quicker output) control operates more rapidly 100 32 Cheaper control equipment 20 7 Simpler form of control, more direct or practical, easier to handle 116 38 More efficient form of control, more versatile, sensitive or accurate 176 57 Safer processing possible 17 6 Process previously not practicable or too costly 63 20 Non-destructive form of testing, non-contact gauge 7 2 New research knowledge 4 1 Other answers 8 3 No advantage - equipment unsatisfactory 4 1

Total number of replies . 1207 392

Number of establishments replying 303* 98.4*

No answer 5 1.6

Total number of establishments 308 100

* Some establishments give more than one reply long delays. Table XI makes this still clearer. Here the number of establishments being served by the service firms in question is presented. It can be seen that the number of customers of some of these firms is very small, but one firm provided an inspection service to as many as 110 customers in 1961. Of the 22 service firms, only half actually fall into the category of firms providing a technical service (Industry group 12 d); the other half are in fact manufacturing undertakings who use their radiography equipment principally to provide a service to outside undertakings, including branches of their own organization. In most cases they service firms outside their own industry as well, but an exception to this is consti- 212 NATIONAL REPORTS

Product group No. of users No. of exposure containers

Inspection ' Other Inspection Other firms users firms Users

7 Chemicals and - 8 - 14 plastics

8 Cement etc. - 3 - 4

9 Petroleum and coal - 8 - 10

10 Basic metals 4 58 13 134

11 Machinery (a) Metal products - 25 - 78 (b) Engineering and 4 57 44 170 electrical goods (c) Vehicles and 4 29 9 44 shipbuilding (d) Misc. 1 4 9. 10

12 Services (a) Construction 1 12 3 44 (b) Gas, water, electricity - 8 - 18 (c) Transport - 2 - 3 (d) Technical services 4 11 6 93 and research

Total 24* 211** 172 534

* 1 firm appears twice ** 7 firms appear twice tuted by two establishments in the shipbuilding industry who service only the members of the association of which they form part. However, it is also interesting to see that a proportionally much higher percentage of the sources used by the service firms contain Ir192. The explanation is very likely that these firms work more in the field and on welds, while many firms with their own equipment employ stationary Co60 facilities. This is further illustrated by Table XII, giving details on the applications of the gamma radiography (objects to be tested). The service firms have their heaviest business in weld testing and in pipe-line testing (which is largely weld control), while the rest apply the technique to a much greater extent for testing castings and forgings. Moreover, these last often have UNITED KINGDOM 213

TABLE X

ISOTOPES USED IN RADIOGRAPHY

Isotope No. of exposure containers used

By inspection By rest By all firms

Cobalt- 60 18 194. 212

Iridium-192 145 289 434

Caesium- 137 9 89 98

Thulium-170 - 6 6

Total 172 578 750

Source known 172 532* 704*

Source not known - 2 2

Total No. of exposure 172 534 706 containers

* Some containers hold more than one source much greater dimensions requiring the higher penetrability of the cobalt rays. Among the "miscellaneous" applications in Table XII are the following:

Examination of submarine cables under water; Inspection of covered conductors for examining lead slabs used in shielding reactor containments; Examination of filled ammunition for quality of the filling and correct assembly; Checking the internal alignment of large vacuum tubes; Locating the plug in lead tubes; Locating foreign bodies in process equipment; Radiography of concrete; Corrosion pit detection and measurement.

Some additional Tables are reproduced from the national report. Table XIII shows the regularity of the use of gamma radiography. Although it is perhaps impossible to define precisely what a continuous or an occasional use really means in gamma radiography, one can conclude that only few companies possess radiography sources without employing them frequently. 214 NATIONAL REPORTS

TABLE XI

No. OF ESTABLISHMENTS USltfG AND PROVIDING AN INSPECTION SERVICE

No. of establishments No. of establishments using an inspection providing an inspection service service

1-9 7

10-24 7

25-49 5

50 or more 3

No answer 2

Total No. of servicing 24 establishments

Total No. of establishments Using an inspection 497 service

From information available in the economic section it can, however, be stated that something between a quarter and a third of all users employed the spot? check method. Table XIV shows what advantages user establishments considered this technique to confer. One side comment in this connection was: "Just to have the equipment around is a deterrent to bad welding and workmanship". Other users consider the presentation of a permanent record to be a marked advantage in contrast to, for example, ultrasonics, but in this respect gamma radiography does not differ from X-ray equipment. Further questions were asked to see whether substantial use was made of contracting out, in terms of either accepting work from other firms or of asking other firms to carry out the work on commission. This question incidentally revealed that 50 establishments did not possess any radiographie equipment of their own; 33 of these therefore, became ineligible, the rest remaining eligible since they used other isotope techniques. The proportion calling in an outside inspection service in addition to using their own equipment was only 24%, whereas as many as 50% provided an inspection service to other establishments within or outside their own organization. Table XV reveals to what extent alternative methods of inspection are also employed by users of this technique, and to what degree these have been superseded by gamma radiography. The most common alternatives are of course conventional X-rays, destructive tests, and ultrasonics, but magnetic particle and dye penetrant tests are also fairly widespread. Only UNITED KINGDOM 215

TABLE XII

PURPOSE OF RADIOGRAPHY

Number of establishments

Inspection Object for testing service Others All firms

Welds 24 153 177

Castings and forgings 10 135 145

Materials to be machined, 5 61 66 testing of components

Pipelines 13 22 35

Maintenance and repairs 1 28 29

Thickness measurement - 8 8

Miscellaneous - 10 10

Total 53 417 470

No. of users 24* 211* 235*

* Most establishments make use of more than one application.

TABLE XIII

REGULARITY OF USE OF GAMMA RADIOGRAPHY

No. of exposure Regularity containers

Used continuously 291

Used occasionally 199

Used rarely 34

Used to provide a service 10

Total 534*

No. of users 211*

* Excluding inspection firms 216 NATIONAL REPORTS

TABLE XIV

ADVANTAGES OF USING GAMMA RADIOGRAPHY

Number of estabs. mentioning each advantage Advantages Service Rest Total (*) firms

Avoiding machining of faulty components— saving of scrap (e. g. due to quicker fault recognition) 3 106 109 46

Greater reliability, or better control and quality of products (e. g. because higher percentage tested now) 4 .120 124 53

Better control of raw materials and bought-in parts 2 43 45 19

Reduced time or labour for inspection 4 40 44 19

Equipment cheaper to buy, operate or maintain 7 73 80 34

Mobility or versatility of inspection equipment 21 123 144 61

Independence of power supplies 7 99 106 45

Better maintenance of machinery or plant possible 1 23 24 10

Non-destructive form of testing 5 178 183 78

More efficient form of inspection (e. g. via panoramic exposure) 10 81 91 39

Improved safety conditions 1 18 19 8

No other means of testing possible - 8 8 4

Others 4 2 6 2

Total number of replies 69 914 983 418

Total number of establishments replying 24* 211* 235* 100*

destructive tests and the use of radium or radon (much more expensive than radioisotopes) have to any extent been replaced by gamma radiography. The "miscellaneous" techniques used were: Eddy currents; particle accelerators; scintillation counters; leak detection by helium and halogen gas detector and thermal conductivity comparator; visual tests, including INDUSTRY ANALYSED BY THE NUMBER OF USERS3 OF ALTERNATIVE METHODS OF TESTING EMPLOYED BEFORE OR SINCE THE INTRODUCTION OF GAMMA RADIOGRAPHY

Destructive Conventional Ultrasonics Radium/Radon Pressure of Magnetic Dye Miscellaneous tests x-rays hydraulic tests particles penetrants

Total No users of other other method methods used Introduce d sinc e Discontinue d Introduce d sinc e Stil l use d Introduce d sinc e Stil l use d Introduce d sinc e Stil l use d Discontinue d Discontinue d Stil l use d Introduce d sinc e Discontinue d Stil l use d Introduce d sinc e Stil l use d Introduce d sinc e Stil l use d Discontinue d Introduce d sinc e Discontinue d Discontinue d Discontinue d Stil l use d

7 Chemicals and plastics 5 1 2 1 3 1 1 2 1 1 1 8 8 8 Cement etc. 2 1 2 1 3 C 9 Petroleum and coal 1 1 1 2 2 5 3 1 4 2 1 1 2 1 8 8 z 10 Basic metals 3 16 25 I 14 7 21 4 13 3 7 4 57 1 58 38 8 24 8 H lla Metal products 15 1 15 1 2 4 6 1 2 7 1 6 2 1 1 22 3 25 en lib Engineering and O electrical goods 28 7 35 2 9 15 16 2 6 5 1 19 2 14 2 6 1 51 6 57 lie Vehicles and shipbuilding 14 4 13 4 2 6 2 1 3 1 1 10 1 7 5 1 1 26 3 29 Z lid Miscellaneous Q manufactures 3 3 1 4 a 12a Construction 6 2 5 2 4 1 1 1 2 2 10 2 12 12b Gas, water, i electricity 1 3 5 2 4 4 3 1 5 3 8 12c Transport 1 1 1 1 1 1 2 2 2 2 12d Technical services and research 4 2 2 1 1 1 1 1 4 4

Total users of alternative methods 135 24 1 102 10 30 61 - 55 4 24 - 21 2 3 72 - 10 51 1 10 25 2 8 198 20 218

No other methods used 78 76 102 190 192 136 156 183

All users 218 218 218 218 218 218 218 218 211 c

Excluding service firms b This is the sum of users and non-users of alternative methods c 7 establishments cover 2 industries each 218 NATIONAL REPORTS the use of closed-circuit television and cameras; electrical current flow; acid pickling; load, density and porosity measurements; fluorescent ink detection; brittle lacquer tests; metallographic tests; and ultra-violet ray testing. Only three firms acquired a particle accelerator. lonization

Fourteen percent of all forms returned dealt with the application of ionization methods; Table XVI summarizes the information obtained. In this context the "number of applications" means different uses, difference arising out of the type of use, the nuclide used or the strength of the source used. The Table does not include the use of fire detectors equipped with a radioactive source; their number in 1961 was estimated at 60000. Apart from this, gas chromatography with ionization detectors is the most widespread application and 108 applications with 256 devices could be accounted for in 75 establishments. The second greatest number of installations was static eliminators: 43 users having 48 applications for 207 devices. As third main use came vacuum gauges where two firms were reported to be using 12 devices. To this should be added the use of radioactive material for triggering or stabilizing the discharge in electron tubes; 19 firms had found 24 applications for this technique. As these firms use the radioactive material as a consumable supply, the concept of device is meaningless here. Table XVII shows the radioisotopes used, and Table XVIII the regularity with which the various forms of ionization methods were applied. The latter Table makes it clear that static eliminators and vacuum gauges are most frequently used in direct production, while gas chromatography is in most cases a research tool. The use .of static elimination has been broken down in Table XIX into treated material or equipment and the nuclide in use. The source strengths applied were very moderate: in two cases they fell below 2 me, in 111 cases they were between 2 and 20 me and only in 8 cases did they exceed 20 me. For 15 devices information was lacking. The advantages offered by using ionization techniques for static elimination and in gas chromatography detectors, as indicated in the companies' replies, are presented in Table XX. Even here the positive attitude towards radioisotope methods is clearly expressed.

Tracing

The survey accounted for a total of 237 applications of tracers in 1961. Fifteen per cent of all forms returned dealt with this technique. This heading embraces the use of tracers both for tagging in its widest sense — i. e. following the progress of a solid, a liquid, or a gas — and for chemical analysis. The UK questionnaire distinguished a number of techniques: wear and corrosion studies, mixing and operating efficiency studies, flow studies, leak detection, tagging, surface reaction studies, other chemical reaction studies, metabolism studies, chemical analysis, impurity and diffusion studies for non-metallic systems and, finally, metal studies. Table XXI shows how such studies were undertaken in the various Static Discharge Gas Vacuum Total elimination stabilization ^ chroma tography gauges Broad product group Subgroup detectors

Number Number Number Number Number Number Number of /,of of of of of of devices applications devices devices users applications devices ^

1 Food 1 11 3 5 6 15 2 Tobacco 6 1 2 6 zC 3 Textiles 57 1 4 4 58 1—4 H 4 Wood, paper 6 6 5 5 12 ra 5 Leather and fur - - - _ 0 6 Rubber - - 7 Chemicals and plastics 60 163 42 73 223 8 Cement etc. 3 1 2 2 4 9 Petroleum and coal 57 (10) 12 12 21 69 o 10 Basic metals 1 1 1 .1 s 11 Machinery (a) Metal products 3 1 1 3 (b) Engineering and electrical goods 5 (18) 23 1 24 32 29 (c) Vehicles and shipbuilding ( 1) 1 1 - (d) Miscellaneous manufacturing 2 ( 1) 7 8 . 8 12 17 12 Services (a) Construction - - - (b) Gas, water, electricity 3 ( 2) 8 4 11 11 (c) Transport - - - (d) Technical services and research 13 ( D 14 8 12 27 207 (24) 256 12 118 183 475

The use of fire detectors excluded ''Number of devices in discharge stabilization not given as this does not correspond to terminology used elsewhere TABLE XVII

ISOTOPES EMPLOYED FOR DIFFERENT FORMS OF lONIZATION, SHOWING THE NUMBER OF APPLIANCES USED

Form of ionization Total No. of devices Isotope Static eliminators Detectors for Vacuum gauges Discharge excluding gas chromatography stabilization discharge stabilization No. of devices No. of devices No. of devices No. of applications''5

Cobalt-60 4 - - (5) 4

Strontium -90 93 128 - (1) 221

Tritium 7 49 - (5) 56

"O Radium-226 5 31 1 (6) 37 O

Thallium- 204 92 - - - 92

Lead-210 - 45 11 - 56

Uranium-238 (3)

Others 2 - - (3) 2

Isotope unknown 4 3 - (1) 7

Total No. of appliances 207 256 12 (24) 475

* The number of devices is not given here. TABLE XVIII

THE REGULARITY OF THE USE OF DIFFERENT FORMS OF IONIZATION

Form of ionization Total No. of devices Regularity of use Static eliminators Detectors for Vacuum gauges Discharge excluding gas chromatography stabilization discharge stabilization No. of devices No. of devices No. of devices No. of applications *

Used on total output 92 1 11 (7) 104

Used on part of output 5 11 - 16 (3) z o Used occasionally 14 10 - (2) 24 o

Research 84 182 - (6) 266 i

Research and production 12 52 1 (4) 65

No answer - - - (2) -

Total No. of appliances 207 256 12 (24) 475

; The number of devices is not given. TABLE XK

ISOTOPES IN STATIC ELIMINATORS , ANALYSED BY THE NUMBER OF ELIMINATORS USED ON THE MATERIAL OR EQUIPMENT SUBJECT TO STATIC

Material or Equipment Film, tape Balances Woven Detonators Paper and Glass' Others AU types fabrics board Isotope No. of No. of No. of No. of No. of No. of No. of Total No. of eliminators eliminators eliminators eliminators eliminators eliminators eliminators eliminators

Cobalt-60 4 4 Strontium- 90 7 62 24 93 Tritium 4 3 7 Radium- 226 3 2 5 Thallium- 204 59 10 1 16 6 92 H Polonium- 210 2 2 oo

No answer 2 1 1 4

Total No. of static eliminators 6 71 72 24 7 17 10 207

No. of establishments 2 20 5 1 4 6 7 43*

Two establishments use eliminators for two types of material UNITED KINGDOM 223

TABLE XX

ADVANTAGES OF USING IONIZATION TECHNIQUES FOR STATIC ELIMINATION AND GAS CHROMATOGRAPHY

Advantage Static eliminators Gas chromatography

No. of estabs. No. of estabs. mentioning mentioning

No. (*) No. (#)

More rapid production 4 9 1 1 Better quality product 14 33 8 11 Reduced product scrap 5 12 2 3 Reduced fire hazard 2 5 - - Process not otherwise practicable 6 14 29 39 More accurate in analysis or measurement 14 33 25 33 Cheaper and quicker analysis 4 9 8 11 Miscellaneous 1 2 5 6 No advantage 1 2 4 5

Total No. of replies 51 119 82 109

No. replying 41* 95.3* 70* 93.3*

No answer 2 4.7 5 6.7

Total No. of estabs. 43 100 75 100

*Some establishments give more than one reply. categories of industry which the UK body had selected. The categories chosen are necessarily somewhat arbitrary, given the virtual impossibility of drawing hard and fast lines between many of the applications mentioned; consequently categories tend to overlap. The sparsity of some of the replies also made a satisfactory classification difficult. The term "number of applications" here refers to different uses, the differences arising out of the nature of the investigation or the material labelled, irrespective of the isotopes used, since frequently several tracers are used in the same investigation. F TRACER STUDY CARRIED OUT IN 1961

Types of tracer study

Wear and Mixing and Flow studies Leak Tagging Surface Other Metabolism Chemical Impurity Metal All uses corrosion operating detection reaction chemical studies analysis and studies Broad product group studies efficiency studies reaction (including diffusion Number studies studies fertilizer studies for of users uptake) non-metals

No. of No. of No. of No. of No. of No. of No. of No. of No. of No. of No. of No. of applications applications applications applications applications applications applications applications applications applications applications applications

1 Food 1 1 3 1 1 7 5 2 Tobacco - - z 3 Textiles 1 1 1 > 4 Wood and paper 2 2 2 i—Hi 6 Rubber 1 1 1 O 7 Chemicals and plastics 2 1 13 3 1 2 7 26 18 1 75 41 8 Cement etc. 2 1 1 1 6 3 9 Petroleum and coal 6 1 1 5 2 2 5 1 24 9 10 Basic metals 2 3 3 1 2 1 3 22 14 lla Metal products 1 1 1 3 1 8 3 lib Engineering and electrical goods 2 3 3 5 5 2 18 5 43 16 lie Vehicles and shipbuilding 1 1 1 3 3 lid Miscellaneous manufactures 2 2 4 3 12a Construction - 12b Gas, water, electricity 6 1 3 1 11 6 12c Transport 1 1 1 12d Technical services and r esearch 2 4 3 5 3 2 4 4 2 29 18 Total number of applications 18 9 30 10 21 19 15 31 56 15 13 237 No. of estabs. replying 17 8 17 10 20 17 12 26 38 13 13 191** 126* No. of estabs. 123*

' Three users appear in two product groups ' Some firms have carried out more than one type of tracer study UNITED KINGDOM 225

A few remarks were made to exemplify the classifications of the reported activities into the group. They are reproduced here as an explanation to Table XXI: Wear and corrosion studies: Most of these are well-known; the wear studies include applications to piston rings, engine components, machine tools, tires, refractory lining, and mill wear during grinding. Corrosion applications mostly deal with the measurement and identification of corrosion products in relation to paints, metals and salt water. Some work has also been done on the mechanisms of mechanical degradation (elastomers, knitting needles). Mixing and operating efficiency: Not used very widely in 1961 — includes applications in the paper industry (pulp mixer, wood-chips mixing processes), in chemicals (dispersions of white lead in PVC, distillation of zinc from blast furnaces), in basic metals (efficiency of hot-metal mixers), in petroleum refining (checking on losses of phenol), and in ceramics (mixing of crystals in refractories). Flow studies and bulk flow: Widely used in processing plants. Examples are to be found in the chemical industry (flow of air in heaped granular fertilizer), in glass manufacture, in engineering (refrigerant mass flow, flow patterns in liquids, ventilation rate measurements on glass ampoules of gas) and in electricity and gas plants (measurement of circulating water flow in power stations, residence time of gas liquor in separator vessels). Leak detection: Includes a number of fairly well-known applications of water and gas leaks. Also, location of surface stream leaks back into a mine through the bed of the stream; leakage investigation in barrel drains to ward off danger of railway track subsidence; in the electrical industry the testing of leaks in transistors by immersion in pressurized gas and leak detection of gas in high voltage gas pressure cables. Tagging: This is the simplest and most direct use of tracers, but it lends itself to a great variety of often ingenious applications. Among many uses one can mention; Studies of the mechanism of fertilizer granulation processes; tagging of potential haematinic compounds and barbiturate antagonists in the drug industry; weld marking for identification after rolling of metal; detection of rotation in the presence of large magnetic fields, by using sealed pellets (motor vehicles); tracing differential elongation of sheath and conductor of mineral insulated coaxial cable; location of thermo junctions in wires in enamelling ovens; rubber identification and sorting of rubber mixes by vulcanizing one of several identical rubbers with sulphur-35; brickwork expansion indication in blast furnaces. Surface reactions: Some of the applications are closely related to electro-plating and corrosion studies as aspects of surface chemistry; they include the study of finishing processes by determining the deposition of heavy metals during brightening. Other types of reactions with solids at surfaces include: Thermodynamic studies in solution with reference to surfaces; detergent efficacy studies; adsorption studies on cloth and on glass; measurement of true surface area of a metal surface by adsorption of activated polar components; and studies of wire lubricant behaviour and surface adsorption. Other chemical reactions: These include polymerization mechanism studies; ion exchange resin studies; reaction of sulphuric acid in car bat- 226 NATIONAL REPORTS

teries; studies of the efficiency of liquid/liquid extraction and mercury cathode separation in chemical research; reaction studies on formaldehyde in beet purification; studies of the mechanism and kinetics of chemical reactions; catalyst studies; gum formation studies; and study of the reactions in a nuclear reactor, Metabolism studies: These have been combined with fertilize/1 uptake studies, which use photographic detection to show activity distribution in samples. As many firms are engaged in the production of insecticides and drugs, a number of their applications more properly belong to the medical or biological fields, but they have been accepted since the end use of the tests is industrial. More directly connected with manufacturing are studies of insecticide and pesticide metabolism and translocation, of insect metabolism, and of the absorption and excretion of insecticides by mammals; biosynthesis studies on hops, barley, and yeast; drug metabolism and absorption studies; the biochemistry of vitamins; and studies of the biosynthesis of wool and rubber. In the steel industry measurements have been made of the uptake of phosphorus from different forms of basic slag fertilizers. Chemical analysis: This covers a number of techniques as stated above. (a) Radioactivation: This technique is not widely used for process and product analysis because generally samples must be sent to a reactor, but smaller, cheaper neutron generators could ease this. Examples include uranium determination in environmental materials; measurement of gold-evaporated film in a vacuum; analysis of semi-conductor and laser materials; analysis of sodium, barium and phosphorus in petroleum products by neutron activation analysis; impurities in a bleaching agent; analysis of oxygen in steel by using a neutron generator; and analysis of rubies for electrical components. (b) Isotope dilution: This method, while well established in research, -is not widely used till now in industrial processes. Examples include: Ana- lysis of pesticide residues in crop plants; analysis of phosphate rock for calcium; assay of vitamin B-12 in productive liquors; and dilution of hafnium in zirconium in atomic reactor research. (c) Radiometry: Examples are very diverse and include: Separation and identification of neomycin factors in pharmaceutical research; physical- chemical studies of trace quantities of tin; determination of the embedment of silicon carbide for grinding silicon wafers in semi-conductor manufacture; distribution of anchorage agents; determination of cystine in proteins; and detection and estimation of "abnormal" groups in the rubber molecule. (d) Gas-liquid chromatography: This powerful analytical tool is as yet not much used in connection with tracers. Examples include; Separation of antibiotics using chromatography of carbon- 14 derivatives; and chromatography of petroleum fractions and measurement of dust layer in plastics research. Impurity tracing and diffusion studies: Examples of impurity studies other than on metals include a number of investigations of impurities and purifying techniques for semi-conductors and radio valves; also studies of vacuum contamination by diffusion pump oil; entrainment studies; and a study of the elimination of strontium in the purification of sugar-beet juices. Examples of diffusion studies include: Diffusion in semi-conductors; permeability studies of protective films, including paints, to water and water UNITED KINGDOM 227

vapour; migration of hydrogen through metal, using tritium autoradiography; a study of diffusion kinetics; diffusion of refractories in glass; and migration of plasticisers and anti-oxidants. Metal studies: These include metal segregation studies; studies of the rate of leaching of zirconium ore; investigation of the diffusivity coefficients in aluminium; labelling of steel-making slags and refractories to trace the source of exogenous non-metallic inclusions; determination of metal reserve without danger of metal contamination; and various casting studies including measuring the solidification boundary in continuously cast slab by autoradiography. Table XXII shows how various radioisotopes were used as tracers in 1961, Table XXIII the regularity of use and Table XXIV the main advantages indicated by the establishments who replied. The UK questionnaire also sought information about the use of radioisotopes as tracers in current research. Of the 123 firms using tracers in 1961 74 replied to the effect that they were also applying tracers in 1963. The number of applications reported was 105, which could be compared with the 203 research applications reported for 1961. Tables XXV and XXVI give the distribution of the research projects over the various industries and the type of application, as presented above. It is a little astonishing to see that a considerable number of the firms which applied radioisotope tracers in research in 1961 have abandoned these methods. However, one should not conclude that the total amount of radiotracer research has decreased. It must be kept in mind that many of the research projects which are approached with tracers are of a short duration and that the tracers are frequently used to give the answer to a certain question. With a satisfactory answer the need for radiotracers may temporarily disappear. It is to be believed that at least a corresponding number of firms not covered by this part of the survey had problems in 1963 where radioisotopes proved helpful.

Massive irradiation

The survey accounted for 100 applications of massive irradiation in 86 establishments. In 1961 most of the work under this heading was carried out on commission by the U.K. A. E. A.; the facilities they employ include a package irradiation plant of 300000 c, spent reactor fuel of about a million curies, and a number of experimental cells of up to 10 000 c, in addition to a linear accelerator. There were, however, eight establishments possessing their own sources (including one linear accelerator), none of them exceeding 600 c. Since 1961 two firms have invested in powerful sources for the sterilization of medical supplies. Table XXVII shows the sources used for various projects in 1961, while Tables XXVIII and XXIX show the purpose of irradiation and how the main purposes were distributed over the various industries. The various plants in use in the United Kingdom were all listed at a recent international conference, so that details about their economics and other relevant data may be found there [10- 12] . As this is a field which is ISOTOPES USED ANALYSED BY THE NUMBER OF APPLICATIONS FOR EACH TYPE OF TRACER STUDY CARRIED OUT IN 1961

Types of tracer study

Wear and Mixing and Flow studies Leak Tagging Surface Other Metabolism Chemical Impurity Metal All uses corrosion operating detection reaction chemical studies analysis and studies Isotopes studies efficiency studies reaction (including diffusion studies studies fertilizer studies for uptake) non-metals

Cobalt-60 7 2 8 2 19 Tritium 1 2 1 5 3 3 15 Phosphorus-32 3 3 4 5 11 3 1 30 O Iodine-131 1 2 1 1 3 3 1 12 2 Sulphur- 3 5 1 1 11 5 4 2 3 2 19 > Krypton-85 1 6 4 2 13 IT- Sodium-24 1 16 6 3 1 3 7 37 8 Carbon-14 1 2 1 6 7 21 11 2 51 T3 Chromium-51 1 1 1 1 2 1 2 9 O ?Q Iron-59 8 1 2 2 2 15 H Gold- 198 1 1 4 6 CO Amimony-124 1 3 1 5 Barium-140 1 1 6 8 Chlorine- 36 1 1 4 2 1 1 10 Copper-64 1 2 4 7 Bromine- 82 1 7 1 9 Miscellaneous a 7 5 6 1 1 4 2 1 47 6 7 87

Total No. of applications 28 11 40 12 22 29 20 48 103 20 19 352

No. of estabs. replying 17 8 17 10 20 17 12 26 38 13 13 191b

a Covers 41 different named isotopes, plus "Rare Earths" and "Fission Products" b Some establishments have carried out more than one type of tracer study UNITED KINGDOM 229

TABLE XXIII

REGULARITY OF USE OF TRACER METHODS

Regularity of use No. of No. of applications establishments

Used continuously 5 5

Used for spot checks 17a 10

Used rarely 9 6

Used for commissioning trials 3 2

Research 189 107

Research and production 14 b 12

Total 237 142c

a 8 for flow studies, b 5 for analysis; 3 for tagging c Some establishments give more than one reply because they have used tracers for different purposes rapidly expanding, the information given in the survey may already be out- dated. Nevertheless, the companies' replies to the question on advantages of massive irradiation are reproduced (Table XXX). It should be pointed out that of the 84 applications 62 concerned research, while 15 were used continuously and 7 less frequently or rarely in "production".

Miscellaneous applications

As everywhere else, there remained also in the United Kingdom a number of applications that could not easily be classified under the five previous headings. The distribution over the broad product groups of the 17 establishments having such applications can be seen in Table II. The main group was the application of luminescent compounds in which radioisotopes were incorporated. Nine establishments accounted for 12 applications of this technique. To this figure should be added another 10 which used only naturally radioactive materials, and which were considered to be beyond the scope of the Survey. Alpha and beta radiography for homogeneity tests were reported from three establishments (seven applications). Finally, one finds a number of odd applications, which were: Detection of an oil-water contact through the casing and tubing in a well bore by a chlorine neutron-gamma reaction technique; Advantages

Better Clearer Analysis Better Process Better Improved Types of control of under- Cheaper mote main- otherwise Miscel- All No control of plant Total tracer study process standing analysis efficient tenance of not laneous advantages answer product efficiency operation of or direct plant practic- processes able

No. of No. of No. of No. of No. of No. of No. of No. of No. of No. of No. No. of No. of estabs. estabs. estabs. estabs. estabs. estabs. estabs. estabs. estabs. replies replying a estabs. estabs. mentioning mentioning mentioning mentioning mentioning mentioning mentioning mentioning mentioning

Wear and corrosion studies 1 2 1 7 13 6 2 5 . 37 17 . 17 Mixing and operating efficiency studies 2 - 1 5 1 1 - 1 - 11 7 1 8 Flow studies 4 2 3 12 6 1 - 6 1 35 15 2 17 Leak detection 2 2 1 - - 1 - 2 1 9 6 4 10 Tagging - 1 2 4 7 6 3 6 2 31 20 - 20 Surface reaction studies 1 2 - 7 5 8 - 5 1 29 16 1 17 Other chemical reaction studies - - 1 9 4 3 - 2 - 19 12 - 12 Metabolism studies (including fertilizer uptake) - - - 11 20 13 - 12 - 56 25 1 26 Chemical analysis 2 5 1 11 19 18 - 11 1 68 36 2 38 Impurity and diffusion studies of non-metals 2 1 - 6 8 9 - 3 - 29 13 - 13 Metal studies 1 - - 9 4 1 - 4 - 19 13 - 13

Total No. of replies 15 15 10 81 87 67 5 57 6 343 180 11 191

No. replying15 13 13 8 55 61 46 5 45 6 252 113 10 123

Replying (%) 11 11 6 45 50 37 4 36 5 205 91.9 8.1 100

Most establishments give more than one reply Some establishments have carried out more than one type of tracer study i.e. multiple answers occur in both rows and columns UNITED KINGDOM 231

TABLE XXV INDUSTRY OF ESTABLISHMENTS ENGAGED IN CURRENT (1963) TRACER RESEARCH

Broad product group No. of applications

1 Food 5 2 Tobacco - 3 Textiles - 4 Wood and paper - 6 Rubber 1 7 Chemicals and plastics 36 8 Cement etc. 5 9 Petroleum and coal 5 10 Basic metals 14 lia Metal products - lib Engineering and electrical goods 19 lie Vehicles and shipbuilding - lid Miscellaneous manufactures 1 12a Construction - 12b Gas. water, electricity 4 12c Transport - 12d Technical services and research 15

Total No. of applications 105

No. of estabs. replying 74

Estabs. with no current research 49

Total No. of establishments 123

Porosity determination of a rock formation by neutron irradiation — enabling evaluation in situ and thus avoiding the necessity for core sample analysis;

Selection of random timing by a Monte Carlo analogue computer, used in nuclear-power-station shielding studies; Testing of photographic film for suitability in conjunction with gamma radiography (using different sources for the tests); Use as target material in neutron generating tubes. Of the 28 applications wholly covered under this heading, 12 were used continuously, 10 intermittently or rarely, while 5 were of a purely research nature. For luminizing, tritium, Pm147 and radium were used; for the other purposes eight various radioisotopes were employed.

Economic considerations

The report states: "The problem of obtaining valid economic data from either individuals or firms is widely recognized by researchers using survey 232 NATIONAL REPORTS

TABLE XXVI TYPE OF CURRENT (1963) TRACER RESEARCH

Type of research No. of applications

Wear and corrosion studies 4 Mixing and operating efficiency studies 2 Flow studies 6 Leak detection 3 Tagging 6 Surface reaction studies 7 Other chemical reaction studies 11 Metabolism studies (including fertilizer uptake) 24 Chemical analysis 22 Impurity and diffusion studies for non-metals 12 Metal studies 8

Total No. of applications 105

No. of estabs. replying 74

Estabs. with no current research 49

Total No. of establishments 123 techniques to collect information. In this particular inquiry the difficulty was increased by the fact that: (1) No one person in the establishment could answer both the technical and economic questions and (2) Some establishments admitted difficulties in making assessments even when willing to do so. This latter problem applied particularly to the questions concerned with savings and isotope-assisted turnover." To add to the clarity of the following tables, these general notes were submitted by the UK national body: "1. Nineteen users of the A.E. A. Bulk Irradiation service were not sent a questionnaire but information about their use of this service was made available by the A.E. A. Consequently, these 19 have been excluded from the tables dealing with isotope-assisted turnover and savings (which add up to 669 establishments) but not from the tables dealing with investment and annual costs, since these were known (i. e. nil for the former and varying amounts covering the service charge for the latter); they are also included in the tables dealing with individual industries and in that part of Table 50 dealing with total turnover. "2. Twenty establishments appear in two industries and so the tables giving an analysis by industry contain up to twenty cases of double answers (in some cases there is an answer for only one industry, or for neither). Consequently the overall number of establishments replying has been adjusted downwards to eliminate such double counting. UNITED KINGDOM 233

TABLE XXVII APPLICATIONS OF MASSIVE IRRADIATION CLASSIFIED AS TO RADIATION SOURCE USED

No. of No. of Source applications es tabs.

Users of U. K. A. E. A. irradiation service: Package irradiation plant 26 24 Cobalt cells 6 5 Spent fuel facility 47 41 Linear accelerator 5 5

84 75

Own source:

Large sources (50 to 600 c of 12 7 cobalt- 60) Small sources 3 3 Linear accelerators 1 1

Total uses 100 86*

* Some establishments use more than one source for its various purposes "3. Forty establishments use one or more techniques primarily for research, others primarily for production control; any double counting arising therefrom has been eliminated in overall totals. "4. A considerable number of establishments — especially those engaged in research — use more than one radioisotope technique. In those tables giving an analysis by technique the overall means for research and production control applications have been calculated on the net number of establishments using isotopes for these purposes, over all techniques involved, thus avoiding double counting; the double counting arising out of the use of both research and production applications is not relevant here since the two means are not combined in the analyses by technique. "5. Radiographie inspection service firms are included with Technical Services and Research and are classified under "Production Control" where this is separated from "Research". "6. Some informants were unable to split their expenditure by technique, and in these cases the amounts were split arbitrarily, usually in equal proportions over all the techniques involved; this should be borne in mind when considering the tables presenting an analysis by technique. " 7. Whenever mean values are given they have been calculated in terms of those giving a positive answer, i.e. excluding no answers and nil amounts. "8. The term DISSAVINGS has been used in a number of tables. In this context it refers to the fact that some firms considered that their use of 234 NATIONAL REPORTS

TABLE XXVIII PURPOSE OF IRRADIATION

No. of , No. of Purpose applications establishments

Medical and pharmaceutical 37 31 sterilization Sterilizations of foodstuffs 3 3 Polymerization 7 7 Cross-linking 10 9 Other chemical reactions 3 3 Mutation studies 3 3 Effects of irradiation on materials 16 16 Miscellaneous 5 4

Total 84 76*

* Some establishments have used this technique for more than one purpose

isotope techniques for a given process had resulted in a net rise in costs, rather than a (measurable) savings, especially where the process in question had been too costly or impracticable to apply before the introduction of radioisotopes. "

Turnover

In Table XXXI is analysed the turnover and isotope-assisted turnover of UK industry in 1961. Here it should be pointed out that the figures for "isotope-assisted turnover" are generally taken from the returned forms. In a first approach the replies concerning total turnover given by the firms was also studied; a few spot-checks revealed, however, that these were not very reliable, as the firms often had misunderstood the meaning of this term. So instead, figures were based on the total sales of the individual firms as given in the 1958 Census of Production and projected forward to 1961. For certain product groups which were not covered by the census data were supplied by the Ministry of Fuel and Power. In those cases where these two sources of information did not cover individual users, the actual figures given by the establishments themselves were used if they clearly referred to total turnover or research budget and not to a research or maintenance budget which formed only a portion of their outgoings. It can be seen that the useful response to the question of "isotope-assisted output" was as high as 75%. It is also clear here that the establishments that make use of radioisotopes together represent quite a considerable fraction of the total UK industry. The highest figures are given by the tobacco industry, but rather TABLE XXK INDUSTRY OF USER ESTABLISHMENTS ANALYSED BY PURPOSE OF IRRADIATION

Purpose of irradiation Chemical Sterilization Others All applications reactions Broad product group Number of Number of Number of Number of Number of applications applications applications applications establishments

1 Food 4 1 5 4 3 Textiles 2 2 1 1 H 4 Wood and paper 1 2 2 m ö 6 Rubber 4 3 7 5 7 Chemicals and plastics 11 8 6 25 22 8 Cement etc. 1 2 3 3 9 Petroleum and coal 4 4 4 lia Metal products 1 1 2 2 lib Engineering and electrical goods 2 7 9 8 lid Miscellaneous manufactures 19 1 1 21 16 12d Technical services and research 3 1 4 3

Total replies 40 20 24 84 70

Number replying 34 19 23 76 66*

* Some establishments have used this technique for more than one purpose TABLE XXX ADVANTAGES OF USING MASSIVE IRRADIATION

Purpose of irradiation Chemical Sterilization Others All applications reactions Advantages Number of Number of Number of Number of es tabs. estabs. estabs. estabs. Base (*) mentioning mentioning mentioning mentioning

Cold sterilization possible 10 1 11 17 Sterilization after packing possible • 8 8 12 Materials dispensable and cheap 6 6 9 Better research technique 1 2 2 5 7 Clean, controllable method of producing chemical or biological changes 4 2 6 9 Miscellaneous 2 5 4 11 17

Total No. of replies 27 11 9 47 71

Number replying 17 10 9 36* 33**+ 50*

No answer 17 9 14 40 33*** 50

Total number of establishments 34 19 23 76 66 100

* Some establishments give more than one reply + Some establishments have used this technique for more than one purpose ** 30 No answers (involving 34 applications) refer to establishments for which information was supplies by the U.K. A. E. A. only TABLE XXXI TURNOVER ANALYSED BY INDUSTRY

Total turnover Isotope-assisted turnover Isotope-assisted Establishments turnover Mean Isotope- Total % of isotope- Broad product group assisted Total Number Mean turnover total AU assisted as % of turnover of turnover as % of (£ million) isotope- No. users turnover total (£ million) estabs. (£ million) sales by assisted (%) perestab. a turnover U. K. industry turnover (£ million)

1 Food 92 18 5.1 3 18.7 3 18 3 1.04 23 e 2 Tobacco 531 12 44.3 49 200 29 11 2 18.0 e 40 3 Textiles 53 21 2.5 2 6.8 1 14 2 0.49 16 4 Wood and paper 286 93 3.1 13 125.4 18 76 12 1.64 52 C 6 Rubber 94 16 5.9 30 28.1 4 12 2 2.34 45 e z 7 Chemicals and plastics 445 82 5.4 23 61.2 9 73 11 0.84 21 8 Cement etc. 77 25 3.1 11 16.0 2 14 2 1.14 61 9 Petroleum and coal 391 21 18.6 24e 8.0 1 22 3 0.36 5 10 Basic metals 848 85 10.0 38 187.5 27 67 10 2.80 26 lia Metal products 157 32 4.9 10e 5.4 1 26 4 0.21 5 lib Engineering and electrical goods 660 96 6.9 ne 18.7 3 74 11 0.25 4 z lie Vehicles and shipbuilding 356 36 9.9 13 6.4 1 23 3 0.28 3 o lid Miscellaneous manufactures 88 32 2.8 lie 1.4 0 30 4 0.05 4 a 12a Construction 123 15 8.2 46 5.4 1 8 1 0.71 14 o 12b Gas, water, electricity 99 7 14.1 7e 0.1 0 18 3 0.04 0 12c Transport 38 3 12.7 0 - 2 0 - - 12d Technical services and research 12 34 0.4 0.6 0 34 5 0.02 5 e Total for all industries 4350 628 14 690 100 522 78 22 c No. of estabs. replying 611 7.1 502c 75 1.37e Only research or radiographie inspection service budget known 46 No answer/no information 31 167 25 Total No. of establishments 688 669d 100 a Based on total sales for U.K. industry as reported in the 1961 Sample Census of Production ° Limited to those establishments for whom both total turnover and isotope-assisted turnover are known; this has been done so as to obtain a true comparison of isotope-assisted turnover in relation to total turnover, excluding no answers on either side c Some establishments appear in two industries d See Note 1 in General Notes to Economic Tables e Estimate .. = Not available 238 NATIONAL REPORTS

high figures are reported from many very important industries, such as the basic metals, petroleum, rubber and chemical industries. Very low percentages are found in food, textile and construction. Also, transportation shows a very low percentage, but it is impossible to establish exactly how low it is. Many of the industries analysed show also a very high ratio of isotope- assisted to total production. Here, group 8 (cement, glass and china) is in the lead, followed closely by paper, rubber and tobacco industries. A very low percentage, on the other hand, is given by some rather important branches — petroleum and coal, and all the subgroups under "Machinery" and "Services". Further details concerning the order of the isotope-assisted output is provided in Table XXXII. Here the amount of isotope-assisted turnover as reported by the firms are split among the various industries. Table XXXIII analyses the isotope-assisted turnover when various techniques are employed and it is easily seen how dominating is the use of gauging. This is due partly to the definition of "isotope assistance"; tracing in research might be considerably important to much higher turnovers, but it is not normally thought of as assisting an output. Radiographed output accounts for less than 10% of the value of gauged products. If one compares Table XXXIII with Table II, there is little doubt that gauging is the absolutely dominating technique for product control in the first nine product groups; however, ionization and tracing might be important in the chemical group. In the metallic sector (groups 10 and 11) radiography and gauging may be equally influenced by several techniques. Group 12 is too complex to permit any clear analysis from the figures given above.

Investment

Table XXXIV shows the total investments made in the various product groups for employing radioisotope techniques. Another approach to this, which includes the splitting up of the investment into research and production control, is shown by Table XXXV. Table XXXVI groups the total investments over the various industries, taking the investment in each particular case into consideration. Finally, in Table XXXVII, the investment is shown listed according to techniques.

Costs

The annual costs, as deriving from capital costs and labour and maintenance are presented in Tables XXXVIII and XXXIX, analysed with regard to industry and technique, respectively.

Savings

The savings and dissavings reported are shown in Tables XL. In Table XLI the savings net of dissavings are put in relation to turnover and investment and in Table XLII to technique and the field of saving. The response to the questions on savings was much lower than to those on turnover or investment and cost (34% against 75 and 88%, respectively). TABLE XXXII

NUMBER OF ESTABLISHMENTS IN EACH INDUSTRY ANALYSED BY GROUPED ISOTOPE-ASSISTED TURNOVER

Isotope-assisted turnover (£ 000) No. of No. of Total estabs. no No. of 1000- 2500- 5000- 10000 Broad product group Under 10-99 100-499 500-999 replying answers estabs. 10 2499 4999 9000 or over

1 Food 7 2 2 - 3 3 1 - 18 3 21 2 Tobacco - - - - 2 1 - 8 11 1 12 3 Textiles 4 2 4 1 3 - - - 14 7 21 4 Wood and paper 5 4 17 15 19 11 4 1 76 18 94 6 Rubber 1 5 2 - 2 1 - 1 12 2 14 7 Chemicals and plastics 36 11 6 7 6 4 2 1 73 25 98 8 Cement etc. 3 1 2 2 2 3 1 - 14 13 27 H 9 Petroleum and coal 11 3 3 2 2 1 - - 22 7 29 m 10 Basic metals 18 13 12 8 5 6 - 5 67 26 93 a lia Metal products 9 6 7 2 2 - - - 26 8 34 lib Engineering and electrical goods 28 20 16 5 3 2 - - 74 23 97 o lie Vehicles and shipbuilding 12 4 3 1 3 - - - 23 16 39 a lid Miscellaneous manufactures 15 10 5 - - - - - 30 6 36 o 12a Construction 1 3 2 1 1 1 - - 8 7 15 12b Gas, water, electricity 15 3 ------18 2 20 12c Transport 2 ------2 1 3 12d Technical services and research 26 7 1 - - - - - 34 2 36

All establishments 193 + 94 82 44 52 33 8 16 522 167 689

% of all establishments 28 14 12 6 8 5 1 2 76 24 100 % of establishments replying 37 18 16 9 10 6 1 3 100

Base 669*

* 20 establishments appear in 2 industries; figure excludes 19 bulk irradiation users mentioned in general note 1 + 154 establishments had a turnover of less than £5000 TABLE XXXIII ISOTOPE-ASSISTED TURNOVER ANALYSED BY TECHNIQUE

Massive Gauging Radiography Tracers lonization Miscellaneous All techniques Isotope- assisted irradiation turnover or research expenditure No. of £mn £mn £rnn £mn £mn £mn Era n <*) « m « <*, « « estabs.

For:

Radiographie inspection3 0 4.8 0 4.8 0.7

Research 0.20 0.01 0.57 0.38 0.03 0.02 1.2 0.2 Production control 588e 53.0 20.7 18.7 0.4 3.5 684e 99.1 i Total 588e 85 57.8 8 21.3 3 19.1 3 0.4 0 3.5 1 690e 100

Mean turnover £000 £000 £000 £000 ' £000 £000 per establishment" £000 H en Research 5 1 7 6 1 4 8 155d

Production control 2900e 380 c c 30 c e d (incl. service firms) 1790 382

a Refers solely to inspection service firms " Excluding no answers c One or two establishments with large turnover distort the mean which without these does not exceed £150 000 d See Note 4 in General Notes to Economic Tables e Estimate TABLE XXXIV

TOTAL INVESTMENT IN ISOTOPES AND RELATED EQUIP MENT, ANALYSED BY INDUSTRY, AND TYPE OF EQUIPMENT

Total investment by type of equipment Total investment Health as % of Isotope Extra Special Broad product group Isotopes physics a a Miscellaneous " Total isotope - equipment structures buildings (<7°) equipment assisted £000 £000 £000 £000 £000 £000 £000 turnover c (1) (2) (3) (4) (5) (6) (V) (8) (9)

1 Food 1 21 0 2 1 0 25 1 0.15 2 Tobacco 16 956 2 2 2 - 978 24 0.37 3 Textiles 2 48 0 2 - 0 52 1 0.64 4 Wood and paper 4 244 5 20 1 0 274 7 0.19 6 Rubber 2 24 0 4 9 - 39 1 0.12 7 Chemicals and plastics 35 379 14 45 103 2 578 14 0.76 8 Cement etc. 6 30 1 2 1 - 40 1 0.21 o 9 Petroleum and coal 6 53 3 5 17 3 87 2 0.86 10 Basic metals 24 194 9 74 152 2 455 11 0.26 lia Metal products 22 57 3 7 28 - 117 3 1.60 o f 0 lib Engineering and electrical goods 17 143 29 166 316 - 671 16' 3.36 o lie Vehicles and shipbuilding 9 21 5 7 17 1 60 1 0.62 d lid Miscellaneous manufactures 51 56 3 64 30 1 205 5 13.8 12a Construction 10 28 1 10 15 - 64 2 0.35 e 12b Gas, water, electricity 5 54 2 1 31 12 105 3 136 12c Transport 0 0 0 - 0 - 0 0 0 12d Technical services and research 21 69 16 81 145 3 335 f 8 51.9e

Total for all industries 231 2377 93 492 868 24 4085 100 0.52

Structures within existing buildings and new buildings erected to shield or house isotope equipment, including laboratories and radiography chambers b General laboratoriboratoryv equipmenteauioment., vehicles, miscellaneous equipmeeauiomennt c Limited to those giving BOTH sets of figures d High figure is due to heavy investment in bulk irradiation equipment e Figure is high because isotope-assisted turnover represents mainly a small maintenance or research budget f Much of this is for neutron generating equipment ( £570 000 in total) TABLE XXXV

TOTAL INVESTMENT IN ISOTOPE EQUIPMENT FOR RESEARCH AND PRODUCTION CONTROL, ANALYSED BY INDUSTRY

Total investment Establishments Investment as % of isotope- assisted turnover D Mean total investment Broad product group For production No. with some a For production For research Total % of all users per establishment For research control investment control £000 £000 £000 £000 (1) (2) (3) (4) (5) (6) (7) (8)

1 Food 22 3 25 17 2 7.3 88 0.02 2 Tobacco 3 975 978 12 2 81.5 - 0.37 3 Textiles 1 51 52 15 2 3.5 14 0.62 4 Wood and paper 14 260 274 88 13 3.1 41 0.18 6 Rubber 11 28 39 13 2 3.0 35 0.08 Z 7 Chemicals and plastics 257 321 578 85 12 6.8 40 0.47 > 8 Cement etc. 3 37 40 20 3 2.0 208e 0.21 H 9 Petroleum and coal 60 27 87 21 3 4.1 19 0.15 10 Basic metals 27 428 455 77 11 5.9 126 0.24 I Ha Metal products 7 110 117 27 4 4.3 25 1.47 lib Engineering and electrical goods 67 604 671 f 82 12 8.2 103 3.04 f He Vehicles and shipbuilding 18 42 60 30 4 2.0 203 e 0.33 lid Miscellaneous manufactures 9 196 205 26 4 7.9 13 13. 8 d -o 12a Construction 0 64 64 11 2 5.8 133 0.35 O 12b Gas, water, electricity 76 29 105 18 3 5.8 154 e 137 e 12c Transport 0 - 0 1 0 0 - - 12d Technical services and research 287 48 335 f 35 5 9.6 273e 8.1 f

Total for all industries 862 3223 4085 578 84 64.6 0.41

No. of estabs, with some investment 560 c 81 7.3 No. of estabs. with nil investment 60 9 No answer 68 10

Total of no. of establishments 688 100 a Excluding 60 with nil investment b Limited to those giving BOTH sets of figures c Some establishments appear in two industries d High figure is due to heavy investment in bulk irradiation equipment e Figure is high because isotope-assisted turnover represents mainly a small maintenance or research budget f Much of this is for neutron generating equipment ( £570 000 in total) TABLE XXXVI

NUMBER OF ESTABLISHMENTS IN EACH INDUSTRY BY GROUPED INVESTMENT IN ISOTOPE EQUIPMENT

Total investment No. of establishments Broad product group £1000- £5000- £10 000- £50000- £100000 With some With nil No £1-499 £500-999 Total 4999 9999 49999 99999 and over investment investment answers

1 Food 9 4 2 1 1 . . 17 3 2 22 2 Tobacco - • - 2 1 4 2 3 12 - - 12 3 Textiles 2 5 5 2 1 - - 15 4 2 21 4 Wood and paper 9 13 51 10 5 - - 88 2 5 95 - - - - G 6 Rubber 2 2 7 2 13 2 15 g 7 Chemicals and plastics 15 11 30 14 13 1 1 85 12 7 104 H 8 Cement etc. 3 5 11 1 - - - 20 3 5 28 m ö 9 Petroleum and coal 3 3 13 - 2 - - 21 3 5 29 X 10 Basic metals 9 11 30 15 12 - - 77 3 13 93 i—i Z lia Metal products 6 3 10 5 3 - - 27 4 4 35 O ö lib Engineering and electrical goods 19 14 27 15 5 1 1 82 7 13 102 o lie Vehicles and shipbuilding 9 7 11 1 2 - - 30 2 7 39 lid Miscellaneous manufactures 12 1 6 3 3 1 - 26 10 3 39 12a Construction 1 .4 3 2 1 - - 11 1 3 15 12b Gas, water, electricity 3 5 7 1 1 1 - 18 2 - 20 12c Transport 1 ------1 2 - 3 12d Technical services and research 5 8 15 4 2 - 1 35 - 1 36

All establishments 108 96 230 75 57 6 6 578 60 70 708

% of all estabs. (% of those with 15(19) 13(16) 33(40) 11(13) 8(10) 1(1) 1(1) 82(100) 8 10 100 some investment)

Base 688*

* 20 establishments appear in two industries TABLE XXXVII

TOTAL INVESTMENT IN ISOTOPE EQUIPMENT IN USE IN 1963, ANALYSED BY TECHNIQUE

Gamma Massive Gauging Tracers lonization Miscellaneous All techniques radiography irradiation

No. of £000 (ft) £000 (ft) £000 (ft) £000 (ft) £000 £000 £000 a (ft) (ft) (ft) estabs. Total investment Research 68 2 11 0 415 10 113 3 30 1 225 c 5 862 21 Production control 1813 44 753 19 56 1 69 2 136 3 396 c 10 3223 79

Total 1881 46 764 19 471 11 182 5 166 4 621 15 4085 100

Mean investment per establishment a Research 1.6 0.8 4.7 1.7 3.8 45. OC 5.4 160 Production control 7.7 4.0 3.1 2.2 45. 3 b 33. OC 7.5 432

Type of equipment (ft) (ft) (ft) (ft) (ft) (ft) £000 (ft)

Isotopes 3 11 6 5 30 1 231 6 Isotope equipment 91 31 45 77 27 6 2377 58 Health physics equipment 1 3 3 3 0 4 93 2 Extra structures d 4 12 7 7 36 35 492 12 Buildings d 1 42 36 8 7 54 868 21 Miscellaneous e 0 1 3 0 24 1

All investment 100 100 100 100 100 100 4085 100 a Excluding those with nil investment " Most of this investment is contributed by two establishments c High figure is due to heavy investment in neutron generating equipment by two establishments d Structures within existing buildings and new buildings erected to shield or house isotope equipment, including laboratories and radioagraphy chambers e General laboratory equipment, vehicles, and miscellaneous equipment TABLE XXXVIII

ANNUAL COST OF USING ISOTOPES, ANALYSED BY INDUSTRY

Annual costs Mean cost per Depreciation Labour and Establishments Broad product group Total establishment a No. with All users £000 £000 £000 (<#>) some costs (%) £000

1 Food 5 2 7 0 20 3 0.4 2 Tobacco 231 5 236 14 12 2 19.7 3 Textiles 12 1 13 1 16 3 0.8 4 Wood and paper 62 26 88 5 91 13 1.0 6 Rubber 7 19 26 1 14 2 1.9 7 Chemicals and plastics 111 97 208 12 90 13 2.3 8 Cement etc. 9 3 12 1 23 3 0.5 9 Petroleum and coal 17 62 79 5 23 3 3.4 10 Basic metals 69 139 208 12 80 12 2.6 lia Metal products 21 45 66 4 29 4 2.3 z lib Engineering and electrical goods 76 374 450 27 90 13 5.0 o lie Vehicles and shipbuilding 10 39 49 3 31 5 1.6 ö lid Miscellaneous manufactures 34 41 75 4 35 5 2.1 12a Construction 11 26 37 2 11 2 3.4 i 12b Gas, water, electricity 19 31 50 3 20 3 2.5 12c Transport 0 0 0 0 3 0 0 12d Technical services and research 41 .62 103 6 35 5 2.9

Total with some annual costs 735 972 1707 100 623 91 I

No. of establishments replying 605 b 88 2.7 No. with nil costs 30 4 No answer 53 8

Total no. of establishments 688 100

Excluding those with nil costs Some establishments appear in two industries TABLE XXXIX

ANNUAL COST OF USING ISOTOPES, ANALYSED BY TECHNIQUE

Massive Annual cost Gauging Radiography Tracers lonization Miscellaneous All techniques irradiation

No. of Total cost £000 £000 £000 £000 £000 £000 £000 (1°) Pfr) eft) (<7°) (<7o) C7») C7°) estabs. a

Depreciation and interest 431 83 109 25 76 32 39 31 28 32 52 17 735 43 Labour and maintenance 86 17 323 75 161 68 88 69 60 68 254 83 972 57 100 100 100 100 100 100 100 O Z Research 48 3 10 3 204 12 95 5 34 2 37 2 428 25 Production control 469 28 422 22 33 2 32 2 54 3 269 16 1279 75

O Total 517 31 432 25 237 14 127 7 88 5 305 18 1707 100

Mean cost per estab. a Research 1.0 0.5 2.1 1.4 1.1 7.4 b 2.4 181 Production control 1.9 2.2 1.6 0.9 3.0 22.4 b 2.8 457

Note: Annual cost of using isotopes i.e. Depreciation and interest on current investment, plus maintenance costs, current operating or research staff costs, and charges for work contracted out. a Excluding those with nil costs b This figure is high because of heavy investment in neutron generating equipment by two establishments UNITED KINGDOM 247

TABLE XL SAVINGS AND DISSAVINGS RESULTING FROM THE USE OF ISOTOPES, ANALYSED BY INDUSTRY

Total savings in 1961 Total dissavings ^

Establishments Establishments Broad product group £000 £000 No. All users No. All users (ft) (ft)

1 Food 10 4 1 0 1 2 Tobacco 10 1 0 - - 3 Textiles 98 9 1 0 1 4 Wood and paper 211 31 5 - - 6 Rubber 27 5 1 - - 7 Chemicals and plastics 1007 29 4 8 6 8 Cement etc. 229 8 1 1 1 9 Petroleum and coal 31 3 0 1 2 10 Basic metals 244 25 4 31 10 lia Metal products 59 7 1 49 2 lib Engineering and electrical goods 618 25 4 50 8 lie Vehicles and shipbuilding 41 7 1 4 2 lid Miscellaneous manufactures 17 7 1 10 3 12a Construction 15 2 0 15 3 12b Gas, water, electricity 27 8 1 1 1 12c Transport - - - - • - 12d Technical services and research 4 5 1 2 2

Total for all industries 2648 176 26 172 42 6

No. of establishments replying 172 a 26 41 a 6 No savings/dissavings 497 b 74 628 94

Total no. of establishments 669 c 100 669 c 100 a Some establishments appear in two industries b See Table XLII for reasons for inability to estimate savings c Excluding the 19 bulk irradiation users mentioned in general note 1 d i. e. extra costs incurred without offsetting measurable benefit - see general note 8 TABLE XLI RELATION OF SAVINGS TO TURNOVER AND INVESTMENT, ANALYSED BY INDUSTRY

Savings net of dissavings *

£000 Establishments Response Net savings Mean savings in terms of Net savings Broad product group (<7o) as "/o of per establishment isotope-assisted as "ja of total Production All users a isotope -assisted Research Total No. £000 turnover investment b control C7») (%) turnover b (1) (2) (3) (4) (5) (6) m (8) (9) (10)

1 Food 8 2 10 0 5 1 2.0 8 0.66 73 2 Tobacco - 10 10 1 1 0 10.0 3 0.66 198 3 Textiles 98 98 4 10 2 9.8 86 1.66 219 4 Wood and paper 2 209 211 9 31 5 6.8 40 0.39 227 6 Rubber 7 20 27 1 5 1 5.4 5 2.04 138 7 Chemicals and plastics 18 981 999 40 35 5 28.5 46 2.45 758 8 Cement etc. 1 227 228 9 9 1 25.3 49 2. 88 943 9 Petroleum and coal 26 4 30 1 5 1 6.0 15 2.15 73 10 Basic metals 2 211 213 9 35 5 6.1 28 0.40 108 lia Metal products 3 7 10 0 9 1 1.1 56 0.35 21 Hb Engineering and electrical goods -1 569 568 23 33 5 17.2 32 9.52 h 356 lie Vehicles and shipbuilding -2 39 37 2 9 1 4.1 52 0.82 132 lid Miscellaneous manufactures - 7 7 0 10 2 0.7 46 0.76 12 12a Construction - 0 0 0 5 1 0 25 0 -1 12b Gas, water, electricity 15 11 26 1 9 1 2.9 14 238 e 125 12c Transport ------12d Technical services and research -1 3 2 0 7 1 0.3 70 0.35 9

Total for all industries 78 2398 2476 100 218 33 ! 24 f 1.29 270

No. of establishments replying 213 c 32 11.6 No answer/nil savings 456 d 68

Total No. of establishments 669 8 100 a This column expresses the isotope-assisted turnover of thoseestablishmentsreplying to the question on savings, as a proportion of the total isotope-assisted turnover (see Table XXXI, col. (5)), and therefore provides an indication of the response to the savings question. It should be remembered that isotope-assisted turnover is itself based on a 75% response b Limited to those giving BOTH sets of figures (cf. note (b) to Table XXXI) c Some establishments appear in two industries d See Table XLII for reasons for inability to estimate savings e This figure is high because isotope-assisted turnover mainly represents a small maintenance or research budget f Response for positive savings = 18%, for dissavings = 6% 8 Excluding the 19 bulk irradiation users mentioned in General Note 1 h Bulk of savings attributable to one firm ' See General Note 8 Technique Total Fields of saving Gauging Radiography Tracers lonization Massive irradiation Miscellaneous £000 (ft) (ft) (ft) (ft) (ft) (ft) (ft) _ _ Raw material 17 9a 15 50 380 a 14 Product scrap 20 21 b 3 12 - - 520 b 20 Labour 6 - 12 C 3 2 - - 224 c 8 Capital costs 27 d 4 - + - 353d 13 Maintenance 0 12e 7 - + - 173e 7 f - 8 - Plant productivity 29 39 - 851 f 32 H Research 1 0 70 28 - - 94 4 m ö Other 0 2 . 1 - + - 229 1 Not specified 0 1 1 0 - - 24 1

(ft) 100 100 100 100 + -

£000 1114 1341 68 124 1 - 2648

By technique (%) 42 51 2 5 0 - 100

Dissaving £000 12 122 15 3 10 10 172

Savings net of dissavings 313 353 69 166 (-14) (-200) 270 as % of total investment -

Including one estimate of £100 000 d Including one estimate of £300 000 Including one estimate of £200 000 e Including one estimate of £150 000 Including one estimate of £100 000 f Including one estimate of £100 000 and one of £350 000 + - Savings only a few hundred pounds 250 NATIONAL REPORTS

However, many of the firms who were for one reason or another unable to make any estimates of the savings indicated the existence of savings. Their replies are summarized in Table XLIII. Many firms indicated why they were unable to make estimates. The most frequent reasons are shown in Table XLIV. Besides, here is presented a selected list quoting from other answers from firms who felt unable to make adequate estimates of their savings:*

"100 tons now made which were not possible before radiation gauging." "Productivity increased nearly tenfold; selling price was however cut." "Perhaps as much as £ 50 000 had we done the wrong thing" (in terms of design of a new plant). "The major question of possible leakage from the surface seemed to be unanswerable except by radioisotope techniques and relieved us of a nagging worry which could not be turned into monetary terms. Had a leakage been established, the cost of flurring might have been £ 10000'.' "Not possible to calculate the eventual financial benefit from prevention of premature service failure in a series of locomotives." "Maintenance — e. g. in one case a £ 50 job prevented a production loss of £ 50 000 " (electricity generation). "Safety — prevention of boiler explosions" (by radiographie inspection). "We would expect considerable difficulty, high scrap and variability of product without this aid. " "Cannot estimate savings because we have never manufactured this product without this aid" (coated paper). "A more consistent product has probably enabled us to maintain sales during what have been very competitive conditions. " "The 10-mc sources are an essential part of the process and were built in at the design stage; as such there are no 'costs' and 'savings'." "Not possible to reduce human monitor costs" (level gauging of packaged phials). "The equipment was installed to gain experience of the technique of continuous, contactless measuring of hot strip, with a view to installing automatic gauge control ..." "The convenience of the method for insecticide analysis has resulted in a larger amount of this work being undertaken. In general terms output per man has doubled at a per capita cost of five times that invested using other techniques. " "Isotopes were installed on the commissioning of the works. . . ; in general therefore other means have not been employed" (steel strip mill). "Higher percentage of repairs to pressure welds necessary, which would not be revealed by hydraulic or air testing. But cost of radiographie testing is lower than cost of using other methods, as less work is required to support pipework than it is for hydraulic testing, where cleaning of pipework bore is necessary after testing" (this from a firm providing an inspection service). "Each gauge is checked for calibration three times in 24 hours to com- pensate for oil build-up. This type of gauge is an integral part of the machine and in the event of gauge breakdown the machine in shut down. UNITED KINGDOM 251

TABLE XLIII

NUMBER OF USERS INDICATING FIELDS IN WHICH A SAVING WAS MADE

Estabs. mentioning fields of saving3 All Fields in which a saving was achieved estabs. (mentioned singly or in combination) eft) No. (ft)

Research only 96 24 Plant productivity only 33 8 Raw material only 17 4 Labour only 17 4 Product scrap only 17 4 Less contracting out only 10 3 Maintenance only 8 2 Capital costs only 7 2 Plant productivity + product scrap 30 8 Plant productivity + raw material 8 2 Plant productivity + maintenance 8 2 Labour + product scrap 8 2 Plant productivity + labour 7 2 Research + plant productivity 6 2 Raw material + product scrap 5 1 Research + miscellaneous 4 1 Maintenance + capital costs 3 1 Plant productivity + raw material + product scrap 24 6 Plant productivity + labour + product scrap 13 3 Research + plant productivity + labour 5 1 Raw material + labour + product scrap 5 1 Plant productivity + raw material + labour + product scrap 9 2 Plant productivity + labour + maintenance + capital costs 5 1 Research + plant productivity + raw material + product scrap 3 1 348 87

Total number of replies indicating fields in which a saving was made 397 b 100 b 46

Number giving a money saving without indicating in which fields it arose 36 4

No savings at all indicated 428 50

All isotope users (representing 669 'establishments) c d 861 d 100

a In only a third of the cases where a field of saving was indicated were the savings expressed in monetary terms k In addition to the combinations specified above a further 49 establishments mentioned combinations .of fields of saving that occurred only once or twice and would make the table too lengthy; they have have therefore not been specified but are included in the total of 397 c Some establishments used several techniques and therefore gave separate answers for each Excludes the 19 bulk irradiation users mentioned in general note 1 TABLE XLIV REASONS FOR INABILITY TO ESTIMATE ANY SAVING FROM THE USE OF RADIOISOTOPES

Techniques

Massive All All Reasons for inability to make or to estimate any saving Gauging Radiography Tracers lonization Miscellaneous irradiation techniques estabs.

No. (ft) No. (ft) No. (ft) No. (ft) No. (ft) No. (ft) No. (ft) No.

Isotope equipment proved unsatisfactory, no longer in use 11 4 . - - - 1 0 1 2 - 13 1 Isotope equipment proved unsatisfactory but still in use 7 2 1 0 2 2 2 2 1 2 - - 13 1 Isotopes are more costly to use than other techniques 1 0 3 1 - - - 4 8 1 5 9 1 New developments in other techniques (e.g. X-rays) have made isotope equipment obsolete or less convenient to use 2 1 1 0 ,- 1 0 1 2 - 5 1 Isotopes merely supplement existing techniques, are a convenient tool for quality control 9 3 15 6 2 2 5 4 - - 31 4 Proved value of isotope technique is not measurable (e.g. better customer relations) 25 8 9 4 - - 2 2 1 2 1 6 38 4 Isotope technique is essential to meet customers' requirements for quality control etc. 8 3 32 13 1 1 1 0 - 3 16 45 5 No other way of doing the work (e.g. tracers) , essential to production (e. g. triggering of electron tubes) 5 1 5 2 7 6 6 5 3 7 6 31 31 4 Isotope technique still being developed , too early to evaluate 5 2 1 0 3 2 2 2 1 2 - - 12 1 Isotopes are only used for a minor part of the work 5 2 7 3 3 2 4 3 - - - 19 2 Isotopes are used for research only (so far): hence savings not meaningful or measurable or will accrue to whole industry 28 9 14 6 60 47 33 25 14 30 - 149 17 Cannot measure benefits arising from prevention of faults or defects or accidents; isotopes provide greater safety 3 1 13 5 3 2 5 11 1 2 - - 25 4 Gamma radiography is supplied as a service, part of business - - 16 7 ------17 2 Costing not possible because records not available or costs cannot be disentangled, or nature of product has changed 4 1 9 4 2 2 2 4 2 11 19 2 Other answers 7 2 2 1 2 2 2 2 - 1 5 14 2

Total replies a 120 39 128 52 83 66 66 58 29 61 14 74 440 51 Number replying 114 37 123 51 79 62 64 57 28 59 14 74 422 49

Don't know amount of extra costs 1 0 3 1 2 2 - - - 6 1 No answer or no reason given for inability to assess savings 98 32 71 29 25 20 28 23 11* 23 4 26 237 28 b Does not apply - gross savings have been estimated 96 31 46 19 20 16 26 20 8 18 - 196 22 Total No. of establishments 309 100 243 100 126 100 118 100 47 100 18 100 861 100 669 c

Includes those who only gave a figure for a dissaving b Corresponds to 26% of all establishments (as against schedules) c Some establishments use several techniques; this figure excludes the 19 bulk-irradiation users mentioned in General Note 1 UNITED KINGDOM 253

We are using eddy current types on other machines which are completely portable, and change-over time is a minimum". "Due to type of raw material, i. e. waste rags containing an undefinable and variable percentage of irregularities, no estimate of savings can be given" (thickness gauge in the paper industry). "Method works (ice detection in aircraft) but not approved for aircraft applications".

Conclusions

The report from the United Kingdom is a real mine of information and thus it was felt appropriate to reproduce such a vast amount of information as given in the economic Tables XXXI to XL/11. Many detailed conclusions will be found in the original national report and the contents will also be discussed in the later parts of the present publication where the economic benefits of the various techniques are outlined. Two important summary Tables are, however, reproduced here from the national report (Tables XLV andXLVI). That third of the establishments that gave details on savings reported a net annual result of £2.5 million. Already this figure is in excess of the total annual costs reported by 88% of the users and which amounted to £ 1.7 million. A comparison has been made of the figures on savings with those of costs for that third of repliers who gave savings' estimates. Although this is not reported in detail it was found that the ratio of savings to investment was in various industries (the number of replies given in brackets):

Annual savings to investment Cost-benefit ratio Paper industry (31) 2.27-1 1-10 Chemicals (35) 7.58-1 1-32 Cement, etc. (9) 9.43-1 1-40 Basic metals (35) 1.08-1 1-5 Engineering (33) 3.56-1 1-15

All industries (213) 2.70-1 1-12

The above cost-benefit ratio was also calculated on the assumption that the annual costs are low and five years' depreciation can be applied (the gauging case). If one applies the same methods to the various techniques of radioisotope use, one finds savings to investment and cost-benefit ratios to be:

For gauging 3.13-1 and 1-14, respectively, For radiography 3.53-1 and 1-15, respectively, For tracing 0.68-1 and 1-3, respectively, 254 NATIONAL REPORTS

TABLE XLV

ECONOMICS OF USING RADIOISOTOPES - SUMMARY BY INDUSTRY

Isotope- Total Total Annual Net assisted turnover a investment cost savings c Industry turnover £mn £mn £000 £000 £000 (1) (2) (3) (4) (5)

1 Food and drink 92 18.7 25 7 10 2 Tobacco 531 200 b 978 236 10 3 Textiles, clothing, footwear 53 6.8 52 13 98 4 Wood and paper 286 125.4 274 88 211 6 Rubber products 94 28.1 39 26 27 7 Chemicals and plastics 445 61.2 578 208 999 8 Glass and minerals 77 16.0 40 12 228 9 Petroleum and coal 391 8.0 87 79 30 10 Basic metals 848 187.5 455 208 213 lia Metal products 157 5.4 117 66 10 lib Engineering and electrical goods 660 18.7 671 d 450 568 lie Vehicles and shipbuilding 356 6.4 60 49 37 lid Miscellaneous manufactures 88 1.4 205 75 7 12a Construction 123 5.4 . 64 37 0 12b Gas, water, electricity 9 0.1 105 50 26 12c Transport 39 0 0 0 - 12d Technical services and research 12 0.6 335 d 103 2

Total for all industries 4350 690 b 4085 1707 2476

"Jo response: by No. of estabs. 89 75 90 92 32 by isotope-assisted turnover 24

a Projections from 1958 census of production b Estimate c i. e. savings net of dissavings d Incl. £570000 in total for neutron generating equipment and For ionization 1.69-1 and 1-8, respectively.

With regard to the total order of savings, the author of the UK report states: TABLE XLVI ECONOMICS OF USING RADIOISOTOPES - SUMMARY BY TECHNIQUE

Total for all Economic information Gauging Radiography Tracers lonization Massive irradiation- Miscellaneous techniques

Isotope-assisted turnover (£mn) Research 0.20 0.01 0.57 0.38 0. 03 . 0.02 1.2 Production control 588 a 57.8 20.7 18.7 00.4 3.5 689 a

a a G Total 588 57.8 21.3 19.1 0.4 3.5 690 2 H Total investment (£000) tn 0 Research 68 11 415 113 30 225 862 Production control 1813 753 56 69 136 396 3223

Total 1881 764 471 182 166 621 c 4085

Annual cost (£000) Research 48 10 204 95 34 37 428 Production control 469 422 33 32 54 269 1279

Total 517 432 237 127 88 306 1707

Total net savings (£000) b . 1102 1219 53 121 -9 -10 2476

Estimate i. e. savings net of dissavings d ,incl. £570000 for neutron generating equipment 256 NATIONAL REPORTS

"In the enquiry covering the year 1957/58 [1] a response rate of 12% of the users was achieved on the savings question; these 12% happened to account for 30% of the total turnover of all users. The amounts saved totalled £ 660 000, and from a more detailed analysis of the different industries' savings it was estimated that a full response to the question would have shown an overall savings, for existing users of radioisotope techniques, of at least £ 3^ million. The present survey shows an actual saving of some £ 2^ million, based on a response rate of 31% of all users. It was decided to assess their representativeness in terms, not of total turnover, but of isotope-assisted turnover — a more useful indication of the representativeness of the figures given. In these terms 24% estimated their savings, which means that some of the larger firms did not venture to make any assessment. Bearing in mind the difficulties involved it is probably no exaggera- tion to estimate an overall saving to industry of £11 to £ 14 million, at existing rates of use. This figure represents the gross savings probably achieved by users of isotope techniques in industry and has been calculated in terms of the 24% of isotope-assisted turnover for which a corresponding savings estimate exists, also taking account of the fact that one user in four did not give the amount of his isotope-assisted turnover. If the annual costs of servicing, maintaining, and writing off the equipment are deducted, one is left with net savings of £ 9 to £ 12 million. While it would be unrealistic to assume that isotope techniques could be usefully extended to all of the 85% or so of UK industrial production not employing them in 1961, there is clearly still scope for very considerable growth. "

REFERENCES

[1] PUTMAN, J. L and JOLLYMAN, N. W., AERE-Report - R2870, Harwell (1959). [2] STUART, D. F. O. and BIRCH, F., Survey on the Use of Radioisotopes in British Industry, Central Office of Information, London (1965). [3] STUART, D. F. O. and BIRCH, F., Atom. No. 94 (August 1964) 176. [4] Proc. Isotope Techniques Conf. 2, Oxford (1952). [5] SELIGMAN, H., Proc. UN Int. Conf. PUAE 14(1956) 13. [6] PUTMAN, J. L., Proc. UN Int. Conf. PUAE 15 (1956) 119. [7] PUTMAN, J. L. and JEFFERSON, S., Proc. UN Int. Conf. PUAE 15 (1956)147. [8] EASTWOOD, W. S. , Proc. UN Int. Conf. PUAE 15 (1956)177. [9] PUTMAN, J. L. , Proc. 2nd UN Int. Conf. PUAE 19 (1958)22. [10] JEFFERSON, S., Industrial Uses of Large Radiation Sources 2 IAEA, Vienna (1963) 231. [11] BAINES, B. D., Industrial Uses of Large Radiation Sources 2 IAEA, Vienna (1963) 243. [12] CRAWFORD, C. G. , Industrial Uses of Large Radiation Sources 2 IAEA, Vienna (1963) 265. UNITED STATES OF AMERICA

The United States of America is quite justifiably considered as one of the world's leading nations in the application of radioisotopes, and it is also clear that most of the development in the work on industrial applications originated there. Hence, it was quite natural that the first investigations into the economic impact of these methods were made in that country. Some of the earlier approaches are mentioned in the introduction to this publication. When the International Atomic Energy Agency invited its member states to take part in the International Survey on the Use of Radioisotopes in Industry, the United States replied that it would be impossible for them to contribute in the way suggested by the Agency, because the preparation and implementation of a survey of this kind in the United States would be an enormous task, and the results of a survey performed in 1958 were still useful. Accordingly, the report on this 1958 survey was submitted, together with more up-to-date material. An evaluation of the trend in radioisotope usage in comparison with 1958 is in progress; unfortunately, the results of this were not ready in time for inclusion in this publication. Because of this, the use of radioisotopes in the United States cannot be presented in the same way as in other national reports. Instead, the three sources available will be presented in chronological order, particular emphasis being placed on the most detailed report, the survey carried out by the National Industrial Conference Board on the situation in 1958. The net value of the total output of the industry covered by the Agency's survey was given in 1958 as US$136 000. In 1961 this figure had increased to US $158 000 million.

ACTIVITIES OF THE UNITED STATES ATOMIC ENERGY COMMISSION

Most of the early radioisotope work was performed in the laboratories of the Atomic Energy Commission or other government research organizations. Parallel to this many important industrial techniques were developed by private enterprises, some of which have now become the world's largest manufacturers of nuclear equipment. When an increasing number of techniques were taken over by industrial firms the Commission withdrew from this field, concentrating instead on sponsoring a few advanced projects, although until 1962 it remained the only body to license the use of radioisotopes. Thus, it kept a very close eye on these developments. At the first two United Nations International Conferences on the Peace- ful Uses of Atomic Energy the spokesmen of the United States presented very significant status reports on the industrial use of radioisotopes [1, 2, 3]. However, realizing that progress had been considerable in other parts of the world, it was decided that a much more comprehensive government-sponsored research programme should be implemented. This started in 1958 with a grant of US $4 million. Among its first projects was the 1958 survey, implemented by the National Industrial Conference Board.

257 258 NATIONAL REPORTS

The expanded research programme has brought about a considerable amount of research work into all aspects of the industrial applications of radioisotopes. A total of more than 200 research projects were sponsored during the period 1958-1963; furthermore, the programme has made important contributions to the documentation in this field [4]. The present status of this programme will be reviewed elsewhere.* Its results are also being presented in a periodical [5] .

EARLY STUDIES OF RADIOISOTOPE ECONOMICS

In 1953 the first estimate of the annual savings from the industrial use of radioisotopes was made by the USAEC. This was based upon discussion with some of the major industrial isotope users and, by extrapolation to all users, a figure of US $122 ± 58 million/yr in direct and indirect savings was obtained. In September 1956 a more thorough survey was carried out by the Commission through personal visits to about 40 large industrial firms and about 100 other institutions. The result indicated that the savings had increased to $391 ± 95 million/yr. This was brought up to date for the year 1957, giving a new total of $406 ± 94 million/yr. Much use was made of this figure, which was quoted frequently at various scientific meetings. The savings were attributed to about 20 techniques [6]. They are reproduced here in Table I. In this Table the corresponding figures of the NICE report are inserted. The purpose of the later survey was to check the reliability of the USAEC estimates by an independent body with experience in industrial investigation. The NICE reported in 1959 that for 1958 it could account for figures that were only one-tenth,of those given by the USAEC [7]. However, it must be remembered that the approaches differed considerably from each other: the NICE summarized only the direct savings reported by the individual companies, while the AEC tried to estimate also the indirect savings, and the savings to the national economy of the United States from better allocation of resources. This difference in approach was pointed out by the chairman of the USAEC in public discussion at a much later date [8] .

THE REPORT OF THE NATIONAL INDUSTRIAL CONFERENCE BOARD (NICE)

In its 1958 survey on the industrial applications of radioisotopes, the National Industrial Conference Board selected only four techniques:gauging; radiography; research; and manufacturing and processing. It divided the participating industries into 21 groups: chemicals; crude petroleum and natural gas; drugs; electric and gas companies; electrical machinery; electronic components and accessories; engineering and architectural services; fabricated metal products; food and kindred products; machinery (except electrical); metal mining; paper and allied products; petroleum refining and related industries; plastics and synthetic resins; primary metal

* E.E. Fowler, these Proceedings UNITED STATES OF AMERICA 259

TABLE I

ANNUAL SAVINGS ACCORDING TO THE USAEC 1957 AND THE NICE 1958

Annual savings in millions of dollars Item A 1C NICB Probably low Probably high

Cigarette density gauges 42.7 57.0 2.9 Metal thickness gauges 18.5 27.8 1.5 Rubber and tire fabric thickness gauges 8.0 20.3 2.8 Plastic and adhesive thickness gauges 2.0 6.1 1.4 Paper and allied products thickness gauges 23.1 24.9 2.8 Other thickness gauges 2.3 6.9 - | Gauges, such as liquid- level, moisture, 7.1 H-C ratio, snow, etc. 2.5 7.6-\ Radiographie testing 28.7 64.6 2.8 Oil-well logging 16.0 24.0- Oil-well stimulation 120.0 180.0 • 0.8 Pipeline oil flow 0.5 0.7 Petroleum refining 5.3 10.1 - 7.5 Other applied industrial tracing 12.5 25.0 1.8 Tool-wear studies 0.8 1.2' 12.0 18.0 Piston-ring and similar wear studies 7.5 • Corrosion studies 3.0 4.6 Other industrial research 12.0 18. 0> Luminescent sources 1.7 2.7 - Miscellaneous industrial applications 0.5 0.8 -

Total: 312.1 500.3 39 Average: 406.2

industries; rubber and miscellaneous products; stone, glass and china; textile mill products; tobacco manufacturers; transportation equipment; and miscellaneous. The last group included only one radiography user. The methods developed in this survey were of great value to the IAEA in the planning and implementing of its international undertaking. It should be pointed out that the response rate to the survey was overwhelming. On 1 March 1958, 945 companies were licensed to use radioisotopes. How- ever, 281 did not qualify for inclusion in the survey as they had stopped using radioisotopes, or had not yet begun, or were dealing in radioisotopes or radioisotope devices or were producers of such devices. All of the 664 260 NATIONAL REPORTS

remaining companies were asked to supply information about their investment in radioisotopes, equipment and supplies, and on the savings from their use during a 12-month period, 1957-58. Of these 523 companies supplied useful data, 65 of the companies supplying information which was not sufficiently detailed to permit reasonable estimates of the savings - in many cases the companies lacked sufficient experience to make comparisons on working conditions with or without the radioisotope aids. Only 56 companies either failed to submit information in time or refused to give any information. It should be stressed that the NICE questionnaires were much more detailed than the one designed by the Agency; e.g., suitable schemes were attached to assess savings. Each of the four techniques had its own questionnaire. The report listed the number of companies that supplied useful data, together with the number of "applications". An individual company could, of course, account for a large number of applications when applying different techniques, or the same technique (e.g., gauging) to different materials. The NICE report is comprehensive, and frequently cites the answers given by the firms. The applications are listed in Table II to correspond to those presented by the other participating countries. As the number of devices, sources, etc., was not included in the NICE report these have to be omitted. Of the four groups selected, gauging and radiography correspond very closely to the Agency's definition of these techniques. Research includes a good deal of tracer work but also certain gauging techniques, such as logging, ionization and massive irradiation studies (no radiation processing had started in 1958). Finally, the manufacturing and processing group contains, among other full-scale tracer studies, analytical routine applications, logging, leak detection and certain ionization and material testing methods.

Gauging

Table III shows how industries applied gauging, and the annual cost and annual saving realized in each group. In evaluating the results, cost-benefit ratios have been calculated wherever possible. Unfortunately, the NICE report provides no details of the number of gauges installed in the various industries. According to various statements, the number in 1957 should have been about 4000 [9], the majority of which, however, were used in cigarette manufacturing. Verbal statements have given much higher numbers for later dates; i.e. 8000 - 9000 gauges in 1964 [10]. One company in the food industry reported the use of thickness gauges for checking soda-cracker dough. Density gauging was applied to the production of baby foods, tomato paste and fish solubles. In the first case an installation of less than US $1000/yr saved the company US $6000/yr in labour and $30 000/yr in valuable material. The remaining companies added up to a total net savings of US $34 000/yr at a total cost of US $13 000/yr. The tobacco industry is surrounded by secrecy and the firms concerned supplied information only on the understanding that all details except the TABLE U

THE USE OF RADIOISOTOPES IN 1958

IAEA Number of applications broad Industry according Number of Gauging Radiography Research Manufacturing Total product to companies and group NICB processing _ 1. Food 14 ' 6 11 3 20 (a) 2. Tobacco (a) - 3 - (3) 0 3. Textiles 15 17 - - - 17 V) H 4. Paper and allied products 93 157 - 5 - 162 > H w 6. Rubber 26 49 - 3 - 52 en O 7. Chemicals 38 29 8 112 - 149 •n Drugs 20 - - 30 6 36 Plastics 30 48 - (b) - 48 8. Stone, clay, glass 20 27 - 14 1 42 9. Crude petroleum and neutral gas 20 5 2 11 45 63 Petroleum refining 32 21 8 79 27 135 10. Metal mining 4 6 - 2 - 8 Primary metals 85 40 102 19 - 161 Metal products 45 - 93 2 - 95 TABLE II (contM)

IAEA Number of applications broad Industry according Number of Gauging Radiography Research Manufacturing Total product to companies and group NICB processing

11. Machinery (except electrical) 26 .3 41 11 2 57 Electrical machinery 16 3 7 21 2 33 Electronic components 19 - - 38 6 44 Transportation equipment 30 6 44 43 6 99 Miscellaneous 1 - 1 - - 1 12. Electricity and gases 4 - 8 1 - 9 Engineering and architecture 59 1 78 72 1 152

Total 523(c> (418) 392 477 99 (1386)

(a) Confidential (b) included in chemicals (c) Several firms appear in two or more groups IAEA Industry according Number of applications Annual Annual net Cost- broad to cost saving benefit product NICB Thickness Density Level Other Total (*) (*) ratios group _ 1. Food 1 5 - 6 13000 34000 1- 3.6 2. Tobacco - (a) - - (a) not available 2955000 (a) 3. Textiles 13 4 - - 17 81000 420 000 1- 6.2 4. Paper 146 3 8 - 157 361 000 2826000 1- 8.8 CO 6. Rufober 47 2 - - 49 284000 2844000 1-11 S 7. Chemicals 3 17 9 - 29 64000 1 247 000 1-20.5 sä Plastics 28 9 6 5 48 119000 1385000 1-12.6 O 8. Stone, glass, clay 19 7 1 - 27 46000 551 000 1-13 TO 9. Grade petroleum - 5 - - 5 2000 41 000 1-21.5 m 5 12 47000 4122000 1-88 S Petroleum refining 4 - 21 n 10. Metal mining - 6 - - 6 11 000 252000 1-24 Primary metals 34 1 5 - 40 216000 1 449 000 1- 7.7 11. Machinery 1 2 - - 3 5600 10400 1- 2.8 Electrical machinery 2 1 - - 3 44000 171000 1- 4.9 Transportation equipment 4 1 - 1 6 13300 279000 1-22 12. Engineering - 1 - - 1 - - - Total: 303 (68) 41 6 (418) (1310000) 18600000 Total without tobacco 1310000 15600000 1-14 (a) Confidential 264 NATIONAL REPORTS total savings would be strictly confidential. It is known that in 1958 almost all cigarette manufacturing machines operating in the United States were equipped with density gauges. The net savings in raw material were valued at US $2 955 000. The textile industry reported the use of thickness and density gauges. The former were most frequently applied to coated fabrics, where raw materials to the value of US $363 000/yr in 13 applications were saved. Den- sity gauging was applied to various liquids used to prepare textile products; as an example the reply may be cited from a firm which applied density gauging to sulphuric acid: by applying density gauging an automatic reading, of its concentration is obtained, making the operation faster, less hazardous and more accurate. Savings were obtained in labour (analysts) and in the use of the acid itself. The savings in the textile industry from the use of gauging totalled US $420000 net, at a cost of US $81 000. In the paper industry the most widespread application was the measurement and control of the basic weight of paper. It was reported that, without exception, paper manufacturers found radioisotope gauges superior to techniques previously available, whether sampling-and-weighing, capacitance gauges or operator experience. Many companies reported savings in raw material, and in scrap as well as other benefits from increased yearly production. Savings in the labour force were not reported, except under particular circumstances, but better use could be made of the workers. One-third of the companies did not report any saving arising from their investment in radioisotope gauges to control the basic weight. They were, nevertheless, satisfied because of increased quality and better customer relations. Some companies actually advertised their use of radioisotope gauges to support their claims to quality products. A number of coating thickness gauges were also reported in the paper industry. They were highly esteemed by the users, primarily because they permit high savings in expensive raw material for coatings, and also reduce the amount of scrap. A company reported savings labour because it was able to save the wages of a paper tester on three shifts, which amounted to US $18 400/yr. In the same company savings also in scrap resulted from reducing the amount of off-specification products from 0. 9 to 0. 2% of the yearly production. The total net saving in the period of investigation was US $183 000 for this company alone. A few applications of level and density gauging were also reported. The savings were not high, except in a few cases of density gauging. Two companies applying gauging to clay slurries attributed savings of US $10000 and US $5000 respectively to the radioisotope methods because it was possible to run the system continuously instead of batch-wise. The application of a gauging device to black liquor saved another company stearn amounting to.US $11 000/yr, because of a 2% improvement in evaporator efficiency. In all, the paper industry benefited by US $864 000/yr from savings in raw material, US $1 million from scrap savings and US $907000 from increased productivity. The total net savings were given as US $2 826 000 for an annual cost of US $361 000. In the rubber industry, thickness gauging was also the main application. On the whole it was found that the savings in raw material were predominant, 265

averaging about ten times the annual cost of the gauges. Several firms also mentioned savings in scrap and labour. Including two applications of density gauging, the total cost for gauging in the rubber industry was US $284 000/yr. Savings amounted to $2 844 000/yr, of which US $2 477 000 came from savings in raw material, US $276 000 from savings in scrap and US $138 000 from savings in labour. In the chemical industry the application of density gauging was the most valuable, although in most cases the economic results from individual gauges were low. Savings were mainly in labour costs (direct recording took the place of analytical operations), increased productivity and improved process control. A saving of about US $1 million could be attributed to density gauging .in the chemical industry; however, most of this sum came from one firm where a gauge was installed to determine the density of the explosive charge in artillery shells. By using this gauge, it became possible to inspect the entire production instead of making elaborate tests on samples. The installation of the gauge cost US $533/yr, and the company claimed to save US $250000 in raw materials and US $576 000 in scrap during the period of investigation. Monetary savings from the use of level gauges in the chemical industry were fairly modest. Nine users accounted for US $17 000 in labour savings, US $10 000 in raw material savings, $13 000 in scrap savings, and $210 000 in increased productivity. The last high figure was due to one company operating a polyethylene production plant; 8 level gauges were employed in this plant. The chemical industry reported total costs of US $64 000/yr and total savings of US $1 247 000/yr. The fairly high cost-benefit ratio in this industry was, however, the result of only two unusually beneficial installations. Thickness gauging was the most valuable gauging in the plastics industry. Here 28 applications accounted for US $356000 in scrap savings, about US $200000 in raw material savings and over US $250000 in increased productivity. Labour savings were low. By using level gauging several companies were able to make important contributions to process economy and productivity because of fewer shut- downs. The use of density gauging led to important savings in raw material, and labour savings and a decrease in scrap were also attributed to the gauges. As a,whole, the plastics industry reported savings of US $1 385 000/yr for cost of US $119 000/yr. Of the savings, US $494000 were in raw material, US $659 000 in scrap and US $282 000 in increased productivity. Some of the most beneficial gauging applications were found in the stone industry. Here particularly the application to the production of abrasive paper can be cited. This process is rather difficult to control and early indications of inhomogeneities in the ready-made product may greatly decrease the scrap. One producer with five thickness gauges (representing a cost of US $8 800/yr, realized that he was increasing his monetary benefits by US $223 000/yr, mainly from the decreased amount of scrap. The savings from density gauging although lower, was still considerable. For the whole stone industry savings reached US $551 000/yr at a cost of US $46 000/yr. 266 NATIONAL REPORTS

In the crude petroleum industry a few gauging applications only were reported, because logging was classified either as research or as manufacturing and processing. In petroleum refining, however, unusually beneficial conditions for radioisotope gauging were reported. A few thickness gauging applications on refinery by-products can be passed over relatively quickly, but the density and level gauging applications are worth considerable attention. Hence, one petroleum refining company that applied density gauging to control catalyst circulation in two cracking units reported that the loss of catalyst after installation had been reduced by US $300000/yr in each unit. One producer of gasoline saved US $2 million in the 12-month period 1957-58, because radioisotope level gauges had made it possible to double the length of runs on thermal units before shutting down for the removal of coke. Another petroleum refining company estimated savings of about US $300000/yr from increased productivity and fewer shut-downs through the use of radioisotope level gauges on delayed coking units. Other refineries reported savings ranging from US $6000 to US $200 000/yr. The whole petroleum trade reported savings of US $4. 1 million at a cost of US $50 000/yr. Most of thé savings originated in increased productivity. A few mining companies reported considerably increased productivity after density gauges were installed to measure slurries. For a cost of $11 000/yr, there was increase of about US $200000 in product value. Further savings in material and labour costs were attributed to radioisotope gauges, total savings reaching US $252 000/yr. Similar applications were also reported in the production of primary metals, but here the most important applications were thickness gauges in rolling and plating mills where, in 34 applications, about US $700000 was saved in raw material only. Further considerable benefits came from decreased labour costs (sampling work became unnecessary) and from increased speed of production. In all, savings of US $1 449 000/yr were realized at cost of US $216 000/yr. A final word should be given on the few applications of gauging in the machinery industry. Thickness gauging was applied to insulating paper used in electrical products, to strip steel for batteries, and to coatings applied to aircraft radomes. The types of savings were similar to those reviewed above; 12 applications gave a net saving of about US $360 000/yr at a cost of US $63 000/yr. Table I shows the total savings from gauging to be about US $18 600 000 net/yr, of which about US $3 million came from the cigarette industry. As a whole, industrial radioisotope gauging is very favourable," the average cost-benefit ratio being 1:14. About US $9 million of the net savings could be attributed to thickness gauging, about US $5. 5 million to density gauging and about US $4 million to level gauging. Looking at the distribution of savings, the savings in raw material were most important and were estimated at rather more than US $8 million. In- creased productivity totalled US $6 million, and decreased scrap over $3 million. Labour savings were somewhat below US $1 million. UNITED STATES OF AMERICA 267

Ra diography

Although gauging was the most important application of radioisotope techniques in 1958, gamma radiography was also frequently used. Table IV summarizes the information available on this particular technique. Here, one deviation of the NICE approach from the Agency's scheme should be pointed out. The cost column covers only "annual investment in equipment and facilities", i.e., depreciation and interest on the invested capital together with replacement of sources. Normal maintenance and operation costs were deducted directly before the net savings were calculated. Accordingly, the cost-benefit ratios calculated for the applications do not correspond exactly to those obtained in the reports of other countries. Radiographie applications were found in 11 industrial categories that can be classified under five broad product groups. In 193 cases, radiographic testing was applied to welds, in 188 cases to castings and in 9 cases to forgings. In one case radiography was applied to the testing of solid rocket propellants and in another case the report did not provide clear information. The non-destructive testing of welds or welded equipment by gamma radiography was reported from the chemical, petroleum and metal industries, and from civil engineering and construction. The applications to welds and castings in the chemical and petroleum fields were rather limited, and represent costs of less than US $40000/yr. The other industries applied radiography much more extensively, each reporting costs of US $50000/yr or more. The engineering industry was the biggest user, as shown by its US $345000/yr in costs. It was followed closely by the fabricated metal products industry with US $272 000/yr and the primary metals industry with US $164 000/yr. The total mechanical industry reported $115 000/yr in costs. The cost-benefit ratios show that the monetary savings were mostly rather modest, the mean ratios of the industrial categories ranging between 1:1.5 and 1:1.6. Only two categories show better economy: thechemical industry (because of one user), and the transportation equipment industry. However, the estimates of the individual companies vary much more. For instance, in the primary metals group which shows a mean cost-benefit ratio of 1:5. 6, one malleable iron company saved US $90000 in capital cost because it used gamma sources instead of a million-volt X-ray unit, although other firms claimed only very low annual savings from converting X-ray testing to gamma-ray testing. It is quite clear that there are good reasons for these great variations because the techniques compared differ. Companies that tested castings, forging and welds destructively before they adopted radioisotope inspection made important savings in finished product scrap, up to US $100 000/yr for a big steel plant. In comparison with X-ray testing, performed by commercial testing firms, the application of its own gamma-ray testing service gave considerable savings to a firm. Compared with radium or high-energy X-ray machinery for testing very thick objects, Co60 was very favourable. On the other hand, many users with a complete testing organization of their own refused to attribute any decreased costs to the use of radioisotope sources, as they could select the most appropriate TABLE IV

SUMMARY OF RADIOGRAPHY APPLICATIONS

IAEA Industry according Number of applications Annual Annual net Cost- broad to Cost savings benefit product NICE Welds Castings Forgings Other Total (*) ratios group

7. Chemicals 5 2 - 1 8 10000 75000 1-8.5 9. Crude petroleum 2 - - - 2 22000 11300 1-1.5 Petroleum refining 6 2 - - 8 9000 17000 1-2.9 i 10. Primary metals 22 79 1 - 102 164000 757000 1-5.6

Metal products 63 30 - •r 93 272000 595000 1-3.2

11. Machinery 15 23 3 - 41 51000 248 000 1-6

Electrical machinery 1 4 2 - 7 7700 9800 1-2.3

Transportation equipment 24 17 3 - 44 56000 692000 1-1.3

Miscellaneous - - - 1 1 740 360 1-1.5

12. Electricity and gas 5 3 - - 8 4900 5000 1-2

Engineering 50 28 - - 78 345 000 401 000 1-2.2

Total: 193 188 9 2 392 940 000 2810000 1-4 UNITED STATES OF AMERICA 269 method in each case and they did not give an economic reason for their choice of gamma radiography. The highest proportional savings were reached in the production of transportation equipment: US $692000 in net savings was obtained in the period of investigation, of which US $503 000 came from decreased labour costs and US $177000 from decreased capital costs. Shipyards contributed most of these figures. One company building submarines reported no less than US $546 000/yr in savings in labour and capital cost from its testing schemes of about 40000 exposures. Finally, as a special case, the application of gamma radiography to solid rocket propellant in the chemical industry may be mentioned. The company in question applied 100% testing of the fuel to seek out voids that might affect the even burning of the propellant. Radioisotope inspection was chosen instead of X-rays because of the lower cost and the mobility of the equipment. The company claimed that this saved them over US $72 000/yr in capital costs. . Over the whole industrial field gamma-radiography testing gave net savings of US $2 180000 in the 12-month period studied. The corresponding costs were US $940 000. About half of the savings could be attributed to lowered capital costs and almost the same amount was saved through lowered labour costs. Only relatively small sums were quoted for savings in scrap or increased productivity.

Research

The use of radioisotopes in research shows the greatest variety of techniques and, accordingly, the highest number of applications. Table V gives a brief summary of the NICE report on research applications. Most of the research applications concern the use of radioactive tracers. The most frequently mentioned were wear studies (about 70 applications), metabolism and uptake studies (50), basic chemistry (40), sorption and surface effect studies (40), process control (40), and analytical applications including activation analysis (30). Other groups which were less frequently mentioned were leak detection, oil-field operation and metallography. In all, tracer techniques accounted for over 400 of the 477 applications recorded. Some of the non-tracer techniques were related to the development of equipment such as density or component-analysis gauges. More than 30such applications were recorded. Twenty research projects on the use of radioisotope sources for the production of light or heat were accounted for, together with about 15 studies of ionization phenomena in gases. The remaining group covered a few studies of radiation effects in materials. It is obvious that it is impossible to give any meaningful interpretation to average values of cost-benefit ratios within such a varying group. Never- theless, it is certain that many of the applications of radioisotopes in research were quite successful. The most common way of estimating savings in research was the direct savings in labour or other research costs through the use of radioisotopes as a research tool. In fact, the bulk of the $12. 5 million savings recorded could be attributed to savings in labour. These savings were, however, not TABLE V

SUMMARY OF RESEARCH APPLICATIONS

IAEA Industry according broad to Typical Number of Annual Annual net Cost product NICE application applications cost savings group (S) ($)

1. Food Metabolism and uptake studies 11 10000 186000 1-19.6 • 2. Tobacco - 3 50000 deficit - 4. Paper - 5 8000 deficit - 6. Rubber Diffusion 3 4000 deficit - 8 7. Chemicals Reaction mechanisms 112 221 000 2324000 1-11.5 Drugs Metabolism, analysis 30 125000 813000 1- 7.5 O Plastics Polymerization jo H (included in chemicals) 8. Stone, glass and clay Glass studies 14 205000 290 000 1- 2.5 9. Crude petroleum Recovery method research 11 45000 deficit - Petroleum refining Catalysis, wear, chemical 79 240 000 5050000 1-22 reactions 10. Metal mining Extraction 2 2000 13000 1- 7.5 Primary metals Distribution, wear, analysis 19 48000 32000 1- 1.7 Metal products Corrosion 2 5000 20000 1- 5 TABLE V (cont'd)

IAEA Industry according broad to Typical Number of Annual Annual net Cost product NICE application applications cost savings group (*) (*)

11. Machinery Wear 11 10000 530000 1-54 Electrical machinery Wear 21 73000 100000 1- 2.4 Electronic components lonization, semiconductors 38 56000 782000 1-15 O -n Transportation equipment Wear, corrosion 43 215000 750000 1-4.5 12. Electricity and gas Analysis 1 160 7 340 1-47 Engineering Wear 72 208 000 1740000 1- 9.3

Total: 477 1530000 12530000 1- 9.5 272 NATIONAL REPORTS

savings in the sense normally used by an accountant as reduction in the payroll rarely took place. Instead, companies,, by being able to perform research investigations in a fraction of the time previously required, had greatly expanded their research output with no increase in research staff. Since the time thus made available for other investigations has a very real economic value, most companies were more than willing to give radioiso- topés credit for producing savings. However, few were able to separate the value of the time saved into labour, capital, administrative and other costs. Instead, the value was measured in terms of the equivalent cost of the work then being performed by radioisotopes compared with the full cost by previous methods. One of the most valuable benefits of radioisotopes in research is the clearer understanding they give of chemical, biological or industrial processes. Many companies said that these were the most important benefits, but only a few were able to give any figures for the period under investigation, although some cases will be discussed in the section below on manufacturing and processing. The research performed will certainly produce results to form the basis for new industrial products. It is, of course, quite impossible to estimate the amount of the revenue to an individual company from these new products, but when firms invest in research with radioisotopes it is clear that the prospects of these revenues are more important than the direct savings in research time. The greatest savings in the period covered by the survey were obtained in petroleum refining. Among the applications included here the wear tests ranked first, one laboratory studying lubricants claiming that they reduced the test costs from US $315 to US $81. Considering the great number of tests performed each year this could account for savings of about US $50000. Another refinery indicated that each test required only six hours as against 500 h for the conventional method and estimated its saving at US $400000/yr. The petroleum industry also benefited from decreased research costs on catalysis, corrosion and the design of process equipment. Other industries also considered wear studies to be important, the engineering services and the transportation equipment industry ranking next to the petroleum industry. However, in the transportation equipment industry the largest single saving attributable to the use of radioisotopes originated from research into the cleaning efficiency of various solvents. A company working with liquid oxygen could show that at a cost of US $30 000 it could save US $600 000/yr using a cheaper but more efficient solvent for cleaning the liquid oxygen lines. The chemical and drug industry benefited mostly from laboratory tracer work, and from metabolism and uptake studies in plants and animals. Using labelled substances, results were obtained more quickly than before and also at much lower costs since the number of test animals could be reduced. As a final example of savings from the use of tracer techniques, a manufacturer of semi-conductors may be quoted. Using radioactive antimony isotopes, he could trace the diffusion of antimony in doped silicon and germanium. The increased accuracy of the method for determining diffusion was worth US $250000 in a 12-month period. Non-tracer research applications failed in most cases to prove any direct savings. As an exceptional case, the experience of a firm in the UNITED STATES OF AMERICA 273 nuclear energy field, which wanted to study the behaviour of solutions in radiation fields, may be quoted. Using a strong radioisotope source they carried out their research programme at a cost of US $30 000. Using a nuclear reactor, it would have cost more than US $150000 in irradiation charges and other experimental costs would have been higher too.

Manufacturing and processing

The applications of radioisotopes in manufacturing and processing were distinguished in the NICE report as a separate group. Ninety-nine applications of this type were accounted for in its survey, producing savings during the period of study of about US $5. 2 million. Table VI shows their distribution in the industrial categories. These savings were presented without any indication of the cost element, as in most cases little or no equipment was needed. Any costs in labour, re-design of plants, etc., were deducted from the gross savings and only net figures were given. Accordingly, it was not possible for the Agency to work out any cost-benefit ratios. Many of the individual applications described in the report have a very general interest, and the beneficial applications and the way the savings were accounted for will be reviewed in some detail. Two food manufacturers were routinely assaying the vitamin Bi2 content of their products by radioisotope dilution technique. The alternative method would be a microbiological technique, which as such did not cost more than the radioisotope method. However, the isotope dilution technique was mych more accurate, and one of the firms, a producer of animal food, claimed that it was now sufficient to make about 3000 Bi2 determinations/yr, although with the other technique about 30000 analyses/yr would be necessary. The resultant saving in labour and other analytical costs was estimated at US $561 000/yr. A second company performing a relatively lower number of analyses saved US $21 000 during the same period. Four pharmaceutical manufacturers also reported on the application of labelled vitamin Bi2 for routine isotope dilution assay. At the level in question it was claimed that the isotope dilution was much faster and less elaborate than any other method, and thus one manufacturer making about 1600 Bi2 determinations/yr attributed to the radioisotope technique labour and other savings amounting to US $64 000/yr. Another benefit of the radioisotope method was its speed. The manufacturing of Pharmaceuticals is normally done batch-wise and, with the slow bacteriological method of determining 612 production, had to be slowed down until satisfactory assay data were obtained. The lack of rapid assay methods also created storage problems. The more rapid radioisotope assay method meant that processing conditions could be adjusted more quickly and the storage of material reduced. Isotope dilution technique was also applied in the assay of vitamin-D on a routine basis with economic success. One producer estimated manufacturing savings at US $40 000/yr by making use of the isotope dilution technique. The chemical industry credited savings of US $800 000/yr to the use of radioisotopes in manufacturing and processing, mainly from one company 274 NATIONAL REPORTS

TABLE VI

SUMMARY OF MANUFACTURING AND PROCESSING APPLICATIONS

IAEA Industry according Typical Number of Annual net broad product to application applications savings group NICB (f)

1. Food Analysis 3 582000 7. Chemicals Tracing, ? 800000 analysis Drugs Analysis 6 190000 8. Stone, glass, Miscellaneous 1 34000 clay 9. Crude petroleum Logging, 45 810000 tracing of flooding operations Petroleum Trouble shooting, 27 2500000 refining mixing studies, pipeline operation

11. Machinery Metal testing 2 206000 Electrical lonization, 2 12000 machinery product control Electronic lonization, 6 38000 components leak testing Transportation Leak testing, 6 7000 equipment material testing 12. Engineering Construction 1 3000

Total: 99 5160000 who had applied tracer techniques to study the kinetics and mechanisms of ethylene oxidation. The information it obtained permitted changes in one plant that led to savings in production costs of US $600 000/yr. The company gained the advantage of greater purity for its products. In another instance a company was able to eliminate several manufacturing steps by using activation analysis to determine the purity of semiconductor material. The resultant saving in time and equipment was estimated at US $150 000/yr. Two interesting examples of the use of radioisotope methods to help in solving a complicated manufacturing problem were reported from the stone industry. One company, engaged in growing synthetic quartz crystals, used radioisotopes to observe the process molt and follow the growth of the crystals inside a high-pressure steel autoclave. An X-ray film was placed on one side of the autoclave and a radiation source on the other. The radiation produced an MX-ray" of the substance under observation. Since the NATIONAL REPORTS 275 crystal was denser than the surrounding melt, its shape could be distinguished in the same way as human organs when the body is X-rayed. Before inaugurating the radioisotope technique, trial and error was the only approach to regulating crystal growth. Now it is possible to know just when to "pick" a crystal. Bad runs were reduced by 25%, saving US $34375 during a 12-month period in 1957-58. In an entirely different application, a manufacturer of pre-stressed concrete pipe made use of radioisotopes in tapping into installed pipe. It is desirable not to release the'piece that is cut from the wall into the pipe since it may later obstruct the pipe. This will happen if drilling is allowed to continue past the point at which the cut-out first breaks loose. However, the drilling is done "blind" by a complicated rig, and visual observation is impossible. To solve this problem a small cobalt-60 source was fixed to the piece to be cut out before drilling began. When the hole was drilling through the cut-out piece with the source fixed to it, the source began to spin in the drilling rig. This motion could be detected by a counter outside the rig, indicating to the operator that he should stop sawing. The company, however, could not estimate the value of this radioisotope application as the disadvantage of allowing the cut-out to remain inside the pipe could not be estimated. Nevertheless the company felt that its ingenuity had raised its prestige and could bring new orders for this type of work. The biggest manufacturing savings occurred in the petroleum industry. In the drilling for and recovery of crude petroleum and natural gas, there were 45 applications of this type. Nearly all the savings came from work in connection with oil-well stimulation. Although radioisotope logging is gaining popular acceptance, most companies did n'ot see any commercial advantage in its use. In fact, only one company stated that it had been able to use radioisotopes to determine the presence of oil-bearing strata where other methods had failed. It was, however, impossible for them to estimate the value of this discovery until production had started, and in any case it would be difficult to assess the contribution from radioisotopes, since so many factors need consideration, such as the cost of drilling, pumping, transporting, refining and marketing the oil. On the other hand, the use of tracers in oil fields was considered to have positive economic value. One large producer reported that he applied radioisotope tracer technique to label the water used in flooding an oil field to increase its productivity. The routes and flow rates of this water could be detected by studying in great detail the radioactivity of the water together with the oil in the producing wells. From this information the operation could be modified to permit increased recovery of the crude oil in the field. A 20% increase in total production could be obtained with the efficient use of tracers, but the amount of the savings could not be estimated in any simple way. Another company, however, attributed savings of US $500000/yr to information obtained by the use of tracers in secondary recovery of petroleum, and from a gas field corresponding savings of US $230000/yr were reported. When wells failed to operate properly radioactive tracers were frequently used to investigate the malfunctioning. Some 15 variations of this technique were reported, e.g., to determine where water enters the bore- 276 NATIONAL REPORTS holes. Two companies reported savings of US $30000/yr and US $50000/yr, respectively. Three companies reported on the use of radioisotopes to detect the interfaces of various shipments of petroleum products being transported through the same pipeline. As a result a total of US $41 000/yr was saved in lower analysis costs and less mixing of various qualities, which in turn led to increased productivity of the transportation plant. This application was also frequently used in petroleum refining; one user did not consider that any monetary savings came from this but indicated that it made the dispatcher's job simpler, but another use gave it a credit of US$200 000/yr, because the information obtained on when the interface arrived at the receiving station could be used to prevent unnecessary mixing of unwanted oil qualities, lowering the quality and the price of the stock. Leak detection on pipe-lines was also reported from several companies. Using this technique, the laborious and expensive practice of digging up underground pipelines for visual inspection was practically eliminated. One company estimated that it saved US $25 000/yr in labour costs, another reported savings of US $20 000/yr. Another use of radioisotopes in pipeline operations was in the location of obstructions. A radioisotope source was sent through the pipeline in a carrier that would stick at the point of the obstruction, the progress of the source being traced with a radiation detector. Formerly the location of obstructions required either the dismantling of equipment or the excavation of piping. One refining company attached a source of radiation to the scraperheads in its chiller pipe scraping units. It was thus able to rapidly locate and remove any heads that had broken. The company reported a saving of US $10 000/yr through reduction of down time on the unit. Another company used radioisotopes to locate a scraper stuck in a 9000-ft-long underground pipeline. It estimated that it saved US $2500, the cost of excavating the line. The very considerable savings in petroleum refining, however, derive their origin from improvements in refinery operations. In most cases tracers were applied to find the causes of malfunctioning equipment or to improve the efficiency of refinery units. One refiner reported four such studies. Three were undertaken to solve foaming problems in a phenol plant, an extraction unit and a coking unit. The fourth study helped to determine the cause of the malfunctioning of a fractionating tower. Savings through the elimination of costs involved in shut-downs and tear-downs for these projects ranged from US $14000 to US $600000, with an aggregate saving of over US $1 million. The company reported that unit production capacity was increased by 1% to 30% as a result of the corrections made. Similarly, another petroleum refining company used radioisotopes to test for leaks in heat exchangers, and reported a saving on this project of about US$75000. In still another instance, a refiner, using radioisotopes to study ways of improving the efficiency of fluid coking units, estimated savings at more than US $40 000. This study also resulted in a 2% improvement in production efficiency of the units. A third refinery reported that it was able to improve the out-put of a crude oil distillation process through the information from a radioisotope tracer study. As a result, the company had been able to increase the value UNITED STATES OF AMERICA 277 of products obtained from the 300 000 barrels of crude oil processed daily. The net value of this work for a 12-month period in 1957-58 was US $500000. A fourth company used radioisotopes to determine how to minimize loss of catalyst in its catalytic cracking units. The resultant decrease in loss of catalyst was saving the company US $240000/yr. Several companies in the petroleum refining industry believed that radioisotope studies devoted to improving refinery operations might produce benefits in the future. One refinery using radioisotopes to find a way to treat catalyst beads in order to prolong their life reported: "We have discovered a method that will markedly cut down wear. This should have considerable economic benefits when put into operation". Similarly., an organization using radioisotopes in fluid catalyst mixing studies (saving US$172000 in research costs) stated: "Additional benefits may come about in the future. The information derived from this work may be used in building new process units or in revisions of existing units". .In the machinery field a number of manufacturing savings from the better understanding of processes obtained by tracer experiments were reported. One firm studying the wear of cylinder sleeves had found that it could reduce the hardness of the metal used and thus cut its cost without increasing the actual wear. The benefits brought about by this change were evaluated at US $180000/yr. Another manufacturer of a similar product could change the material, which gave him a saving of US $26 000/yr. A manufacturer of electric blanket wire used radioisotopes to label splices in the wire. When blankets are wired these splices must be removed. The use of radioisotopes permitted rapid location of the splices and reduced labour costs by US $12 000/yr. Six electronic component and accessory companies used radioisotopes to improve their manufacturing processes. Although the savings were slight, the non-monetary advantages of these applications were considered important. A company making telephone repeaters used in submarine cables found that radioisotopes were very useful in testing equipment for leaks. A radioisotope in gaseous form was injected into the equipment before it was sealed. After sealing was complete, inspectors checked the entire surface for tell-tale radiation that would appear if a leak were present. Since a radioisotope whose radiation dissipates within a short time was used, the safety hazards were minimal. The company considered the test vital: "Any leak in this system after the equipment has been placed in operation would require repair work estimated at US $500 000 per defective unit. To date no defects have been reported". Several manufacturers of gas-discharge tubes were incorporating radioisotopes into their tubes to provide a source of ions for more reliable initi- ation of the discharge. The radioisotopes used included gaseous forms that were incorporated into the tube and solid forms that were plated on to steel wires in the tube. Previously, one manufacturer had used radium bromide, a chemical compound of the natural radioisotope, radium. However, the radium was more expensive and more hazardous than the radioisotopes that replaced it. Also, gaseous radioisotopes could be injected along with the normal filling gas through the automatic devices normally employed for that purpose, whereas the radium bromide had to be put in place manually. 278 NATIONAL REPORTS

No cash value could be assigned to this production use of radioisotopes, but one firm stated that it saved over US $12 000 in a 12-month period by using this technique in production research. Another company indicated that "no direct savings have been realized, but the use of radioisotopes has enhanced the characteristics and extended the operation of our devices". One firm found the phosphor-exciting properties of radioisotopes useful in the production of electronic tubes. In this application, the efficiency of phosphor screens for special cathode-ray tubes was tested with radioisotopes before the screens were inserted in the tubes. Previously, this component could not be tested until the entire tube was assembled and the electrons or X-rays in the tube excited the phosphor. The company estimated that the ability to test the screens prior to assembly saved US $1500 - US $3000 a month. A few manufacturing applications of various isotope techniques were reported in the transportation equipment industry. In one semi-production use a radioisotope was used to check the wall thickness round an oil hole that fed a main bearing of an engine. Several hundred engines so examined showed below-standard wall thickness. It was demonstrated that the thin walls were caused by a shift in the part being driljed rather than to a lack of precision in the drilling machine. In another company, ions produced by the radiation from a radioisotope source were carried by an air blast over critical plastic parts to ensure that dust and lint would not cling to them. An aircraft manufacturer used radioisotopes to tag bucking bars used in the manufacture of its planes. If such tools were inadvertently sealed inside a structural member during fabrication, they could be located quickly with a radiation detector. Failure to find them could cause a serious accident when the aircraft was flown. Another aircraft manufacturer regularly used a tracer on its production lines to ensure that a hermetically sealed component was truly leak-tight. The company estimated that it saved US $7000/yr from this use because it eliminated the handling and re-work time previously required. Still another aircraft manufacturer used radioisotopes intermittently in a manufacturing operation. A radioisotope was added to a penetrating oil, which is then used to determine the degree of fit of a flush rivet in wing panels. In a few cases radioisotopes were regularly incorporated into products. For example, one aircraft manufacturer used radioactive tritium combined with a phosphor to provide a light source that was much safer than the radium source it replaced.

Summary of the NIC B report The economic content of the NICE report has been summarized in Table VII. Table VIII (taken directly from the report) contains the same material as the previous Tables but presents it according to industry. It should be made clear that the survey performed by the National In- dustrial Conference Beard did not try to evaluate the factual savings in the 12-month period of investigation but to summarize industry's own attitude to the savings. There is little doubt that the savings to the US industrial economy must have been greater than the US $39 million that could be pin- UNITED STATES OF AMERICA 279

TABLE VII

ECONOMIC SUMMARY OF THE NIC B SURVEY

Annual cost Annual net savings Item («million) ({million)

Gauging (1.31) 18.59 Radiography 0.94 2.81 Research 1.53 12.53 Manufacturing and processing - 5.16

Total: (3.79) 39.09 pointed. In many cases quoted above and many more which are contained in the full text of the report, the companies were not ready to provide the interviewers with figures, although it was evident that great economic advantages were gained. The cost-benefit ratios obtained for gauging are, although varying greatly, fairly reliable and demonstrate the very good amortization conditions that can be obtained by these devices. The same reliability can be expected for gamma radiography. This was a well-established technique and the cost-benefit ratios did not vary greatly; in general it was found that the investment paid off in one year or so. This agrees well with the general feeling of people working on non-destructive testing, so no doubts need be thrown on the figures. The two remaining groups (research, and manufacturing and processing) are more complicated. It was obvious that in these applications even firms that were using almost identical methods judged their economic importance quite differently. In a few cases the development might have proved that the figures quoted were somewhat over-optimistic, but in general the firms who replied probably tried to make conservative estimates. Many of the persons engaged in these fields felt that the savings in research and in manufacturing could easily have been multiplied by a factor of two or more without falling outside the criterion of reasonableness used by the NICE to examine the companies' replies. It was impossible to describe in detail the technical aspects of the applications contained in the NICE report. The full comprehensive text can be consulted [7]. Additional information on how the industry of the United States of America uses radioisotope techniques may be found in a similar publication [10] .

RECENT STUDIES

The NICE Survey must be considered as an isolated effort, but the US Atomic Energy Commission wants to follow the development of the industrial applications of radioisotopes. For this purpose several trend studies have TABLE VE!

ESTIMATED ANNUAL RADIOISOTOPE SAVINGS1 (during a 12-month period in 1957-58)

Number of Gross annual investment in equipment and facilities4 Net saving5 2 companies supplying For For Industry useful data3 Use each use Total each use Total («) («) («) («)

Chemicals 38 294336 4449955 Gauging 64227 1 247 117 Radiography 9828 75169 Research 220281 2324469 Mfg. and processing 803200 Crude petroleum and natural gas 20 70248 820350 Gauging 2186 41262 Radiography 22444 11306 TJ O Research 45618 (42218)? 70 H Mfg. and processing 810000 en Drugs 20 125 883 1006117 Research 125883 813367 Mfg. and processing 192750 Electric and gas companies 4 5076 12351 Radiography 4916 5011 Research 160 7340 Electrical machinery 16 124804 294036 Gauging 44250 171495 Radiography 7727 9823 Research 72827 100718 Mfg. and processing 12000 TABLE VlII(cont'd)

Number of Gross annual investment in equipment and facilities4 Net saving5 2 companies supplying For For Industry 3 useful data Use each use Total each use Total (*) ($) («) («) Electronic components and accessories 19 55845 819605 Research 55845 781655 Mfg. and processing 37950 Engineering and architectural services 59 553519 2 147 362 Radiography 345336 401 455 Research 208183 1743267 Mfg. and processing 2640 Fabricated metal products 45 276 956 615467 Radiography 272036 595387 Research 4920 20080 O m Food and kindred products 14 31949 803220 Gauging 13354 34335 Research 18595 186405 Mfg. and processing 582480 Machinery (except electrical) 26 65283 994 938 Gauging 5624 10370 Radiography 50473 247 674 Research 9186 530 894 Mfg. and processing 206000 Metal mining 4 13368 265451 Gauging 11368 252451 Research 2000 13000 Miscellaneous 1 740 360 Radiography 740 360 TABLE Vm (conf d)

Number of Gross annual investment in equipment and facilities4 Net saving5 companies supplying For For Industry2 useful data3 Use each use Total each use Total («) (*) («) («)

Paper and allied products 93 369056 2818319 Gauging 361 056 2826319 Research 8000 (8 000)a Petroleum refining and related industries 32 295 360 11 671 158 Gauging 46978 4122398 Radiography 8960 16557 Research 239422 5052103 Mfg. and processing 2480100 i Plastics and synthetic resins 30 119 264 1385022 s Gauging 119264 1385022 "O

Primary metal industries 85 427 799 2238617 Hg Gauging 216182 1448799 GO Radiography 164047 757388 Research 47570 32430 Rubber and miscellaneous products 26 288 327 2841064 Gauging 284527 2844864 Research 3800 (3 800)a Stone, clay and glass 20 206 830 874742 Gauging 46 5006) 551 097 Research 205330 289270 Mfg. and processing 34375 Textile mill products 15 81349 419927 Gauging 81349 419927 TABLE VIII ( confd)

Number of Gross annual investment in equipment and facilities4 Net saving5 companies supplying For For Industry2 useful data3 Use each use Total each use Total (*) («) ($) («) Tobacco manufacturers b 49 500b 2905822 Gauging b 2955322e Research 49500 (49500)3 Transportation equipment 30 285324 1720533 Gauging 13330 279315 Radiography 56164 692338 Research 215830 750880 CO Mfg. and processing 7000 g Total: 3740816 39113416 a O TJ Based on estimates supplied to NICE by radioisotope users and only examined for reasonableness Standard Industrial Classification m Some companies reported for divisions or subsidiaries operating in more than one industry and are therefore listed'more than once. However, regardless of the number of licences held by a company for work in various divisions or plants, if the company operates in only one industry, it is listed only once in the 8 tabulation. Out of 664 companies eligible for inclusion in the census, 523 supplied data that could be used in this Table, including 83 of the country's 100 largest industrial firms. Sixty-five others supplied partial data, but were not included in the tabulation Cost of structures and equipment are amortized in accordance with reporting companies' practices. When amortization period was not stated, 20 years* straight-line amortization was used for structures and 5 years for equipment Difference between net annual investment and gross savings. Net annual investment is difference in cost of radioisotope equipment and equipment it replaced or would have replaced. Individual net annual investments are sometimes negative amounts, reflecting lower costs of radioisotope equipment Figure taken from p. 112 of the report Net deficit. Costs exceeded savings that could be measured during the census year Confidential Because proprietary information is involved in data collected from tobacco companies, annual costs of equipment and facilities for gauging cannot be listed, but they have been taken into account in figures for net savings do CO 284 NATIONAL REPORTS been performed; the first part of one such study (made by Arthur D. Little Inc. ) was submitted to the IAEA as a part contribution to its international survey. The interesting section of this report is an extrapolation of the savings in the period 1958 - 63. All the methods involved a multiplication of the NICE values of savings by a ratio in each of the four techniques. The results are shown in Table IX. In the first four methods the same ratio was used

TABLE IX

RESULTS OF FIVE EXTRAPOLATION METHODS {$ millions)

Method Method Method Method Method Method Use category 1 2 3 4 5a 5b

Gauging 35.2 48.5 50.4 47.2 45.4 45.4 Radiography 5.3 7.3 7.6 7.1 4.0 4.0 Research and development 23.6 32.6 33.9 31.8 20.3 31.9 Manufacturing and processing 9.8 13.6 14.1 13.2 6.7 6.7

Total: 73.9 102.0 106.0 99.3 76.4 88.0

TABLE X

EXTRAPOLATION OF 1958 NICE SAVINGS ($ millions)

1963 extrapolated values Use category NICB savings Low High

Gauging 18.6 35.2 50.4 Radiography 2.8 4.0 7.6 Research and development 12.5 20.3 33.9 Manufacturing and processing 5.2 6.7 14.1

Total: 39.1 66.2 106.0

for each of the four use categories, while in the fifth method separate ratios were developed for each of the use categories. In the five extrapolation methods, the NICB estimate of savings was: (1) Multiplied by the ratio (1963:1958) of the numbers of total industrial by-product licences. UNITED STATES OF AMERICA 285

(2) Multiplied by the ratio (1963:1958) of the total number of curies distributed by Oak Ridge National Laboratory. (3) Multiplied by the ratio (1963:1958) of the number of curies of isotopes distributed to US commercial firms. (4) Multiplied by the ratio (1963:1958) of the values of sales of radiation detection and monitoring devices. (5a) For gauging, multiplied by the ratio of sales of control and measuring devices; for radiography, multiplied by the ratio of radiography licences; for research, multiplied by the ratio of US research and development funds spent by private commercial industrial firms; for manufacturing and processing, multiplied by the ratio of the manufacturing and processing component of the gross national product. (5b) Multiplied by the same ratios as in (5a), except in the research sector, where the ratio of sales of radiation detection and monitoring devices is used. In Table X the final results of estimated ranges of savings are presented, selecting the lowest and the highest estimated saving in each of the four use categories.

REFERENCES

[1] AEBERSOLD, P.C., Proc. UN Int. Conf. PUAÉ 14 (1955) 3. [2] CROMPTON, C.E.. Proc. UN Int. Conf. PUAE 15 (1955) 124. [3] AEBERSOLD, P.C. and FOWLER, E.E., Proc. 2nd UN Int. Conf. PUAEJJ (1958) 76. [4] Radioisotopes in World Industry - Abstracts of Selected Foreign Literature, ISAEC Report TID-6613 (+Suppl. I-IV) (1961-64). [5] Isotop. Radi.Technol._1 (1964). [6] Studies in Business Policy No. 87, NICE, New York (1958). [7] McMAHON, J.J. and BERMAN, A., Radioisotopes in Industry, USAEC Report NYO-2977 (1959). [8] Int. Atomic Energy Agency Bull. 6 (1964) 15. [9] HAFNER, J.W., Literature Survey on World Isotope and Radiation Technology, USAEC Report nTRI-1194-13 (1963) 15. [10] Radioisotop. Rep. 1 (1964) 128. [11] Cutting Industrial Posts with Isotopes, Atomic Energy Law Rep. No.256 (1960) New York.

VENEZUELA

As central statistics on radioisotope use in Venezuela are not available, it was impossible to ensure that all users received the questionnaire.Instead, 37 major industrial firms were approached by the Institute Vénézolane de Investigaciones Cientificas (I. V. I. C. ), the national body for the survey in Venezuela. However, only a few firms responded to the approach. Twelve replies were received, nine of which stated that no use was made of radioisotopes. Of the three users two were in the petroleum industry and one in the tobacco industry. The number of companies in these broad product groups are six and four respectively. The tobacco firm used a density gauge, but only for occasional control of firmness in cigarettes. Total investment for the equipment was $6000. One petroleum refinery reported the use of gamma radiography for welding control when process units were being repaired. The other also used gamma radiography, also for welding control, through the services of an independent company (Industria X-ray de Venezuela). The same company also used radioactive-labelled go-devils for locating obstructions in pipelines. This company has submitted a case history reproduced below.

THE USE OF RADIOISOTOPES IN THE PETROLEUM INDUSTRY

Radiosotopes are used by the Venezuelan Oil Corporation for the following purposes: (1) X-ray inspection of welds; (2) Detection of internal scrapers (go-devils). A description of these operations is given below.

1. X-ray inspection of welds

For this operation use is made of the services of a company (Industria X-ray de Venezuela) specializing in weld radiography. The radioisotope used is probably cobalt. Inspection of welds using X-rays is sometimes carried out in the construction of gas pipelines. During the current year this operation has been carried out three times, covering a total period of 10 d, in connection with laying the Anaco-Caracas pipeline; during 1962 it was used for 45 d (the time taken by the welding operations in the construction of the 120 km-long Casigue-La Fria gas pipeline. It is necessary for inspectors to be near the team developing the films to check that the welds are sound and to ensure that the plates are properly positioned in the welded sections between pipes. Since 1958, various inspectors have been engaged on this work, and the contracting company has also employed various operators.

2. Detection of internal scrapers (go-devils)

For internal cleaning of the pipelines a go-devil is used, consisting of two circular metal plates connected by a tubular spindle. Round the edges of these plates are rings of neoprene or some similar material. A radioisotope of cobalt is placed in a steel nipple welded to one of the plates. The

287 288 NATIONAL REPORTS nipple is suitably "bushed" at the other end so that the capsule is entirely enclosed. The pipe-clearing operation is performed when welding on the line has been finished. The go-devils are generally obstructed through faulty construction of the pipelines, or by objects such as clay, sand, sardine-tins, sticks, branches of trees and rags. If a considerable length of the pipeline is buried, it is difficult to locate the go-devil, and the radioisotope can be used for detecting its position. This operation is carried out by the Venezuelan Oil Corporation, advised by technicians of the Venezuelan Institute of Scientific Research. Efforts are always made to apply the rules recommended by the radioactivity technicians but sometimes, owing to unpredictable circumstances connected with the rough character of these operations, it may happen that employees of our Institute absorb radioactivity. During construction of the Casigua-La Frfa gas pipeline the calibration of the detectors became affected through discharge of the batteries and faulty handling by workers who were employed on sectors of the line that crossed rivers and ravines in the bush. The go-devil was obstructed three times. After localization a hole had to be dug to uncover the section of pipe concerned. The dimensions of the hole were 2m X 2m X 1m and six men were used, working in turn. Digging took six hours. The welder then cut the pipe and two workmen extracted the go-devil. The technicians of the Venezuelan Institute of Scientific Research removed the capsule and placed it in its lead box. SomCv of the personnel employed visual measurements to determine the radioactivity absorbed. Subsequently, a thorough medical examination was carried out to determine the state of health of these workers, and it was recommended that three workmen and one employee should be subjected to no further radioactivity for at least one year. The work is still under the technical direction of the expert staff of the Venezuelan Institute of Scientific Research. It has been decided that, in future, operations of this kind willbecarried out by the companies contracting for the pipeline so that greater care will be taken in their construction. It has also been recommended that a source of lower radioactivity than the cobalt source should be used, or that some similar method, in which less radiation is used, should be employed. The cobalt sources used were successively of 10, 200 and 1000 c. YUGOSLAVIA

The survey in Yugoslavia was carried out by the Yugoslav Federal Nu- clear Energy Commission; Mr. L. Barbaric was responsible for the report. The survey covers the conditions valid in 1962 but statistics were provided also for 1963. The rapid development that is taking place is shown by the statistics for the total number of users: at the end of 1960 there were 26 industrial enterprises using radioisotopes; at the end of 1962 this figure had increased to 60 and at the end of 1963 to 89. The method used in the survey was to collect all available information concerning the use of radioisotopes and to make more detailed technical- economic studies of some typical applications and interesting individual uses. A questionnaire similar to the one suggested by the Agency was used and information was obtained from 47 enterprises. The response rate was thus high enough to provide a representative survey. The Yugoslav industrial output reached in 1961 the value of Din 1.55X10^ i.e. US$2100 million, accounting for 50% of the gross national product.

ACTIVITIES OF THE NATIONAL ATOMIC ENERGY AUTHORITIES

The Federal Nuclear Energy Commission, founded in 1956, has carried out systematic measures to develop production and application of radioisotopes. In the five-year period 1957-62 approximately Din 2000 million were spent on this development programme. For the time being, almost all radioactive material that Yugoslavia needs can be produced in the reactors and accelerators of the Boris Kidriö Institute and other research institutes operating under the Commission's scheme. A school for the application of radioisotopes has been established where, up to 1962, more than 500 attendants had been trained. The development, within the Commission's activities, of equipment for the measurement of nuclear radiation and gamma radiography cameras has been of direct industrial impact. This production has been transferred to industrial enterprises that continue its development and market new products also. At present the activities of the Commission are limited to isotope production and synthesis of labelled compounds, solution of general and specific problems, and performance of tracer investigations that the individual user would not be equipped to perform. Research on new principles of application is also carried out.

CONTENTS OF THE REPORT

In Table I are shown the number of enterprises which made use of the various techniques at the end of 1963. Interesting details on the development are revealed by the figures in Table II of the number of users at various dates .

289 Broad Total Gauging Radiography lonization Tracing M.I.* Misc. No. of No. of No. of No. of No. of No. of No. of No. of users No. of No. of product group users users gauges users sources users devices Res. Prod. users users

1. Food 3 1 5 1 2 2. Tobacco 3. Textiles 3 1 ' 1 2 2 4. Wood, paper 10 6 8 3 3 1 5. Leather, fur 6. Rubber 4 2 2 2 2 7. Chemicals, 10 5 10 2 2 3 3 1 plastics H 8. Cement etc. V) 9. Petroleum 4 1 2 1 1 . 1 1 and coal 10 Basic metals 12 5 11 3 3 2 2 11. Machinery 35 1 2 31 93 1 1 ' 3 3 12. Services 2 5 25 Not identified 6 2 2 1 1 3 3 Total 89 22 41 42 124 11 11 13 15 1

* Massive irradiation. Remarks: Enterprises only making use of services of others, e.g. in gamma radiography, are not accounted for in this.Table. YUGOSLAVIA 291

TABLE II

NUMBER OF ISOTOPE USERS IN YUGOSLAVIA

Technique End of 1960 End of 1962 End of 1963

Gauging 3 10 22 Radiography 22 33 42 Tracing 1 28 }l7 Others - 12 ^

Total 26 60 89 (104 applications)

Gauging

The distribution of gauges is shown in Table III. Gauging is applied to a wide number of industrial processes. Those installations in use before 1961 employed imported equipment; more recent installations are mainly of domestic construction. Thickness gauging was applied to the production of cellophane foils, PVC foils, paper and laminated paper. In the first case it was claimed that a reduction of 3-4% in scrap was obtained from better product control; moreover, 10-15% more of the production could be classified as Class I cellophane instead of Class II cellophane. Apart from this, it is stated that the development of the packaging industry would not have been possible without these gauges, as other control methods would not have permitted the same precision. The reason for this is that modern packaging machines require a homogeneous material that could not have been produced without the use of nuclear gauges. Thickness gauging was also applied to various metals such as aluminium and copper, and alloys such as steel and bronze. Further details were, however, not revealed. Density gauging is reported from the food industry (sugar refining), the paper industry (pulping), the rubber industry (latex solutions), and the chemical industry (sodium hydroxide). Important uses of level gauging are reported from various industries. In the food industry it is applied to the level of water in steam boilers in plants processing vegetable oils. In the manufacture of wood products, such as fibre-boards, level gauging is, applied to the containers in which pre- heating of wood chips takes place. For this application comparisons were made of the process economy before and after the reconstruction so that full use could be made of information obtained from level gauging. There was a decrease in power input of 630 kW, a decrease in the need for steam of approximately 1.2 t/h, and an improvement of 20% in the physical quality of the product. At the same time, process1 costs were decreased, as the number of workers to control heating and defibration was reduced from three to one. In one of the three factories investigated, the reconstruction cost TABLE III

NUMBER OF ISOTOPE USERS IN YUGOSLAVIA

Number of devices Broad product group users Thickness Density Level Other Total gauges gauges gauges devices

Food 1 1 4 >5 Textiles 1 1 1 Paper 6 3 2 3 8 Rubber 2 2 2

O Chemicals 5 1 1 7 1 10 50 H Petroleum 1 2 2 en Basic metals 5 8 3 11 Machinery 1 1 1 2

Total 22 14 6 14 7 41 YUGOSLAVIA 293

Din 77 million; the annual savings were Din 160 million, giving a cost- benefit ratio of 1:8. The savings are given as several per cent of the total output value. The "other gauges" represent an inhomogeneous group, including portable back-setter gauges for corrosion control, logging devices used in the prospecting of oil, and three component analysis gauges. These concern the determination of C/H ratio in petroleum fractions, of alloy composition by back-scattered beta radiation at an industrial research institute and the determination of Zn and Pb by X-ray fluorescence in a metal refinery.

Radiography

Gamma radiography is the most widespread radioisotope technique in Yugoslavia and is considered a highly important method in the non-destructive testing of metal products. The distribution of the number of users of gamma radiography as well as the number of sources in use is shown in Table IV. The survey included

TABLE IV

THE USE OF GAMMA RADIOGRAPHY IN YUGOSLAV INDUSTRY IN 1963

Number of Number of firms Broad product group Number of sources active users served by others

Petroleum 1 - 1 Basic metals 3 - 3 Machinery 31 30 93 Services 5 45 25 Others 2 - 2

Total 42 75 124 two factories for boilers and power plant equipment, three factories for locomotives and railway vehicles, one pipe factory, two factories for the production of metal products, and three industrial research and service institutes. The main gamma ray sources in use are Co60, Ir192 and Cs137.

It should be pointed out that gamma radiography has a more prominent position in Yugoslavia in comparison with X-ray radiography and ultrasonics than in most other countries. These methods, it is claimed, are more reliable and work independently of any disturbances in the power supply. The savings that can be attributed to radioisotope use will thus become much greater than when they are determined relative to other methods of non- destructive testing. 294 NATIONAL REPORTS

In the boiler factory gamma radiography was applied to control welds, steel and castings, to the detection of inhomogeneities in steel products, and to the control of ready-made products. It was claimed that the access to this technique permitted a reduction of 20% in the thickness of the main wall. The testing also made possible the use of automatic welding apparatus, which decreased welding costs by 10-15%. Other important economic factors arose from the decrease in the number of rejects or other scrap. In a factory that made constructional material for industrial plants, gamma radiography was used for internal control and for testing the final products. The investment in gamma radiography was Din 2.8 million and it is claimed that in one year savings in power and in materials of about Din 81 million were obtained. This corresponds roughly to 2.5% of the output value. In addition, the output value was increased. In a similar factory it was stated that gamma radiography equipment valued at Din 1 million permitted a decrease of about Din 900000/yr in power consumption and scrap. In another machinery shop, where the investment in gamma radiography equipment amounted to the same sum as a month's output, a 10% decrease in labour was obtained, together with a considerable decrease in scrap (5% of the output). As no information is available on operation costs, it is impossible to establish a cost-benefit ratio for these applications. From the details revealed it is nevertheless proved that the benefits are substantial and the investment in equipment pays for itself in a very short period. The Institute of Material Testing, as one of its services, provides a service in gamma radiography to various enterprises and also in the erec- tion of buildings or other constructions. According to the experience of this institute, gamma radiography control of welds may decrease failures from 70 - 5%, if permanent control is maintained. Making an economic analysis in one enterprise with a foundry capacity of 32 000 t/yr, the Institute recorded that because radiography control was not used in an early stage of production, Din 72.5 million/yr were spent on thermal treatment and machining of details which, due to internal failures, had to be scrapped. lonization

lonization applications reported were the elimination of static charges in the textile, paper, rubber and chemical industries. The remaining ones concern the introduction of alpha-emitting sources to triger-off fluorescent lamps.

Tracing

The use of tracers is reported frequently, in research within branch research institutes and in process control within firms. In the former group were wear tests and basic corrosion studies. On a full industrial scale radioisotopes were used to determine the time for homogenization of cattle food, the retention time in a bleaching tower for wood pulp, and the flow rate of oil in pipelines. Moreover, studies of the viscose process and in the production of superphosphate were reported. The wear of the lining material in a blast furnace was checked by means of installed Co60 sources. In ad- YUGOSLAVIA 295

dition a large number of hydrological investigations with tracer techniques can be accounted for.

CONCLUSIONS

Although the industrial use of radioisotopes is still at an early stage in Yugoslavia, its economic impact is solid and convincing. As examples only are given, neither the average cost-benefit ratio nor the gross annual saving obtained from their use can be estimated. The Yugoslav report expresses the role of radioisotopes in the country's industrial economy: "All comparisons are invariably in favour of the application of isotopes. But the question arises whether, with the introduction of isotope application itself, a climax has been reached regarding the economic effect attainable in the given circumstances, or whether, when applied, such an effect could or should increase further. It is evident that only a longer period of application may serve as a basis to establish a criterion enabling some more realistic assessments of the economic effect and its precise quantitative expression. The short period of application in industry does not permit the deduction of a statistical time series of data for individual enterprises giving the results over a larger number of years, which would thus make it possible to evaluate the progress of a plant, or to compare, by means of the same data from other enterprises, the different results achieved. "On the other hand, the application of radioactive isotopes in industry in most cases cannot be considered in isolation, but rather as part of a general policy of modernizing the technological process on the basis of modern scientific and technical achievements and methods. For this reason the survey on the application of radioactive isotopes in Yugoslav industry cannot give a complete picture of the degree of isotope applications in general, since their introduction in the technological process is often not an isolated phenomenon but an integral part of a wide reconstruction where the application of isotopes finds its place as part of a whole. If this is so, it is not easy to discover the direct and real influence of the application of isotopes itself, regardless of the influence of other elements involved in such a reconstruction. "

INFORMATION ABOUT NON-PARTICIPATING COUNTRIES

When preparing this survey the International Atomic Energy Agency invited those 25 of its Member States whose national reports were received, and, in addition a further 12, from whom it was considered contributions could be made. Most of the latter group excused themselves with the very good reason that their industry was not applying radioisotope methods to such an extent that a participation in the survey would be worth while, but they showed great interest in the survey and were in most cases represented by observers at the Study Group Meeting on Radioisotope Economics, concluding the survey. Only two countries with a widespread industrial use of radioisotopes did not participate, namely Hungary and the Soviet Union. In both cases the reason was given that no appropriate organization was available in the country to make a valuable contribution to the survey. In the case of Hungary no information is available on how radioisotopes are applied in industry, although scientific literature reveals extensive work on radioisotope applications to technical problems. The authorities of the USSR have, however, shown considerable interest not only in the development of industrial isotope techniques but also in evaluating their economic importance. A. Petrosyants, chairman of the State Committee for Use of Atomic Energy, stated in an article in the "Economic Gazette" on 3 November 1962: "The Institute of Economics of the USSR Academy of Sciences has estimated that already in 1961 - the third year of the current Seven Year Plan period - ojar country has saved some 200 million roubles as a result of the introduction of isotopic techniques and instruments into the national economy. This is a substantial gain, but this is only the beginning. All those working in industry know only too well that the time in which investments are amortized is a vital indicator of their efficiency. It is worth noting that the expenses incurred by introducing isotope instruments were repaid frequently within a period of 30 days. In other words, an instrument installed in a plant fully compensated its cost practically during the first month of operation. Another estimate of the Institute of Economics of the USSR Academy of Sciences has revealed that the use of isotope instruments solely to control and automate production processes over the past year has yielded a saving of over Rb 43 million. These figures speak for themselves. They above all stress that the executives of the economic councils, the managers and chief engineers of the enterprises, as well as other executives, should recognize the potentialities of atomic energy for industry and encourage in every way the introduction of new techniques and instruments in the production lines of the basic plant. It should be borne in mind that instruments based on the employment of radioactive isotopes can be used where instruments operating on other physical principles cannot be used. A few examples may illustrate the economic advantages and technical expedience of isotope instruments and techniques in industry. As a rule, the level of molten metal ürthe crystallizer of a continuous steel pouring 297 298 NATIONAL REPORTS installation is controlled by visual means. A six-position level regulator was installed on a continuous steel pouring installation. This raised the efficiency of the installation 21%, and made it possible to produce hundreds of tons of steel ingots a year in excess of the normal level of output. Idle time and losses of metal through breakdowns were eliminated. On the whole a saving of Rb 53 000/yr per instrument installed at plant was secured. It is worth noting that the instrument itself costs as little as Rb 300. Transversing radioisotopic level gauges for blast furnaces have been developed, and are already being introduced. Such instruments have been installed, for instance, at two blast furnaces. The steel workers justly call them "analysers", for they show how the furnaces function. The instrument provides reliable information and enables the operatives to regulate the blast-furnace process. After the instrument was installed the specific consumption of coke dropped by le%, while the efficiency of the furnace showed a 2% rise. The annual economic effect derived from the two blast furnaces is Rb 160000. A sizable economic gain has been ensured by the employment of radiotracer techniques used for the study and subsequent improvement of production processes. The Institute of Economics of the USSR Academy of Sciences, which conducted studies at seven iron and steel works, estimated that the cost of 11 investigations with the help of radiotracer techniques amounted to Rb 272000. The introduction of recommendations developed on the basis of these investigations has made it possible to establish the optimum technological conditions of operation of the open-hearth furnaces with the object of cutting down the smelting time. As a result, the over-all saving derived is Rb 1.4 million. With each study costing approximately Rb 25 000 the saving derived from each newly introduced process is Rb 131 000. Forty per cent of the saving comes from lower consumption of raw materials, fuel and other materials. Radioisotope instruments are being used successfully for gauging the thickness of cold rolled ferrous and non-ferrous metal bands. For instance, at a non-ferrous processing plant each isotope thickness gauge installed on a foil rolling mill yields a saving of Rb 44 800/yr. After these instruments were installed the operating rate of the mills was increased 10%. Additional quantities of metal foil worth tens of thousands of roubles have been obtained, and waste has dropped by 7. 2%. Thanks to the decrease in waste alone saving of Rb 126 000 has been secured. On the whole, automatic control of the thickness of rolled foil has raised the productivity of the foil rolling shop by 6. 9% and lowered production costs by 3%. The introduction of isotopic thickness gauges increased the productivity of the mills by 12% (as a result of time saved on the gauging operation). The waste due to varying thicknesses of band and loss of thick and thin ends was diminished. Thanks to this the output of quality foil per ton of ready production costs dropped 3%. At a steel rolling mill it has been possible to raise the productivity of the 4-high and 12-high mills by 11. 5% and that of the 6-high mills by 17%. The production costs dropped 4-5%. In certain cases the positivity allowance for various kinds of rolled metal has been decreased by 2 - 5%. NON-PARTICIPATING COUNTRIES 299

To exercise control over production processes in on-dressing, gamma- relay instruments were introduced. They have been installed on reloading devices to issue signals as soon as the flows are clogged. These instruments have helped to eliminate breakdowns and improve the rhythm of the crushing section at the ore-enriching plant. The loading and unloading of bunkers and the crushing of the ore is now done automatically with the help of gamma- relay instruments. Thanks to this the productivity of the mills has risen 6%, and the quality of concentrated ore has improved too. Twenty radioisotopic instruments installed in the crushing section of the ore plant have yielded a saving of about Rb 80000. One of the chemical works in eastern Siberia employs a radioisotopic level gauge that automatically controls the disposal of the hydrogenated mass and slime in high pressure separators. Four instruments now do the work of 24 workers who controlled and regulated the level of the hydrogenated mass. The instruments cost only Rb 2000 roubles, the saving being more than Rb 40 000/yr. At the same plant 30 gamma-relay instruments have been installed on the conveyors at points of reloading. They have replaced 17 workers who controlled the clogging of the flows. The annual saving is nearly 10 times greater than the cost of the instruments. Radioisotopic instruments and techniques have been widely used in prospecting for minerals and in the control of extraction of oil, gas and certain ores in Azerbaijan, Bashkiria, Tataria, the Urals, the Ukraine, the Krasnodar Region, the Kuibyshev Region, Central Asia, and the Checheno- Ingush Republic, as well as in other areas. Last year about 200 geophysi- cal organizations used such technique s to test 18. 8 million metres of wells. The Institute of Economics of the USSR Academy of Sciences has estimated that the economic effect derived from, the use of radioisotopic methods and instruments in extraction and prospecting of minerals and ore- enrichment is in excess of Rb 65 million/yr, including Rb 55 million for the oil and gas industry. The further use of radioactive isotopes on a broad scale will definitely yield even greater economic advantages. Already new and more efficient radioisotopic instruments are being developed and tested. " The Agency tried to obtain the reports to which Mr. Petrosyants refers, but without success. However, part of this material has been published [1]. At a national conference in Riga in 1960 [2] several papers were devoted to the "economic effectiveness" of radioisotope use, a term that very well corresponds to what the Agency survey calls a "measurable saving". Some of the points raised in the Soviet literature are discussed in the economic reviews of the various techniques.

REFERENCES

[1] MIKHEEV, G. F., POSTNIKOV, V.I., The effectiveness of the use of radioactive isotopes in the national economy, . State Publishing House of Literature in the Field of Atomic Science and Technology, Moscow 1962. (English translation AEC-tr-5898, Washington 1963). [2] Trans. All Union Conference on Radioactive Isotopes and Nuclear Radiation in the National Economy of the USSR, Riga 12 -16 April 1960, particularly: SAVITSKY, P.S., The use of Radioisotopes and Nuclear Radiation in the National Economy at Present and in the Future", I 7; 300 NATIONAL REPORTS

MIKHEEV, G. F., The Economies of Radioisotopes and Nuclear-Radiation Techniques in Industry. I 21: MIKHEEV, G.F. and FEITELMANN, N. G., The Economic Effect of Using Radiometrie Methods in Pro- specting and Exploiting Oil and Gas Deposits, IV 47. Ill

TECHNICAL AND ECONOMIC SUMMARIES

THE.USES OF RADIOISOTOPE GAUGES IN INDUSTRY

J. F. CAMERON DIVISION OF RESEARCH AND LABORATORIES, IAEA, VIENNA

1. INTRODUCTION

A radioisotope gauge consists basically of a sealed radioisotope source of radiation, a detector, and an electronic indicating unit for visually displaying the detector output. The degree of absorption or scattering of the radiation by a material, as measured with the detector, is used to measure properties such as thickness, density, composition and level; the different instruments being named after the property being determined, e.g. thickness gauge or level gauge. Depending on whether the source and detector are on the same or opposite sides of the material, the instruments are known as backscatter or transmission instruments respectively. They are further classified according to the type of radiation used, e.g. beta transmission thickness gauge or gamma backscattering density gauge. The physical properties which can be determined are: (a) ^Thickness, or mass per unit area, of homogeneous sheet materials such as aluminium or steel or of heterogeneous materials of constant composition such as paper or plastic; (b) Coating thickness, such as paper or textiles coated with rubber, plastic or abrasives; (c) Plating thickness, such as tin on steel; (d) Density of materials of constant thickness, such as liquids or slurries in a pipe, or of tobacco, in cigarettes; (e) Levels of solids or fluids in containers; (f) • Elemental composition of certain materials; (g) Density of mate'rials in large bulk, such as concrete, soil or rock strata.

In addition to the above, the instruments are also used for such varied purposes as pressure gauges, flowmeters, torquemeters and as position indicators. Radioisotopes became available in quantity around 1947 from nuclear reactors and the first beta transmission thickness gauges were installed on paper mills about 1949.

2. DESIGN OF RADIOISOTOPE INSTRUMENTS

In the design of radioisotope instruments, close collaboration between physicist and engineer is essential. Whilst the basic design is the job of the physicist the practical realization of a suitable instrument is the responsibility of the engineer. In the first place, the physicist examines each problem theoretically, selects the best method and tests it experimentally. In close collaboration with the physicist, the engineer then takes this basic

303 304 TECHNICAL AND ECONOMIC SUMMARIES design and constructs an instrument to withstand the environment in which it must work. Theoretical considerations in the design of radioisotope instruments which determine the choice of the most suitable method, source, detector and indicating unit are now well understood. However, the specialized knowledge which permits the construction of ionization chambers with a negligibly small temperature coefficient, D.C. amplifiers with a stability, better than 0.01%, and source-detector mountings which do not distort under arduous industrial conditions is possessed only by relatively few people who have been designing, producing and servicing industrial instruments for many years. For these reasons, the construction of almost all radioisotope instruments is carried out by specialized firms posessing a thorough knowledge of the basic physics, electronics, radiation protection and engineering involved. These firms have, over the years, with accumulated experience, refinement of techniques and advances in detectors and electronic components, developed instruments to give an extremely high degree of reliability and accuracy under the most arduous industrial conditions. Radiation intensity can now be measured with an accuracy of 0.01%, and the thickness of steel at 600°C from a rolling mill can be controlled to better than 1%. The stage has now been reached where a selection can be made from standard stocks of components to assemble a basic radioisotope gauge which will meet almost any requirements. Research work on development of new components and physical principles such as brems Strahlung sources and radioisotope X-ray fluorescence is done mostly in government or private laboratories specializing in research. The industrial manufacturers are usually too occupied with finding immediate practical solutions to the many problems with which they are continually confronted, to spend time developing new techniques or thoroughly investigating the reasons for the phenomena they uncover. Thus, in some countries, very profitable relationships have sprung up between research laboratories and gauge manufacturers. The manufacturers can bring their problems to the research laboratories for investigation, and the latter, apart from solving the problems, can develop physical technique s to meet existing demands or discuss possible applications of promising new techniques. Nearly all the instruments use transmission geometry largely because the accuracy obtained is better than that with backscatter geometry. As a general rule backscatter geometry is only used when transmission geometry is not possible, as for example when only one side of a substance is available for measurement. However, there are important exceptions to this rule, especially in analysis and coating thickness measurement using beta particle or X-ray scattering and X-ray fluorescence techniques, which can only be done with backscatter geometry. Transmission of beta particles and electromagnetic radiation is used to determine all the properties listed above. However, to determine thickness, or mass per unit area ((a) above) transmission of beta particles or low energy electromagnetic radiation is most used. Gamma transmission is generally used for (d), and (e) and gamma backscatter for (g). Coating thickness is generally measured by transmission of beta particles, and plat- ter thickness by X-ray fluorescence or beta particle backscatter. RADIOISOTOPE GAUGES IN INDUSTRY 305

Analysis is accomplished with low-energy electromagnetic radiation, both with transmission (preferential absorption) and backscatter (X-ray fluorescence) geometry, but to a limited extent with beta particle back scattering and absorption. Alpha particles are only used to a limited extent for (a). Radioisotope flowmeters, torquemeters and alignment devices depend on changes in source-detector geometry. The detector used in most thickness and density gauges is an ionization chamber mainly on account of its stability and simple, rugged construction, lonization chambers for beta particle detection have a volume of a few liters and are filled to at least one atmosphere with a clean, dry gas such as argon. A thin "window" is provided for the admission of beta particles. Gamma ionization chambers have thicker walls and are filled at pressures up to 100 atm. For detecting low-energy electromagnetic radiation, a high atomic number gas, such as xenon and krypton is used to fill the chamber. In level gauges and package monitors Geiger counters are preferred because of the simple associated electronic circuitry.

3. FEATURES OF RADIOISOTOPE INSTRUMENTS

Statistics

One of the most distinguishing features of a radioisotope instrument is that a measurement of a quality X is derived from a radiation intensity I subject to statistical fluctuations due to the random nature, of the emission of radiation. Nothing can be done to eliminate these variations, but their effect can generally be made small. The standard deviation on a total of N counts is *JN and the coefficient of variation or relative standard deviation is

Sensitivity

The sensitivity, S, is defined as the fractional change in detector output I/I which results from a given fractional change in the quality, X, being measured, i.e.

(1)

and is usually expressed as the change in detector output for a 1% change in X. For electromagnetic radiation and for beta particles, the intensity I after traversing a material of mass per unit area m, is related to the intensity lo in the absence of the material by an equation of the form

I = lo exp. -/^m

where ju is a function of the radiation energy and of the atomic number of 306 TECHNICAL AND ECONOMIC SUMMARIES the absorber and is called the mass absorption coefficient. Then 6 I/I = jum. 5 m/m

In measuring m, minimum relative error, om/m. is obtained when the radiation energy is chosen such that Aim = 2, if the largest cause of error is statistical fluctuations. This gives a first estimate of the radiation energy, and then one can look more closely at the most appropriate sources from the points of view of availability, price, unwanted (difficult to shield) radiation, and specific activity. Similar relations can be derived for backscattering measurements, coating thickness measurements and analysis.

Accuracy

The accuracy of'measurement, when statistical variations are most important, is defined as the relative change in the quantity being measured, ôX/X corresponding to twice the value of the coefficient of variation of the fluctuations in detector output. Thus, if the detector count rate is such that N counts are recorded in the measuring time, the coefficient of variation is 1//N. Now, from equation (1) the value of 6X/X when 6I/I = 2/jN is 1/S 2/sfa Accuracy = 2/s/N = 200/s/N percent. (2)

Accuracy is then given with 95% confidence limits. Thus, if in a particular measurement S = 3, and an accuracy of 0.5% is required, then N = (200/3X0.5)2, so that 104/0.75 counts must be recorded. Causes other than statistical variations may limit accuracy. For example, with scintillation counters in which the mean anode current is measured, drift in gain of the photomultiplier between standardization checks may be the limit of accuracy. If so, the magnitude of the drift should be stated in terms of the error it causes in the quality being measured. The accuracy achieved in practice is a function of many things, the most important of which are thickness of material and container, source activity, detector efficiency, source detector distance and measuring time constant. By suitable design an accuracy of about 1% can usually -be achieved in measuring thickness and density. Typical source activities used are:

Thickness gauges: beta 10-30 me brems Strahlung 100-500mc Density gauges: gamma 100-500 me Level gauges: gamma 10-500 me beta 1-5 me.

Measuring time constants vary from 10 m/s for fast steel-sheet sorting to 100 s for many thickness and level gauges. RADIOISOTOPE GAUGES IN INDUSTRY 307

4. ADVANTAGES OF RADIOISOTOPE INSTRUMENTS

The criteria used in selecting the best instrument for a specific measurement are the technical advantages, cost and economic benefits. The first consideration is probably the technical advantages; the ideal instrument being the one which measures the desired quality to the required accuracy, irrespective of cost. Then, if the price of the ideal instrument is prohibitive, even when possible economic benefits are considered, a compromise selection may be necessary.

Technical advantages

The most important advantage of radioisotope instruments is that no contact is required with the material being measured. Consequently they are used for measurements on continuously-produced materials travelling at high speed and at high temperature, on soft or malleable materials, such as paper and on materials such as precious metals where the surface finish is important. In the food industry, non-contact measurements ens.ure sanitary conditions throughout the manufacturing process. Scanning across a continously-produced sheet to measure profile non- uniformities is made more easily with a non-contacting instrument. Measure- ments are accomplished non-destructively and without changing the material in any way. The penetrating nature of high-energy gamma radiation enables measurements to be made through the walls of sealed containers. Densities or levels of solids, liquids or slurries in pipes and tanks, for instance, can be determined mined using an externally mounted source and detector. When the measuring system is mounted externally, installation and servicing are greatly facilitated. For detecting interfaces in pipe-line pumping operations, for example, gamma density gauges are.preferred to alternative methods which are cheaper or more accurate, but are installed inside the pipe-line, simply because when the radioisotope instrument fails it can be replaced or serviced without any hold-up to the pumping operations. Measurements on abrasive, corrosive or extreme temperature materials can be accomplished without difficulty. Compared with X-ray machines, radioisotope sources are compact and relatively inexpensive, the radiation energy and intensity are stable and they require no electrical power supplies. For use in the cramped conditions existing on most production lines, these advantages are very important. For materials produced to a constant mass per unit area, radioisotope instruments have an advantage as they measure this directly. Absence of moving parts in non-contact gauges means that maintenance problems are greatly reduced. The versatility of the radioisotope gauge, as compared with other instruments which are restricted to certain types of materials, may be an important consideration. In a mill producing different metals, for example, a universal gauge greatly simplifies maintenance. 308 TECHNICAL AND ECONOMIC SUMMARIES

Cost

Radioisotope instruments range in price from about $1500 for a rudimentary basic gauge consisting of a source, a detector and indicating unit to $20000 or more for a sophisticated instrument, engineered to operate continuously and accurately, and indicate the material quality in the conditions prevailing, with perhaps automatic standardization, computer interpretation of detector output and automatic control of the process. In the low price range come simple on-off "switches" such as are used for indicating when soap in a carton reaches a required level. They consist of a low-activity source, a Geiger counter and a ratemeter unit operating a relay. When it is required to cover a wider range of levels or for measurements on larger containers, the price soon rises due to the required increase in source activity, number of detectors etc. For continuous, accurate, reliable measurement of, for example, mass per unit area on a continuously produced material, rudimentary basic components alone are practically useless. Firstly they have to be rigidly mounted, in position with respect to the web of material. When it is borne in mind that the mounting will be subject to knocks and probably used by operators to climb on the machine, it will be appreciated that a sturdy construction is required. Then allowances must be made for build-up of dust and other extraneous material on the source or detector, for temperature variations, source decay, material composition changes etc. For scanning across a web, an elaborate construction is required. Soon the cost of the basic components is negligible in comparison with the other essential controls and components. It must also be borne in mind that practically every instrument is custom-made. Machines vary in size and shape, and mountings, temperatures, speeds and controls are different. The same basic components are used but they are assembled differently to meet individual requirements. To the basic cost of the gauge must be added the cost of servicing and insurance. Although these instruments use a specialized technique, they are fundamentally similar to many process control instruments, and it is found that the appropriate factory technician soon masters the art of periodic adjustment, fault localization and repair. Insurance coverage varies considerably from company to company and from country to country. Sometimes it is not excessively higher than for other instruments of similar capital cost, but at other times it is unrealisti- cally high.

Economic benefits

The economic benefits are covered by Mr. Forsberg in the next paper.*

5. REGULATIONS ON THE USE OF SEALED SOURCES

The nature of the hazards from radiation has become very clear as a result of radiobiological work carried out during the last twenty years. In-

Miscellaneous industrial applications of radioisotopes, this Report. RADIOISOTOPE GAUGES IN INDUSTRY 309

deed there is probably no other single type of hazard which has had such an enormous effort devoted to its study. The United States Atomic Energy Commission spends US $40 million/fyr on radiobiological research and the Medical and Agricultural Research Councils in the UK spend about £ 500000/yr on similar though less extensive studies. With this knowledge, recommendations have been drawn-up by the Inter- national Commission on Radiological Protection which state accumulated dose and rate of accumulation of dose which it is recommended should not be exceeded. The ICRP also recommends that the accumulated doses should be kept as far below the maximum levels as possible. Appropriate national bodies have formulated regulations for the use of sealed radiation sources based on the recommendations of the ICRP. Some of these regulations are summarized below. The dose rates at the stipulated distances from the radiation source shield or demarcating barrier must not be exceeded and these levels apply to "unclassified" workers, i.e. workers who are not required to carry dosemeters or have periodic medical inspection.

Belgium 0. 1 mr/h at 10 cm France 2 mr/h at l m Germany, Federal Republic of 0. 75 mr/h at the surface Sweden 2 mr/h at l m UK 0.75 mr/h at the surface USA 5 mr/h at l m USSR 0. 3 mr/h at l m and 10 mr/h at the surface.

The marked differences between the regulations are due to the degree of severity used in interpreting the ICRP recommendations. The dose rates from industrial instruments can always be kept below these limits when appropriate measures are taken. These measures involve fir atly the use of the smallest possible source activity, which is achieved by reducing the source detector gap to a minimum compatible with the measurement and using a sensitive detector such as a large volume, high pressure, ionization chamber. Scattered and direct radiation is kept to a minimum by appropriate shielding, collimators and guide plates. How- ever, the construction of a source shield is much easier and the price is lower when relatively high maximum dose rates are allowed. For instruments such as level gauges where the cost of the source, shield and mounting is an appreciable proportion of the total cost of an instrument, this means that radioisotope instruments are more competitive in price with conventional instruments. ' Differences from one country to another also hinder export and import of instruments as special designs have to be made for each country. In some countries the licensing of radioisotope gauges involves a vast amount of paper work and delays of up to six months are not uncommon in obtaining licenses. These difficulties also hamper the full application of radioisotope gauges. 310 TECHNICAL AND ECONOMIC SUMMARIES

6. APPLICATIONS INCLUDED IN THE SURVEY

Gauging is by far the most common industrial application of radioisotopes, accounting for about half of the total number of applications and for almost all the routine, continuous applications. As shown in Table I, the use of radioisotope gauges is particularly widespread in the paper, chemical, tobacco and basic metals manufacturing industries. Almost all gauges are used for continuous measurement. Table II shows the number of instruments used in different countries for measuring thickness or mass per unit area (including coating and plating thickness gauges), density (including tobacco gauges) and level (including switches and package monitors) and for component analysis. All other instruments (for moisture content, flowmeters, alignment etc. ) are grouped together under miscellaneous. Variations from one country to another in the relative number of instruments in each industry are largely due to the different major industries in each country. Thus, in Finland 72% of the radioisotope gauges are in thé paper industry, whereas in the United Kingdom the corresponding figure is only 18%. However, there are other differences from one country to another shown in Table I,, which need an explanation. Why, for example are there 897 tobacco gauges in the United Kingdom, 59 in the Netherlands and none in France and the Federal Republic of Germany? The number of cigarettes produced in the last three countries in 1961 was 13, 47 and 56X109 respectively, so the difference cannot be explained in terms of total production. The reason can probably be found in. the point mentioned by Mr. Somer in the Danish report, that in cases where high taxes are placed on the finished'cigarettes and not on the raw tobacco, the raw tobacco is relatively cheap and savings are correspondingly small. Nevertheless, the success achieved with beta gauges in producing cigarettes of uniform weight must lead to their eventual adoption by all manufacturers. Many of the other variations from one country to another can be explained by good salesmanship for, or ready availability of, particular instruments. The relative numbers of instruments in each industry is mainly a re- flection on the number of processes to which the radioisotope gauges can be applied. Thus, there are relatively more level and density gauges in the petroleum and coke and basic metal industries and relatively more thickness gauges in the wood and paper industries. In Table III is shown for each industry and for each type of instrument, the material being measured or controlled. It is apparent that a surprisingly large proportion of the everyday things we use and know have been produced with the aid of radioisotope instruments. Many foodstuffs such as chocolate, biscuits and ice cream are controlled with thickness and density gauges, and package monitors control the quantities of a wide range of foodstuffs (soup, beans, beer, meat, coffee etc. ), in tins, packets and bottles. The production of most cigarettes and many artificial, natural and coated textiles and fabrics are controlled with beta gauges. Almost all paper, board and plastic and coated papers are similarily controlled. The high quality of modern tires is partly due to the control of radioisotope instruments. Density and level gauges are widely used in the production of cement, glass and petroleum and coal. Most sheet-metal rolling mills are equipped TABLE I NUMBER OF INSTRUMENTS IN DIFFERENT INDUSTRIES

Number of gauges

Country Year Food Textiles, Wood Chemicals Glass, Petr. Basic Not and Tobacco clothing, and Rubber and minerals, and Machinery Services Total metals identified drink footwear paper plastics cement coal

Argentina 1963 . . 2T 3T - IT 11 20 log 4T - IT - 33 IL

Australia 1962 ÏD ' 32D 3T 12T . 20T ID 30L 2T 2L 2L . ID 3V 4L IV IV 125 9L H _ _ O Austria 1961/62 . . 16T 5T 7T 3V 2T . ^ . 34 m IL O

Belgium 1962/63 4L 4D 2T 42T IT 9T 6L IT 9T . 3L . SL 10L O ID 20L M 26L IV

Canada 1963 IT 464D IT 165T 8T 17T IT 9T 17T 43T 22T 1394 13D 16D 16D 11D 4D 135D 9D 35D 10L 12L 85L 9L 6L 12L 30L 4L 203 log 36V

CSSR 2T 5T 3T 8T 58T 5T ID 6D 2D 115 IL 15L 5L 2L 2L

Denmark 1963 3T 72D 6D 56T 2T 5T 2D ID IT 2L 5L 6L 6L 6L 174 1CA

. . . Finland 1961/62 2T 31T IT 3T 4L 2D IT 69 17L ID 2L 5L TABLE I (cont.)

Number of gauges

France 1961 7L * 81T 166T 35T 38T 2T 16T 20T 16T * * 15D 40L 8D 2D 7D 279L 16D 6L 111 102L 1CA 125L 164L 119L 27V 5L 1465 IV 8CA 10V 15V 5CA 94 log 24V

Federal Republic 1962/63 IT . 1ST 382T 69T 427T 86T 63T 198T 20T 11T 3T of Germany ID 5D ID 5D 16L 2D ID ID ID 1347 2L 5L 22L 71, 20L 20L 7L

Japan 1961 - - 6T 20T 11T 1ST 8T IT 46T 14L 5T 3T 42L 26L 2D ID 2D 7D 4D 9D 6D n 3V 56L 1L 7L 9L 10L 2L 1L o 6V 3V 2V 11V 4V z o Netherlands 1962 . 59D . 63T 10T 11T 9L 5T 7D £ 3L 128L 1L 8L o O) Norway 5T 48T 4T 6T 2T G 3D ID ID 84 9L 3L 2L

_ Poland 1962 . 5T 4T ID 10L 3L 8T 98L . 44L Hog 33L 3L 219 8 log 1CA

_ Portugal 1962 - . - 3T - IV . 1L - 2V . 8 IV

South Africa 1961 . 59D . 10T 11T 2L . 12D . 3V 10V ID 2L 113 IV 2V

Number not known and included in "not identified" TABLE I (cont.)

Number of gauges

• Country Year Food Textiles, Wood Chemicals Glass, Petr. Basic Not and Tobacco clothing, and Rubber and minerals, and Machinery Services Total metals identified drink footwear paper plastics cement coal 0

Spain 1962 - 2D . 4T 6T 12T . . 12V . 2V IV 41 5 2L

Sweden 1963 10L 20D 20T 140T 10T 75T 10T 4D 10L 1ST . . g ID 30L 5L 20L 480 HOL o > G United Kingdom 1961 IT 897D 72T 357T 41T 71T 17T 4T 93T 51T HT . O 2D 3D 25D 2D 8D ID HD 9D m 16L 2L 161L 34L 20L 45L 27L 12L 2037 ICA 1CA 1CA 19CA 3V 2CA 2CA 4V 12V G United States 1957 ca.4000 C of America 1964 8000-9000

Yugoslavia IT 3T IV IT 8T IT ID 2D 2D ID 41 4L 3L 7L 2V 3V IV 314 TECHNICAL AND ECONOMIC SUMMARIES

TABLE II

NUMBER OF DIFFERENT TYPES OF INSTRUMENTS

Number of instruments

Country Component Thickness Density Level Various Total analysis

Argentina 11 - 2 - 20 log 33

Australia 39 35 45 - ô 125

Austria 30 - 1 - 3 34

Belgium 64 5 74 - 1 144

Canada 284 703 168 - 203 log 1394 36

CSSR 81 9 25 - - 115

Denmark 67 81 25 1 - 174

Finland 38 3 28 - - 69

France 374 48 858 14 77 94 log 1465

Federal Republic 1231 17 99 - - 1347 of Germany

Japan 127 31 154 - 29 341

Netherlands 89 66 149 - - 304

Norway 65 5 14 - - 84

Poland 17 4 188 1 9 log 219

Portugal 3 - 1 - 4 8

South Africa 21 72 4 - 16 113

Spain 34 2 2 - 3 41

Sweden 270 25 185 - - 480

United Kingdom 718 957 317 26 19 2037

Yugoslavia 14 6 14 - 7 41 RADIOISOTOPE GAUGES IN INDUSTRY 315

TABLE m APPLICATIONS OF DIFFERENT INSTRUMENTS IN EACH INDUSTRY

Industry Type of gauge Applications

Food and Thickness and mass Sheets of dough and thin slabs of chocolate. beverage per unit area

Density Liquid foods in concentration plants (fish, meat, etc.); air content of ice cream; fruit juice, syrup, condensed milk, etc. ; fat content of baby meat food; ground corn slurry in production of starch and gluten; tomato paste.

Level Package monitors controlling contents (soup, meat, beans, coffee, beer, etc.) of cans, bottles, packets, etc. Limestone and coke in lime-kilns for sugar refining; sugar and chemicals in storage vessels, hoppers, reaction vessels, fermenting tubs, etc. ; grain, sugar beet; separation of fat from protein; evaporated grain syrup (whisky manufacturing).

Tobacco Density Monitoring and controlling average cigarette weight.

Level Empty and underfilled package monitors.

Textiles, Thickness and mass Thread mass per unit length; control of warpknit clothing and per unit area fabrics in heat setting; coating in production of footwear cellulosic fabrics, tufted carpets, leathercloth, tire cords; fabric impregnation. Adhesive coated surgical dressing, linoleum, footwear materials. Water uptake and evenness of wear of paper-makers felts. Fabric wear.

Density Polymer and synthetic yarn solutions before spinning; sulphuric acid.

Level Contents of reaction vessels.

Wood and Thickness and mass Paper of all qualities and thickness; paperboard, paper per unit area chipboard, pulp. Coated and laminated paper; coatings on paper; ink on paper. 316 TECHNICAL AND ECONOMIC SUMMARIES

TABLE III (cont. )

Industry Type of gauge Applications

Wood and Density Timber; straw building board, liquors in digesters; paper (cont. ) clay slurries and solutions, black liquor feed to evaporators.

Level Wood chips and pulp in containers, reaction vessels; digesters, bleaching towers; chlorine levels in bleaching towers.

Rubber Thickness and mass Rubber sheet on calenders, rubber goods; foam- per unit area rubber; rubber coating of tire cords; coated fabrics; tires; floor covering, etc.

Density Latex solutions; degree of polymerization of butadi- ene and styrène.

Level Powder in packets.

Chemicals and Thickness and mass Plastic sheets, tapes, etc. plastics per unit area Coated metal, paper and fabrics, laminated products, adhesives. Walls of plastic bottles.

Density Process solutions, brine, salts, acids, detergents, plastic and organic solutions, slurries, explosives, etc.

Level Many liquids, solids, liquified gases and slurries in containers and reaction vessels, e.g. methanol. sulphuric acid, carbon dioxide, sulphur dioxide, asphalt, coal, coke, lime, cement, explosives, plastics, catalysts. Contents of bottles, tubes and packets.

Analysis Chlorine and sulphur content of plastics.

Various Thickness of walls of pipes, tanks, etc.

Glass, minerals Thickness and mass Paper and textiles coated with abrasives; glass and and cement per unit area asbestos fibres; asbestos cement panels.

Density Cement, lime, asbestos and mineral ore slurries; mineral wool blankets.

Level Molten glass in furnaces; lime, sand and cement slurries; clinker, plaster.

Analysis Mineral ores by X-ray fluorescence; boron, lead, etc. in glass. RADIOISOTOPE GAUGES IN INDUSTRY 317

TABLE III (cont.)

Industry Type of gauge Applications

Glass, minerals Various Density and moisture gauges; and cement scintillation scanning of fire bricks for furnaces. (cont. )

Petroleum Thickness Coal seams, asphalt sheet products (roofing paper and and coal shingles); cement slurries (used in wells).

Density Petroleum and petroleum fractions (e. g. for process control or interface detection in pumping operations); sand-water brine, coal, coke, catalysts; sulphuric acid content in alkylation reactor.

Level Coal, coke, etc., in bunkers, hoppers and skips; catalysts in reaction vessels, liquids in reaction vessels; hydrocarbons in cracking units; petroleum in delayed coking units; hydrocarbons in trays in distillation columns; hot oil in melting tanks; alignment of machines in coal and coke preparation. Propane and butane level in filling cylinders.

Analysis S, Co, Pb content and carbon/hydrogen ratio of hydrocarbons; H2S content of gas. Ash content of coal.

Various Bulk density of coal in bunkers. Logging- Wall thickness of piper tanks, etc.

Basic metals Thickness and mass Hot and cold rolled-sheet metal, tubes, etc. per unit area Coated and laminated metal products. Tinplate, galvanized iron.

Density Powdered and slurried ores.

Level Coal, metal and core ores in storage bunkers, hoppers, etc. -, liquid metals in cupola and blast furnaces and in crucibles and moulds; load level in electrothermal kilns and furnaces; dust in electrostatical precipitators; chemical solutions and slurries; sodium in tubes; ores and leaching solutions in pressure vessels.

Analysis Metal ores (Cu, Fe, etc.) by X-ray fluorescence.

Various Moisture in powder or slurried ores or other charge materials and in foundry sand; logging; wall thickness of pipes, tanks, etc. 318 TECHNICAL AND ECONOMIC SUMMARIES

TABLE III (cont. )

Industry Type of gauge Applications

Machinery Thickness and mass Paper, rubber, plastic, textile and metal sheets, per unit area tapes, etc. both coated and uncoated; condenser paper: carbon steel and rubber compound for batteries; plastic coated radoms. Pipes and tubes.

Density Rubber latex; sulphuric acid; condensed milk; pulverized coal-, fuel.

Level See basic metals.

Various Moisture measurements.

Services Density Silt in dredging; gas, steam, steam/water, fluidized coal, etc.; sand, concrete, cement.

Level Liquids and liquid gases in containers and bottles. Water in steam boilers.

Analysis

Various Soil density and moisture gauges; wall thickness of pipes, tanks, etc. with radioisotope instruments: these mills produce the sheet metal used in car bodies, for instance. Tin plate and galvanized iron production is controlled with X-ray fluorescence and beta backscatter gauges. Construction of dams, buildings, roads and airfields are controlled with the aid of radioisotope density and moisture gauges. The radioisotope sources used in instruments are summarized in some of the national reports and these are reproduced in Table IV. Most continuously-produced sheet materials come within the beta-particle range, so about 80% of thickness gauges use beta-particle sources., Sr90/Y90 and Tl204 are the beta-particle sources most used. Kr85 is an alternative source to Tl204 and, although at the time of the survey it was not extensively used, it is expected that it will gradually replace Tl204 as it has the advantage of a longer half-life and complete absence of contamination difficulties. The small number of Pmi47 sources in use reflects the small proportion of very thin sheet materials produced. Cei^/Pri44 and Rui06/Rh.i06 are used on materials whose thickness is beyond that covered by Sr90/Y90. Co60 is the preferred high energy gamma source for level gauges and density gauges and the large number of level gauges in use accounts for the fact that there are more Coßo sources in use than any other isotope. Cs137 is the other high-energy gamma-ray source used in level and density gauges. Ra226/Be is the neutron source most used at the time of the survey, but is RADIOISOTOPE GAUGES IN INDUSTRY 319

TABLE IV RADIOISOTOPE SOURCES USED IN INSTRUMENTS

Total activity Country Radioisotope Number of sources (me)

Federal Republic of Germany Co60 622 13182 CS'37' 43 6071 Au1»» 1 7 Trn170 1 200 71204 248 1157 Sr90/Y90 102 1518 Pm'47 19 1425 Kr85 18 459 Ru107/Rhl07 2 50 Ra22« 9 66

Netherlands Co«» 111 Cs'37 46 T 1204 ' 18 Sr90/Y90 88 Pm'47 - Kr85 30

South Africa Co60 8 656 Csl37 5 560 Ir 192 4 400 T1204 19 350 Sr90/Y90 61 1120 Ra226/Be 4 32

United Kingdom Co«° 84 Cs«7 40 Cs134 1 Ir192 1 Na24 1 Tmi™ 10 J1204 155 Sr90/Y90 115 Pmi« 8 Kr85 14 Ce144/Pr144 8 Ru io6/Rh 106 2 C14 1 H» 2 Ra226 6 Pb2!» 2 P0210 1 320 TECHNICAL AND ECONOMIC SUMMARIES

rapidly being replaced by Am241 and Ac227 The other sources are used only infrequently.

Thickness and mass per unit area

A typical transmission beta thickness gauge on a paper mill is shown in Fig. 1. Source and detector are mounted at the extremities of the C-shaped bracket and the indicating unit is sited near the mill operator and some distance from the point of measurement. In order to measure variations in thickness across the sheet, an O-frame is used in which the source and detector synchronously scan across the sheet (Fig. 2).

Fig.l Typical transmission beta gauge head Coating thickness is measured by using two gauges, one before and one after coating and taking the difference. In producing abrasive paper, beta gauges employing Sr90/Y90 are used. Weights are measured of the backing material plus adhesive, backing material plus adhesive plus abrasive before and after preliminary curing and after the final coating is applied. Non- uniformity at any stage of the production is immediately revealed and cor- rected with this arrangement. The information from beta gauges is often fed into computors for calculating averages or ratios or whatever is required and the computor output used to control the process. Bremsstrahlung gauges have been developed for use in strip mills where metals may be rolled from 6 mm down to 0.1 mm. This range in thickness cannot be covered with beta particles. A typical gauge head is shown in Fig.3. This instrument uses a Sr90/Y90/Al bremsstrahlung source and a water- cooled ionization chamber. RADIOISOTOPE GAUGES IN INDUSTRY 321

Fig-2 O-frame mounting for transmission beta gauge

Gamma gauges on continuously produced materials are few in number and used only on thick steel strip.

Density gauges

Density measurements are usually made on materials in containers such as tanks, reaction vessels or pipes. The source is therefore usually a hard gamma emitter such as Co60 or Cs137 and an ionization chamber is used on the detector. Source and detector are generally mounted on the outside of the container as illustrated in Fig. 4. Very high sensitivities can be achieved; for example in monitoring latex polymeration when the total change in density is 0.94-0.97 g/cm3, an accuracy of 1% can be achieved, which corresponds to measuring absolute changes in density of 0.05%.

Package monitors and level gauges

Package monitors are essentially simple thickness gauges designed to examine, on a conveyor line moving at high speed the packing level of 322 TECHNICAL AND ECONOMIC SUMMARIES

Fig. 3 Bremsstrahlung gauge head

Fig. 4 Gamma transmission density gauge such products as drugs, soap powders, foodstuffs, dentifrices, rifle car- tridges etc. in solid, liquid or paste form, either before or after the containers are sealed. In its most commonly used form, a source and detector are mounted so that the packages to be monitored interrupt the beam of radiation passing from the source to the detector. The packages being inspected thus absorb some of the radiation so that the intensity of radiation reaching RADIOISOTOPE GAUGES IN INDUSTRY 323

the detector is greater when an empty packet is examined than when a full container is inspected. This increase in radiation intensity is arranged to operate either on alarm or a rejection mechanism to remove the faulty containers. Up to 200 packages/min can be inspected. A similar technique is employed to maintain and control the level of a variety of products in their containers. Most level gauges are of the simple "switch" type where the material interrupts the beam and actuates an alarm or operates a control. For a continuous indication of changes in level, various arrangements of source(s) and detector(s) are used to cover the desired range. Multiple or extended sources and detectors can cover ranges from 2 mm to 10 m and diam. of 1 to 10 m. An alternative method is to arrange electronically for the source and detector to follow the level.

Component analysis

The principle methods used for analysis are X-ray fluorescence, transmission of low-energy electromagnetic radiation (preferential absorption), backscatter of beta particles and low-energy X-rays and absorption of beta particles and gamma rays. Radioisotope X-ray fluorescence is sensitive and specific and is rapidly coming into use. Sensitivities obtained are as good as are obtained with the more sophisticated X-ray generators and crystal spectrometers. A close rival to X-ray fluorescence is preferential absorption of low-energy X-rays. The latter method is not as specific as the former, but is used in the many systems with only one or two variable components, such as sulphur in hydrocarbons. Backscattering of beta particles and low-energy X-rays are not specific methods of analysis, but have a small number of important applications. Absorption of beta particles and gamma rays is used exclusively for determining the hydrogen content of hydrocarbons.

Various

Instruments in this category include soil density and moisture gauges, portable gamma backscatter wall-thickness gauges, alignment devices, flowmeters, torquemeters and borehole logging tools. Soil density is measured using a gamma backscatter technique. In the most common form of this instrument a 10 to 100-me source of Co60 and a Geiger-Müller counter detector are separated by about 20 cm of lead and enclosed in a watertight container. When this probe is placed on the surface of the soil or lowered down a borehole, the intensity of radiation backscat- tered decreases with increasing density of the soil and, when calibrated, can be used as a measure of soil density. The moisture, or more strictly the hydrogen content of soils, is obtained by measuring the number of neutrons from a fast neutron source which are moderated by the hydrogen atoms in the soil and reach a slow neutron detector placed near the neutron source. Portable gamma backscatter gauges are used to determine the wall thickness of pipes and tanks. The measuring head is so designed that 20 fj,c Co60 or Csi37 sources are placed almost in contact with the pipe and a scintillation counter about 3 cm immediately behind the source. Such an instru- 324 TECHNICAL AND ECONOMIC SUMMARIES ment can measure in the range 1-20 mm of steel with an accuracy of about 5%. For aligning two components, a highly collimated source is placed on one component and a collimated detector on the other. This type of device is used, for example, in emptying coke ovens to ensure that the pusher car and the coke wagon are aligned and that doors are open before pushing commences. Several types of flow meters have been developed but they all use the flow to move an element containing a radioisotope source with respect to a detector. Radioisotope rotameters, hinged gate and propeller flow meters have been constructed. A torquemeter has been constructed using the same principle. Radioisotope borehole logging is widely used in prospecting for oil, gas, coal and other mineral deposits. The most used method is a measurement of the natural gamma activity of the strata by which one can discriminate between shale, sandstone and limestone, for example. Neutron moderation is used to obtain hydrogen content and porosity, gamma backscatter for density and neutron activation for a wide variety of analyses.

7. DEVELOPMENTS SINCE 1961

Thickness, mass per unit area and density gauges

In the measurement of continuously-produced sheet material, the stage has now been reached where a large proportion of the total production is monitored with radioisotope gauges, particularly paper, plastics, tobacco and metal. Many of these gauges, however, are over 10 yr old and are being gradually replaced. At the request of the user, the replacement gauges generally incorporate all the developments which have been made in the intervening years. Although a large proportion of the total production of paper, for example, is made with the assistance of radioisotope gauges, this paper is mainly of an inexpensive grade such as is used for newspapers and is produced by the very big, fast mills. A larger number of smaller mills producing mainly finer grades of paper are only now installing beta gauges. The reasons for this are partly the success achieved by gauges in the larger mills and partly the point mentioned before about having to produce a more uniform product in order to remain competitive. Machine builders also accept radioisotope gauges as a standard instrument and now automatically make provision for them on new machinery. As pointed out previously, the reliability and stability of radioisotope instruments are now extremely good. When the instruments are used for continuous measurement, however, it is apparent that even the relatively infrequent failures which they have should be reduced as much as possible. One of the main causes of failure is electronic valves and, for this reason, some manufacturers are transistorizing their equipment, even though it will take several years to obtain sufficiently good statistics on the rate of failure under operating conditions to decide which system is superior. RADIOISOTOPE GAUGES IN INDUSTRY 325

Beta gauges are used mainly in the production of paper and plastic sheet and in coating operations. On some modern paper machines, when all the process variables are controlled, the sheet can be produced with variations in mass per unit area less than 0.5% so that beta gauges are not essential for control, although they are still required to verify that the accuracy is maintained. Also, as samples can be taken, paper could be produced on all machines without beta gauges, although there would be larger variations in thickness. With plastics, however, the present production rate of high quality sheet would not be possible without the best modern beta gauges. Con- trol of extruders which have a large number of adjustable elements and which produce wide sheets of thin plastic is possible only with the latest developments. In one type of instrument, the measuring head is purged with air, thermostatically controlled to ± 0.5°C in order to eliminate errors due to temperature effects on the detector or in the source detector gap. C-frames and O-frames are used to obtain profiles of the sheet thickness and these are recorded on x-y plotters. From the trends indicated in successive profiles, steps are taken to keep up uniform sheet thickness. The overall change in indicated detector output due to electronic drift, temperature changes, mechanical misalignment etc. is now better than ± 1% per 24-h run. Similarly most operations involving the coating of paper or textiles or steel would be almost impossible to control without beta gauges. While the number of applications of thickness or mass per unit area gauges is tending to approach a saturation value in some countries, the number of density gauges continues to increase. As more industrial chemical processes go over to automatic, computer control the use of all instruments including density gauges increases. More attention is now being given to the development of sensitive, stable ionization chambers for gamma detection in response to the demand for increased stability and accuracy for process control. Many new developments in thickness and density gauges, apart from gradual improvements in performance, would not be expected, but there have been some developments which could have important economic benefits. One notable new technique to be extended from a laboratory instrument to production line measurement and control is radioisotope X-ray fluorescence. On a tin-plate production line, several H3/Zr sources with a total activity of about 40 c„ excite Fe K X-rays in the iron below the tin coating. These X-rays are detected by an ionization chamber directly behind the sources and the intensity decreases exponentially with increasing tin thickness. With a time constant of 10 s, variations in tin thickness of ± 1% in the range 0.1 to 1.5 lb/basis box can be detected. As the tin plate is covered with a thin film of oil a measurement using beta-particle backscatter is impossible. This technique can be applied to many coating processes. Accurate continuous measurement of thread and fibre thickness has never been accomplished satisfactorily. However, a beta gauge has recently been developed which can measure fibres of thickness down to 1 dernier with an accuracy of 1% when a time constant of 20 s is used. The beta particles from a 200-me source of Kr85 pass through a wide-angled slot into an ionization chamber and yarn to be measured is located in the slot. Such 326 TECHNICAL AND ECONOMIC SUMMARIES

a device, when brought into practical use on spinning machines or extruders in factories, will have enormous repercussions in the textile industry. Two instruments have recently been developed which illustrate the range of conditions under which radioisotope gauges can now operate; one is for measuring fluid density in a borehole, and the other for measuring the thickness of continuously-produced white-hot steel sheet. In oil-well reservoir studies, determination of the variation with depth of the bore-hole fluids enables the petroleum engineer to deduce many well characteristics. A gauge has therefore been constructed to measure density in the range 0.77 to 0.84 g/cm3 with an accuracy of 0. 02% at pressures of 100 atm and in the temperature range 7°C to 65°C in a probe not exceeding 11.5 cm diam. Because of the restriction on size and the accuracy required, a beta-particle source and a special ionization chamber are used. Measurement of the thickness of steel plate up to 4 m wide, 5 to 40 mm .thick at a temperature of about 1000°C as it comes from a rolling mill, has, up to now, presented many difficulties. A solution has recently been developed which involves probably the largest ionization chamber ever used industrially. Because of the temperature, the detector and the source have to be some distance from the sheet of hot metal. With this bad geometry a highly sensitive ionization chamber is required and a chamber with a 400-mm diam. was designed. To obtain a picture of the variations in thickness across the sheet it was decided to move the source across the sheet. Instead of using several ionization chambers or moving one across in synchronism with the source, one large one 3 m long was constructed. This is placed behind a steel heat shield and cooled by blowing air over it. With a 500-mc source of Co6° an accuracy of ± 0.1 mm was obtained. A digital presentation of the thickness is used so that operators can readily see the trends from one run to another and take the appropriate control measures.

Level gauges

Few significant improvements have been, or can be made to instruments in the level gauge category as they are practically all satisfactorily simple and reliable. The number of such instruments continually increases as the advantages become more widely known and more and more applications are found. The numbers at present installed are sometimes astounding; in the USSR as many as 400 are installed in one mine and in France 200 are installed in one large power station on crushers, powdered-coal feeders and electrostatic precipitator hoppers.

Analysis

Although all radioisotope instruments are basically analytical, the term radioisotope analysis is generally reserved for elemental analysis. It is in this field that the most marked industrial progress has been made. Up to 1961 there were only one or two industrial instruments but these have now increased to about 50. Most of these are installed in the oil industry and use the preferential absorption of H3/Zr or Pm147/AI brems Strahlung in elements of high atomic number to measure the sulphur content of hydrocarbons in hydrofiners. Sulphur content in the range 0.1 to 5% by weight RADIOISOTOPE GAUGES IN INDUSTRY 327

can be measured continually with an accuracy of 0.03% independently of variations in the hydrogen-carbon ratio. The same technique is used to measure and control tetraethylleod content in blending operations on chlorine content of plastics. Many other feasibility studies have been made of this technique and that of radioisotope X-ray fluorescence and laboratory instruments at present being evaluated will eventually result in increasing industrial applications of these techniques.

ACKNOWLEDGEMENTS

The author gratefully acknowledges the information received from Messrs. P.J. Harvey and L. Taylor (Ekco Electronics Ltd. ), H. Finch, R.Y. Parry, D. Peters andS. J. Wright (Baldwin Industrial Control), J. Bosch (Frieseke & Hoepfner G.M.B.H.), E. Bell (Saunders-Roe & Nuclear Enter- prises Ltd. ), S. Margolinas (Société d'Applications Industrielles de la Physique).

ECONOMIC BENEFITS OF RADIOISOTOPE GAUGING

The national reports give mo re details of the economic benefits of radioisotope gauging than of the other techniques. One reason, of course, is that this application is the most widely used. It is equally important, however, that nearly all these methods are almost always introduced directly into industrial production to reveal detailè about the qualities of the product, and that the information provided can be used to alter the production conditions. The benefits are therefore more striking and more easily calculated than when other techniques are employed. The introduction of a gauge in a production line may influence the process economy in one or more ways. It may decrease the consumption of raw material or energy, increase production either through a decrease in scrap or an increase in the productivity of existing units in general; it may lower the labour costs or it may have a direct or indirect influence on the price of the ready-made product. In order to establish cost-benefit ratios for gauging applications, a general presentation of the structure of the gross savings and costs can be made.

STRUCTURE OF GROSS SAVINGS

Raw material savings

Using gauges, an industrial operation can be performed within closer tolerances and often with a lower average cost than before. Industrial products have qualities (such as density, thickness, area, weight, concentration) which vary within certain limits. This has to be accepted, and in practice it is prescribed that the final product should either fall within predetermined limits or in any case should not fall below a given value. In^these cases, the nqrmal operation is so arranged that the average is of a higher value than that actually desired to ensure that even with normal statistical fluctuations the product will always be acceptable. A good gauge will often allow the average value to be kept nearer to the minimum as the statistical fluctu- ation of the product will diminish. The result may be that less raw material is needed for a certain amount of production, or, conversely, that there is an increase in output from a given amount of raw material. In these cases the estimates of gross annual savings can be obtained using either of these schemes: 1. (a) Tolerance average value without gauging Tolerance avera.ge value with nuclear gauging Difference or in % Cost of raw material per ton Annual production in tons Gross annual savings (b) Tolerance average value without gauging Tolerance average value with nuclear gauging Difference or in %

329 330 TECHNICAL AND ECONOMIC SUMMARIES

Marginal product price per ton Less value added in production per ton Increased production per year in tons Gross annual "savings"

Product scrap savings » In many cases the product has to be rejected if it falls outside the given limits. Installation of a gauge will therefore produce a decrease in the amount of scrap. The estimation of the value of this will depend on the fate of the scrap. Sometimes no use at all is found for it, but usually it can be sold at a lower price or returned to an earlier stage of production. Here the most appropriate scheme to follow would be as follows: 2. Scrap per year without gauges, in tons Scrap per year with gauges, in tons Decrease in tons (a) Product price per ton Gross annual savings or: (b) Loss of product price per ton (if sold at a lower price) Gross annual savings or: (c) Value added between scrapping the product and the stage where it could be re-fed per ton Gross annual savings

Labour savings

In some applications, gauges will decrease the number of man-hours necessary for watching a process or even release labour force by speeding up certain time-consuming analytical work. This requires, however, the installation of expensive equipment supplementary to the nuclear gauge. The savings estimates can best be expressed in the decrease of man-hours, using this formula: 3. Man-hours saved per year Average price per man-hour Gross annual savings

Increased productivity

For the reasons stated earlier, the efficiency of plants can be increased when the process being gauged is the bottle-neck of the production line. This might be the case, for example, if the product is dried and the drying period determines the whole rate of production. A fall in the average will here allow faster operation, and therefore a higher output. A decrease in the amount of scrap may also result from faster adjustment of machinery after periods of maintenance or a change in the quality of the product. Further, the shortening of these adjustment periods will also result in an increase in the use of a given plant and thus raise its RADIOISOTOPE GAUGING 331 productivity as a whole. These cases, where the gauge gives an early indication of abnormal conditions so that a shut-down is avoided, can be similarly considered. This is one of the important reasons for using many level- gauges. Either of the following methods might be applicable here: 4. (a) Production per year with gauges Production per year without gauges Difference orin% Marginal product price per ton Less cost of raw material and value added in production per ton Gross annual "savings" (b) Reduction of shut-downs and decrease in adjustment time, hours/year Production per hour, ton Marginal product price per ton . Less cost of raw material and value added in production per ton Gross annual "savings"

Increased price

The most quoted advantage of nuclear gauging is an increase in quality, which makes the product more competitive, although no direct benefits are obtained. The increased quality of the product will in the long run influence the pricing of the product. This is a highly indirect effect, difficult to estimate and is beyond the scope of the survey. But there might also be a marked effect on the short-term price, and for this a simple scheme can be proposed: 5. Price of gauged product per ton Price of ungauged product per ton Difference or in % Annual production in tons or in money Gross annual "savings"

Other advantages

Certain other economic benefits may arise from nuclear gauging, e.g. from lower capital cost compared with other methods offering the same technical advantages, or from increased safety, which means that units are allowed to work without human attendance. Simple schemes can be constructed for all these and similar situations. It should be pointed out that for certain cases some of the methods described above are complementary while in other cases only one approach would be correct. In several cases there is a choice of schemes. The approaches described above have been frequently used in the national reports, although the economic benefits have sometimes been calculated differently. 332 TECHNICAL AND ECONOMIC SUMMARIES

STRUCTURE OF COSTS

The structure of costs is fairly simple for gauging, as most of the costs derive from the installations. Operation and maintenance costs are relatively small, and sophisticated health physics instrumentation is rarely needed. Insurance premiums are generally similar to those charged for other plant instrumentation of comparative value. As most radioisotopes used in gauging devices have a long half-life, sources need to be changed only infrequently, and the the cost of radioisotopes should not be included, but should be added to the cost of the equipment and given an appropriate yearly depreciation. This is a sound approach also because usually the firms selling nuclear instrumentation do not specify the source costs separately from the rest of the instruments on their invoices. In the national reports, most countries have chosen five years as the depreciation period and charged 6% interest. In certain industries, e.g. the manufacture of cigarettes, a shorter depreciation period was often chosen because of uncertainty about the future of this trade.

ALTERNATIVE METHODS

With the definition of savings used in the survey, i.e. a measurable difference in costs between the method used prior to the introduction'of radioisotope techniques and the new radioisotope method, the "reference level" is in most cases well-defined. It represents a laboratory control at a late stage or after the end of processing, or a manual qualitative control. Thus the cost-benefit pattern should be relatively easy to obtain. However, more and more Industrial equipment using various physical measurements is being developed. Thus a fair comparison should include a cost-benefit evaluation for an alternative method that might produce another "reference level". Al- though such calculations are of great importance to industry in selecting gauging principles they are very difficult to perform as they require a large number of parameters. It should be pointed out that such considerations have generally not been covered by the companies in their replies.

EXAMPLES OF SAVINGS FROM THE NATIONAL REPORTS

During the Study Group Meeting on Radioisotope Economics that ended the survey, the methods of establishing the economic benefits from radioisotope use were scrutinized carefully. Some case studies from the reports, from the scientific literature and from the experience of the participants were presented. A number of typical gauging applications will be described below, and the information on gauging in the national reports will be summarized. To a certain extent one can foresee that the savings pattern and the savings themselves will be similar from one factory to another and from one country to another. But great variations must also be expected. If two gauges are installed for an identical purpose their economic importance RADIOISOTOPE GAUGING 333

may not turn out to be identical. Two designs of the same instrument may not give the same accuracy and speed; these qualities are dependent less on the competence of the manufacturer than on the demands of the customer and the price'the latter is willing to pay for the instrument. Moreover, the size of plants will have a considerable impact upon, e.g., the amounts of raw material saved. Finally, the speed with which changes of the input factors influence the production will differ in each plant. Other points that must be kept in mind are the actual market situation and the influence of legislation. When economic benefits are calculated the situation is simplified and it is assumed that a plant can sell the increased production resulting from the installation of nuclear gauges. If it cannot, an increase in output is meaningless. Correspondingly, if the price of raw material is low and its supply to the individual factory unlimited, the situation is quite different from when it is dear or limited. The price and supply of raw material as well as other production factors may differ considerably from country to country. Also these factors change from year to year, although fortunately the period during which the investigations were performed was a fairly stable one, with small changes in the supply and price of raw materials, the demand for industrial products was high and prices good, even if in some countries there were excess capacities in some industries. The effect of legislation is mainly from taxation. In some countries certain raw material is more expensive than in others because of customs or other duties. In other countries the product itself is subject to taxation. Some countries impose a turnover tax on industry, and others an energy tax. Also labour costs and social security costs differ considerably in the countries participating in the survey.

THICKNESS GAUGING

Table I shows how industry in the participating countries was equipped with thickness gauges. In this and the corresponding Tables which follow, only 20 countries have been considered. Israel and Venezuela have been omitted because they had very few applications; Italy and Switzerland because the reports did not give sufficient attention to radioisotopes; and the United States because details of the number of gauges are not available. Table I shows that the paper industry is the chief user of thickness gauging with 1531 devices installed in the 20 countries. Second are chemicals and plastics followed by basic metals and machinery (here considered together), the textile, rubber and cement industries. The remaining industrie s have very few applications of thickness gauging.

Paper industry

As paper thickness gauging is the most frequently used, it is appropriate to start with it. Although it is found in all the countries, the quality of the data differs from country to country. Table II shows the number of paper machines, gauges and production; isotope-assisted output above 2000 t/yr is also listed for each country (this figure has been chosen as a criterion of 334 TECHNICAL AND ECONOMIC SUMMARIES

TABLE I

THE NUMBER OF THICKNESS GAUGES IN VARIOUS INDUSTRIES

Country Broad product group 1 . Foo d 7 . Chemical s an d plastic 8 . Cemen t 6 . Rubbe r 9 . Petro l an d coa 2 . Tobacc o 3 . Textil e 4 . Woo d an pape r 10 . Basi c metal s 11 . Machiner y 12 . Service s No t identifie d Tota l

Argentina - - 2 3 - 1 - - 4 - 1 11 Australia - - 3 12 - 20 - - 2 - 2 - 39 Austria - - - 16 5 7 - - 2 - - - 30 Belgium - - 2 42 1 9 - 1 9 - - - 64 Canada 1 - 1 165 8 17 1 9 17 43 22 - 284 Czechoslovakia - - 2 5 3 8 - - 58 - 5 - 81 Denmark 3 - - 56 2 5 - - 1 - - - 67 Finland - - 2 31 1 3 - - - - 1 - 38 France - - 81 166 35 38 2 - 16 20 - 16 374 Federal Republic of Germany* 1 - 18 382 69 427 86 16 198 20 11 3 1231 Japan - - 6 20 11 13 8 1 46 14 5 3 127 Netherlands - - - 63 10 11 - - 5 - - - 89 Norway - - 5 48 4 6 - - 2 - - - 65 Poland - - - 5 4 - - - 8 - - - 17 Portugal 3 South Africa - - . 10 11 ------21 Spain - - - 4 6 12 - - 12 - - - 34 Sweden - - 20 140 10 75 10 - - 15 - - 270 United Kingdom 1 - 72 357 41 71 17 4 93 51 11 - 718 Yugoslavia - - 1 3 - - 1 - 8 1 - - 14

Total 6 - 215 1531 221 723 125 31 481 164 58 22 3577

* Based upon the national report and other sources of information; the total is probably still too low TABLE II INSTALLATION OF THICKNESS GAUGES IN THE PAPER INDUSTRY

Annual Annual Annual Isotope- Number Number of Number machines isotope - output production assisted of machines of with assisted per Country of output paper thickness gauges output machine >2000 t/yr paper machines gauges Cfr per gauge > 2000 t (%) (1000 t) of total) (1000 t) (1000 t)

Argentina 156 104 3 3 228 n. a. . 2.2 Australia 43 37 12 32 311 40 10 8.4 a Austria n. a. 66 16 24 507 54 17 7.8 5 &s Belgium 77 66 42 64 373 76 6.5 5.8 o Canada 249 249 165 66 7016 ~60 (24) 28 3 Czechoslovakia n. a. n. a. 5 - 456 n. a. r - *a Denmark 28 28 56 (200) 141 n. a. - 7.2 m Finland 113 100 31 31 1706 50 28 17.0 O > France 562 300 166 55 2347 55 ,7.8 7.8 a Federal Republic of Germany 850 406 382 95 2632 ~95 (6.5) 6.5 2 üü Japan n. a. 500 20 4 3319 n. a. - 6.5 Cl Netherlands 179 167 63 35 679 n. a. - 4.0 Norway n. a. 100 48 48 750 49 7.8 7.5 Poland n. a. n. a. 5 - 542 n. a. - - Portugal 60 15 3 20 97 n. a. r 6.5 South Africa n. a. n. a. 10 - 155 20 3.1 - Spain 346 100 4 4 341 n. a. - 3.4 Sweden 252 233 140 60 1931 80 11 8.3 United Kingdom n. a. 461 357 58 2903 52 4.2 6.3 United States of America n. a. 1060 n. a. - 15450 n. a. r 14.8 Yugoslavia n. a. n. a. 3 - 178 n. a. - -

n. a. = not available 336 TECHNICAL AND ECONOMIC SUMMARIES paper production on an "industrial" scale). The figures for the number of machines and paper production were reached in co-operation with the Forest Product Branch of the Food and Agriculture Organization of the United Nations. The figures given for gauges in the Tables have to be treated with some care, as the national reports did not normally list laboratory instruments and in-line gauges separately. The number of laboratory instrument inmost countries is, however, low relative to those mounted in the factories. It is also known that machines are installed in paper board and wallboard plants, but the number is much lower than for paper production. The figures for gauges in Denmark and the Federal Republic of Germany are probably too high, but it was not possible to find any satisfactory explanation for this. Three groups of countries can be distinguished. The first has a very high rate of installations, about 60% or more of the bigger machines being equipped with gauges. To this group belong Belgium, Canada, Denmark, France, the Federal Republic of Germany, Sweden and the United Kingdom. A second group has about one thickness gauge to every three machines: Australia, Austria, Finland and the Netherlands. The final group shows very low percentages: Argentina, Japan, Portugal and Spain. Information on the number of paper machines in Czechoslovakia, Norway, Poland, South Africa and Yugoslavia was not available. The figures for isotope-assisted output were taken from the national reports or obtained directly from the national bodies. When a comparison is made between the isotope-assisted output and the number of gauges the countries with high averages can be found. The average annual output per machine is listed in the Table for comparison, and these averages are high for Canada and Finland also. Table II shows the economic contents of the reports insofar as it was possible to establish data for the thickness gauging of paper. Savings have been estimated for relative isotope-assisted output and the cost-benefit ratios have been calculated. It is obvious that even the averages vary considerably from country to country. In general it is evident that high savings, measured in percentage of isotope-assisted output, correspond to low cost- benefit ratios, i.e. high benefits at a given cost. It might be expected that extremely beneficial results would be found in countries with a high value of output per gauge. This, however, is not so. The four countries with low cost-benefit ratio and with savings of 0. 6% of this output and higher include Finland with 28 000 t/gauge but also Australia, Belgium and Norway with 10000, 6500 and 7800 t/gauge respectively. Canada and Austria, who top the statistics on output per gauge, are at the bottom for cost-benefit ratios. Similarly one finds that Australia and Finland report very high annual net savings per gauge, and Austria and Canada very low. The remaining countries show much the same benefits, ranging from US $ 5000 (Sweden) to US $8400 (Belgium). Table III shows considerable variation, both in savings given in percentage of isotope-assisted output and in the cost-benefit ratios. Finland, Australia, Belgium and Norway show in both cases the highest values. In all four countries the net savings per gauge are much higher than in other TABLE III ECONOMICS OF THICKNESS GAUGING OF PAPER

No. of Savings in gauges on percentage of Cost- Annual net savings No. of which isotope- - benefit Country Total Per gauge Type of savings gauges information' assisted ratio (US«) (US S) was obtained output

Australia 12 12 270000 22000 0.7 1:15 Raw material, scrap Austria 16 16 42000 2600 0.1 1.4 Scrap, increased productivity Belgium 42 42 350000 8400 0.7 1:10 Increased quality , scrap 55 O Canada 165 70 116000 1500 0.1 1:2.8 Capital costs, increased productivity H O Finland 31 48* 750000 15500 0.6 1:20 Scrap, raw material (labour) O France 166 1200000 7300 0.11 1:4 Raw material, scrap > (estimate) 0 O Netherlands 63 360000 5700 0.15 1:6.2 Scrap, increased productivity O Norway 48 24* 260000 10500 0.6 1:10 Better control, scrap, raw material (estimate) Sweden 140 80 400000 5000 0.2 1:5 Scrap, increased productivity United Kingdom 357 (32%) 580000 (5000) 0.4 1:4 Raw material, scrap, increased productivity United States n.a. - 2825000 - 0.3-0.5 1:8.8 Scrap (36<7o), increased productivity (33%), of America raw material (31<7o)

* Including level gauges n.a. = not available 338 TECHNICAL AND ECONOMIC SUMMARIES

countries. In Finland this is obviously due to the high quantity measured by each gauge, but in the other countries there must be another explanation. Bearing the varying figures in mind, it is worth looking at the various ways thickness gauges influence pape r p reduction economy. The thickness gauge in its common form provides a measure of the weight per unit area that is read by the operator. This reading is used by him. for adjusting the supply of water and pulp, and the speed of machinery, to keep a constant weight. As was explained above, any material will show deviations from the average value. The thickness gauge is a better aid than other methods in keeping the paper within the limits, and it also allows a lower average to be kept without producing thin paper. Accordingly, less pulp is needed for a given production, and the decrease in the consumption of raw material may be between 0. 3 and 1%. This type of saving is achieved in some paper mills producing high-quality writing and printing paper that is sold at a given price per square metre. Savings cafc be estimated using formula (l.a). Less expensive paper such as newsprint, however, is marketed and sold not per square metre but per unit weight. The scheme suggested above will therefore not fit, for the producer is not interested in keeping a particularly low value above the given average. But the customers (the printing firms) are interested in getting as many square metres as possible out of a given weight of paper, and they will put a certain pressure on the paper manufacturer to keep a low average thickness. This explains why a firm in the United States report attributed no savings to the radioisotope gauge but nevertheless advertised that it sold gauged products. The radioisotope gauges have, however, another advantage that reveals itself when production is re-started after a stand-still or the machinery is readjusted for another thickness. The direct reading of the deviation from any given thickness speeds up the adjustment considerably: between 5-30 min, according to various statements. This means that an increase in the value of production of 0. 3 - 1. 2% if the stops or changes in quality take place once a day. If they occur frequently, the output and consequently the per- centual "savings" will increase. The besv way of calculating this type of savings is by using formula (4.b). The product obtained in the adjustment period may be sold as sub- standard, but it is normally taken back into production. The value added by the production of this paper is, of course, lost, and an alternative method of estimating the savings would be to use formula (2.b) or (2.c). Whether this or the previous approach should be made depends on the market situation. The methods are alternatives but either of them could be used in combination with (4.b), as the rapid readjustment is an additional advantage to the raw material savings. It should also be mentioned that before gauging was installed part of the paper production was found to be outside the specification and was sold at a lower price. This is a "scrap" problem that adequate use of the gauges would completely eliminate. Scrap savings can therefore be estimated using formula (2.b). In some plants the lowered average value may speed up production because of the quicker drying of the paper, and here additional productivity could be gained, to be evaluated, as in the previous case, using formula RADIOISOTOPE GAUGING 339

Large savings in labour were not reported in the survey, probably because the introduction of a gauge seldom replaces a worker but reduces the number of variables he has to control. The savings pattern of plant is usually mixed, typical example being a case study from the United Kingdom report to the survey. One establishment employs four transmission-type basic weight gauges to monitor production, each using 25 me of T1204. The total investment was. £10 750 including £2000 in 1961. Running costs are small but are not given. Savings arise from the quantity of sub-standard paper produced both during the setting-up period and in the course of production. During a period of weight change on a paper machine the valve controlling the quantity of feedstock is re-set. The re-setting of this valve, prior to the installation of a thickness gauge, had been based on the experience of the operator. The operator's judgment was faulty, and the sampling and weighing had to be repeated until the correct weight was established. One sampling, cutting, and weighing operation might take about five minutes under both the old and the new system); during this time about 5 cwt of paper will have been produced that may have to be scrapped. Weight changes on two paper machines will therefore cause a loss of at least £25 000/yr in loss of production. Other factors leading to savings, but which cannot readily be calculated, are the maintenance of correct weight through the ability to detect changes or trends immediately. This saves paper which might otherwise have to be rejected, and the saving is about £35 000/yr. The total savings of £60 000, in raw material, product scrap and plant productivity, represent 2% of the isotope-assisted turnover and suggest that the investment in the gauges is amortized in just over two months. At the Study Group Meeting on Radioisotope Economics, a similar experience from a United States paper mill was cited: "A very practical reason for holding close to the nominal weight is that we, in effect, give away the amount by which the actual weight of the paper exceeds the nominal weight. Since most of our production is in sheets, and since lightweight sheets are a source of complaints we habitually run to the heavy side. While the exact cost of this giveaway is still the subject of some controversy, the least that can be saved is the cost of the raw material. We expected a reduction in giveaway of about 0. 5%. This would save enough raw material to run the mills for a day and a half each year. While it is difficult to put the exact dollar value on the benefits, we can state that we gain a week or more of productive time each year by cutting down the lost time and also by saving raw materials equal to the amount required for about 1. 3 days per year of production. " In this light, the extremely high and low values given by the various countries can be interpreted. Regarding Finland, the extremely high benefits can be attributed to the overall size of the paper machines; in Australia raw material is quoted as the primary field of saving, which indicates the high quality of the paper produced. The very low value of the savings in Canada, despite the high average production per installed gauge, may be explained by the high percentage of newsprint paper produced in that country. According to the Food and Agri- culture Organization of the United Nations no less than 86% of Canadian paper production falls into this category, while the corresponding value for the 340

Scandinavian countries (Finland, Norway and Sweden) is between 30 and 50%, and for the remaining countries under consideration below 28%. However, it is also clear that the general attitude of a country's industry may considerably affect the ways in which savings are estimated. As a whole, installation of thickness gauges is undoubtedly a sound investment in the paper industry, giving savings of 0.1 - 0. 7% of the production value and paying for themselves on the average in less than one year.

Textile, chemicals and plastics, and rubber industries

In order to find a group of the same size and importance in thickness gauging as the paper industry, three of the broad product groups distinguished in the survey have to be grouped together. This grouping has the advantage, however, that a number of applications can be discussed together which have much in common technically. Table IV gives the economic information from the national reports regarding this technique. It is obvious that the picture here is quite different from that of paper; the range of the savings is much wider, the cost-benefit relation is better, and raw material tends to be the dominating reason for savings. The technical processes in these industries largely explain why this is so. The products (plastic sheets or tubes, textile fabrics, coated or laminated material, rubber sheeting and tyre threads) are almost without exception sold per unit or per area. The use of gauging methods allows the quantity of often expensive raw material to be reduced, by keeping the specifications within closer limits and at a lower average level than otherwise would be possible. Savings can be estimated using formula (l.a). The prospects for the gauges tend also to be better in scrap savings than in the paper industry. While extended rubber and also certain plastic materials can be fed back if they do not meet the specifications, many fabricated products cannot. Thus a product that is outside the specifications must either be scrapped or sold at considerably reduced price. Formulas (2. a) or (2.b) may be applied. The national reports contain several cases where considerable savings have been obtained. For example, in the rubber industry savings of 1. 25% in raw material and 0.75% of scrap in the production of tire cords was reported. In the textile industry the Yugoslav statement may be quoted on cellophane foils where scrap was reduced by 3 - 4% and the rest of the production up-graded by 10 - 15%. The Spanish report shows a 15% reduction in raw mate rials in plastic production together with a certain decrease in the scrap rate. The Netherlands report states that in PVC-coated textiles saving of 25 - 50 g PVC/m2 may be obtained. As the shortened version of the French report does not contain several examples that were in the original, these are therefore quoted here. "In one firm manufacturing plastic coatings the tolerances have been decreased from 0.05 mm to 0.02 mm; and for each change of process which takes place every three hours on the average, there has been a saving of 1 or 2 min in adjustment time. The plant's output is 1100 t/month, raw material costs are F.Fr.l/kg and labour costs F.Fr.0.3/kg; the saving on raw material is estimated at 2%, corresponding to F. Fr. 260 000/yr. The savings resulting from less scrap and quicker adjustment account for 3.2% or F.Fr. 120 000/yr. The yearly savings are TABLE IV ECONOMICS OF THICKNESS GAUGES IN THE TEXTILE, CHEMICALS AND PLASTICS, AND RUBBER INDUSTRIES

No. of Savings in gauges on percentage of Cost- Annual net savings No. of which isotope- - benefit Country Total Per gauge Type of savings gauges information assisted ratio (US«) (USS) was obtained output

Argentina 3 1 12000 . 12000 n. a. 1:10 Scrap, raw material Australia 23 33* 100000 3000 0.8 1:5 •Raw material, scrap (labour) o Austria 12 5 80000 16000 1-1.5 1:10 Raw material, scrap g Finland 6 2 600 300 0.35. 1:1.2 Scrap S France 154 16 180000 12000 0.5-3 1:2-1:40 Raw material, scrap o Netherlands 21 21 164000 8000 n. a. 1:6-1:16 Rawmaterial, scrap, increased productivity I z Norway 15 n. a. 30000 n. a. 0.8-1.6 1:5 Raw material, scrap o Spain 16 2 90000 45000 5 1:50 Raw material, scrap Sweden 105 65 500000 8000 1-7 1:4-1:16 Raw material, scrap United Kingdom 189 371* 3 000 000 8000 1.6-2.5 1:2-1:9 Raw material, scrap (labour) United States n. a. " 6300000 ~ n. a. Iî6-l:20 Raw material (50%), scrap (20%), of America others (30%)

* Including level gauges n.a. = not available 342 TECHNICAL AND ECONOMIC SUMMARIES thus about F.Fr.400000 for .the installation comprising two thickness gauges, the cost of which was F.Fr.40000. The installation cost of the gauges was thus amortized in little more than one month. In a firm producing coated textiles, where five thickness gauges were installed, the estimated labour savings are F.Fr. 3000/yr for sampling and weighing, apart from savings in raw material and scrap estimated at approximately F. Fr. 40 000/yr. This would mean that the installation cost was amortized in two years. In a firm manufacturing plastic tubes two gauges were installed, and the savings in raw material from the decrease in rejects are estimated at F. Fr. 35 000/yr. Products not conforming to specifications are recycled but there is still a loss of about 0.5%. On this basis the amortization period would be about one year. In a plant for PVC-coated textiles producing 4 million metres a year (value F.Fr. 32 million), the savings are mainly in raw material. They are estimated at 2%, representing F.Fr. 320 000/yr, which corresponds to 1% of the output value. Seven thickness gauges were installed; they were amortized in about six months. It is worth noting in addition that the cost of a gauge is very low compared with that of a modern coating machine, which costs about F.Fr. 600 000. In the manufacture of coated canvas for tire casings, thickness gauges allow tolerance to be reduced, resulting in raw material savings totalling about 1% of the product value. The installation of the gauges cost about F.Fr. 200000 and about the same amount is saved annually in raw material. In conclusion, the figures furnished by the various users obviously depend upon the nature of the products, but on the average a thickness gauge controls an annual production of about F.Fr. 2 millions and the annual savings are about F.Fr. 40 000." A participant of the study group meeting from the United States presented two case studies of the application of thickness gauges to polyethylene sheeting and tubing fabrication, and to inner liners of tires. In the first example the factory was run first with, then without, the use of the gauge. Two striking economic factors were observed: firstly, a small increase in throughput of 1 to 4%, amounting to US $ 3000 - US $ 12 000/yr; secondly, scrap reduction of 3.5%, and upgrading of 2.7% of the production from second class to first class. These savings amounted in all to US $29000/yr. The actual cost of installation was US $ 15 000, so that the cost-benefit ratios were very impressive. The second case brought about gross savings of 4. 75% in raw material estimated at US $ 71 000/yr at an installation cost of US $30000. To sum up the examples of thickness gauging presented in the national reports one very favourable cost-benefit ratios are frequently reported ranging from 1 : 5 to 1 : 50, depending on the type of production. The economic benefits come from saving of raw material and reduction of scrap as well as to an increase in general productivity. This group is somewhat inhomogeneous but a reasonable range of the average net annual saving seems to be US $ 5000 - US $ 10 000 per gauge. RADIOISOTOPE GAUGING 343

Metal industries

A large number of thickness gauges are installed in the basic metal and machinery industry to control strips and sheets of steel or other metals and alloys. Although such thickness gauging applications were reported from 16 of the 20 countries listed in Table I, very few economic details could be gained from the national reports. Nevertheless, the report from the Netherlands states that five gauges, corresponding to an investment of HF134000 (US $9500), brought about net savings of HF1 20000 (US $5500)/yr. A cost-benefit ratio of 1: 3.4 could be calculated from this data. The average savings were US $1100 per gauge. Considerably higher savings were mentioned in the NICE report on conditions in the United States in 1958, where 17 users accounted for about US $656000/yr net savings. Including gauges for other purposes such as plating thickness, the savings reached nearly US $1.5 million a year. The reported savings came mainly from raw material, because the gauges can operate closer to the prescribed average. Quite considerable savings in scrap were also reported, because there was less likelihood of producing material outside the specification. It was several times pointed out that the non-contacting gauging methods had the advantage because no product had to be scrapped because of scores or scratches. The amount of raw material saved ranged from 0.5- 5%, and the scrap saved from 0.1- 3% of the total production value.

Stone industry

A particularly beneficial application in this group is the gauging of abrasive paper. The production of this material is a complicated technical procedure where a mixture of a glue and sifted sand is added to a base of paper, paper board or a textile material. Factories normally operate with a high proportion of scrap, but using radioisotope gauges, this has been reduced considerably, and large savings in scrap have frequently been reported; they may amount to several per cent of the total output.

DENSITY GAUGING

The number of density gauges reported in the survey was 2069 (see Table V). There are in general two types of density gauges worth consideration. One type is used in cigarette manufacturing, the other is applied to fluids of various kinds. In Table VI the information on the cigarette industry is summarized. Although it is somewhat incomplete, several interesting facts can be dis- cerned. Cigarette density gauges are installed to a very considerable extent in 11 of the countries listed in theTable, while in 10 countries there is not a single gauge. In two countries the relative amount of installation is very low, as shown by the high averages of cigarette production per gauge. (A modern cigarette machine may produce 200 - 400 million cigarettes a year.) However, for the remainder there is probably almost 100% installation in Canada, Denmark, South Africa and the United States. The 344 TECHNICAL AND ECONOMIC SUMMARIES

TABLE V

THE NUMBER OF DENSITY GAUGES IN VARIOUS INDUSTRIES

Country Broad product group 1 . Foo d 7 . Che m i cal s an d pía tic 2 . Tobacc o 6 . Rubbe r 8 . Cemen t 3 . Textil e 4 . Woo d an pape r 9 . Petro l an d coa 10 . Basi c metal s 11 . Machiner y 12 . Service s Tota l No t identifie d

Argentina Australia 1 32 - - - 1 1 - - - - - 35 Austria Belgium - 4 - - - - - 1 - - - - 5 Canada4 13 464 - 16 - 16 11 4 135+ 9 35 - 703 Czechoslovakia 1 - - - - 6 - 2 - - - - 9 Denmark - 72 6 - - - 2 1 - - - - 81 Finland - - - - - 1 - - 2 - - - 3 France - - - - - 15 - 8 2 7 - 16 48 Federal Republic of Germany* 1 - - 5 1 5 - 2 1 1 1 - 17 Japan - - - - - 2 1 2 7 4 9 6 31 Netherlands - 59 ------7 - 66 Norway - 3 ------1 1 - - 5 Poland - - - - - 1 - 3 - - - - 4 Portugal South Africa - 59 - - - 1 - - 12 - - - 72 Spain - 2 ------2 Sweden - 20 - 1 - - - 4 - - - - 25 United Kingdom 2 897 - 3 - 25 2 8 - 11 9 - 957 Yugoslavia 1 - - 2 2 1 ------6

Total 19 1612 6 27 3 74 17 35 160 33 61 22 2069

* Figures are low because of poor response rate + Classification is probably sometimes inappropriate TABLE VI THE USE OF DENSITY GAUGES IN THE CIGARETTE INDUSTRY

Savings in Annual Isotope- Annual Investment Annual percentage of No. of production of assisted production net Country Total Per gauge isotope- gauges cigarettes output per gauge savings (US$) (US $) assisted (1000 million) (million) (US«) (%) output

_ _ _ _ _ Argentina 22.9 . . Australia 32 18.5 90 505 50000 1600 45000 0.07 Austria - 8.7 ------a Belgium 4 12.3 n. a. (3 100) - 2800 20000 1 5 55 Canada 464 36.7 100 80 1200000 2600 none 0 O Czechoslovakia - 19.4 ------Denmark 72 6.0 ~100 85 n. a. n. a. none 0 3 Finland - 5.8 ------s France (1)+ 41.6 - • - - - - - o Federal Republic of Germany - 55.8 ------Japan - 132.5 ------Netherlands 59 12.0 60 120 224000 4000 140 000 n. a. o Norway 3 1.4 43 200 7200 2400 500 0.1 Poland - 49.7 ------Portugal - 6.4 ' - - - - - South Africa 59 10.1 100 172 180000 3000 50000 n. a. Spain 2 26.4 n. a. (13 000) n. a. n. a. n. a. n. a. Sweden 20 6.7 n. a. (300) n. a. n. a. n. a. n. a. United Kingdom 897 130 n. a. (150) 2800000 3100 30 000* n. a. United States of America n. a. 518 (100) n. a. n. a. n. a. 2955000 n. a. Venezuela - 22.8 ------

* Response rate very poor; savings refer to one user only + Experimental use only n. a. = not available 346 TECHNICAL AND ECONOMIC SUMMARIES

figures in brackets for Sweden and the United Kingdom indicate a very high rate of installation, but it is known to be lowe r in No rway and the Nethe rlands. The figure for Australia may be taken with a certain reservation, because of the exceptionally high figure for production per gauge. Savings in the percentage of isotope-assisted output were accounted for only by Australia, Belgium and Norway. A complete explanation for this unusual picture is difficult to find. The two advantages offered by cigarette density gauging are increased homogeneity and decreased consumption of raw tobacco. Normally, tobacco is a very cheap raw material, so there is little reason for a producer to install a gauge to save raw tobacco. The main reason for installing a gauge is an extra precaution by the manufacturer against under-filled cigarettes being delivered to the customers, for this could cost a fortune in decreased sales. It is known that producers deliberately over-fill cigarettes instead of cutting the raw material consumption to a minimum. In a few countries, however, the state has put a heavy tax on the raw tobacco and this changes the picture considerably. As taxation can increase the cost of raw material by a factor of ten, it is therefore extremely ad- vantageous for a firm to cut the consumption of its raw material down to the lowest possible point without conflicting with the packing demands. Such considerations show how national conditions affect the saving patterns for a radioisotope application. The absence of figures for the industry also reflects the secrecy which surrounds cigarette manufacturing. Density gauging on liquid and slurries was only in its infancy during the survey period, and therefore the number of applications was rather low. The response to the questions on its economic importance was even lower, and when they were available the figures were amalgamated in the reports with the figures for the more widespread applications. Only few case studies can therefore be given here as examples on the advantages from using thickness gauging on liquids. In the French survey are a number of case studies on the installation of density gauges in the chemical industry. The most important one, on the gauging of latex solutions, showed an increased productivity of F. Fr. 60 000/yr. In another similar case annual savings of about F. Fr. 120 000 for an installation of six gauges were reported; the amortization period was about one year. In the first case it was only a couple of months. Very similar figures could be found for the corresponding uses in the United States industry. An important example was given by the Netherlands, where density gauges are applied to continuous dredging operations, where it is important that the concentration of the solid material is kept within certain limits; if it is too high, there is a risk of sedimentation in the pipelines and also of blocking and ruining the pumps. On the other hand, keeping the concentration of solids unnecessarily low means low efficiency of the pumping plants, high running cost and, possibly, the need for installing more dredging units than necessary. Although no value in florins was put on the savings, they were no doubt many times higher than the investment made in gauges. They were probably a percentage of the dredging costs, which run to many millions of florins a year. In South Africa, according to the national report, density gauges are applied to ore pulp in gold mining. Because of smoother operation and de- RADIOISOTOPE GAUGING 347 creased labour costs the savings are approximately R800 (US $ 1100)/yr per gauge. The cost-benefit ratio is not exeptional, but reasonable: 1:3. Some other cases of density gauging were also given in the NICE report on the conditions in the United States in 1958. Important cases here were the density gauging of unpleasant liquids, such as sulphuric acid and sodium hydroxides. Both direct savings in labour and intangible ones from decreased hazards to the workers were frequently quoted.

LEVEL GAUGES

The extent to which level gauging was introduced in various industries at the time of the survey is shown in Table VII. Although the economic information is scattered and not easily comparable, it is obvious that the savings reached are in many instances very considerable. One striking difference between level gauges and thickness and density gauges is that the savings for level gauges are to a very large extent credited to labour and increased productivity in general is second in importance. Even where the industries were not able to express the savings in monetary terms, these reasons were indicated.

Chemical and related industries

As the chemical and petroleum refining industries are the main users of these gauges, these industries will be discussed first. The United States report gives several examples of the benefits derived from level gauges in these industries. One company applied eight gauges (five to measure the level of a high-pressure catch-pot on a polyethylene system and three to measure the level in a low-pressure polyethylene reactor) and credited US $ 200000 to the installation, in the words of the reporte*-: "Had the radioisotope level gauges not been adopted, the plant would have had to be re-designed to minimize production losses". Seven other users were more cautious in their estimates, but said that in total US $ 17 000/yr were saved in labour costs and US $ 33000 in other production factors. Despite the average low savings, all the companies were satisfied because of benefits such as improved quality of product, greater continuity of operations and increased safety. One user states that in a critical and hazardous process radioisotope level gauges were the only reliable means he had found for his operation. Improved level control resulted in fewer process inter- ruptions and thus greater productivity; this was reported by users in these and other industries too. The highest individual savings to any one company in the United States survey were attributed to level gauging. One produce r of gasoline saved US $ 2 million in a 12-month period in 1957-58 because radioisotope level gauges had made it possible to double the length of runs on "thermal" units before shutting down for the removal of coke. Another petroleum refining company estimated savings of US $ 300 000/yr from increased productivity and decreases in shutdowns through the use of radioisotope level gauges on delayed coking units. Other petroleum refineries reported savings from US $6000 to US $ 200 000/yr. One of them found that a radioisotope level gauge elimi- 348 TECHNICAL AND ECONOMIC SUMMARIES

TABLE VII

THE NUMBER OF LEVEL GAUGES IN VARIOUS INDUSTRIES

Country Broad product group

8 1 55 ex _^ Cu "cS t« flja. nj o 43 n) •g o 1« TU it5 nj •0 Xl 'S 0 O 1 o 5 1 •8 i o f J3 u S n) to 1 LL H H 3: U U û. ça a) ^ t

Argentina ------1 - 1 - - - 2

Australia - - - - - 9 - 10 4 2 - - 45

Austria - - - - - 1 ------1

Belgium 4 - - 5 - 10 G 2G 20 - 3 - 74

Canada 10 - - 12 - 85 9 G 12 30 4 - 168

Czechoslovakia 1 - - - - 15 5 - 2 2 - - 25

Denmark - - - - - 6 - G G 2 5 - 25

Finland - - - 17 - 5 - 4 2 - - - 28

France 7 - 6 11 - 102 40 125 164 119 279 5 858 Federal Republic of Germany* 2 - - 5 - 22 16 7 20 20 7 - 99

Japan - - 42 26 - 56 1 7 9 10 2 1 154

Netherlands - - - - - 3 9 128 1 - 8 - 149

Norway - - - 9 - - - - 3 2 - - 14

Poland - - - - - 44 10 33 3 - 98 - 188

Portugal ------1 - - - - 1

South Africa ------2 - 2 - - - 4

Spain - - - - - 2 - - - - * - - 2

Sweden 10 - - 110 - 30 - 5 10 20 - - 185

United Kingdom 16 - - 2 - 161 34 20 45 27 12 - 317

Yugoslavia 4 - - 3 - 7 ------14

Total 54 - 48 200 - 558 133 398 304 234 418 6 2353

* Figures are low because of poor response rate RADIOISOTOPE GAUGING 349 nated a shutdown on.a refinery unit in 1957-58^ saving US $ 10 000 in labour costs alone. Another refinery reported that it formerly opened a petcock to determine the oil level in a coker. By replacing this inaccurate method with a radioisotope liquid level gauge, the refinery was able to realize US $ 98000/yr on each of two units because of fewer repairs and increased productivity. An advanced use of a level gauge was reported by a big UK chemical firm. The purpose of this application was to determine the liquid profiles in absorber towers in operation. By this means the positions of flooding were determined, so that chemical engineers could modify the towers to increase the throughput. This operation not only saved the building of two new towers at a capital cost of about £100000 each, but enabled the increased throughput to be achieved with the existing towers six months earlier than would have been possible by building the new ones — an additional financial advantage of about £50000. Thus a single gauge application saved the firm £250 000. This same firm is using a variety of density or level gauges and estimates a total saving of £300000 from all these applications in 1961, for an annual investment of £5000, which includes only £250 for the radioactive material. The French report showed many examples of the applicability of level gauging. There were several cases showing that savings of F. Fr. 40 000/yr could be obtained from the installation of a level gauge at a cost ofF. Fr.3000. The average was, however, lower: F. Fr.3000 gross (US $600). In the petroleum and coal group, where level gauging was the predominant technique, the Australian report gives savings of US $ 25 000 for an investment of about the same amount (30 gauges). Savings correspond to 0.2% of isotope-assisted output. Much lower figures are given by a Finnish user, and in Belgium a user refused to credit any measurable savings to the use of radioisotope level gauges. On the other hand, very high savings were reported from the Netherlands (cost-benefit ratio- 1:21) and Sweden. In Poland level gauges are used to gauge liquid ammonia at 300 atm, as well as for sulphuric acid and for gases such as carbon dioxide, sulphur dioxide and coal gas. The first case, in the fertilizer industry, is most interesting. In the synthesis of ammonia liquid ammonia is separated from the synthesis gas in high-pressure scrubbers, and the gas returns to the synthesis chambers. The level of the liquid ammonia must be maintained. Should it be too low, the gas enters the low-pressure liquid ammonia storage tanks, opens security valves and results in gas losses. If the upper permissible liquid level is exceeded, ammonia flows into the synthesis chamber with the synthesis gas and the reaction will stop. Conventional mechanical types of level measuring devices exist, but catalyser particles or other impurities often stick in them and they fail to indicate extreme levels. Electrical.contact level indicators placed inside the vessels also fail. After these gauges were introduced production increased by 0.7%; in addition, certain other costs also decreased, but they were more difficult to estimate. The Japanese report shows a total of 154 level gauges, two thirds of which belong to this group (if the textile industry is included). On the average, annual savings of US $ 3600 - US $ 5300 were attributed to each gauge; surprisingly, the labour cost contributions to this sum were very small. 350 TECHNICAL AND ECONOMIC SUMMARIES

Wood processing industry

At the study group meeting two almost identical applications of radioisotope level gauges in the wood processing industry were reviewed. The first one was presented by the Swedish delegate. In this country the "Defibrator" company has sold for many years complete installations for the production of board pulp according to the Asplund process. The equipment consists, in its simplest version, of a preheater where the wood chips are treated with steam for a suitable time before entering the "defibrator" where they are mechanically disintegrated. The residence time in the preheater is critical and has to be regulated within close limits for each quality of pulp. The preheater is pressurized to some 10 atm and it is therefore very difficult to obtain a measurement of the chip level by conventional means. The system used comprises a radioactive level gauge with a Co60- source and two G-M-detectors, mounted one above the other. In this way three level readings can be obtained: low (both detectors responding), normal (one detector responding), and high (neither of the detectors responding). The level gauge must have a high degree of reliability and it is so designed that a change of the dose rate at the detectors of ± 7. 5% in 3 s at 2 mr will be indicated with 99. 9% certainty. The manufacturer gives no figures for the economic significance of the level gauge, but states that there is no satisfactory alternative solution of the level controlling problem. About 300 complete pulp-making units have been delivered, the majority having been ex- ported from Sweden to about 25 countries in all parts of the world. In all cases the shielding of the source has been arranged so as to comply with the local legislation. The Yugoslavs presented a similar case which was also included in their national report. They indicated savings in power steam and labour, together with a quality increase. Cost-benefit ratio was 1: 8; the annual savings corresponded to several per cent of the total output value. For similar applications in the Japanese industry savings of US $67 000/yr were reported by one firm.

Metal industries

In blast furnaces, smooth operation necessitates the maintenance of a constant level of feed material in the shaft, and corresponding precautions have to be taken in the melting of scrap or pig iron in cupola furnaces in foundries. Because of the extreme conditions in the shaft, conventional principles for level gauging fail. Radioisotope gauges, however, withstand the conditions well; therefore they are now frequently found in such furnaces. The signal from the gauge can easily be used for starting a charging process when the material in the shaft approaches the lower level. The economics of these level gauges are referred to in several of the national reports, as well as in literature. The French report gives a great number of examples (savings ranging from F.Fr. 1000 to 10 000/yr per gauge), while the Netherlands give one only providing savings of HF1 10 000/yr. RADIOISOTOPE GAUGING 351

Glass industry

A few level gauging applications were reported from the glass industry. The best evaluation of the economic importance of this technique was made in the report from the United Kingdom. A firm manufacturing moulded glass containers uses four level gauges containing 200 me of Co60 to control the supply of raw materials into the furnace. Each gauge is mounted on one of the channels or feeders supplying glass from the melting furnace to the moulding machines. On three of the furnaces the level gauge operates an automatic control system so that the glass level in the furnace remains constant. Although the gauge works through about two feet of brick and refactory, the control is normally better than 1/32 in. On the fourth furnace the charging system for feeding in the raw materials is not adaptable to automatic control. The accurate control of glass level enables a constant weight of glass to be delivered to the moulding machine, so increasing the uniformity of the product. The main advantage of the isotope method over others is that there is no interruption or interference with feeder operations. Most other methods require some forms of probe to be inserted in the feeder or the furnace. The total investment is £2650, and annual costs €200. Annual savings, mainly from reduction of rejects, are estimated at £190000, a 5% saving on isotope-assisted turnover. The same type of application was mentioned in some of the other national reports. However, no saving estimates were given.

Power engineering

Many industries make use of steam from a steam-boiler as a heat source. Radioisotope level gauges have in several countries been widely applied as safeguards against dry-boiling. The indirect value of an insurance against dry-boiling and, consequently, against explosions in the boiler is high, but falls outside the scope of the survey. This is another example, however, where legislation may have an impact upon the economics of an installation. If, as in some countries like Sweden (see the national reports) steam boilers may be left without human supervision after a gauge has been installed, quite high savings in labour can be recorded. In fact, Swedish case studies gave figures up to US $ 10000/yr for a continuously operating small boiler; the average was, however, lower. In France, the most frequent user of level gauges was the power producing industry with purposes similar to those described above. However, no estimate of their economy was given in the report.

OTHER APPLICATIONS

This group contains component-analysis gauges, logging devices and miscellaneous source-detector combinations. The total number of gauges in the various industries is listed in Table VIII. Information on the economic aspects of the applications of component- analysis gauges was found only in the French survey. Here two cases were 352 TECHNICAL AND ECONOMIC SUMMARIES

TABLE VIII THE NUMBER OF MISCELLANEOUS GAUGES IN VARIOUS INDUSTRIES

Country Broad product group

O a 0, 0) •a o. E n) Q. a O 43 •o o ? nt c id 5T •o o

Australia ------3 - 1 2 - 6

Austria ------3 - - - - 3

Belgium ------1 - - - - 1

Canada ------203 36 - - - 239

Denmark ------1 - - - - 1

. France . - 1 - 8 1 104 - 15 27 29 185 Federal Republic

Japan - - - 3 - 6 - - 3 2 11 4 29

Norway -

Poland ------1 8 1 - - - 10

Portugal - - - - - 1 - 1 - - 2 - 4

South Africa - - - - - 1 - - 2 - 3 10 16

Spain ------2 1 3

United Kingdom - - - 1 - 1 1 19 3 6 14 - 45

Yugoslavia - - - - - 1 - 2 3 1 - - 7

Total - - - 5 - 18 3 365 48 25 61 44 569 RADIOISOTOPE GAUGING 353

reported, both from the petroleum industry: the determination of sulphur in hydrocarbons and of lead in hydrocarbons. The first one was said to save 2000 working hours a year spent on analysis, which was estimated at F.Fr. 50 000. The installation cost of the gauge was F.Fr. 30 000. The cost-benefit ratio was about 1:7. For determining lead economies of about the same rate were reported: 1:6. Although this type of installation was quoted by several countries, no additional information was available. How- ever, the literature contains some details on installations for which much more attractive cost-benefit ratios could be constructed [1] . One application which may be of a great economic importance in the future, and which was briefly described at the study group meeting, is the automatic coal-cutting machines developed in the United Kingdom. They have been used by the National Coal Board since 1962. The method relates to the mechanical mining of coal and particularly the mechanization of coal cutting in narrow seams (one metre thick and less). Two types of automatic mechanical coal cutters have been developed, each of which is controlled by the use of gamma-ray back-scattering from a source mounted on the underside of the machine. The gamma rays back-scattered from the floor of the out seam indicate by their intensity whether the floor is composed of coal or shale; it is even possible to arrange automatically that a floor thickness of one inch of coal is kept above the shale. In this way the cutting machines are guided along coal seams without cutting either the floor or the roof of the coal seam. The importance of this in maintaining coal quality and increasing output per man-hour is, of course, obvious. In 1962 an investigation was done by the coal board into one of these machines, the Midget Minor, operating underground in a mine over a period of about nine months, and the result of this test showed that the machine represented an economy of about £10000/yr. The use of radioisotope sources in logging for oil, gas, coal and mineral deposits has won general acceptance during the last ten years. However, the evaluation of this technique is subject to great controversy. In most cases, the national surveys have not been able to report any savings from the use of improved logging techniques. A statement is often made that when drilling prospecting holes, all possible techniques will be used to collect the most extensive and accurate information about the underground strata, and thus there are no advantages in any particular type of logs. On the other hand, when production wells are drilled, the position of the productive zones are known and the simplest log is used to check their presence; this is generally not a radioisotope log. The Argentine report may be contrasted with this. In the French report also it is stated that one user attributed F.Fr. 300000 to isotope methods because other logging operations would be superfluous. Finally, in the estimates made by the USSR Academy of Sciences for 1960, no less than a third of the total savings to the economy (Rb 65 million) were credited to logging operations. The extent of well logging is very large. According to the USSR report, 9 million running metres of wells are inspected every year, of which 3 million metres are subject to tracer methods for checking cementing, frac- tioning, etc. An additional 1.6 million running metres were logged in coal 354 TECHNICAL AND ECONOMIC SUMMARIES

TABLE IX ANNUAL SAVINGS (IN ROUBLES) TO USSR ECONOMY FROM THE APPLICATION OF RADIOISOTOPES IN OIL AND COAL INDUSTRIES

Oil and Gas (Rb) Searching and prospecting 9 million

Studying the geological section of wells 11 million

Checking on the technical state and quality of capital repair of wells 25 million

Checking on the development of the deposit and intensifying production 10 million

Subtotal 55 million

Coal

Prospecting and drilling 8-11 million

Total ' 63 - 66 million prospecting. Table IX shows the estimated savings in underground work with radioactive isotopes. The same principles as in oil logging are used for surface and sub- surface determination of soil density and moisture. A great variety of instruments of this kind are marketed, and they have obviously found an extensive use in recent years. However, their economic importance was reviewed only in one case, in the Spanish report: a moisture-density gauge was amortized in three months. The economy of the odd source-detector combinations varies very much, of course, from one case to another. Here economic information on a few types will be dealt with. The first one is reported from Denmark and South Africa and concerns the checking of cast alumina bricks for porosities and average density. This is done by measuring the absorption of gamma radiation in the bricks. The cost is quite low. By sorting out faulty blocks and choosing those with the highest density for the most heavily eroded parts of glass furnaces, the time between re-linings can be increased considerably. The method is still too new to be evaluated with certainly, but a minimum value of US $ 30 000/yr was given in the South African report. The Danish statement at the study group meeting was still more optimistic. Under favourable conditions a radiometric method can be used to determine the wall thicknesses of containers, e. g., for corrosive liquids. A Danish study of such a tank for sulphuric acid with wall thicknesses of 60 - 70 mm could be performed at a cost of about one third of that for a complete radiographie inspection. RADIOISOTOPE GAUGING 355

SUMMARY AND GLOBAL OUTLOOK

Although the completeness of the data and its manner of presentation differed from country to country, the general approach of the national bodies towards the definition of savings was the same. It should therefore be possible to compare the results and to sum up the total savings gained from the use of radioisotope gauging in industry throughout the world. To do this it is necessary to summarize the best available data from the participating countries and those important industrial nations who decided not to contribute directly to the survey. It is evident that only a few participating countries made estimates as to their own total savings. On the average, the response to the questions on savings was poor, and most national bodies hesitated to scale up the available economic details from the sample to the whole industry. To meet the request of those bodies and persons who initiated the survey, the Secretariat of the International Atomic Energy Agency and the experts who advised the Secretariat on these questions, decided to estimate for each participating country and also for world industry the total net annual savings. Great care must be taken in making this estimate. Whenever possible, the figures given by the national bodies were accepted if they seemed reasonable. For the remaining countries, further up-scaling was made taking into account such factors as the standard values for average savings per gauge, the amount of isotope-assisted output and well-established cost- benefit ratios. Table X shows how this approach worked out. In the first column is the total number of gauges and in the second and third the available information on investment and annual savings. The number of gauges upon which this information was based is also given, and information on whether the savings were accounted gross or net. In the last two columns are presented one high and one low estimate of the net annual savings for the country in question. The estimates should be self-explanatory as far as the first 20 countries are concerned. The figures provided by the national bodies are in most cases either given as the low level figures or are within the two estimates. Only for Czechoslovakia and Poland have the national figures been used for the upper estimate, not for any doubts on the reliability of figures given in local currency, but because the official exchange rates to the dollar over- rate the value of the currency. The low estimates are therefore based on a modest correction. For the United States the figures for 1963, estimated by Arthur D. Little, Inc., for the Atomic Energy Commission, are used. For the Soviet Union estimates made by its academy of sciences, and referred to previously, have been used. It is believed that these estimates are sound and that the approach corresponds reasonably well to the one chosen by the Agency. There is no figure for the total number of gauges installed in the USSR, but it is stated that in the early 1960's more than 2500 were being installed yearly. For 1961, the savings from installation of gauging to check and control industrial processes were given as Rb 60 million, and the savings in the coal and oil industries were Rb 63 - 66 million. After deducting that which could be attributed to tracer applications, a total of about Rb 110 million (about US $ 100 million) remains. TABLE X WORLD SAVINGS ESTIMATE FOR RADIOISOTOPE GAUGING

Investment Annual savings Estimated annual savings (US$) No. of No. of No. of Country gauges gauges (US $) gauges (US $) Low High included included

Argentina 33 23 293 000 2 25000 gross 200 000 400000 a Australia 125 450 000 125 550 000 net 500000 600000 z •R Austria 34 30 110000 21 120000 net 120000 180000 > Belgium 144 46 170000 46 320000 net 520000 840000 Canada 1394 70 325 000 70 115000 - 800000 2400000 Czechoslovakia 115 - 115 1500000 net 1000000 1500000 Denmark 174 - - 300000 1 000000 Finland 69 69 160000 52 750000 net 750000 900000 o France 1465 4000000 3 200 000 net 2600000 3800000 'Zo Federal Republic of Germany ~2000 ~1000 2000000 (300) 900 000 net 5000000 8 000 000 £ Japan 341 2 500 000 net 2000000 3000000 n Netherlands 304 169 620000 169 730 000 net 1000000 1 500000 CO Norway 84 ~ 300 000 net 300000 300000 C Poland 219 2900000 net 1900000 2 900 000 Portugal 8 South Africa 113 100 300 000 67 150 000 net 200000 300 000 l Spain 41 4 125000 net 150000 300 000 Sweden 480 . 2000000 2400000 net 1800000 3000000 United Kingdom 2037 92% 5400000 34% 3 200 000 gross 7500000 12000000 Yugoslavia 41 125000 400000 Subtotal ~26. 7 million ~43.4 million United States of America -9000 35. 2 million 50.4 million USSR ? 100 million 100 million Grand total ~162 million ~194 million RADIOISOTOPE GAUGING 357

Table X shows that the net savings from the applications of radioisotope gauging in world industry ranges from US $ 162 million to US $ 194million/yr. These figures apply to only the direct savings to industry itself and do not include customers' savings, intangible savings or savings to the national economy as such from the better allocation of resources.

THE USE OF IONIZATION METHODS IN INDUSTRY

C.G.CLAYTON WANTAGE RESEARCH LABORATORY ATOMIC ENERGY RESEARCH ESTABLISHMENT, WANTAGE, BERKS., ENGLAND

1. INTRODUCTION

The class of radioisotope application based on the interaction of radiation with gases has resulted in the most widespread distribution of radioisotopes into the community, although the general application of the techniques is not uniformly spread throughout the world. In some countries these particular techniques are responsible for a significant proportion of the economic savings from isotope use, in other countries there are virtually no applications based on ionization in gases. In the United Kingdom the present survey, covering the year 1961-62, indicates that 14% of all isotope applications fall into this category. Apart from direct industrial savings, the value of techniques such as gas chromatography in scientific experiments in widely diverse fields is considerable and not likely to decrease in the future. There appears to be an increasing awareness of the benefits from using radioisotopes in problems concerning gases and it is likely that, with further development, there will be a substantial increase in the number and range of applications of this type. The present paper reviews the various applications of isotopes using ionization in gases and includes their use in (1) Smoke detection; (2) Gas chromatography; (3) Cold-cathode gas discharge tubes; (4) Gas flow measurement; (5) Lightning conductors; (6) Static charge eliminators; (7) Vacuum measurement. As far as possible information has been drawn from papers generally available in the world scientific press. If emphasis appears to be on papers published in English this is merely because these were more readily available and understandable to the author. Sources in the United Kingdom have been used exclusively for unpublished information. Not all the techniques and applications listed here are of equal importance, nor are they at the same stage of development. Static charge elimination, for example, which was one of the earliest examples of the application of isotopes in industry, is not now as popular in the United Kingdom as it was, mainly as a result of recent legislation concerning the use of sealed sources. In other countries the use of radioisotope static eliminators appears to be well established. Although there are many advantages claimed for systems of gas-flow measurement using radioisotopes, industry appears to be slow to take full advantage of these methods. Radioisotope ionization

359 360 TECHNICAL AND ECONOMIC SUMMARIES

chambers have increased in number rapidly during the past few years and are now an accepted and integral part of an important method of analysis by gas chromatography. Whereas smoke detectors are now widely installed in the more industrialized countries, the application of radioisotopes in cold-cathode discharge tubes is restricted to those countries manufacturing these devices. The use of lightning conductors incorporating radioisotopes is generally widespread.

2. THE IONIZATION CHAMBER SMOKE DETECTOR

The losses to the economy of a country through damage caused by fire are too well appreciated to require elaboration here. However, some idea of the actual magnitude involved can be obtained from the fact that in the United Kingdom alone the estimated damage during 1963 was £66000000 not counting the foreign currency required to replace capital equipment, the loss of output from interrupted production programmes and the disturbance in management that even the smallest fire involves. In addition there is always the human misery and suffering attendant upon disasters of this kind. lonization smoke detectors using radioisotopes are making a substantial contribution to this problem by giving early warning against fire. In the United Kingdom there are approximately 250000 detectors in use in 1500 to 2000 different installations and there is at least an equal number in the rest of Europe. The number of installations in the United States of America is estimated as being more than 250 000. In the past three years in the United Kingdom 500 fires have been detected at such an early stage using these devices that in 80% of the cases the extent of the damage was virtually negligible. At present ionization smoke detectors are installed in one in every four computers manufactured in the United Kingdom. The savings from their use is already substantial. Some idea of the general acceptance of smoke detectors can be obtained from the fact that they are approved by the Insurance Companies and considered by the Fire Offices' Committee of the United Kingdom to be the only worthwhile type of smoke detector. Similar attitudes are expressed by equivalent organizations in a number of countries. In particular circumstances, when installations of ionizing smoke detectors are approved by the Fire Offices' Committee, reductions of premiums can be obtained. The first idea of using an ionization chamber as a smoke detector is attributed to GREINACHER [1] who described a differential ion chamber to determine the dust content of air and suggested the possibility of detecting smoke by the same means. MALSALLEZ and BREITMANN [2] and JAEGER [3] also worked on the same problem but their designs were not completely satisfactory, mainly due to instabilities in electronic components available at the time. The first satisfactory instrument was described by MEILI [4] and this, basically, is the design which is now adopted in commercial installations. Its operation depends on the fact that the current in a saturated ionization chamber containing a radioisotope source emitting a-particles will decrease lONIZATION METHODS IN INDUSTRY 361

following the introduction of heavy smoke particles into the chamber. The decrease in current arises for the following reasons: (i) Air molecules are ionized as a result of inter action with «-particles, (ii) Smoke particles act as condensation nuclei and themselves become ionized by charge exchange with the ionized air molecules. The heavy mass of the smoke particle results in a greatly reduced mobility compared with the mobility of air molecules, (iii) The probability of re-combination is increased due to the presence of the low mobility, ionized smoke particles. The proportionate change in current is much greater than the proportion of heavy particles introduced into the gas. Thus, a change of about 10% in current occurs when the concentration of combustion products is only 1 part in 104 by weight.

SEALED lONIZATION CHAMBER HT+Ve

TO CONTROL CIRCUITS RADIOACTIVE SOURCES T

OPEniN lONIZATIOl N 4? CHAMBER

Fig.l Circuit diagram of ionization-chamber smoke detector

A diagram of a practical system is shown schematically in Fig. 1. It consists of two similar ionization chambers, one being completely sealed and the other open to the atmosphere, and thus to any smoke particles which may be present. The sealed chamber is operated in a saturated state and gives a constant current over a wide voltage range. Its dynamic impedance is about 50% higher than that of the open chamber. The sealed chamber thus acts as a constant current device so that for a given reduction in current, and hence increase in resistance in the open chamber which is operated in an unsaturated state, the voltage rise at the junction between the two chambers is greater than would occur if the sealed chamber were replaced by a resistor. The mid-point of the two ionization chambers is fed to the trigger voltage of a cold-cathode discharge tube. Under normal operation, in the absence of smoke, the trigger electrode potential is too low to cause the tube to ignite. As the current in the open ionization chamber decreases, however, the trigger electrode potential rises and the tube "fires". In routine installations, the discharge current (approx. 15 m A) is used to actuate a relay warning device either in the same building or, in some cases, in the local fire station. In the early designs of this type of smoke detector the preferred radioisotope was Ra226 but nowadays Am241 is used with an activity of 65 juc. 362 TECHNICAL AND ECONOMIC SUMMARIES

The normal operating currents are approximately 10~9 A so that insulation resistance should be at least 1012 f2. In many industrial environments it is difficult to maintain this high value of insulation over long periods but this can usually be overcome by "purging" the open ionization chamber with clean air at regular intervals. It is claimed, however, that the required insulation can be maintained even under conditions of 100% humidity over a period of several days by suitably treating the insulating surfaces. Areas with a high concentration of condensed steam, such as at the wet end of a paper mill, or in a laundry, should be avoided, but this problem can usually be overcome by suitably siting the instrument. Intense electric fields, from welding and brazing equipment, for instance, and concentrations of 15 - 20% or more of heavy organic vapours can affect the performance of instruments of this type, but with these reservations, radioisotope smoke detectors of this design have considerable value.

3. IONIZATION DETECTORS IN GAS CHROMATOGRAPHY

One of the most important developments in gas chromatography in recent years has been the introduction of high sensitivity ionization detectors first suggested by POMPEO and OTVOS [5] and developed mainly by LOVELOCK [6, 7] . With the advent of the argon detector the separation of multi- component mixtures can be carried out with a few micrograms of sample. The ability to detect such small quantities has also enabled the advantages of high efficiency conventional columns [8] and capillary columns [9] to be taken up since neither can function satisfactorily with the large samples required to operate the less sensitive thermal detectors. As a result of the low pressure drop across these columns, and the inherent low plate capacity, extremely short analysis times and sensitivities, corresponding to over 106 theoretical plates, have been achieved. Besides the solution of research problems, gas chromatography incorporating ionization detectors is also now being used for "on-stream" analysis of a wide range of components in industrial chemical and biochemical processes. A detector for use in gas chromatography should be simple, reliable, have a rapid response time and provide an electrical signal capable of operating recording equipment. Above all it should be sensitive. A range of ionization detectors with varying characteristics for different applications is now available and the underlying physical principles of each is described below.

'General principles of the ionization detector

If a gas is made to flow slowly through an ionization chamber in a radiation field, the number of ions collected depends on the strength of the field, the density of the gas, the ionization cross-section of the gas molecules and on the recombination coefficient of the ions produced in the gas. If a second gas is allowed to mix with the first, a change in collector current will result if the ionization cross-sections or the recombination co-efficients of the two gases are different. This change in collector current provides a means of distinguishing between the two gases, and, in combination with lONIZATION METHODS IN INDUSTRY 363 the gas-liquid Chromatographie column, of identifying them, and forms the basis of the simplest form of ionization detector. Ionized molecules present in gas mixtures also undergo interactions specific to the gases present and these are also used in more sophisticated devices to identify the constituents of the mixture, as are other physical properties, such as ion mobility and electron affinity. The ultimate limits of detection are determined by the efficiency of the ionization and recombination processes, by interference from ionization in the carrier gas and by the sensitivity of the measuring instrument. It is common practice to "back-off" the "dark" current due to the carrier gas and the ultimate limit to sensitivity in the test gas then results from the random nature of ion production, and the time response of the measuring instrument at its maximum sensitivity.

The cross-section detector

This was the first type of ionization detector to be used and it still possesses several advantages over alternative types. It is the only method capable of measuring gas concentrations up to 100%, it can be used with any type of carrier gas and, in theory, there is no restriction as to the impurity gas or vapour with which it can operate. The response to any chosen impurity can be calculated from published values of ionization cross-sections of the constituent elements of a complex molecule. Its main disadvantage is a relatively low sensitivity which makes it unsuitable for many applications, the smallest detectable volume concentration of the impurity gas being about 1 part in 104 of that of the carrier. The physical basis of this method has been described in detail by OTVOS and STEVENSON [1] and an outline only will be given here. When an ionization chamber is exposed to particles having a range greater than the dimensions of the chamber, the rate of production of ion pairs, i, is given by the relationship,

i = KP/RT E X Q, (1) where X is the total molar fraction and Q is the cross-section for ionization of the gas mixture, Pis the pressure in the chamber, Ris the gas constant, and K is a constant determined by the chamber geometry and the radiation intensity. In general the denser polyatomic gases and vapours result in an increased total radiation absorption compared with light carrier gases such as H or He and are therefore detected on account of the increase in current which is produced. A practical design of a chamber based on this principle is shown in Fig.2. The volume is large enough to provide a measurable current but not too large to result in significant gas hold-up. Typical volumes are between 0. 5 and 5. 0 ml. Sr90/Y90or Pm147 sources are preferred: the range of H3 ß-particles and »-particles is too small in gases at atmospheric pressure. 364 TECHNICAL AND ECONOMIC SUMMARIES

GAS OUTLET

-PTFE

-BRASS

SOURCE OF MONIZING RADIATION

SCALE (cm)

CARRIER GAS INLET

Fig. 2 lonization cross-section detector *polytetrafluorethylene

The performance of this detector has been discussed by Lovelock and a brief summary is given in Table I.

Argon ionization detector

This is the most common of all the ionization detectors and depends for its operation on two basic reactions: (1) The excitation of argon to its metastable states; and (2) Energy exchange reactions between the metastable states or argon and other molecules having ionization potentials less than the potentials of the metastable states in argon (11.7 eV). In an ionization chamber using argon as the carrier gas, the increase in current I caused by the addition of vapour with concentration C is given by the relationship

CA(x + y) I = + B, (3) CA {1- aexp [b(V- 1)]} where A, B, a and b are constants [6, 11] . V is the applied potential, x is the primary electron concentration and y is the initial concentration of metastable states. Provided the recombination and space charge limits are not exceeded, there is a rapid increase in current with increase in vapour concentration tending to an infinite current at some finite vapour concentration. This result is borne out experimentally and practical detectors always include some means of limiting the total current at high vapour concentrations, lONIZATION METHODS IN INDUSTRY 365

TABLE I

PERFORMANCE OF DETECTORS USED IN GAS CHROMATOGRAPHY

Type of detector Argon Electron Electron Characteristic Cross- section detector detector capture mobility detector detector

Carrier gas H2 A A A Background current 10"9 - KT8 1CT8 3xl(T9 3xlCT10 (A) Lowest detectable 2 X 10"7 4X1CT13 3X10"14 10'" impurity (g/s) propane propane carbon carbon dioxide tetrachloride Detectable All Most organic Halogen and Permanent substances and inorganic oxygen gases and vapours compounds organic vapours

either by using a series resistance or by operating with space charge control at high currents. The outstanding characteristics of the argon detector are its high ionization efficiency and ability to respond to almost all volatile components. The production of metastable states and the subsequent ionization of vapour molecules by collision are both efficient processes provided the ionization potential of the vapour molecules is sufficiently low. Each primary electron from Sr90/Y90 in an ionization chamber such as the one shown in Fig. 3 can generate 104 metastable states and the probability of ionization by collision approaches unity. A total ionization efficiency of 10% has been observed in some argon detectors. The principal disadvantages are the maximum detectable vapour concentration., which lies between 1 part in 103 and 1 part in 105 by volume, and the fact that the performance is seriously impaired by the presence of water vapour in the carrier gas. Also this detector will not respond to gases whose ionization potential lies above the potentials of the metastable states in argon, and included in these gases are many inorganic compounds and the permanent gases. Attempts to overcome this deficiency with this type of detector have been made [12] using He (ionization potential = 20. 8 V) in place of argon, but only a limited success has been reported, probably due to the impurities present in the He used as carrier. The main alternative to the argon ionization detector is the flame ionization detector. However, the ionization efficiency of the argon detector is about one thousand times greater than the flame detector so that although it is capable of detecting a similar range of compounds, the argon detector results in a correspondingly greater signal for the same rate of sample input. As a result measurements with the argon detector can often be made with relatively simple amplifiers, and, since the signal strength is large, fast response times can be obtained. 366 TECHNICAL AND ECONOMIC SUMMARIES

GAS FROM COLUMN

BRASS BODY

RADIOACTIVE FOIL

CENTRAL PROBE

LEAD RADIATION SHIELD

GAS TO FLOWMETER

TO AMPLIFIER

Fig. 3 Argon ionization detector

The design of a commercial argon ionization detector is shown in Fig. 3. A cylindrical construction is adopted, the anode forming the high voltage central electrode within an outer electrode made from a radioactive foil; in this case 20 me Sr90/y90. The sensitivity is such that it is possible to detect 1 part of the test gas in 108 parts of the carrier (equivalent to 10"11 moles, approx. ).

Electron capture ionization detector

The rate of re-combination between positive and negative molecular ions is between 10b and 10b times greater than between free electrons and positive ions. The presence of a gas or vapour capable of capturing free electrons to form negative ions is, therefore, readily observed in a free electron gas as an increased rate of recombination, and hence a decrease in ionization current. The magnitude of the current I with a test gas at concentration C, is given by the relation,

I = Ig exp(-KCx), (3)

where Is is the saturation current with the carrier gas alone, K is a constant determined by the field strength and the electron affinity of the test gas, and x is a constant determined by the dimensions of the ionization chamber. lONIZATION METHODS IN INDUSTRY 367

PTFE BRASS

Fig. 4 Electron capture ionization detector *polytetrafluorethylene

A design of electron capture detector due to LOVELOCK [13], is shown in Fig. 4. Carrier gas is arranged to flow in the opposite direction to the negative charge carriers. When these are free electrons their drift velocity greatly exceeds the linear gas velocity so that their collection is unhindered. Negative molecular ions, however, drift slowly to the anode and the gas flow increases their time of transit across the chamber and therefore their probability of encountering a positive ion. The carrier gases most generally used are He, N and H. Argon may be used but results are then difficult to interpret quantitatively due to other forms of ion-ion interactions which may occur. General performance characteristics for this chamber are given in Table I. Although this detector has a limited dynamic range its response to different concentrations of the test substance obeys Beer's law closely enough to permit calibration or calculation when the quantities to be measured are outside the linear range. The dynamic range can be varied by altering the applied potential. The electron capture ionization chamber is particularly suitable to quantitative analysis of the halogen compounds, ozone, oxygen and certain oxygen-containing compounds such as volatile nitrates. For these gases and vapours it is the most sensitive detector available, and is especially important since these substances are difficult to measure at low concentration by other methods. In the high resolution capillary tube columns suggested by GOLAY [9], the maximum load which can be handled is approximately 1 jug. Difficulties in the collection and identification of the lesser components emerging from such a column have largely been resolved by the use of the electron capture detector.

Electron mobility detector

Few of the permanent gases can be measured at low concentrations with the detectors described so far. Methods of analysis for these gases are 368 TECHNICAL AND ECONOMIC SUMMARIES based, either directly or indirectly, on changes in the mobility of electrons in the noble gases when other gases are present. In the direct method argon is used as the carrier gas. It is ionized in a localized region near the cathode by radiation having a small range in the gas; such as a-particles or low energy j3-particles from Ha. Electrical pulses are applied to an anode at some distance from the ionized region and the duration of the pulses is adjusted so that in the pure gas there is insufficient time for electrons to drift to the anode and the current is small. With a second gas present, the mean velocity between collisions is reduced and, as a result, there is an increase in the bulk drift velocity towards the anode. During the application of the pulse, therefore, there is an increase in collector current proportional to the concentration of the second gas. The circuit diagram of the generating and collecting system shown in Fig. 5 uses a detector similar to the electron capture detector of Fig. 4.

PULSE GENERATOR

' ^ •o5: i> l O-OOlJ ohm a <> u F "* :

Fig. 5 Circuit diagram of electron mobility detector using the same ionization chamber as for the electron-capture method

A feature of this method is that the detector can be rendered insensitive in turn to the di-, tri-, and polyatomic gases simply by decreasing the duration of the applied voltages. This detector is sensitive to nearly all the permanent gases and volatile substances. The response to other rare gases is slight or negligible. It is insensitive to nitrogen and does not respond to halogenated compounds and other highly electropositive gases. The low concentration of test gas which can be studied limits the general application of this method in gas analysis and its main usefulness is confined to low concentrations of water, carbon dioxide, carbon monoxide and the permanent gases.

Applications

The widespread application of ionization chambers in gas Chromato- graphie units can be appreciated when it is realized that one firm in the United Kingdom has over 700 of its instruments installed in research and plant-control laboratories throughout the world in industries producing cement, coal, chemicals, fertilizers, food, gas, glass, petroleum products, soaps and detergents, telecommunication equipment and textiles. Recently lONIZATION METHODS IN INDUSTRY 369

units incorporating the argon detector have been used for direct "on-stream" analysis. The following examples illustrate the choice of ionization detector for different applications of gas chromatography.

Mine-gas analysis

One of the principal hazards in a coal mine is the presence of methane in the atmosphere which may also include lower hydrocarbon gases such as H, CO, CÜ2 in varying quantities. When conditions are very bad the methane concentration may rise to 80% but under favourable conditions the the concentration is only a few parts per million of any sample. In normal practice tests for methane are made at the coal face using either a flame safety lamp or a methanometer. Research is now being carried out to show variations in the detailed composition of mine gas and to correlate the results with varying methane concentration as indicated by the statutory tests. Samples are taken underground using either balloons or glass or aluminium bottles filled to several atmospheres by means of a two-stage pump and presented to a gas Chromatographie unit operated at ground level. A system now in operation uses a Linde Sieve Column and a cross- section detector, because of its high sensitivity to both organic and inorganic gases and its wide linear range over the expected concentrations. Helium is used as the carrier gas. A typical analysis is shown in Fig. 6.

2O-I T TEMPERATURE PROGRAMMED AT IO°C/min

ROOM TEMP

Chromatograph showing the identification of methane in mine gas using a cross-section detector

Column: 2-ft molecular sieve 5A Carrier gas: Helium

Pesticide analysis

The use of pesticides to spray crops is well known and highly effective, but the toxicity of some pesticides is high and regular analysis on the quantity 370 TECHNICAL AND ECONOMIC SUMMARIES of residual pesticides on crops must be carried out. The problem is however complicated by the large quantities of other organic materials extracted from the crops during treatment of their residues. However,, since many pesticides are strongly halogenated, with very strong electron-capture characteristics, an electron-capture detector can be used, so that the pesticides can be analysed without interference from the solvent or from other extracted materials. The relative performance of the electron-capture and argon detectors is shown in Fig. 7.

45- DETECTOR: DETECTOR: 4O- ARGON IONIZATION ELECTRON CAPTURE 35- SAMPLE 3O- ALDRIN + DIELDRIN ^,25- IN GRAIN EXTRACT

J2O- -20 Note :3ppm DIELDRIN HARDLY -15 _ 3ppm DIELDRIN PIO 10 j sH I ppm ALDRIN 5 - O P START START

Fig. 7 Comparison of the performance of argon ionization and electron-capture detectors used with a gas Chromatographie column to identify aldrin and dieldrin in grain extract

Analysis of acetylene and other hydrocarbons in oxygen producing plant

In the industrial production of oxygen, small quantities of hydrocarbons from the air intake stack may concentrate in a liquid oxygen reservoir with a potential danger of explosion. The control level for acetylene in liquid oxygen, for instance, is ~ 0. 5 ppm, although this figure will vary according to the design of the plant. Above this value acetylene is less soluble and could crystallize out. Acetylene crystals are readily detonated and could trigger-off a major explosion. An automatic analyser incorporating an argon ionization detector is now in use for the routine analysis of acetylene and other hydrocarbons in this plant. Sensitivity for acetylene with the chromatogram of Fig. 8 is 15 ppm full- scale and the lower limit of sensitivity is 0. 05 ppm. Accuracy of absolute calibration is ± 5% full-scale deflection and reproducibility is ± 0. 5% full- scale.

4. STABILIZATION OF COLD-CATHODE GAS-DISCHARGE TUBES

A cold-cathode, gas-filled valve will ignite when a voltage in excess of the ignition voltage is applied to the electrodes. The ignition voltage, lONIZATION METHODS IN INDUSTRY 371

ACETYLENE SENSITIVITY: I5p.p.m. FULL SCALE.

30-

20H UJ

^=^=s—- n PU I AtNC. ._ n irr A Me 1O_ ISO BUTANE un f —PROPYLENE ^OXYGENPROPANE

Measurement of acetylene impurities during oxygen production by means of a gas Chromatograph column and an argon ionization detector Acetylene sensitivity: 15 ppm full scale; Limit of detection: 0.05 ppm defined as the lowest voltage which, when applied indefinitely, will cause breakdown, is determined by the electrode geometry and the type and pressure of the filling gas. Breakdown is not initiated as soon as the ignition voltage is exceeded. There may be a delay (usually called the ignition delay time) depending on whether or not ions or free electrons are present in the field space. If the probability of an ionizing particle being present is small, the delay may be large, and wide variations in the breakdown potential are then observed. Without special arrangements, an electron will be liberated in the field space by cosmic radiation, or by radiations from natural radioactive contamination in the materials used for valve construction. Under these circumstances an ignition delay time of several seconds may be observed. The ignition delay time may be reduced by using photo-emissive electrode surfaces and this can be satisfactory if some source of illumination is available. Nowadays the problem is overcome in cold-cathode discharge tubes by including a radioisotope within the valve envelope and hence deliberately introducing ionized species within the discharge region. In this way a predictable performance is obtained by ensuring that breakdown always occurs at very nearly the same voltage. The first isotope used to control the ignition delay time was Ra226 contained within a small, sealed platinum tube. However, for reasons of high cost, low efficiency, inconvenience of handling, health hazards and waste- disposal problems, either U232 as uranium oxide, Ni63, Kr85 or H3 are preferred. The use of Sr90/Y9° has been reported for experimental studies in Japan [14], but there seems to be no argument in favour of this isotope , in routine production. Some physical properties of these isotopes are given in Table II. Ni^3 is mainly used in the United States of America. It is electroplated on to a small disc which is usually welded as a "flag" on to one of the 372 TECHNICAL AND ECONOMIC SUMMARIES

TABLE II

SOME PROPERTIES OF RADIOISOTOPES USED TO CONTROL IGNITION DELAY TIMES IN COLD-CATHODE DISCHARGE TUBES

Energies of emitted radiations Isotope Half- life a ß y (MeV) (MeVmax) (MeV)

H3 12.3 yr - 0.018 - Kr«5 10.6 yr - 0.67 (99.6%) 0.51 (0.4%) 0.15( 0.4%) Also Bremsstrahlung Ni63 125 yr - 0.067 - Ra226 and 1760 yr Many Many 0.01 to Most abundant decay 4 to 8 3.0 0.6 products 1.12 1.76

Sr90/y90 28 yr/2.7 d - 0.54/2.25 - U232 and 74 yr Many Mainly Miscellaneous decay 4.5 to 8.8 0.05, 0.34, below 0.3 products 0.58, 1.55, 2.25 electrode supports. Because of the difficulty of handling, storage and waste disposal, this isotope is not used in the United'Kingdom or the Netherlands. Although similar arguments can be applied to the use of U232 it is still used by one manufacturer in the. United Kingdom. When Kr85 is used it is mixed with the filling gas, but the associated 7-ernission (0. 4%, 0. 51 MeV) and the high\value of the ß-particle energy and accompanying bremsstrahlung radiation means that, in small low- pressure valves, a large proportion of the total radiation emerges from the glass envelope. From this point of view H3 has an advantage since the low energy ß-particles emitted by this isotope can easily be contained. In addition, should accidental escape of the gas occur, the maximum permissible concentration of H3 in air is greater than that of Kr85. In use, H3 is either mixed with the filling gas, or introduced in the form of tritiated zirconium painted on to the electrode structure, REIFENSCHWEILER [15] . It has the further advantages of easy storage and handling and, in the gaseous form, there is no problem of waste disposal since the maximum activity in general use is about 20 ^uc. This means that the maximum repe- tition frequency, as determined by the ion re-combination time, may be achieved without significant variation in breakdown voltage. A typical improvement, obtained by including H3 within the envelope, is shown in Fig. 9 which is a histogram obtained by repeatedly measuring the ignition voltage in two valves, one containing H3 and one without, and subjected to the same steadily increasing voltage waveform. The result of two batch tests to determine the probability of a tube containing either H3 lONIZATION METHODS IN INDUSTRY 373

(a) T Inrni.nT , m,i T ,i , 80 lOO I2O I4O I6O ISO 2OO IGNITION VOLTAGE (VOLTS ) —

Fig. 9 The effect on the ignition voltage of including 20 ^c H3 in the envelope of a cold cathode discharge tube (a) Without H3 (b) WithH3

or TJ232 being ignited within a certain time is shown in Fig. 10. It is seen that 70% of the tubes containing tritium ignited within 1 ms whereas 70% of the tubes containing U232 ignited in 10 ms. Apart from the need to control accurately the ignition delay time of reference tubes used in voltage stabilizing circuits, the importance of voltage stability in cold-cathode discharge tubes in general has increased with the introduction of transistors. Whereas with 'hard1 valves an "over-voltage swing", caused by ignition delay, might be tolerated without harm, over- voltages applied to transistors are likely to give rise to excessive conduction currents and lead to a high probability of component failures.

5. THE MEASUREMENT OF GAS FLOW BY INDUCED lONIZATION

The measurement of gas flow using ionization produced by radioisotopes dates from 1928 when BLAKE [16],first suggested the continuous ionization method. Since this date several patents have been granted on more sophisticated systems and a number of papers have been published indicating various advantages of these methods. However, although it is known that these systems are in use in a number of countries, there appears to be very little published information on the performance of the instruments, or on the applications for which they are being used. It seems likely that in view of 374 TECHNICAL AND ECONOMIC SUMMARIES

IOOO

URANIUM OXIDE ( DISTRIBUTION OF lös TUBES)

IOO

1-0 TRITIUM (DISTRIBUTION OF i92 TUBES)

o-oi I IO SO 9O 99 99-99 l PROBABILITY (°/o)

Fig. 10 Variation of ignition time in cold cathode discharge tubes containing either U232 or H3 the increasing number of problems in this field, including the need for high accuracy at high velocity where pressure-loss systems cannot be tolerated, and the demand for a system to measure mass flow, an increased number of instruments will be in use in the future. Two main systems of measurement have been proposed and an outline of each will now be given.

Gas-flow measurement by continuous ionization

In this method ions are produced continuously, using an a- or ß- emitting source, and are collected either in the same region as they are produced or at a separate region some distance downstream. The particular advantages of the continuous ionization systems are that they offer a method of measuring mass flow and linear velocity which is independent of velocity profile provided the range of the ionizing radiation is large compared with the dimensions of the pipe. In addition they are sensitive to rapid changes in flow and, since they can be designed without impeding the flow, no pressure loss is introduced into the system. Applications occur at high and low flow rates and in principle there is no serious limit to the maximum cross-sectional area of pipe in which measurements can be made. With large diameter pipes, however, a multi- electrode structure will probably be required and this will offer some impedance to the flow. With pipe diameters greater than about 1-| times the range of /3-particles in the gas, consideration would have to be given to the ionizing source in order to achieve a uniform concentration of ions over the cross-section of the pipe. Since an electric current is provided directly by these instruments they are suitable for use in automatic control systems. lONIZATION METHODS IN INDUSTRY 375

ALPHA/ RADIOACTIVE PARTICLES MATERIAL

Fig. 11 Measurement of gas flow by induced ionization system having ionizing source and detector at the same point

Ionizing source and detector located at the same point

A schematic diagram of a system first described by OBERMAIER [17] is shown in Fig. 11. Two electrodes comprising an ionization chamber are mounted in the gas stream and the space between them is ionized. An a-emitter may be used, with its advantage of high ionization density, since the electrode separation can be kept small. At low gas velocities most of the ions are collected by the applied field of the ionization chamber but, as the gas velocity is increased a greater proportion of ions is swept out of the chamber region. There is a decrease in current with increase in gas velocity. A quantitative relationship between ionization current and gas velocity has been derived by SHTEINBOK [18] who showed that, apart from gas velocity, the ionization current at a given gas temperature also depends on the humidity, pressure and chemical composition of the gas. If the variation in gas composition is not sufficient to affect the ionization current seriously, the instrument is capable of being calibrated to measure mass flow. The principal disadvantages of this method of gas-flow measurement are that the operational range ds very restricted and, in practice, the collector current is highly sensitive to the voltage stability of the detector. In common with other systems of gas-flow measurement by induced ionization the collector is a high impedance device so that leakage currents in the electrode supports must be kept small (< 10~12 A). From this point of view the presence of water vapour and organic condensâtes in the gas can be troublesome and may invalidate general-application.

Ionizing source upstream of the detector

The basic diagram of this sytem, first described by BLAKE [16], is shown in Fig. 12. At low flow rates the ions produced in the region of the source move downstream "towards the ionization chamber but recombine 376 TECHNICAL AND ECONOMIC SUMMARIES

METALLIC FOIL DC AMPLIFI CONTAINING \ p UMI M tw [ A 1 /*-»--*- —- \ ^ GAS • 1 FLOW If] nf:^ ( •* / W — -, / ) Vi / 1

IONIZING SPACE

Fig. 12 Basic diagram of flow-measuring system with ionizing source upstream of the detector before arrival. As the flow rate is increased, ions begin to arrive at the electrodes and the collector current then continues to increase with increasing flow rate. An additional patent taken out by MELLEN [19], also includes a means of determining direction of flow. The separation of the source from the two ionization chambers shown in Fig. 13 is such that, even when there is.no flow, a small ionization current can be measured in each chamber. When the gas flows the instrument indicates both the direction and magnitude of the gas movement. An analysis of this system of gas flow measurement has recently been made by CLAYTON and WEBB [20] who have examined, both theoretically and experimentally, the effect of such factors as the strength of the ionizing source and the separation of source and detector, on the operating range of the instrument. In this analysis account was taken of the continuously increasing gas velocity which may arise between source and detector. The collector current, I, is found to be given by the relationship,

U2AJp (1+pl) (1+pd) I = X (4) U2p +JA (l+pd)3 log (1+pl) ~ 3 X 109 Amp where, A (cm) is the cross-sectional area of the pipe; J is the number of ions per cm3 produced in the ionizing region when the gas is moving with unit velocity; U (cm/s) is the velocity at atmospheric pressure corresponding to the same mass flow as in the pipe; 1 (cm) is the distance between the ionizing region and the detector; d is the effective distance, measured in the pipe to increase the pressure P at the ionizing source to atmospheric pressure, PO . Thus, Po = P + (dP/dx)d; p= (dP/dx)/P, values of (dP/dx) being available in standard tables [21] ; X is the recombination coefficient for ions in the gas; e is the electronic charge in e. s.u. (electrostatic units). Curves, calculated from equation (4) and showing the variation of collector current with mass flow in a 2. 5-cm diam.pipe, for selected values of ion transit distance, are exhibited in Fig. 14. The initial part of each curve shows a square-law relationship which can be predicted from equation lONIZATION METHODS IN INDUSTRY 377

BETA-EMITTING RADIOISOTOPE SOURCE

Fig. 13 Basic system to determine direction and velocity of gas flow. The two ionization chambers are sufficiently close to the source for a small current to be detectable when there is no flow.

10-

10_9

io u io

IQ- O-OI 0-1 1-0 IO-O too MASS FLOW

Fig. 14 Variation of collector current with mass flow for several values of ion-transit distance

(4) and there is also a useful quasi-linear region when the ion-transit distance is below 1000 cm. Experimental curves for ion-transit distances of 7. 5 cm and 28. 5 cm obtained using the instrument shown in Fig. 15 are given in Fig. 16. The 378 TECHNICAL AND ECONOMIC SUMMARIES

CONNECTED TO AMMETER

INSULATED HIGH VOLTAGE INSULATED CENTRAL REMOVABLE ELECTRODE SUPPORT ELECTRODE SUPPORT SECTIONS

J GAS FLOW

M \ \ , \ •— i ••" •— i >— i tS; WWIWYWSl 1?!— \ \ KZzy \ \ ifll CENTRAL \\ \HIGH-VOLTAGE ELECTRODE * ELECTRODE

CONNECTOR TO HIGH VOLTAGE 4 ft

Fig. 15 Schematic diagram showing construction of flow-meter unit

6 -

< 5-

2-O 4-O MASS FLOW (g/s )

Fig. 16 Comparison of experimental and theoretical relationships between current and mass flow in the method of gas- flow measurement by continuous ionization theoretical curves, also reproduced in Fig. 16 were obtained from equation (4) and indicate the potential use of this result for instrument design studies. The operating range of this instrument is determined by the strength of the source which can be tolerated, the maximum ion-transit distance avail- lONIZATION METHODS IN INDUSTRY 379 able and the sensitivity of the measuring equipment. In the instrument shown in Fig. 12, using a 6-mc Sr90/Y90 source at a distance of 7. 5 cm from the electrodes, the working range extended from 0. 03 g/s to 1 g/s air at STP. This corresponded to a variation in current between 5 X 10~10 A and 6X 10~9A. It is suggested by CLAYTON and WEBB [20] that the upper limit of velocity measurement, but not of mass flow, may be increased by slowing down the gas velocity by mounting the source and detector in a length of pipe of increased diameter. The effect of impurities in the gas which change the values of ionization cross-section and re-combination coefficient, is to change the number of ions entering the ion chamber, and hence the measured current, even though the mass flow is constant. Not all impurities are troublesome however (CLAYTON and WEBB [22] ), and Fig. 17 indicates some gases which do not appreciably affect the performance of the instrument. This work is still at a preliminary stage.

NITROGEN AIR

IO 2Û 3O 4O SO 6O 7O 8O 90 LINEAR VELOCITY (cm/s)

Fig. 17 The effect of using different gases in the flow-meter of Fig. 15

Apart from the measurement of gas flow, the use of ionization induced in a flowing gas has also been proposed [23] for the measurement of the thickness of tube walls and cooling channels in gas-turbine rotor blades. The latter problem is especially difficult because of the small diameter (0. 012 to 0. 018 in) of the channels and their inaccessibility to measuring instruments. In this method a collimated ß-particle source, such as Sr90/Y90 or Ce144/Pri44 mounted outside the turbine blade, is arranged to ionize the gas within the cooling channel at a point where the wall thickness is required. A gas, such as air or argon, is then passed at a constant rate through the tube or channel and into an ionization chamber where the ion current is measured. For a given source, the magnitude of the ion current is inversely related to the wall thickness. With components such as turbine 380 TECHNICAL AND ECONOMIC SUMMARIES blades the main function of the method is to give comparative values of the wall thickness at corresponding points in a large number of identical components.

Gas-flow measurement by the mean velocity method

The principle of this method, which was suggested by MELLEN [24] , is based on a measurement of ion-transit time between two points of known separation. In the original system proposed by Meilen, a spark gap was used as the ion source but in many applications this arrangement has the disadvantage that the presence of the electrodes introduces disturbances to the flow pattern. This is especially important at supersonic velocities. Radioisotope sources are intrinsically safe compared with spark discharges and this is important if the flow of inflammable gases is to be measured. When using radioisotope sources the ions are produced in "bursts", either by interrupting a beam of a- or ß-particles with a high speed mechanical shutter, or by deflecting the particles with a periodically applied magnetic field. It is essential that: (1) The duration of each period of ionization is short compared with the ion-transit time; (2) The gas velocity is large compared with the diffusion velocity so that the character of the "ion-pulse" is not lost; (3) The ion-collection time is short compared to the ion-transit time; and (4) The phase shift in the amplifier is short compared to the ion-transit time. The main advantage of the method is that it is insensitive to impurities and its principal disadvantage is that it measures linear velocity and not mass flow. However, a value for mass flow can be obtained if the gas density is measured simultaneously. A combined instrument for this purpose has recently been developed by FLANAGAN and NOE [25] . Various methods of displaying the information have been suggested. SHUMILOVSKII and MEL'TTSER [26, 27] suggested a circuit to measure the time delay directly, but a more useful technique is to use the increase in current from the arrival of the ion wave to trigger the modulator, and thence to display the resultant signal as a recurrent train of electrical pulses. Since the gas velocity is inversely proportional to the ion transit time, and this in turn is inversely proportional to the recurrence frequency, the latter is directly proportional to gas velocity. In one system, (see Fig. 18) developed by FLANAGAN and NOE [25] , the radiation from a source of 5 me Sr90/Y90is interrupted using an AI disc containing an aperture through which radiation passes at each rotation of the disc. An electrical signal in synchronism with the ion wave is con- currently derived from a second aperture in the Al disc by using a small electric light bulb and photo-transistor. This signal is arranged to trigger a multivibrator which is then returned to its original quiescent state by a second signal derived from the arrival of the ion wave at the detector. The multivibrator output pulse length is thus directly proportional to the ion- transit time. lONIZATION METHODS IN INDUSTRY 381

AMPLIFIER

FEEDBACK TO MODULATOR MEASUREMENT OF TRANSIT TIME

Fig. 18 The mean velocity method of gas-flow measurement

Successive pulses from the multivibrator are smoothed to give a voltage E proportional to the product of transit time (t) and pulse frequency (f) which is controlled (by controlling the speed of rotation of the disc).so as to make the output voltage equal to a constant reference voltage R. Thus,

E = kft = R

(5) and f = R/k- l/'t = KV, where V is the linear velocity of the gas and k and K are constants. By making R proportional to density (i. e. to the output from a radiation density gauge) the instrument can be made to measure mass flow. The practical range of these instruments depends on the ion-transit distance which in turn depends on transit time,, and this should always be less than 1 to 1.5s because of ion re-combination. For a 3-m transit distance the upper limit of gas velocity exceeds 30 m/s while the lower limit is about 2 m/s. Reproducibility depends on the alignment of source collimator,, slit and second collimator and on the stability of DC levels in the trigger circuits. In practice these can be made less than 1%. With the disc system reproducibility is within 3%. An interesting method of display has been suggested by MEL'TTSER [28] who proposed that the phase shift of the ion wave, rather than its transit time, should be measured. The basic circuit is shown in Fig. 19. Since the ion wave in region B is delayed with respect to that in A, the currents in detectors 3 and 4 will be different in phase. The advantages claimed for this system are that the irradiation period can be extended beyond that 382 TECHNICAL AND ECONOMIC SUMMARIES i r

3 -r- MODULATOR

U-r- RADIOISOTOPE SOURCE

PHASE MEASURING CIRCUIT

Fig. 19 The system of gas-flow measurement using the phase shift between two electrode systems allowed in the transit time system and that narrow band amplifiers may be used in the measuring circuits. The derived relationship [29] between the phase angle and mean gas velocity V is

4 = 2jrfl/V, where f is the modulation frequency, and 1 is the distance over which the phase difference is measured.

6. RADIOACTIVE LIGHTNING CONDUCTORS

Although the use of lightning conductors incorporating radioactive isotopes is fairly widespread (one estimate [30] suggests approximately 50000 are installed throughout the world), there is little direct experimental evidence in the scientific literature to support the advantages claimed for this system. On the contrary, what evidence there is [31] suggests there is virtually no improvement to be gained from the use of such devices. The chief grounds for recommending the use of radioisotopes in lightning conductors appear to be based on an analysis of the experience of users before and after installation of the system. Protection of buildings against a direct strike by lightning is generally accomplished by the use of the lightning rod first introduced by Franklin. This system of protection (see, for instance "Code of protection against lightning", Parts I, II, III, National Bureau of Standards, Handbook H-40, or British Standard Code of Practice CP-1: 1943, "Protection of structures against lightning", British Standards Institution, London) consists of one or more pointed terminals mounted on the ridge of gable roofs, on chimneys, or on other elevated structures, and connected to ground by a substantial conductor so that lightning striking such a terminal will be safely conducted to earth without damage to the structure. The function of the Franklin rod is to reduce the maximum field strength by steady corona discharge and thus reduce the probability of a lightning strike. If the corona current is not sufficient to prevent breakdown, the Franklin rod produces a high field lONIZATION METHODS IN INDUSTRY 383 region and so gives a preferred, safe path for the strike to be conducted to ground. Surrounding the Franklin rod is a so-called "cone-of-protection" which has its apex at the rod and has a half-angle of 45°. This is adequate for tall, thin structures but the effectiveness of the Franklin rod is greatly reduced when mounted on large area buildings with flat roofs since the cone- of-protection is then insufficient to cover the building. The advantage claimed for lightning conductors with radioisotopes is that the emission of radiation from the source produces an ion-current so as to increase the effective height and hence the area of the base of the cone-of-protection. As a result the number of rods and earth-conductors is reduced and, correspondingly, the total cost of a satisfactory installation. Consider the negative charge which builds up in the lower portion of a cloud and induces a positive charge on the earth's surface directly under- neath. As the charged cloud is blown along by wind, so the induced positive charge on the earth's surface moves along as well. If the surface of the earth is not smooth but contains structures which are conducting, or semiconducting, then the positive charge moves to the top of these structures. The presence of a Franklin rod results in a concentration of positive charge and an increase in field strength. If the field strength is not sufficient to induce break-down, a corona discharge takes place to the rod. The magnitude of this discharge can exceed 10~3 A at 50 kV/cm. For the radioisotope to be effective it should give a comparable current which is stable in the presence of an electric storm. In fact the maximum current available from a pure ß-emitter is approximately 5 X 10~5 A/MeV-c so that a considerable source strength would be required to give a comparable current. In the United Kingdom an exemption order has been obtained to use 1-mc sources of Ra226 and, in fact, the largest source activity generally installed is 700 /uc. This source activity is, however, exceeded in some overseas installations. The very small currents available from isotope sources in lightning conductors compared with typical corona discharge currents during thunderstorms makes the advantages claimed for the isotope system difficult to understand. This general conclusion is borne out by the experiments of MULLER- HILLEBRAND [31] who attempted to determine the degree by which radioisotopes affect the corona current from lighting conductors. He found that although corona discharge currents originating at elevated points may affect the lightning path, the emission currents from radioisotope lightning conductors are much too weak to build up the required space-charges. An increase of 100000 times in the source strength used in these experiments would be necessary to change the electric field at a distance of several hundred meters. The fact that a large number of lightning conductors are reported to be in satisfactory operation is in sharp contrast with the results of the only available experimental evidence. This strongly suggests that a systematic investigation of the characteristics of lightning conductors equipped with radioisotope sources would be worthwhile. 384 TECHNICAL AND ECONOMIC SUMMARIES

7. ELIMINATION OF STATIC ELECTRICITY USING RADIOISOTOPES

Various effects due to electrostatic charges, which develop on insulating material and arise from frictional motion or surface separation, are well known and include: (1) The attraction of atmospheric dust, which is an important problem in the laminated glass and photographic film-making industries and in textile manufacture, especially using synthetic fibres. (2) The attraction or repulsion of sheets of material which often cause great difficulties in handling - especially during high-speed processing. (3) A fire hazard due to the generation of spark discharges following the accumulation of electrostatic charges. This problem is particularly important where there are inflammable atmospheres, as in the petroleum industry, or where dangerous chemicals or explosives are being manufactured. (4) The possibility of mild electric shock, causing personal discomfort rather than danger, from touching a charged surface. Apart from increasing the atmospheric humidity, employing an electrically conducting dressing, or grafting hydrophilic coatings on insulating textiles [32], most methods of static elimination rely on the production of ions in air to form a conducting path to neutralize the electrostatic charges. Electrically operated ion generators have the advantage of being able to produce a larger ion concentration than radioisotope sources although the latter have the advantages of being cheap, self-contained and intrinsically safe electrically, since they do not require a power supply. However, because they cannot be switched off there is a potential radiation hazard from radioisotope sources unless they are very small or are suitably protected and controlled by automatic shutters. Two methods are in use for eliminating static charge using radioisotope sources:

1. Direct ionization

In this method, which is the one most commonly employed, the isotope is mounted in an earthed container and arranged to produce the largest possible number of ions between the charged surface and the nearest electrical conductor, A possible arrangement of sources (PUTMAN [33] ) for a moving charged sheet is shown in Fig. 20. The radioactive source is mounted at positions a, b or c depending on whether it is required to discharge one or both sides of the sheet. In each practical application there is an optimum distance for the source from the charged surface so as to provide adequate space for ionization together with efficient charge collection. CAMERON [34] finds that the optimum distance for Tl204 jS-particles lies between 30 and 45 cm and this is confirmed by MEDVEDEVA and ROIZEN [35] who also found the most effective distance for Sr90/Y90 /3-particles to be between 60 and 70 cm. The optimum distance for a-particles is- between 3 and 6 cm. If metallic conductors are present near the charged surface, some modification to these distances may be required. Beta emitters, having energies between 0. 7 and 2. 3 MeV, produce from 50 to 150 ion pairs/cm and are useful for dissipating static charges over lONIZATION METHODS IN INDUSTRY 385

EARTHED CONDUCTOR CHARGED MOVING \ INSULATED SHEET «., ^TTTTTITTTTTITT«

(c) (—* -iillliiillllli'»

EARTHED CONDUCTOR

Fig. 20 Possible positions of radioisotope source to eliminate static charge on moving sheet ® shows possible position of radioisotope static eliminator Positions (a) and (b) each irradiate one side of the materials In position (c) both sides of the material are irradiated

large areas. Alpha emitters, which are mainly used to dissipate charge over small areas, have a much higher specific ionization (30000 to 60000 ion pairs/cm) but a short range (5-7 cm). The properties of a number of isotopes used for static charge elimination are given in Table III.

Rate of discharge

The rate of discharge for T12U4 (CAMERON [34] ) measured at the optimum distance is 0. 005 juA/mc. This rate is too small for fast moving surfaces but with an activity of 1 me/cm of width, most industrial static problems can be controlled on material moving with velocities up to 50 - 100 cm/s. Sryu having two ß-particles per disintegration is nearly twice as efficient as T12U4 and covers a larger area, since the optimum distance is greater. Alpha emitters are about 50 times as efficient per particle emitted.

2. Ion blowers

Static eliminators based on blowing ionized air over charged surfaces have been designed by QUINTON [36] and LJUNGGREN [37]. In this instrument the source, which is completely enclosed in a chamber, provides a source of ions which are blown against the charged surface. They are less efficient than direct ionization static eliminators and their range of effectiveness is limited by recombination usually to between 1 and 2 m. LJUNGGREN [37] concludes that ion blowers can be used efficiently to supply static charge eliminating currents up to 0. 1/uA from ß-emitting sources (< 100 me) without radiation hazard. They do not however offer a means of using more active sources efficiently for static elimination because of the limiting action of ion recombination. An ion blower producing ions of one polarity (MARTIN [38] ), though not limited in its performance by recombination, has the disadvantage of being useful against charges of one sign only. 386 TECHNICAL AND ECONOMIC SUMMARIES

TABLE III

SOME PROPERTIES OF ISOTOPES USED IN STATIC ELIMINATORS

(a) Alpha emitters

ex-Range Max. permissible Half- Energy 8- Half Other Screening cone, in air in Isotope life (MeV) thickness radiations required working space (yr) (cm of air) (jjc/cm3)

5 10 p0210 0.38 5.3 4 y(one in 10 ) Negligible 2 x 10' Ra226 1620 Many 3.2 - 6.8 Many y's At least 2 x 10'7 4- 6 5 - 10 cm Pb

241 Am 470 5.5 4 Low energy 2 mm Fe 10-io y's

(b) Beta emitters

H.3 12.3 0.018 ~0.1 NONE Negligible 8 x 10"6 Kr85 10.6 0.67(99.6%) 25 y 0.51 MeV 3 mm Fe lu"5 (0.4%) Sr'O/Y90 28 0.54/2.25 135 NONE 3 mm Fe lO"7 T1204 3.9 0.77 30 X-ray 3 mm Fe 3 X 10"8 (2%) S 35 0.2 0.167 2.2 NONE 0.5 mm Al . 3 X 10"7 C" 5760 0.155 2.1 NONE 0.5 mm Al 5 X 10'5

Pm"7 2.6 0.22 3.5 NONE 2 mm Fe IQ"7

Applications

One of the most useful applications of static eliminators is in laboratory microbalances where they are used to eliminate electrical disturbances, particularly from polished glassware. About 30% of the total installations of static eliminators in the United Kingdom are for this purpose. Usual source strengths are 2 me Tl204. An automatic mechanical shutter ensures that the source is closed when the balance case is open. Other applications of Am241 include installations in high-speed ticket machines in airports (using about 30 /uc) and in the slow-speed production of light-weight paper. An application of H3 to eliminate static charge on very fast-moving pap er, 0. 02 mm thick, in a coil-winding machine, has been reported by REASBECK [39] after two years of successful operation. He used about 15 c H3 chemi- sorbed on a titanium strip 9 mm wide and about 15 cm long. Since the range of H3 /3-particles in air is only 4. 2 mm the sources were mounted as close lONIZATION METHODS IN INDUSTRY 387

POSITIONS OF H3 STATIC ELIMINATORS

PAPER O-O2mm THICK MOVING AT O-5 m/s

Fig. 21 Schematic diagram showing positions of 15-c H3 static eliminators against the rollers in a coil- winding machine as possible to the paper coming through the rollers (see Fig. 21). Before the application of these sources the paper frequently wound itself round the rollers but this problem was completely resolved once the sources were installed. An important application of static eliminators in the past has been their use in the textile industry to prevent "fog" marks appearing on material standing overnight on looms and caused by the attraction of atmospheric dust. Originally about 3500 Sr90/Y90 sources, each of approximately 6 me, were installed for this purpose but now almost all have been withdrawn because of the possible health hazard. This can be controlled easily in the laboratory but in the factory it cannot be assumed that everyone will take the prescribed precautions however simple they may be. The regulations for the use of radioactive sources in factories (The Ionizing Radiations (Sealed Source) Regulations, 1961) enforce a number of precautions which most managers regard as quite onerous and have led to the withdrawal of most of the static eliminators. The chief compulsory measures are: (1) Radioactive sources to be registered with the Factory Inspectorate; (2) Radioactive sources to be adequately screened and guarded; (3) A register to be kept of employees working near to sources; (4) Employees to be examined medically once a year and the results to be registered; (5) Employees to wear a film badge which is to be periodically measured by a neutral body and the dose recorded; and (6) An instrument (and someone capable of using it) is to be provided tp measure the radiation intensity. The return of static eliminators to the United Kingdom textile industry is awaiting the development of a suitable ur-emitting source. The motor car industry in the United States of America uses ion blowers containing an a-particle source (BROWNELL [40] ) to remove deposited dust and cotton fibres from surfaces to be painted. This problem is particularly important when painting plastic surfaces because their low conductivity results in the build-up of very large static charges. Uncharged air 388 TECHNICAL AND ECONOMIC SUMMARIES

RADIOACTIVE SOURCE AIR BLOWER FOIL CONTAINING T|2O4

Fig. 22 Schematic diagram of ion blower for static- charge elimination

will not remove the particles but ionized air first neutralizes the charge and then blows off the particles. Precautions against explosions resulting from the ignition of anaesthetic gas mixtures in operating theatres are described by QUINTON [41] . He used a 50-mc Tl204 source in the arrangement shown in Fig. 22 which was found to be effective in removing static charges at distances up to 2 m. Several attempts have been made to introduce static eliminators into the domestic market and one form of brush containing about 200 juc of Po'210 is generally available in the United States of America for general house- hold use. In general the main problems with devices of this kind are those of storing before distribution and of disposing of the sources after the mechanical life of the equipment is over. With Po210 (T^ = 138 d) the mechanical life might reasonably be expected to exceed the time for the source to decay below its useful value so that in this case the disposal problem is relatively simple. The use of Am'241 (T^ = 470 yr) is attractive from the point of view of its long half-life but poses serious problems of source disposal.

8. VACUUM MEASUREMENT BY IONIZATION

The ionization gauge, in the form of a simple triode structure, is one of the oldest devices (BUCKLEY [42], DUSHMAN and FOUND [43]) and still the most widely used for measuring gas pressure under high vacuum conditions. In this gauge electrons from a thermionic cathode are accelerated by a grid at a positive potential so that, if the accelerating voltage is greater than the ionization potential of any gas which is present, there is a probability of ionization by collision. The positive ions so formed are collected by an outer cylindrical electrode at a negative potential. Provided the pressure is below that at which more than one ion is produced per electron, the number of ions formed per second, and hence the resultant current is proportional to gas pressure. At higher pressures the current tends to saturate at a constant value, independent of pressure. In practice the upper limit for most triode ionization gauges is about l /um (Hg). Although SCHULTZ and PHELPS [44] have developed a higher pressure ionization gauge to operate up to 1 mm (Hg), in general measurements of lONIZATION METHODS IN INDUSTRY 389 pressure above 10~2 mm (Hg) require either a heat conductivity-type instrument (10~2 to 1 mm (Hg)), such as the Pirani, thermocouple or ther- mistor gauge, or a mechanical manometer (10""1 to 103 mm (Hg)). The advantages of the ionization-type gauge have now been retained for high-pressure operation by the introduction of the radioisotope ionization gauge first developed by DOWNING and MELLEN [45] . Figure 23 shows a schematic diagram of this gauge. It consists of a large and a small ionization chamber, each with its own a-emitting source. (In the early design Ra226 was used but Am241would be a more appropriate isotope. ) By using the two chambers the instrument has a linear response for air from 10~3 to 103 mm (Hg). The large chamber has a volume of 50 cm3 and, with a source of 100 ;uc Ra226, has a sensitivity for air of about 10~10A/mm (Hg). The small ionization chamber, which is used in the range 10 to 103 mm (Hg), is designed to reduce ion current loss due to re-combinat ion. It has a value of 0. 2 cm3, a source of 1. 5 /uc Ra226 and a sensitivity for air of about 1.5 X 10-13 A/mm (Hg).

PRE-AMPLIFIER COMPARTMENT

SMALL lONIZATION CHAMBER

LARGE lONIZATION ^~- CHAMBER SMALL SOURCE-

LARGE SOURCE

TO VACUUM SYSTEM

Fig. 23 Outline of "Alphatron" radioisotope ionization gauge

The sensitivity of this instrument depends on the ionization cross-section of the gas being measured so that calibration is required for each type of gas. Owing to re-combination, measurements for gases heavier than air are not linear in the range 102to 103 mm (Hg). 390 TECHNICAL AND ECONOMIC SUMMARIES

The principal advantage of this gauge is that it has no filament to burn out and there is no possibility of chemical reaction between the gas and the cathode. The use of up to 100 /uc of Ra226 equivalent in a gauge for general use will, however, probably require special consideration and permission in most countries. The use of H3 as an alternative source has been suggested by SPENCER and BOGGESS [46] but details of the performance of their instrument are not available to the author. An ionization gauge similar to the one described above but incorporating 500 /je Ra226 has been used by BEYNON and NICHOLSON [47] at temperatures up to 200°C to measure the latent heat of vaporization of 14 different organic compounds.

9. CONCLUSIONS

The applications of radioisotopes based on the interaction of radiation with gases has been shown to play a useful part in a variety of industrial and scientific problems.

Smoke detection

There is a continuous increase in the number of installations and instruments using radioisotopes are now approved by fire insurance committees in several countries. Recent improvements in sensitivity are likely to increase the future usefulness of these devices.

Gas chromatography

Following the first introduction of the argon ionization chamber into gas Chromatographie equipment, several other designs have been developed to enable low concentrations of a wider range of gases to be measured. There are applications in a wide range of industries and, besides laboratory installations, gas Chromatographie columns incorporating ionization detectors are also to be found in plant process control. The range of interactions of ionizing radiation with gases, whereby identification of impurities may be carried out at low concentration, has by no means yet been exhausted. There is a great deal of activity in this field and further development and improvement in instrument performance can be expected in the future.

Cole}- cathode discharge tubes

Radioisotopes in general, and particularly the introduction of Ha, has enabled a significant decrease in ignition delay time to be obtained. It is not expected that there will be any further important development in this field by virtue of the continued use of radioisotopes. It is, however, worthwhile pointing out that optimum performance from the use of radioisotopes is achieved using sources with activities large enough to require special dis- pensation (in the United Kingdom above 1 ^uc). Special permission to use higher activities has not yet been requested for all valves at present in pro- lONIZATION METHODS IN INDUSTRY 391 duction so that, from this point of view, some further improvement in performance can be expected.

Gas-flow measurement

The use of radioisotopes to measure gas flow is claimed to have several advantages. In particular there is the possibility of measuring mass flow or the linear velocity of gases flowing at high speed without impedance to the flow. Although several different instrument designs have been suggested there are virtually no examples in the literature describing the industrial performance and application of these instruments. Examples of performance characteristics to substantiate the claims is therefore required.

Lightning conductors

Although the use of radioisotopes in lightning conductors is widespread, there is no universal opinion that the system has outstanding merit. Addi- tional experimental evidence is required to establish unequivocally the benefits to be gained from the use of radioisotopes.

Static charge eliminators

This was one of the first applications of radioisotopes and is still the most popular technique in the class of applications referred to in this paper. In general, early attempts to use radioisotopes to eliminate electrostatic charge on fast moving sheet and in bulk powders and liquids have now been abandoned as unrealistic. Large H3 sources (15 c) have however been shown to solve an important problem in dissipating charge on paper moving at a speed of 0. 5 m/s. In the United Kingdom recent legislation relating to the use of sealed sources has resulted in some static eliminators using ß-emitting sources being withdrawn from service. The possible replacement with «-emitting sources is being investigated.

Vacuum measurement

An instrument using Ra226 ("Alphatron") has been developed for measurement in the range (10~3 to 103 mm (Hg)). It is mainly in use in the USA and in Japan.

ACKNOWLEDGEMENTS

Unpublished information used in this paper and not referred to in the text has been very kindly supplied by a number of people including D. J. Bearman and S. H. S. Farley of the Minerva Detector Company, R. Gittens of W. G. Pye and Company (who manufacture gas Chromatographie columns and ionization detectors referred to in this paper and who freely made available information for use in Sections), D. H. Wright of Hivac Ltd. (who kindly 392 TECHNICAL AND ECONOMIC SUMMARIES supplied the information used in Fig. 9), M. E. Bond of The Mullard Radio Valve Company (who supplied Fig. 10) and F. Andrews of the Radiochemical Centre. The author is also grateful to Dr. J. L. Putman for many helpful suggestions.

REFERENCES

[1] GREINACHER, H., Über ein Differential- lonometer und seine Anwendung zur elektrischen Messung des Staubgehaltes der Luft, Bull. SEV. ji3 (1922) 356. [2] MALSALLEZ, P. and BREITMANN, L., L'utilisation des phénomènes radioactifs dans la prédétection des incendres et analyses de gaz, Rev. Gen. Electr. 43 (1938) 279. [3] JAEGER, W., Die Ionisationskammer als Fenermelder, Bull. SEV. J31 (1940) 197. [4] MEILI, E., The ionisation chamber smoke detector, Bull. SEV. 43 (1952) 3. [5] POMPEO, D.J. and OTVOS, J.W.. (to Shell Development Co.), US Patent 2, 641,710 (1953). [6] LOVELOCK, I.E., A sensitive detector for gas chromatography, J. Chrom, l (1958) 35. [7] LOVELOCK, J.E., An ionisation detector for permanent gases, Nature 187 (1960) 49. [8] SCOTT, R.P.W., Gas Chromatography, (DESTY, D.H., Ed.) Butterworths, London (1958) 189. [9] GOLAY, M.J.E., Gas Chromatography, (DESTY, D.H., Ed.) Butterworths, London (1958) 36. [10] OTVOS, J.W. and STEVENSON, D.P., Cross-sections of molecules for ionisation by electrons, J. Amer. Chem. Soc. ^78 (1956) 546. [11] LOVELOCK, J.E., Measurement of low vapour concentrations by collision with excited rare gas atoms, Nature 181^(1958) 1460. [12] BERRY, R., An ultra-sensitive ionisation detector for permanent gas analysis, Nature j^88 (1960) 578. [ 13] LOVELOCK, J.E., Ionisation methods for the analysis of gases and vapours, Analyt. Chem. J33(1961) 162. [14] KATO, M., TOMURA, F. and YOSHINAKA, Y., Removal of the irregularity of the discharge characteristic of the discharging gap for arresters, 3rd Japan Conf. on Radioisotopes, 59/p-25, T-25, (1959). [15] REIFENSCHWEILER, O., A suitable tritium carrier for gas discharge tubes. Proc. 2nd. UN Int. Conf. PUAE_1£ (1958) 360. [16] BLAKE, A.E.. Apparatus for metering gaseous fluids, US Patent-1, 808, 709 (1931). [17] OBERMAIER, A. A., Ionisation type gas flow meter, US Patent 2,627,543 (1953). [18] SHTEINBOK, N.I., Fundamental problems in the use of radioactive isotopes for measuring purposes, UspekhiFiz. NAUK. j>4 No.2 (1954). [19] MELLEN, G.L., Velocity metering of gas flow, US Patent 2,611,268 (1952). [20] CLAYTON, C.G. and WEBB, J.W., The measurement of mass flow and linear velocity of a gas by continuous ionisation, Int. J. appl. Rad. Isotopes, to be published. [21] PERRY, J.H., Chemical Engrs Handbook, McGraw-Hill, London (1950). [22] CLAYTON, C.G. and WEBB, J.W., to be published (1964). [23] WALKER, D. A. (to Rolls Royce, Ltd.), Improvements in or relating to measuring apparatus, British Patent 903,180. [24] MELLEN, G.L., Gas flow speedometer, Electronics 23 2(1950) 80. [25] FLANAGAN, T.P. and NOÉ, E.G., Brit. Scientific Inst. Res. Assoc., private communication (1964). [26] SHUMILOVSKII, N.N. and MEL'TTSER, L. V., The use of radioactive isotopes for measuring the flow speed of gases and for the automatic control of gas flow by the ion tracer molecule method, Dokl. Akad. NAUK SSSR J.06_No.4 (1956) 661. [27] SHUMILOVSKII, N.N. and MEL'TTSER, L.V., Automatic control of gas flow by the ion tracer method, Priborostr. No.2 (1956). [28] MEL'TTSER, L.V., On the use of radioactive methods for controlling the flow and dust-content of gaseous media., Akad. NAUK SSSR (1956). [29] MEL'TTSER, L.V., The choice of operating conditions for a phase-type ionisation flow meter Auto- mation and telemechanics, Akad. NAUK SSSR (1958). [30] STARLING, B., private communication (1964). [31] MÜLLER-HILLEBRAND, D., Beeinflussung der Blitzbahn durch radioaktive Strahlen und durch Raum- ladungen, Elektrotechnische Z. 83 (1962) 152. [32] ROBERTS. R., Modification of textile fibres by radiation, Textile Recorder ^79 (1962) 59. lONIZATION METHODS IN INDUSTRY 393

[33] PUTMAN, J.L., Radioisotopes Review Sheet, A6. Static Elimination, Isotope res. Divn, AERE (1962). [34] CAMERON, J.F., The use of Tl204 in radioactive static eliminators, AERE Report I/R 1216 (1953). [35] MEDVEDEVA, V.S. and ROIZEN, I.S., The utilisation of radioactive isotopes in safety techniques, A.E.G.-trans.-4492 (1957). [36] QUINTON, A., The use of radioactive isotopes to overcome electrostatic charges in hospitals and industry, Radioisotope Conference, Oxford 1954, Butterworths (1954) 188. [37] LJUNGGREN, K., An iron blower for the elimination of static electricity, Int. J. appl. Rad. Isotopes £ (1957) 105. [38] MARTIN, T.L., Production of unipolar air with radium isotopes, Electr. Engng N.Y. ^73 (1954) 28. [39] REASBECK, P., "The use of tritium as a static eliminator at the 10-20 curie level", Radioisotopes in the Physical Sciences and Industry 2 IAEA, Vienna (1962) 157. [40] BROWNELL, L.E., Radiation uses in industry and science, USAEC, (1961) 144. [41] QUINTON, A., Safety measures in operating theatres and the use of a radioactive thallium source to dissipate static electricity, Brit. J. appl. Phys. Supp. 2, Static Electrification, S92 (1953). [42] BUCKLEY, O.E., An ionisation manometer, Proc. Nat. Acad. Sei. US 2 (1916) 683. [43] DUSHMAN, S. and FOUND, C.G., Studies with the ionisation gauge, Phys. Rev. F7 (1921) 7. [44] SCHULTZ, G.J. and PHELPS, A.V., Ionisation gauges for measuring pressure up to the millimeter range, Rev. sei. Instrum. 28 (1957) 1051. [45] DOWNING, J.R. and MELLEN, G., A sensitive vacuum gauge with linear response, Rev. sei. Instrum. r? (1946) 218. [46] SPENCER, N.W. and BOGGESS, R.L., A radioactive ionisation gauge pressure measurement system, J. Amer. Rocket Soc. 29 (1959) 68. [47] BEYNON, J.H. and NICHOLSON, G.R., A radioactive ionisation gauge and its application to the measurement of latent heat of vapourization, J. sei. Instrum. 33 (1956) 376.

ECONOMIC BENEFITS OF IONIZATION METHODS

The extent to which ionization methods have been adopted by industries in various countries is shown in Table I. It must, however, be pointed out that the information is incomplete. Several techniques may have been used in a particular country, but the relevant information is not always given in the national reports. When completing the survey questionnaire forms most firms using a technique did not want to credit the ionization applications with any measurable economic benefits. Very few of the national reports therefore reveal savings from such applications, and the discussions of the "Study Group Meeting on Radioisotope Economics" did not throw much light on their existence. There is little doubt that if an industry uses a particular technique it does so for economic reasons. The question is, however, whether these reasons fall within the scope of this survey. Following the classification made in the previous paper and using the records of the discussions at the study group meeting, it is possible to reach certain conclusions regarding measurable savings, and, in a few cases, to make estimates about their size.

EXAMPLES FROM THE NATIONAL REPORTS

Smoke detection

Fire and smoke detectors were reported in large numbers by Canada, Czechoslovakia, the Federal Republic of Germany, the Netherlands and the United Kingdom, etc. The economic importance of such installations is obvious, and any efforts that can be made to check a fire in the early stages are worthwhile. It was reported therefore that in some cases the signals from the radioisotope detectors went not only to the factory itself but also to the nearest fire station. The intangible savings from reducing the number or extent of industrial fires are of course very high; each year the value of damage from fires is very much higher than the savings from gauging or radiography. Direct savings could only be attributed to smoke detectors if insurance companies were ready to reduce the premiums upon installation of such devices; but there was no report that this happened. A careful study of the efficiency of these detectors might be useful, as was pointed out at the study group meeting, for if considerably less fire damage could be indicated in plants equipped with such detectors their wider use would be encouraged, and possibly also more fairly adjusted insurance premiums.

Gas chromatography

The use of ionization methods for gas chromatography detectors, such as those reported in the previous paper, has been important in the determination of low quantities of substances in gases and liquids. These methods therefore are an addition to the research tools provided by radioisotope techniques for the physical and life sciences. As gas chromatography can be automated, considerable savings in analysis time can be achieved.

395 TABLE I THE NUMBER OF IONIZATION SOURCES IN INDUSTRIES

Broad product group Country 1 Food 2 Tobacco 3 Textile 4 Wood and 6 Rubber 7 Chemicals 8 Cement 9 Petrol 10 Basic 11 Machinery 12 Services Not Total Includes Excludes paper and plastics and coal metals identified

Argentina * Australia * Austria * Belgium - - - 2 - 1 ------3 a Canada ------1022 1022 a e Czechoslovakia - - 2 - 2 6 - 6 - - - - 16 a,b e.f Denmark - - 41 - - 4 - - - - - 45 a Finland - - 7 1 ------8 a France + - - 3 2 - 4 - - 8 - 7 24 a.e.f Federal Republic ö of Germany * Japan ------12 22 - - 34 c Netherlands - - - 4 - 12 ------16 a.b d,e 4 a.b Norway - - - 1 2 1 ------O Poland - - - - 18 ------18 a Portugal * South Africa 1 ------10 11 a,b n Spain - - - - - 9 - - - - 49 - 58 a,d c« Sweden c United Kingdom 15 6 58 12 - 223 4 69 1 46 38 - 472 a,b,c d,e,f Yugoslavia " 2 3 - 2 2 ~ ~ • 1 " 1 11 a

Total 16 8 114 22 24 262 4 75 13 77 87 1040 1742

a) Static elimination b) Gas chromatography detectors c) Vacuum gauges d) Lightning conductors e) Fire and smoke detectors f ) Discharge stabilization

* The national survey did not cover ionization applications + Figures refer to number of "applications" only. lONIZATION METHODS 397

The only good case study available on ionization methods is in the United Kingdom survey. Here an installation in the man-made fibre industry was described. A manufacturer of cellulose acetate yarn and plastics uses a Sr90 source in conjunction with an ionization chamber as a detector in gas chromatography. This is employed in the following way: In an established process for the manufacture of yarns and fibres cellulose acetate is dissolved in solvents and the solution is extruded into a stream of air. The solvents evaporate, leaving the acetate in the required form, but an important part of the process is to recover the solvents from the air stream. One method widely used to recover these solvents is to absorb on to activated charcoal and steam out and fractionate them later. The optimum economic working of the process depends on maintaining the correct balance between solvent recovery efficiency, steam consumption and the rate of replacement of charcoal. More economic working has been made possible by recent advances in gas chromatography techniques, whereby the exhaust air from the recovery plant is continuously analysed for solvent content. The Chromatographie technique used demands a radioactive source in the detector unit. The extent of the improvement is that a saving of £ 50 000 was made in 1961 on a recovery plant with annual operating costs of about £ 250 000. The total investment of £ 7 000 in isotope equipment in this plant includes also 56 fire and smoke detectors; £ 4 000 of this amount was invested in 1961. Running costs are a mere £ 100/yr. The cost of the equipment was therefore amortized in under two months. The same report reveals a number of similar applications, but most of them were used entirely for research purposes. The Netherlands report also gives some cases where the benefits of gas chromatography are considered to be significant, but without going into detail.

Discharge stabilization

The addition of radioactive material to cold-cathode tubes is a widespread technique but, unfortunately, nothing of an economic nature is revealed in the national reports or in the scientific literature.

Gas flow measurement

Applications of this technique were not mentioned in the national reports.

Lightning conductors

As Mr. Clayton points out in his summary, the evidence of the positive effect on ionization sources is not yet complete. If there is one, a determination of its economic importance can be made analogous to the smoke and fire detectors discussed above. A Spanish firm stated, however, that these conductors were cheaper to install than others having the same effects. Savings were given as Pta 60000 (US $1000) for each installation. 398 TECHNICAL AND ECONOMIC SUMMARIES

Static charge elimination

The most important application of an ionization method to industrial processing would be., no doubt, the efficient elimination of static electricity by radioisotope sources. At present, because of the low discharge and the health precautions that must be taken, the technical and economic success of this method is not yet assured. It must be admitted that radioisotope techniques have not proved efficient for all types of static eliminations, but the disadvantages of other methods are even greater [1], The United Kingdom report reveals certain definite advantages. It stated that 41 users, with 207 eliminators, claimed in 14 cases that they obtained a better product quality by using static elimination; in a further 14 cases they obtained more accuracy in analysis and measurement; and in four and five cases they achieved more rapid production and a reduction in scrap respectively; in six cases it was stated that the process would not have been practicable otherwise; and in two cases that fire hazards are reduced. Only one user reported no advantage. A list from the USSR study on the economic effectiveness of radioisotopes may be added to the applications mentioned in the previous papers. The use of radioisotope static elimination in one case permitted the increase in warping speed by a factor of four (the rate of warping could be increased from 60 to 210 m/min). In another factory the warping rate of acetate silk could be increased from 150 to 350 m/min, and at the same time the number of breakages decreased by a factor of three. At a glass fibre plant a radioisotope source eliminated the possibility of benzene vapours igniting during washing of the glass fibres. As a final example, static charges in the range of 10 000 V at a cinema film factory that could have caused Sparks exposing the film have been eliminated. Losses of several million roubles a year were reported from that plant alone. In view of these facts, it is surprising that no report apart from the United Kingdom one contains information on the economic benefits of static elimination. The Belgian report refers briefly to one case where considerable savings must have been obtained: printing of a four-colour journal, where the scrapped number of pages decreased from 30% to 4% after static eliminators were installed. The large number of Canadian sources for elimination of static charges actually fall outside the scope of the survey, as they apply natural radioisotopes (radium) only; nevertheless they have been included in Table I.

Vacuum gauges

Vacuum gauges based upon ionization of gases were reported from Japan and the United Kingdom, but in neither country was it clear which types of savings could be attributed to them or the extent of the savings. lONIZATION METHODS 399

SUMMARY AND WORLD OUTLOOK

It is very difficult to estimate total savings from the use of ionization applications on a world-wide scale. The report to the survey from the United Kingdom shows (with a 29% response from ionization users) savings of £ 121 000, and for annual costs (based upon a 91% response) the figure was £ 127 000. However, the bulk of the savings derived from production control and particularly from a decrease in raw material costs and product scrap, while the cost came from the research budget. In comparison with the big technical applications such as gauging, radiography and tracing the ionization devices represent very low costs and probably also low savings. Excluding the figures from the Soviet Union, global net savings can be estimated at US $1-2 million/yr. In view of the figures from the United Kingdom and the positive points raised in some of the national reports concerning individual applications, this figure can be considered a conservative estimate.

REFERENCE

[1] HENRY, P. S. R., Textile Inst. Ind. l (1963)4.

GAMMA-RADIOGRAPHY: A ROUGH COMPARISON WITH OTHER NON-DESTRUCTIVE TESTING METHODS

J.Th. BERING RÖNTGEN TECHNISCHE DIENST N. V. ROTTERDAM

INTRODUCTION

It is known, from the reports of different countries, that gamma- radiography in many cases represents the most important industrial application of radioisotopes. Gamma-radiography belongs to one of the best applied methods of what is called non-destructive testing. Nowadays, the importance of non- destructive testing in industry is generally accepted. In designing and calculating, the design-engineer will start from the assumption that the material applied will have the properties claimed in the specifications. Destructive testing is a method which is still applied to determine whether or not these materials do comply with the specifications. These tests can be carried out on final products as well as on test bars. Although, with some knowledge of statistics, numerous products can be tested in this way, absolute certainty concerning the quality of a certain object is unobtainable. Since this certainty is an increasing requirement, an attempt was made to replace destructive testing by non-destructive methods, which was partly successful. These destructive tests, which aimed at defining the homogeneity of materials, have been replaced by non- destructive methods. When tests must determine, for instance, tensile strength, elongation and notch effect, destructive testing is often the only method of enabling these properties to be expressed in figures. Non-destructive testing has certainly not displaced destructive testing; nowadays both are applied, one complementing the other. A combination of the two methods will often give better results than the individual applications of destructive or non-destructive methods. It is no secret that the development of the electric welding procedure and, to a less extent, of other welding procedures, has contributed to the considerable progress in non-destructive testing. In welding practice non- destructive testing appeared to be indispensable. Without disparaging the achievements of other investigators, one must credit the discoverer of X-rays, W.C. Röntgen, for being the first to apply radiation, which he discovered, to industrial radiography. In 1896 he made a radiography of his own shot-gun by means of anX-ray tube and a photographic plate (Fig. 1). The picture is a reproduction of this exposure. The barrels' bullets and strikers are clearly visible. This radiograph was commented upon by Röntgen himself. At the moment we call this interpretation of the radiograph. Röntgen found a thin spot in the barrel, for which he wrote "Materialfehler" (defect) on the photographic plate.

401 402 TECHNICAL AND ECONOMIC SUMMARIES

Fig. l First radiograph made by W. C. Röntgen

Röntgen had to make do with heavy and dangerous X-ray equipment and photographic plates which were not very sensitive to X-rays. It is much easier for the present X-ray operator. He has at his disposal X-ray units especially designed for him and especially adapted films and tools. This keeps his personal radiation dose small, whereas, at the same time, the problem of the high tensions in the X-ray unit is settled. It is not exactly certain who was the first one to apply radioactive material to industrial radiography. Replacing the heavy X-ray tube by an amount of radioactive material is obvious. Shortly before the second world war and shortly after it, gamma rays emitted by natural radioactive isotopes were used incidentally for radiography. The high price and the restricted choice of natural radioactive ma- GAMMA-RADIOGRAPHY 403

MeV Isotope Half- life Remarks gamma energies Cobalt-60 5.3yr 1.1, 1.3 60 Europium -164 5 yr 0.12, 0.34, 0.41, 1.2 Similar to Co 60 Tantalum -182 120 d 0.15, 0.22, 1.13, 1.22 Similar to Co Antimony -124 60 d 0.12, 0.61, 0.65, 0.73 Has hard gamma Scandium -46 85 d 0.88, 1.12

Iridium -192 70 d 0.3, 0.47, 0.60 Activates strongly Selenium -75 127 d 0.12, 0.14, 0.27. 0.4 Low specific activity Hafnium- 191 46 d 0.48, 0.34

Cerium -141 28 d 0.14 Low specific activity

(Cerium -144 275 d 0.22, 1.2 Fission product. (Praseodymium Soft gammas masked by 1.2 MeV terial were factors which hampered general use. The possibility of applying artificial radioisotopes changed the situation considerably. A 1947 publication mentions the use of lanthanum-140 in the USA. It is one of the first examples of gamma-radiography with artificial radioisotopes. La140 is a radioisotope with a half-life of 40 hr and a gamma-ray energy of 1.6 MeV. However, the rather high energy of the radiation and the short half-life make this radioisotope less suitable for radiography. In 1949 Eastwood of the AERE in Harwell published Table I of isotopes that could be used for radiography. On comparing it with data published in national reports, one can see that Ir192 and Co60 in particular are still applied; other radioisotopes are sometimes used for special purposes. In about 1955 Cs137 became available but, due to its lower specific activity and, in the beginning, to the difficulties with the encapsulation, it was not widely applied. Radiography with neutrons, revealed with generators as well as with a Ra-Be source, for instance, is one possibility. Because of a quite different way of the absorption and scattering of neutrons, neutron-radiography covers a very special field of application. For instance, a paraffin inclusion in 30 cm of lead can easily be found in this manner. The extent of these applications is very small and it is not likely that it will increase in the near future. The very small direct influence of neutrons on photographic emulsion is a problem to be solved in neutron-radiography. Special screens must be used to convert the neutrons into gamma-radiation. 404 TECHNICAL AND ECONOMIC SUMMARIES

Bremsstrahlung sources could be used instead of X-ray tubes, but, in view of the dimensions of these sources, extensive application did not succeed; the developments in this field, however, are followed with interest. To make a justified comparison of gamma-radiography with other methods, a rough conception of those factors which influence the choice of the radiation source for radiography, is necessary.

PRINCIPLES OF RADIOGRAPHY

Figure 2 shows the basic principle of radiography. The radiation source is mounted at some distance from the object under examination. The kind of radiations under consideration here are X- and gamma-radiation.

RADIATION SOURCE

Fig. 2 Principle of radiography

Behind the object a radiographie film is placed. The radiation pene- trates the object and, when the distance between object and source is large with regard to the material thickness, the relation between the intensity of the radiation in front of and behind the object is given by the well-known relation:

iT j = J-T 0p-»*e * \i)(1)

where I0 = intensity of radiation before the object, II = radiation intensity behind the object, ju = total linear absorption coefficient. This depends on the energy of the radiation applied and on the atomic number, the mass number and the density of the material under examination, d = thickness of the object. GAMMA-RADIOGRAPHY 405

In the object we assume an inhomogeneity with dimension di in the direction of the radiation beam. Then the intensity of radiation behind this defect becomes:

where n1 is the total linear absorption coefficient of the material in which the inhomogeneity exists. In practice the inhomogeneity is nearly always a hole filled with air or with another gazeous substance. For instance, cavities, cracks, porosity, laminations etc. In that case ß1 is very small with regard to ß and we could write equation (2) as:

I2=I0e-«d-di). (3)

In combination with equation (1) we could write:

d I2/Ii=e" l.

To enable detection of the defect with photographic film, this relation must sufficiently deviate from one. As a rule, for radiography, it should be possible to detect a certain percentage of the thickness examined, so, for a certain object, d and di have fixed values. In that case ß only defines the extent of l2/Ii and as, for a certain object the atomic number, mass number and density are fixed values and the wave-length of the radiation used defines the value of the quotient. For a certain thickness one must use a fixed radiation energy, depending only on the sensitivity required. The choice of photographic film is very important. Fine-grain films require a long exposure time but, as a rule, they give better contrast and a sharper image. , The exposure time can often be shortened by applying thin metal screens to both sides of the film, for instance, 0. 08-mm-thick lead screens. The electrons made free by the photoelectric effect in the screen contribute to the photographic density of the film. As often happens in optics, the radiation source must be preferably a point- source, or it should be so far from the film and the object that the dimensions can be ignored. It has been proved that the sharpness with which a certain defect appears on the film greatly influences the smallest defect to be proven. In fact, sharpness and contrast cannot be separated; the image quality, a combination of sharpness and contrast, indicates the smallest defect that can be detected. Image quality is expressed in a percentage of the maximum thickness. Efforts have always been made to replace the rather expensive and time- consuming X-ray film. The use of cheaper X-ray paper is obvious, but the lower sensitivity is a disadvantage. The smallest perceptible difference in density is also smaller because one does not look through but at the picture . 406 TECHNICAL AND ECONOMIC SUMMARIES

The application of fluorescent screens, called fluoroscopy, is more successful, in particular the modern method where an electronic image amplifier and a television screen are mostly applied, nearly always in combination with an X-ray apparatus. The Zerox process, an electrostatic method which makes a darkroom superfluous, also offers many possibilities, especially from the economic standpoint. Although some practical applications are known already, its field of application is still small. When being roughly handled in moist surroundings, the photographic film is more satisfactory. The polaroid process, well-known from photography, can also be used for radiography, although small defects such as cracks are difficult to eliminate.

RADIATION SAFETY

The dose rates which could arise from radioactive sources and X-ray equipment for industrial radiography are such that the maximum permissible doses could be exceeded. For X-ray apparatus an exposure rate of some hundreds of röntgen per minute in the primary beam is normal. For megavolt X-ray units this can add up to some thousands. As a rule, the radioisotope dose rates for gamma-radiography are lower. The continuous emission of radiation, however, makes safety precautions necessary during storage and transport. The sources are packed in containers made of lead, tungsten or de- pleted uranium. Most containers are provided with remote-control and the lead containers have a steel casing around the lead for fire-protection. To avoid radioactive contamination a source for radiographie purposes should be encapsulated. The most important requirements to be made to the capsule material are: (1) Non-leakage of the radioactive material; (2) It should be resistant to corrosion, wear and slight mechanical influence; (3) Its dimensions should be at a minimum. Requirement No. 3 needs some explanation. One of the most important advantages of radioisotopes with regard to X-ray apparatus is their low weight and their small dimensions. These advantages .should not be nullified by the container. To keep the operation of the container simple, a tube, in most cases fully or partly bent, surrounded with lead or other protective material, is used. Fig. 3 shows a cross-section of such a container. In the middle of the S-shaped tube the source is surrounded by lead. The weight of this container is defined by the required shielding, the diameter and wall thickness of the tube and the radius of the bend. The wall thickness of the tube and the radius of the bend depend again on the dimensions of the capsule. In Fig.3 are two containers with equal shielding, one with a normal type capsule, the other with a capsule which was specially designed for this container. GAMMA-RADIOGRAPHY 407

ALUMINIUM KAPSEL R.T.D. KAPSEL

6-45 kg G-20

Fig. 3 Protective containers for radiography

A method of judging the building of containers is to calculate the weight of the sphere, taking as radius the minimum shielding of the container. Then the weight of the sphere is divided by the real weight of the container. The result indicates what could be called the efficiency in the use of lead. For many containers this figure is too low, often due to the application of too big a capsule, and only in a few cases because of their poor design. The dimensions of most radioactive sources for radiography are only some millimetres; the outer dimensions of the capsules need not be much larger. In Fig. 4 is shown the capsule which we have used for three years. It is made of monel and can be used up to 100 c Ir192.

PRACTICAL EXAMPLES

To give a good idea of radiography here are some examples of examinations which can be carried out, and the apparatus used. Fig. 5 shows a radiographie examination of circumferential welds in a pipeline. The X-ray tube is situated on one side of the pipe, and the X-ray film on the other side. Several exposures must be made to radiograph the whole weld. Fig. 6 shows a reproduction of a radiograph of a weld; a crack is clearly visible as a sharp dark line. Radiography with a cobalt-60 source is shown in Fig. 7. In the casting only big defects had to be detected and, because of the great material thickness, high-energy radiation could be used. 408 TECHNICAL AND ECONOMIC SUMMARIES

Fig. 4 Small isotope capsule for Ir192

Fig. 5 Radiography of a weld with X-rays

The container, mounted on a trolley, is placed at 15 m distance from the casting; the remote-control box at 10 m from the container. Fig. 8 shows the container in detail. Fig. 9 shows a container for Ir!92; the weight is about 25 kg, the lead protection is 6 cm. In Fig. 10 a special application of radiography, called "on-stream inspection", is shown. The source is positioned some distance from a pipe and the wall thickness is projected on the film. By measuring the projected wall thickness and making some calculation, the real wall thickness can GAMMA-RADIOGRAPHY

Flg. 6 Radiograph of & weld

Fig. 7 Gammaradiography with Co60 source be determined. In this way corrosion in pipes can be detected. This method is used for gas-distribution pipes, refineries, chemical plants etc. to measure the decrease in wall thickness. Fig. 11 shows a radiograph of a bend in a pipe, made by theon-stream method; the difference in wall thickness is clearly visible.

COMPARISON OF GAMMA-RADIOGRAPH Y WITH X-RADIOGRAPH Y

Image quality

For certain material thicknesses an X-ray unit can give the desired image quality by setting the high voltage on the X-ray tube. For radiography with radioisotopes one must choose an isotope with a suitable energy to obtain the desired image quality. As the number of radioisotopes suitable in practice for gamma- radiography is restricted the choice of radiation energy for examination is also restricted. In practice only a few material thicknesses exist whereby radiographs made with isotopes can compete, in image quality, withX-radiographs. Con- 410 TECHNICAL AND ECONOMIC SUMMARIES

• . =::

Fig. 8 Container with remote-control for Co60

Fig. 9 Container with remote-control for Ir192

sidering the image quality, the use of isotopes must certainly not be seen as a progress. The results are often worse, because the radiation is too hard. GAMMA-RADIOGRAPHY 411

ENLARGED IMAGE

TßOE THICKNESS

Fig.10 Principle of "on stream inspection"

Fig.ll Radiograph of a pipe bend

Exposure time

Since, particularly in recent years, the specific activity has increased, especially for Ir!92, high-activity sources at small dimensions can be realized; for instance, a cylindrical source 1 mm long and 1 mm diam. can have an activity of 15 c. As far as Iri92 is concerned, the exposure times for the X-ray and gamma-ray method can be approximately equal, provided that the lack of sharpness is kept constant. Co60 sources emit gamma-radiation with rather high energy; they could be compared with an X-ray unit of, for instance, 1.5 MeV - 2 MeV. A source 412 TECHNICAL AND ECONOMIC SUMMARIES of about 1000 c would be necessary to reveal the same exposure time. These high activities make it necessary to use radiation sources with relatively large dimensions which causes the lack of sharpness to be much greater than that revealed with megavolt X-ray units.

Practical utility

The practical utility of a radiation source is defined by its weight, dimensions and the possibility of getting the source at the desired place. In this respect Iri92 has absolute advantages for X-ray equipment that gives the same image quality. It is impossible to examine many objects with X-ray tubes; in other cases the absence of electricity is a reason for choosing gamma- radiography. An X-ray tube with a special motor generator can be used, but this increases the price of the unit and decreases the possibility of bringing the whole unit to the desired place. Under these circumstances an examination by Ir!92 is carried out even on material thicknesses which are normally not considered for an inspection with such highrenergy radiation. In that case one must be content with an inferior image quality; it is better to have such a radiograph than to have none. It should be noted that, in recent years, manufacturers of X-ray equipment have improved their apparatus appreciably, reducing dimensions and weight. The application of gas as an isolation and cooling medium around the tube and transformer favourably affected the weight of the unit. Fig. 12 compares the dimensions and weights of different modern X-ray units with those of 1950. The figures inside the squares indicate the tube voltage and current (e.g. 300/3: 300 kV, 3 mA).

1950 1961

i l l 60 40 20 0 l l i l 85 kg 120kg 40 kg 77 kg

Fig. 12 Comparison of weight and dimensions of X-ray sets GAMMA-RADIOGRAPHY 413

Reliability

An X-ray unit, however well-constructed it may be, always appears to be rather delicate. Also, because of the demand for lightness and for small equipment the reliability is deteriorating. A user of some X-rayunits should dispose of spare units. In our institute we use daily 60 X-ray units. Two men are continuously engaged in maintenance of the equipment. Be- sides that we have to spend HF1. * 47 000/yr for repairs to be done by the manufacturers- in most cases damage of X-ray tubes and high tension transformers. For radioisotopes the situation is as follows. We now have available 86 Iri92 sources with a total activity of 200 c and 5 Co60 sources with a total activity of 50 c. We do all repairs to the containers ourselves and have two men fully employed for the maintenance and repair of the containers. We find that disturbances in the remote-controlled containers can lead to dangerous situations. Containers are therefore inspected once every three months. Concerning reliability we must conclude that radioisotopes in well- constructed containers are less subject to disturbances than X-ray apparatus, particularly when the latter must be fed by means of generators. The pro- ductional loss caused by disturbances in X-ray units is actually much greater than for radioisotopes, because, when an X-ray unit is becoming defective it generally no longer operates.

Radiation safety

During work in our institute there seems to be no difference in the personal dose received from X-ray units or from radioisotopes. This, however, applies only when the equipment is in good order and condition. Disturbances causing radiation danger occur relatively more in isotope containers than in X-ray equipment. A disturbance in an X-ray tube, however, can cause a much higher dose.

COMPARISON OF RADIOGRAPHY WITH OTHER NON-DESTRUCTIVE TESTING METHODS

The aim of the so-called magnetic particle inspection and the penetrant (dye-check) method is to prove surface defects, particularly cracks.. There is no question of competing with the radiographie method. If the mentioned defects are to be traced, preference should be given to the magnetic or penetrant method. Inspection with ultrasonic waves is quite another question. In principle, all defects to be found-with radiography can be detected with ultrasonics; in particular, where cracks are concerned, this method is capable of giving even better results. In applying ultrasonics there is practically no limit as far as material thickness is concerned. There is no danger in its application. The im-

* 3.62 HF1. =US$1. 414 TECHNICAL AND ECONOMIC SUMMARIES pulse energies used are too low to cause any damage to living cells. Conse- quently legal regulations do not apply to the operation. The initial expense and costs of maintenance for ultrasonic equipment are low in comparison with those required for radiographie equipment. Its dimensions are small and its weight is very low. Feeding by means of batteries is possible and the reliability of the equipment is reasonable. The equipment can be used nearly everywhere, even under water. So far we have discussed the exclusive advantages of the ultrasonic method. Problems begin with the operator. He must have wide experience and a good knowledge of the behaviour of ultrasonics and material structure. The means of registration is a second problem. This can be obtained with a cathode-ray tube or a recorder. The relation between the registration obtained and the object, however, is more difficult than for the X-ray film. Moreover, the results depend on the experience of the operator. Understandably one always tries to apply this method automatically or semi-automatically, in order to avoid a personal influence on the results. The fully-automatic method has been applied for years in pipe mills for examining longitudinal welds. In results and speed this method is superior to any other. Automatic units for examining aircraft wheels, castings, pipe material etc. are used with success. With regard to its application for examining circumferential welds in pressure vessels and tubing, the situation is completely different, because automation has not yet been practically realized. In these cases ultrasonic inspection is generally unacceptable and preference should be given to the radiographie method with which one can simply see whether the inspection was carried out correctly, even though certain defects cannot, or can hardly, be proved. For the sake of completeness, it should be noted that ultrasonics cannot be applied to materials in which the velocity of the ultrasonic waves of porous materials.is low, e.g. layered structures and some kinds of cast iron. The following conclusion can be made. For many problems the ultrasonic method will give better results than radiography. If the examination can be automatized nothing stands in the way of its application. However, if this is impossible the results will depend on the professional knowledge and responsibility of the operator, and in such cases the radiographie method is often chosen, because skilled persons can see whether a radiograph was made correctly or not. Other means of non-destructive testing, e.g. eddy current, leak testing, thermopaint methods, electrical methods, magnetic methods etc., cannot compete with gamma-radiography because the defects that can thus be detected cannot in most cases be determined by radiography.

CONCLUSION OF THE COMPARISON OF THE METHODS

Should someone intend to apply radiography one should consider its possibilities and limitations, whereby it may be preferable to include other methods. (1) For work normally done by radiography one cannot expect an image quality better than that obtained with an X-ray unit. In the most favour- GAMMA-RADIOGRAPHY 415

able case it will be the same, but generally a lower sensitivity will be obtained. (2) One should not compare a proper X-ray unit and radioisotopes; the auxiliary equipment must be included in the comparison, e.g. motor generators for X-ray equipment and the containers for radioisotopes. (3) Radioisotopes, in particular Ir192, are indispensable when radiographie inspection must be done in inaccessible places. (4) Ultrasonic inspection can often compete with radiography, but has not yet been generally accepted, because personal influence on the result of the method is large.

ORGANIZATION, NATIONAL REPORTS

From the national reports it can be seen that, in some countries, non- destructive testing is carried out or directed by a Central Institute. This is, in my opinion, the best situation. As a rule, an Institute will be objective in its choice of methods and have available all equipment necessary to carry out examinations correctly. The number of isotopes used depends on the number of central institutions existing in the country in question, and on the extent of their activities in the field of non-destructive testing. In such cases radioisotopes will be applied only if the facts, mentioned before, make it strictly necessary. If a country has no central institute, and smaller concerns start with radiography, preference is always given to isotopes, because this requires less investment. The fact that the results obtained are not comparable and sometimes even insufficient is not considered. A real impression can only be obtained when the number of sources for radiography is compared with the value of industrial production in the broad product groups 7 through 11. Countries where non-destructive testing is carried out by one or more institutions are: Denmark, Sweden, the Netherlands, and Belgium. This is not the case in countries like Canada, the Federal Republic of Germany, Japan, the United Kingdom and Yugoslavia. In order to draw further conclusions, one must know how many central institutes exist, how many customers they serve and how many sources they use. As many reports do not mention such details, it is impossible to draw final conclusions.

BIBLIOGRAPHY

Recommended Practice for Radiographie Inspection of Fusion Welded Joints for Steel Plates up to 2 inches (50 mm) (IIW/IIS-6-58). Recommended Practice for the X-ray Inspection of Fusion Welded Joints on Aluminium and its Alloys and Magnesium and its Alloys up to 2 inches (SOmm)thick. (IIW/IIS-35-59). Recommended Practice for the Radiographie Inspection of Circumferential Fusion Welded Butt Joints in Steel Pipes up to 2 inches (50 mm) Wall thickness (IIW/IIS-36-59). Handbook on Radiographie Apparatus and Technique (IIW/IIS-46-60). Recommended Practice concerning Radiographie Image Quality Indicators (I. Q. I. ) (IIW/IIS-62-60).

ECONOMIC BENEFITS OF INDUSTRIAL RADIOGRAPHY

As indicated by the national reports, gamma radiography is a widespread and generally accepted method in non-destructive testing. The 20 countries on which reliable information as to the number of. sources was available had no less than 2686 gamma radiography sources in use in the period of investigation. A detailed summary is made in Table I. From this summary it can be seen that the largest number of sources are applied in the machinery industry, followed by the services group and by the basic metals. It should be pointed out, however, that included in the services group are some sources owned and applied by firms that specialize in general non- destructive testing, and whose customers will be found throughout the entire industrial field. A number of firms classified under such broad product groups as "petroleum and coal", "chemicals and plastics" and "cement, glass and china" also own gamma radiography sources for their own use. Single users were recorded in the textile industry (Japan), the wood and paper industry (Federal Republic of Germany) and the rubber industry (France), and the food, tobacco and leather industries did not report any uses of gamma radiography. When evaluating the comments of the national reports on the economic importance of gamma radiography a number of applications have to be distinguished for which the cost-benefit pattern may differ considerably.- Eco- nomic benefits from gamma radiography are estimated only by defining very carefully the alternative method. Another difficulty is that a genuine economic comparison can be made only where the results obtained by the two methods are of the same quality. Otherwise, the decreased cost for a somewhat lower quality of result has to be compared, for example, and such a comparison is subject to considerable personal bias.

TYPES OF APPLICATION UNDER REVIEW

Final product control

The philosophy behind testing methods is complicated. However, many of the problems are simplified if the discussion is limited to one technique only such as gamma radiography. Most products, where it is at all reasonable to apply radiography, are so important that the future user requests a certificate of testing. Even if this is not the case, there is no doubt that it is in the interest of the producer to verify the quality of his products. In the introductory period of physical testing methods it might not have been so, but today's market for industrial goods involves other requests. Thus, it is not relevant to compare gamma radiography for final product control with no testing at all. A statistical destructive test is in many cases also out of the question, because the items are too costly and complicated. Ultrasonics, the best physical practice competing with radiography, has the general drawback that it does not give a certificate of the same value of evidence as a film. Nor is it applicable to as many material testing problems as radiography. The most relevant comparison is therefore with other

417 418 TECHNICAL AND ECONOMIC SUMMARIES

sources of ionizing radiation. A number of economic situations can be distinguished: 1. Formost materials in most factories experience proves that X-rays are superior to radioactive sources to obtain the same quality of results. Only with very thick materials (e.g. 40 mm steel) does conventional machinery not give sufficient penetration, and here Co60 sources compete very advantageously because of their lower capital cost compared with radium or highly penetrating X-rays. 2. When performing only a few radiographs in a year, the longer exposure times entailed with gamma sources are important. Panoramic radiography using e.g. a Co60 or Co137 source will then be cheaper for the individual user than X-ray radiography, again mainly because of decreased capital cost. 3. Gamma radiography offers certain advantages from an administrative and economic point of view when large areas such as a number of welds in pressure vessels are to be examined. As the radiation from a radioisotope source is emitted in all directions, large areas can be covered in one single exposure. Using X-ray tubes one would have to make many exposures moving the source, and so the total exposure time and the number of working hours for radiographing one piece of equipment would be much longer than when gamma sources are applied. 4. Another application where gamma radiography is superior is for the inspection of material of such a shape that X-ray tubes cannot be used. A typical example is a thin tube. Here the economic comparison is again very difficult, but it could be done by assuming the costs for running several X-ray tests from various angles which together might give the corresponding information. 5. In radiography of inaccessible places such as ships' hulls, gamma radiography is easier to use than X-ray radiography. This discussion is based entirely on the assumption that the object to be tested is of such importance that final testing is necessary, e.g. steam boilers, merchant ships and high-pressure vessels. But the smaller the importance of an object (possibly determined by the severity of an accident resulting from failure) the smaller is the tendency to test it. The mechanical engineering industry produces an enormous number of parts not subjected to any physical testing. Instead, the quality is maintained by spot checks or by statistically applied control schemes, including both destructive and non-destructive testing. Several examples of economic comparison between over-all non-destructive testing and the use of statistical methods can be found in the literature on quality control. For a large number of medium-value industrial products this comparison is relevant, using radiography as the standard non-destructive method. Finally, it should be pointed out that a good reason for non-destructive testing is the decrease in claims. On the one hand these claims can be very- expensive (this is therefore a tangible saving) and on the other hand considerable intangible savings might follow because a large number of claims have an impact on the producer's reputation, thereby affecting his sales and the net benefits. INDUSTRIAL RADIOGRAPHY 419

Use in remote areas

Many industrial products are used in remote areas, and repairs must often be made on the spot. With satisfactory road conditions and a sufficient supply of electricity, X-ray and gamma radiography compete in the same way as at an industrial plant. If this is not the case, the situation is different and gamma sources normally have the advantage. When a test is considered vital, e.g., in mounting or repair of pipelines in populated areas, then gamma radiography with Co60 or Ir192 should be compared with the cost estimate of transporting a repaired part to the nearest place where X-ray radiography is available, or of transporting an X- ray apparatus and power supply to the spot. In such a comparison, the use of radioisotopes means very high savings. These arguments concerning remote areas are equally valid for industrial plants where hazards from explosions are great, so that high voltage installations that could release electrical discharges have to be avoided. Regarding thicker materials, the comparison should be made between a Ra source and a Co source, which can both be transported under the same conditions. The capital cost of the Co60 source is, of course, much lower.

Control in industrial production

In many instances companies use gamma radiography for internal control of castings or ingots looking for flaws, cracks or other defects and inhomogeneities. The reason for this inspection is that, if these defects are detected at an early stage in production, one can save machining costs on parts that will not pass the final product control. This type of testing has considerable economic significance. In many cases gamma radiography is the only applicable testing method, and the gross savings figure is obtained from the number of rejects per year, multiplied by the average cost of machining before the faults would eventually have been detected. Other physical methods, such as ultrasonics, are of course also used for inspection. The over-all picture seems to be that, if they can be applied, they are preferred for technical or economic reasons. This means, with a certain over-simplification, that once gamma radiography is chosen, the comparison should not be made with the alternative but with the "no testing" situation. As was envisaged in an earlier paragraph, results achieved with Co60 can also be reached using Ra or high-energy X-ray machines. But the capital cost of these sources is possibly prohibitive: a comparison with these might give still higher estimates of "savings" than using "no testing" as a criterion. According to the definition for this survey, savings should be expressed as the difference between the radioisotope method and the economically best alternative.

Testing in reasearch

Heavy industries interested in gamma radiography tend to apply much research in production in order to find whether this improves the product. 420 TECHNICAL AND ECONOMIC SUMMARIES

As it is too costly to scrap the results of these test runs, they are then processed normally and the products sold if they do not turn out too badly. But it is obvious that in these cases testing has to be done much more carefully and some companies have made it a rule to apply gamma radiography to all products from such runs, even if this is not done in the regular production. The economic benefits will of course be the same as in normal production control.

EXAMPLES OF SAVINGS FROM NATIONAL REPORTS

Economic details on gamma radiography were provided in the reports of 13 of the countries participating in the survey. However the information was in most cases incomplete, ranging from one case study to rough estimates for the whole industrial field. Only a few examples on each of the four types of applications listed above will be reviewed here. In the case of welding control, which is probably the most widespread application (it accounts for half of the applications in all countries), a typical list of benefits is given in the section of the NICE report on the procedures of non-electrical machinery. "Firms that replaced X-ray machines and radium sources with artificial radioisotopes are achieving savings through lower equipment and maintenance costs or elimination of radium rental fees. Fifteen companies reported decreases in the annual cost of equipment and facilities that ranged from about $200 to over $29 000 for a 12-month period during 1957-58. "For example, a large manufacturer of heavy machinery would have had to spend over $119 000 on X-ray equipment to get the same benefits obtained from a radioisotope unit costing $8800. In addition, the company reduced its labour cost associated with radiographie inspection by $24 000 because of the increased portability and capability of a radioisotope source. "Similarly, a smaller company reported an annual equipment saving of $420 and a reduction in direct labour cost of $4000. One producer of oil- field machinery, using a few hundred dollars' worth of Co60 for radiographie inspection, estimated that the annual rental cost of an equivalent amount of radium would be $30000. Regarding the fabricated metal products industry it is similarly stated: "Most companies in the metal-fabricating industry state that their only saving from the use of radioisotopes has been in the lower cost of the equipment. These equipment savings ranged from several hundred dollars a year on an annual basis to nearly $100000 in one case. However, most equipment savings ranged from $2000 to $15 000/yr. The largest saving occurred in cases where the alternate method was an X-ray machine. When radioisotopes displaced radium, the saving in cost of equipment was generally much less. " Some companies, however, experienced other savings. Twelve companies, for example, reported labour savings ranging from $1000 to $45000. One of these companies saved $2500 because the multiple-exposure capabilities of radioisotopes saved half a man-year of labour. Another company, which constructs power plant equipment and piping, reported saving $15 000 in labour costs in a 12-month period during 1957-58 because "with radioisotopes one man can-radiograph 200 ft at a time, whereas with X-ray machines it took five men to radiograph 1 ft at a time". Still another com- INDUSTRIAL RADIOGRAPHY 421 pany obtained a 35% increase in inspection productivity, with a resultant $15000 saving in costs. Three companies, however, experienced increased labour costs because they either had had no previous inplant inspection or had increased their inspection activity when they acquired radioisotope equipment. Only two companies reported savings in raw materials as a result of using radioisotopes to inspect their products. One, a manufacturer of pressure vessels, reported saving $2000 in a year because he was able,by radiographing the welded joints in pressure vessels, to use thinner material for the walls. A saving in scrap was reported in three instances. One valve manufacturer was able to save $4000 in finished-product scrap in a 12-month period in 1957-58 by eliminating the destructive method of testing previously used. The experience of a company manufacturing stainless-steel vessels was similar. It formerly had tested plugs cut out of welds. By going over to radioisotope radiography, it saved $2000 in finished-product scrap. The third company saved $5000 on scrap. Radioisotope radiography increased the net profits of two of the companies. The profits of one were raised $10500 in a 12-month period in 1957-58 because of increased sales directly traceable to its radioisotope inspection. The other believed that its profits on additional sales were about $20000. In addition to the savings reported, most companies also attributed improved quality of product and better customer relations to the use of radioisotopes for inspection. A number of companies noted that an increasing number of customers were demanding radiographie inspection of welds and castings, thus making it vital for fabricators to be able to offer such service. In turn, the ability to offer such inspection had become a strong selling point. Another benefit reported is the improvement in welding skill that results when 100% radiographie inspection was instituted and the radiographs of the welds were, discussed with the welders. Another benefit cited is the greater design freedom. Radioisotopes can inspect structures for soundness that are too complex to be examined by X-ray machines. Also for the application of radioisotopes in testing of welds in the field and in the repair of existing plants, a number of gamma radiography applications were recorded. Two typical examples of this type of application are given in the French report to the survey: 1. The construction of a pipeline for natural gas includes 100% gamma radiography control of 80 welds/km. The cost of this control corresponds to 0.3 - 1% of the cost of the pipeline. For pipelines of 600 mm diam. that cost about F.Fr.400 per m, the control costs amount to F.Fr.4000 per km. On an average 8 - 12% of the welds are unsatisfactory, some are easily repaired, and others need re-welding. In this case savings are mostly indirect, but in any case the cost of applying X-rays would have been much higher than F.Fr. 4000 per km. 2. The other example is taken from the power industry. A technique has been developed here that permits the determination of corrosion of pipes in thermoelectric power stations by gammagraphy. It is possible by this technique to measure the thickness of the pipes and a packet of 14 boiler pipes can be studied simultaneously to a height of 40 cm. Thus significant 422 TECHNICAL AND ECONOMIC SUMMARIES corrosion can be detected and the rupturing of these tubes prevented. The cost of a full inspection control of one boiler is about F. Fr. 30 000. If a 250 MW boiler has to be stopped because of a rupture the loss is about F. Fr. 140 000/d, and it normally takes a week to repair and restore it. Now, when corrosion is watched continuously, the exchange of tubes can take place during the periods of regular maintenance. Testing of ingots and castings forms about one third of the applications reported to the Agency survey. In some cases, where the castings are delivered to external firms, the testing is a kind of product control. How- ever, in most cases some further treatment is made in the plant itself; the detection of faults by gamma radiography will therefore cause internal savings, primarily in labour and machining time. The report of the United Kingdom describes a case study of a complex nature but the main savings are of the above type. "A manufacturer of pressure vessels uses 18 Co60 sources from 0.3 to 3.2 c continuously to inspect welds, castings and forgings, and materials to be machined, as well as to check maintenance and repairs. The factory produces pressure vessels to carry the most severe conditions of pressure and temperature. A casting as produced by their foundry is quite valuable in itself but this is of little consequence when compared with the final machined and assembled component. Radioisotopes (natural and artifical) are used for two major purposes: (a) The most important, to check the quality of the casting produced and to give guidance in the technique used in order to enable the production of an article free from blemishes. (b) To establish that castings leaving the foundry are of such quality that they will pass through the entire factory without interruption, no matter what further testing and inspection is applied. The saving then is at least sixfold: (a) No unsound castings produced, thus saving labour and foundry materials; (b) consequently also saving of labour spent in producing castings rejects; (c) minor faults in castings can be repaired when they can still be heat- treated, etc. ; (d) saving in machining time spent on producing bad castings; (e) production programme can rely on quantities at the end of the cycle being identical with those at the beginning - hence more efficient production; (f ) elimination of customer complaints and replacement of faulty parts. In some categories therefore some idea of saving in money terms is possible, but in others, such as the value of a smooth flow through the works, it is very difficult to arrive at. The total investment in the method is relatively large at £52 000, including £23 000 spent in the year of the survey. These and the running costs of £6000 per annum are fully justified by the estimated annual saving of £500000 representing 25% of the turnover to which isotope techniques were applied. " This is an unusually positive case. In fact these 18 sources out of the 706 reported by the United Kingdom contribute 40% of the total savings attributable to the industrial use of gamma radiography. INDUSTRIAL RADIOGRA PHY 423

"It should be stated in fairness", the United Kingdom report states" that some firms, using gamma radiography to test a higher proportion of their products than would otherwise be possible, claim only an increase in quality of their products but estimate an overall financial loss equal to the estimated cost of the service. Against this apparent loss may be balanced the commercial advantages of enhancement of the firm's prestige, much more difficult to assess in financial terms. However, several other firms are able to identify increased business resulting from their improved testing techniques - up to 2 5% of their isotope- assisted turnover. These sales advantages are dealt with separately in the report." The same favourable view on gamma radiography is given by a few of the other national reports, e.g. the Polish and Yugoslav. For instance the Yugoslav report quotes one institute that found savings in one steel plant of about Din 72.5 million/yr, i.e. $100 000 in thermal treatment and machining. Finally, research with gamma radiography can lead to important improvements. The French report gives an interesting example of this. Natural gas contains appreciable quantities of sulphur, and in transporting unpurified gas corrosion is a serious problem. To select the most resistant constructional material for pipelines, gamma radiography was used as a research tool. By this method the corrosion rate was reduced, and the savings in one case amounted to F. Fr. 30 millions. These are only some examples of the economic importance of gamma radiography as revealed in the national reports. The Soviet Union is one country where gamma radiography is highly esteemed, and it is therefore only fair to the technique to quote what the most reliable Soviet authorities say on the economic effectiveness of gamma radiography [1] : "The basic shortcoming of gamma radiography compared with X-rays is the long exposure time normally required. However, factors such as portability, independence from power supplies and low price will eventually lead to the general use of gamma-ray sources. " To obtain a comparison of the cost of X-ray and gamma-ray radiography, an analysis was made of the costs for testing 30 - 40 mm-thick steel in a locomotive repair plant and a shipyard. The costs for 43792 radiographs were compared. For gamma-ray testing the costs were Rb 4 8 166, for X-ray testing Rb 57 161, thus gamma radiography is about 16% cheaper. The main differences were in wages (Rb 2900), maintenance (Rb 1800), depreciation (Rbl300) and transport expenses (Rb900). The number of radiographs taken each year in the Soviet Union is, however, several millions, so that the savings are considerable. In testing welded seams of pipelines, considerable savings were reported in comparison with statistical destructive testing (cutting out parts of the welded seam^nd re-welding). About 10000 km of pipelines are laid in the Soviet Union each year, so that if 2% of the welds on the average and 100% on important portions are tested the total savings reach Rb 4 million/yr. In total, the report says, the savings from gamma radiography in 1961 for the entire Soviet industry can be estimated at Rb 25 million. As the demand for quality control increases, the use of gamma radiography will also increase, and in 196 5 the savings may reach a total of Rb 80- 90 million/yr. 424 TECHNICAL AND ECONOMIC SUMMARIES

Intangible savings

In several cases the national reports describe benefits such as increased safety and fewer complaints. These benefits are probably also those that in the long run are most important, and persuade industry to apply modern testing methods. It is obvious that the hazards to life and property from badly working equipment are such that the manufacturers are extremely interested in making certain that their goods are sold with sufficient security margins. As far as gamma radiography is concerned, it is sufficient to point out such important applications as welding control of steam boilers, ship plates and pipelines to show its direct importance in a modern industrial society. Although most of the savings here are either to the benefit of the customer or of an intangible nature, it is quite clear that the safety aspect can be interpreted in terms of direct savings as the number of returns is reduced. Many important industrial units are sold under guarantee and even a small number of guarantee claims will soon become more expensive than the implementation of any reasonable testing programme. The direct costs of holding spare parts for exchange in case of a failure are also very high, particularly in a market situation where the demand exceeds production capacity. Even in this case the intangible savings probably greatly exceed the direct ones because reliability is a very strong selling argument. Non- destructive testing methods, including gamma radiography, are important in helping to maintain high reliability. In conclusion, all the evidence shows that indirect savings are much more important to industry than the direct ones. The benefits to industry and to society in general are therefore probably much higher than the rather modest saving figures which are quoted from the firms contributing details to the national surveys. It is pointed out in several reports that the savings from gamma radiography could not be properly evaluated because industry cared much more for high quality and a good reputation than for keeping its costs down. The costs for gamma radiography services are therefore often higher than what the absolute minimum of security would require, but it is also clear that industry is willing to pay and even increase these costs, particularly in a market with demands for increasing quality. It is thus very likely that although gamma radiography is an old and well-established technique, its importance is not decreasing. In certain fields it will be successfully replaced by other testing methods, e.g., radioisotopes (as was illustrated in the economic summary of gauging) or those based on quite different physical principles. Gamma radiography, however, will probably find an increasing number of fields and more extensive use in well-established ones through the increasing demands made by modern technology on construction materials and on ready-made goods for industrial and private use.

SUMMARY AND WORLD OUTLOOK

As in the case of gauging, the Agency Secretariat is interested in summarizing the reported savings from gamma radiography and in trying to INDUSTRIAL RADIOGRAPHY 425

TABLE I

THE NUMBER OF GAMMA RADIOGRAPHY SOURCES IN INDUSTRIES

Country Broad product group Tota l No t identifie d 1 . Foo d 2 . Tobacc o 6 . Rubbe r 4 . Woo d an pape r 3 . Textil e 7 . Chemical s an d plastic 8 . Cemen t 9 . Petro l an d coa 10 . Basi c metal s 11 . Machiner y 12 . Service s

Argentina - - - - - 1 - 5 2 1 18 - 27

Australia - - - - ~ - - 1 12 7 30 - 50

Austria 3o0n 30 Belgium - - ' 1 17 13 20 - 51 Canada ------5 60 45 35 - 145 Czechoslovakia ------8 - 12 138 10 - 168 Denmark ------1 - 20 - 21 rinianTlinlnnAa 4 1 3 8 France* - - - - 1 11 1 19 80 300 50 38 500 Federal Republic - - I - 10 15 6 40 200 28 - 300 of Germany*

Japan - - 1 - - 8 - 39 112 2 8 170 Netherlands 127 135 Norway 1 1 13 1 - 16 Poland * ------60 20 - 80 Portugal* ------10 - - 10 South Africa - - - - - 1 - - 2 14 31 - 48

Spain ivi ft 1 7rr _ _ _ Sweden ------10 20 50 80 United Kingdom - - - - - 14 4 10 147 364 167 - 706 Yugoslavia ------1 3 93 25 2 124

Total - - 1 1 1 45 28 57 461 1534 510 48 2686

* Approximate figures. 426 TECHNICAL AND ECONOMIC SUMMARIES

TABLE II

GLOBAL SAVINGS ESTIMATED FOR GAMMA RADIOGRAPHY

Estimated annual savings Number of Annual savings reported (US«) Country sources (US $) Low High

Argentina 27 no estimate >! Australia 50 66000 Austria 30 no estimate Belgium 51 no estimate • see below see below Canada 145 no estimate Czechoslovakia 168 no estimate Denmark 21 no estimate Finland 8 no estimate „ France ~500 4000000 2000000 8000000 Federal Republic of ~300 12000 see below Germany Japan 170 4800-65001 850000 1 500 000 Netherlands 135 700000 700 000 700000

Norway 16 no estimate see below Poland 80 800 000 400000 800000 Portugal 10 no estimate 1 South Africa 48 no estimate • see below see below Spain 17 330002 j Sweden 80 100000 100000 200 000 United Kingdom 706 37000003 5700000 11400000 Yugoslavia 124 200 OOO4 500000 1500000

Subtotal ~10.3 million. ~ 24. 1 million 16 countries (900) 1. 8 million 4. 8 million United States of 4. 0 million 7. 6 million America USSR 22 million 22 million

Grand total ~38 million ~58 .million

1 Average per source. 2 One source only. 8 Gross savings of responding group (28%). 4 Figure refers to three applications only. INDUSTRIAL RADIOGRA PHY 427 estimate a figure for the amount saved by the use of this technique throughout the world. In Table II the reported savings are summarized, and estimates are made for total savings. Individual savings were estimated only for the seven countries for which full details on the extent of gamma radiography usage were available. The low and high estimates were made as for gauging. For 16 countries, who did not provide savings figures themselves but where indications of number of sources or number of users were available, a very conservative estimate was made. This gave a net annual saving of between $1.8 million and 4.8 million. For the United States of America the figures from the up-dating of the NICE survey were used, ranging between$4 and 7.6 million. For the Soviet Union the figure of Rb 2 5 million given in Ref. [l] was accepted, and the corresponding value in dollars was taken as $22 millions. According to the Survey, global savings from the industrial use of gamma radiography amounted to $38 million net (low estimate) and $58 million net (high estimate).

REFERENCES

[1] MIKHEEV, G. F. and POSTNIKOV, V. I., The Effectiveness of the Use of Radioactive Isotopes in the National Economy, Moscow (1962).

EMPLOI DES SOURCES IMPORTANTES DE RAYONNEMENT

P. LEVÊQUE SERVICE DE PHYSICO-CHIMIE APPLIQUÉE CENTRE D'ÉTUDES NUCLÉAIRES DE SACLAY, FRANCE

Les utilisations industrielles les plus répandues des radioéléments sont basées sur les propriétés de leur rayonnement. Mais les radioéléments peuvent aussi être considérés comme une source d'énergie. Certes il ne s'agit pas de puissances importantes; en effet 1 c d'un rayonnement de 1 MeV ne représente que 5.92 . 10'3 W. Compte tenu du prix de vente des radioéléments (même pour les prix les plus bas pratiquée pour les livraisons importantes) il n'est pas difficile de voir que cette énergie est chère. Il s'agit donc de l'employer au mieux dans des cas où une autre énergie ne peut être utilisée.

I. BILAN DE DIX ANS D'EFFORTS

Les utilisations des radiations ionisantes ont fait l'objet de nombreuses publications et brevets. Le bilan des applications réelles est plus modeste. Il est résumé dans le tableau I. Industriellement parlant, il ressort de l'examen de ce tableau que le traitement des fournitures médicales est l'application la plus importante et qu'il se développera. Il faut d'ailleurs remarquer que l'introduction de nouveaux modes de stérilisation a bouleversé les conceptions du conditionne- ment. La recherche du meilleur rendement énergétique de la source de rayonnement a amené le développement d'emballage plus compact. De plus, cette méthode qui permet de stériliser dans un emballage étanche, provoque des changements complets de fabrication. On peut citer, par exemple, les se- ringues qui sont fabriquées maintenant en polystyrène et jetées après utilisation. On voit apparaître un enchaînement de faits provoqué par ce nouveau mode de stérilisation. Il faut aussi attirer l'attention sur une indispensable coopération entre le fabricant, le conditionneur et les specialists de l'irradiation. On avait pensé tout d'abord que les applications chimiques seraient de loin les plus importantes. Il faut bien reconnaître que ce n'est pas le cas. Nous reviendrons ultérieurement sur ce point plus en détails. Enfin, l'industrie alimentaire est dans l'expectative. Le traitement des aliments par un procédé quelconque est toujours suspect aux yeux du consommateur. Après une longue période de recherche où les Etats-Unis ont fourni l'effort le plus important, il semble que nous arrivions à l'aube des réalisations pratiques. Les premières autorisations de traitement ont été données aux Etats-Unis et au Canada. D'autres pays, comme l'Angleterre et la France, ont déposé des demandes d'autorisations pour des produits donnés. Le développement de cette nouvelle méthode reste conditionné par l'accueil que lui fera le public.

429 430 TECHNICAL AND ECONOMIC SUMMARIES

Source de Procédés Firmes Production rayonnement

Bromure d'éthyle cobalt 60 Dow Chemical 400 t/a Polyethylene en feuille accélérateur W.R. Grâce 1500 t/a Polyethylene réticulé accélérateur Radiations Applications $ 15 millions/a comme isolant de fils, etc. General Electric Rayahem (73, 5 millions F) Stérilisation de fournitures accélérateur Ethicon Hospital Supply Co. BÇPfo du marché médicales Section, Dickinson Co. américain des Smith & Nephew Ltd. (GB) sutures Stérilisation de poil de chèvres cobalt 60 Westminster Carpet Co. 2250 t/a (Australie) Dégermeage de Pomme de terre cobalt 60 Comm. En. Atom. 500 t/a Canada Résine d'acétal de polyvinyle accélérateur Tokyo Rayon pas d'indication (Japon) S emiconducteurs accélérateur 6 au moins des grands fabri- 20 millions d'unités/a cants de semiconducteurs

II. COUT DE L'ENERGIE IONISANTE

L'examen du tableauIImontre que les accélérateurs et les sources semblent se partager le marché d'irradiation. J'aimerais discuter un peu plus en détail ce point. Pour les installations industrielles d'énergie ionisante, il faut utiliser les mêmes critères que ceux que l'on utilise pour estimer le prix du kWh d'électricité d'origine nucléaire. Nous parlerons donc du prix du kWh installé, et du prix du kWh. La comparaison sera faite pour une même puissance installée (15 kW) et un même rythme d'amortissement (5 ans). La décomposition du prix est sommaire car il faut avant tout donner des ordres de grandeur. En particulier, le poste main d'oeuvre et entretien a été pris de même valeur dans les deux cas. On peut discuter cette approxi- mation mais j'ai estimé que si l'accélérateur coûte plus cher en entretien que la source, celle-ci exige par contre un personnel en service continu si l'on veut utiliser au mieux son rayonnement. Le prix de l'installation complète d'une sourse industrielle de 6°Co a été déterminé en se basant sur les coûts publiés d'installations existantes. Ces coûts peuvent être approxi- més (fig. I) par la formule

N=100X A0-815, où N est donné en nouveaux francs et A en curies. SOURCES IMPORTANTES 431

TABLEAU II DÉCOMPOSITION DES PRIX

Accélérateur Source

Nbre d'heures d'utilisation par an 2 000 6000 Nbre de kWh par an 30 000 90000

Investissement 1, 5 • 106 F 8 • 106 F (basé sur la courbe de la fig. 1) kW installé 10s F 5, 3 • 10s F Amortissement annuel 0, 35 • 106 2 . 10« Complément source 0, 6 . 106 Total 2, 6 - 106 Frais annuel de fonctionnement 0, 16 • 106 0,16. 106 (main-d 'œuvre + entretien* assurance) 2,76« 10«

Prix au kWh 17 F Prix au kWh 30 F

10'

10a 10' 5 10s 2 10° Figure 1 Activité en curies © Source américaine I Source anglaise D Source australienne X Source japonaise 432 TECHNICAL AND ECONOMIC SUMMARIES

II faut remarquer que: a) Le prix du kWh source est surtout déterminé par les investissements. La main d'oeuvre n'intervient que pour 5% dans le prix du kWh. b) Le prix du kWh source est à peu près le double du prix du kWh accélé- rateur. Pour de dernier la main d'oeuvre plus l'entretien intervient pour 30%. c) Pour passer au prix du traitement il faudra tenir compte de l'efficacité de l'installation* . Il semblerait à première vue que les accélérateurs soient toujours plus avantageux, d'autant plus que leur puissance va en augmentant; on parle d'installations de 30 kW et pour un avenir pas très éloigné de 100 kW. Le prix du kWh ne pourra aller qu'en s'abaissant. De son côté, le prix du cobalt 60 ira en diminuant, mais il ne semble pas possible de descendre en dessous de 2, 5 F (~0, 5 $ ) le curie, en supposant d'ailleurs que le prix du neutron soit nul [2]. Le césium 137 extrait des produits de fission ne peut entrer en compétition avec le cobalt 60 que si son prix** au curie est le 1/4 de celui du cobalt 60. Est-ce à dire que les sources n'ont aucune chance? Cer- tainement pas; elles semblent mieux adaptées aux installations de petite puissance (de l'ordre du kWh). D'autre part, au cours du dernier congrès sur l'utilisation des fortes sources (AIEA, Salz bourg, 1963) une remarque importante a été faite: pour assurer une continuité de production avec une irradiation par accélérateurs il faut installer deux appareils. Il faudrait revoir dans ce cas le prix de revient de l'irradiation en tenant compte d'une capacité de production pouvant varier d'un facteur 2 pendant les pannes d'un appareil. La lutte reste donc très ouverte et l'on verra encore pendant un certain temps les deux types d'installation s'affronter.

III. CHIMIE SOUS RAYONNEMENT

Voyons maintenant plus en détail les utilisations de cette énergie ionisante en chimie. Cette branche de l'activité industrielle a été la cause de beaucoup d'espoir mais aussi de déception; d'espoir, car pouvoir apporter directement dans la masse d'un produit l'énergie nécessaire à une réaction permettait d'envisager la production de produits nouveaux non contaminés par des catalyseurs chimiques et possédant des propriétés particulières (pour les matières plastiques: résistance à la chaleur, pour des fibres: compatibilité avec certains colorants); de déception, car si l'irradiation a fait progresser en particulier la chimie des macromolécules, les chimistes ont trouvé rapidement le moyen de créer des produits à propriétés équi- valentes par des procédés purement chimiques infiniment moins coûteux. Le développement industriel de la chimie sous rayonnement est conditionné par des facteurs économiques. Afin de se fixer les idées, rappelons que le taux de transformation d'un produit est égal à:

10-4 X MX G %/106 rads. ou M est la masse moléculaire du composé réagissant et G le rendement ou nombre de molécules transformées par 100 eV d'énergie absorbée.

* L'efficacité est le rapport de l^énergie absorbée dans le produit à l'énergie produite par llnstallation. ** En effet pour une même puissance il faut 4 fois plus de césium 137 que de cobalt 60. SOURCES IMPORTANTES 433

On voit pourquoi les réactions les plus intéressantes sont celles où le produit GX M est grand: réaction en chaîne (G grand) ou transformation des macromolécules (M grand). Les réalisations industrielles confirment ce point de vue (tableau I). Afin de calculer rapidement de coût de l'irradiation on peut utiliser cette règle approchée: il faut 3 kWh d'énergie absorbée dans un matériau pour produire 1 molécule gramme d'un produit quelconque se G = 1. Ceci permet de fixer très rapidement les objectifs à atteindre pour une ré- action donnée. Les échecs essuyés dans le passé ne sont pas sans appel et je voudrais prendre pour exemple une de nos recherches en France: l'irradiation du latex. Un certain nombre de publications ont paru depuis la Conférence de Genève en 1958, concernant, soit l'étude des mécanismes et des rendements radiochimiques de vulcanisation, soit la technologie des traitements des élastomères vyniliques sur le caoutchouc et la polymérisation par irradiation. Une nouvelle voie s'est ouverte; le traitement du caoutchouc à l1 état de latex. Il n'est pas nécessaire de rappeler les travaux antérieurs effectués sur ce sujet, car une excellent revue en a été faite [3], Nous avons alors envisagé l'irradiation du caoutchouc en phase aqueuse à l'état de latex. Le procédé mis au point en France [4, 5] se distingue des précédents par le fait qu'il arrive à une utilisation directe du latex et d'une dispersion aqueuse de noir de carbone. Les pellicules obrenues par mélange et séchage des produits irradiés ont d'excellentes propriétés mécaniques, pour des doses de l'ordre de 13 Mr. Si on ajoute au latex un sensibilisateur tel que le chloroforme, on peut abaisser la dose nécessaire à des valeurs de 1 à 2 Mr. On arrive donc dans la zone où l'irradiation du caoutchouc devient économique selon les estimations américaines. Signalons que presque simultanément aux travaux français ont paru deux communications à la Conférence sur le caoutchouc naturel de Kuala-Lumpur (Malaisie 26 au 30 Septembre 1960), traitant aussi de l'irradiation du latex. Une publication japonaise [6] arrive à des résultats remarquablement concor- dants avec les travaux français (niais ne mentionne que l'irradiation du latex sans addition de charges renforçantes). Un travail américain [7] émanant du Laboratoire Good Year étudie surtout l'irradiation du latex pour son utilisation dans les mousses. La reticulation augmentant le module, la mousse réalisée ensuite par des procédés classiques, y compris la vulcanisation chimique, est plus ri- gide, avec la même quantité de caoutchouc par unité de volume; on possède une même rigidité avec une quantité de caoutchouc moindre, d'où économie. Les mêmes chercheurs ont aussi obtenu un caoutchouc à mise en oeuvre améliorée par coagulation d'un latex irradié, procédé qui s'apparente à celui déjà réalisé, d'incorporation de latex prévulcanisé chimiquement à un latex normal,puis coagulation (produits commercialisée sous la désignation PA 80). Les chercheurs de Good Year n'ont pas ajouté de charges renforçantes du latex. Nos premiers essais ont été effectués avec une source de cobalt 60 mais, pour des questions de prix de revient et de production, une installation pilote a été montée sur l'accélérateur Dynamitron des Etablissements Adany. Il a fallu surmonter un certain nombre de difficultés technologiques: pompe 434 TECHNICAL AND ECONOMIC SUMMARIES de circulation et cellule d'irradiation devant s'adapter à une puissance de faisceau d'électrons de 15 kW. Le premier objectif a été d'obtenir un produit ayant les mêmes caractéristiques mécaniques que celui mis au point par irradiation gamma. Ce premier stade est franchi et nous passons maintenant à la fabrication de quelques dizaines de tonnes de produit, étape intermédi- aire avant la réalisation en vraie grandeur. Les calculs de prix de revient permettent d'envisager cette application avec un optimisme raisonnable. Parmi les applications actuelles il faut citer le traitement des macro- molécules. Comme dans les réactions en chaine les petites causes engendrent ici de grands effets. C es derniers peuvent aller dans le sens d'une diminution ou d'une augmentation des poids moléculaires. D'une manière générale, on peut dire que les polymères possédant un carbone tétrasubstitué se dégradent; les autres se réticulent. Une matière plastique réticulée acquiert des propriétés nouvelles; sa masse moléculaire peut devenir pratiquement in- finie; la substance devient insoluble ou infusible et moins sensible au vieil- lissement. L'irradiation du polythene est la plus ancienne des applications connues. Elle se pratique surtout sur des câbles et sur des feuilles (embal- lages rétractables). Le greffage de monomères sur différents polymères n'a pas connu le débouché industriel attendu car des procédés chimiques sont venus le concurrencer. Dans le domaine de la synthèse chimique, l'annonce faite par la Dow Chemical de la production de bromure d'éthyle par irradiation, a réveillé l'intérêt des chimistes rebutés par d'anciens échecs (Hexachlocyclohexane, phénol, catalyseur). Le G élevé de cette réaction la rend intéressante et il serait bon de refaire un inventaire des réactions possibles à la lumière de données économiques plus précises. Ce dernier exemple mérite quelques commentaires. Remarquons tout d'abord qu'il répond à un des critères énoncés précédemment: à savoir que la réaction à un G élevé. Cependant il est semblable à celui de toute autre réaction d'halogènation sous rayonnement. Or, dans les années passées la fabrication de l'hexachlocyclohexane sous rayonnement a été abandonnée car la production de ce composé par photochimie était déjà réalisée. Les prix de revient des deux procédés étaient comparables et de ce fait il n'a pas été possible d'investir de nouveaux capitaux dans une industrie déjà équipée. Nous pensons donc qu'un procédé de chimie sous rayonnement n'a de chances d'être réalisé dans une firme que s'il s'agit, soit d'une production nouvelle, soit d'un remplacement d'une installation déjà largement amortie.

IV. PERSPECTIVES D'AVENIR

Dans l'état actuel des faits on peut prévoir ainsi le développement des utilisations des fortes sources: a) la stérilisation des fournitures médicales doit se développer rapidement, b) l'utilisation des rayonnements pour traiter les aliments dépendra es- sentiellement du franchissement de deux obstacles: les autorités sanitaires, et le public. Il est trop tôt pour prévoir un développement certain. c) La chimie sous rayonnement devra surmonter la concurrence des pro- cédés classiques basés en général sur des réactions purement chimiques. SOURCES IMPORTANTES 435

Aux Etats-Unis de nouveaux procédés sont à l'essai: le bois, matières plastiques, le traitement de fibres textiles pour améliorer leurs propriétés. Nous avons déjà essayé en France les deux derniers procédés. Pour la fabrication de composés: bois, matières plastiques, nous nous sommes heurtés à la concurrence des procédés classiques de polymérisation. Pour les fibres textiles, il s'est révélé que pour des traitements de surface, le passage de la fibre dans un ozoniseur conduisait à des réactions semblables à celles obtenues par irradiation. Ces exemples montrent que la chimie sous rayonnement doit sans cesse repousser les assauts de méthodes con- currentes qui sont en général plus économiques. Ceci revient à dire que le prix de revient reste le facteur prédominant qui conditionnera le développe- ment des utilisations des fortes sources de rayonnement. Nous avons fait le tour des applications réelles. Bien d'autres réactions sont en étude dans les laboratoires du monde entier. Il faut espérer que cet effort de recherche permettra de mettre au point des substances nouvelles dont nous saurons bien trouver l'utilisation.

RÉFÉRENCES

[1] Chemical Engineering News, (1963) 80. [2] PUIG, J.R., Large radiation sources in industry, Conference proceedings, Warsaw, Vol.11 (1959) 321-339. [3] LAMM, A. et LAMM, G., Revue générale du caoutchouc 3-8 (1962). [4] Brevet français, P.V. 825.362 du 26.4.1960. [5] LAMM, A. et LAMM, G., Communication au Symposium DKG, Berlin (1960). [6] MAMORU ASAO et YUJI MINOURA, Communication à la Conf. Caout., Kuala Lumpur (1960). [7] GREGSON, T.C., ROGERS, T. H., BANGS, L. B. et PEABODY. D.W., Communication à la Conf. Caout., Kuala Lumpur (1960).

ECONOMIC BENEFITS OF MASSIVE IRRADIATION

Recent scientific literature and statements made by scientists, e.g. at the IAEA conferences on large radiation sources in 1959 and 1963 and also at the Study Group Meeting on Radioisotope Economics, indicate a considerable future for the industrial application of massive irradiation. However, up to the time of the international survey very few applications were realized and in no respect was it possible to obtain a general picture of how industry would benefit by this technique. Mr. Leveque's review is quite comprehensive, and very little was in fact added to it during the discussions of the Study Group Meeting. This was partly because the economic benefits are obtained by the customers and not by the processing firms, and partly because many of the benefits are intangible and fall beyond the scope of the survey. However, there are certain domains where savings could be attributed to the use of intense gamma radiation sources in comparison with other means of sterilization. Table II of Mr. Leveque's paper indicated for a particular application that the costs per kWh for a gamma source were twice those for an accelerator. There are, nevertheless, cases where much more efficient use could be made of gamma radiation; furthermore, the trend is towards decreases in the price of Co60. Hence, one can foresee that before long a company having several choices of radiation sources will choose a gamma source for economic reasons. Direct savings may also be seen in the sterilization by gamma radiation of, say, medical or pharmaceutical supplies. Using this technique one could permit earlier processing operations to run without the normal sterility which is expensive to maintain. Finally,, the use of radiation for chemical synthesis may decrease the cost of producing certain chemicals. The Dow ethyl-bromide synthesis is the first example of this technique; more are expected to follow. The national reports, even where they refer to installations of massive irradiation gamma sources, say very little about costs and outputs. As far as savings were concerned, the United Kingdom report mentions cases where firms recorded a few hundred pounds a year, but this figure was heavily outweighed by firms who reported losses. The NICE survey in the United States of America in 1958 found one user who credited a radioisotope technique as a rather important way of saving money in radiation research, compared with reactor radiation. Similar cases were not found in any other report. Since the period of the survey, a number of plants have been erected or their construction started, so that in a few years much operation experience on the applicability and'economics of the massive irradiation technique will be available. The International Atomic Energy Agency will keep a close watch on this field, and probably perform a special study of its economic implications.

437

THE USE OF RADIOISOTOPES IN INDUSTRIAL TRACING

KNUT LJUNGGREN ISOTOPE TECHNIQUES LABORATORY STOCKHOLM, SWEDEN

CHARACTERISTICS OF RADIOACTIVE TRACERS

Tracing means that a certain object, phase, substance or element, whose transport or transformation one wishes to study, is labelled with a specific agent which will behave throughout the investigated process in the same manner as the matter under study and, in addition, enable selective and ready detection to be made at a chosen point or stage during or after the process. The principle of tracing should not be credited to radioactive isotopes — salts and dyes were used for water tracing long before the discovery of radioactivity — but the applications of the principle of tracing have been extensively developed with the availability of radioactive substances as tracers. Objects, phases, and substances can be traced by means of suitable " conventional" tracers in many cases, but elements only by using their own isotopes. All isotopes of a given element possess the same physical and chemical properties disregarding the small differences attributable to isotope effects which are almost without exception negligible in this context. Therefore radioactive isotopes (and enriched stable isotopes) of an element can be used to establish a number of the essential physical and chemical properties of the element and its compounds. Determination of solubility, vapour pressure and diffusion and s elf-diffusion coefficients can be mentioned as examples. Similarly, only isotopes can be used for following an element through chemical reactions to shed light upon complicated reactions where the element both before and after the various stages of the reaction appears in several chemical compounds. A famous demonstration of the possibilities of this technique has been given by Calvin in his work on photo-synthesis. In these applications the radioisotopes are an absolutely unique tool and the information they render could not have been obtained in any other way (stable isotopes can be used as well but the measuring technique involved is much more complicated). Nevertheless, it seems as if the greatest practical industrial benefits have been derived from radioisotopes in their role as labelling agents for objects, phases and substances. Here an absolute chemical identity is no longer required; the tracer merely has to fulfil a limited number of not very exacting physical and physico-chemical conditions. This type of tracing is often referred to as physical tracing in contradistinction to the above- mentioned true chemical tracing. There are a number of reasons to explain why radioisotopes have acquired such widespread use as physical tracers at the expense of the "conventional" tracers: (1) The measurement of nuclear radiation can be made with an extreme sensitivity which means that the amount of tracer can be kept so small that no interference with the studied process has to be risked.

439 440 TECHNICAL AND ECONOMIC SUMMARIES

(2) The measurement is absolutely specific and no substance of any nature (unless it is also radioactive) can falsely indicate presence of the tracer or disturb the measurement in a qualitative sense. (3) As isotopic identity between the tracer and the traced substance is not required, the tracer can be selected from a large number of nuclides, covering a wide range of half-lives and radiation characteristics, to suit the experimental conditions in each single case. In particular, it is possible to use a gamma-emitting nuclide in most investigations. This has the advantage that measurements of tracer concentration can be carried out through pipe and vessel walls which makes cumbersome sampling unnecessary and, again, guarantees that the system studied is left undisturbed. (4) The sensitivity of the radiation measurement together with the absence of any interference with the process studied makes the radioactive tracers excellently suited for investigations of full-scale process operation under normal plant conditions. (5) Radioactive material and radiation detection instrumentation required for industrial tracing are, generally speaking, quite inexpensive. Only in isotopic tracing, e. g, when C14-labelled organic compounds or radioisotopes of very high specific activity are needed, may the cost for the tracer reach a prohibitive level for all but the smallest-sized experiments.

TRENDS IN RADIOISOTOPE TRACING METHODOLOGY

Labelling techniques

In true chemical tracing the demands imposed on the tracer are clearly defined by the problem studied itself. The potential possibilities of carrying out isotopic tracing have been improved by the availability of a number of only recently produced isotopes of some elements with radiation characteristics and half-lives more suited for experimental work than those existent hitherto (see Table I). When physical tracing is satisfactory, there are numerous ways of obtaining the tracer. A common method for making a tracer for a solid material is to irradiate a portion of the material itself and to use the induced activities for the radiation measurement. In reported investigations, irradiated sand has been used for sand tracing [1], irradiated cement raw meal for cement mixing and transport studies [2, 3], irradiated lining materials for identifying sources of non-metallic inclusions in steel, etc. [4J. The predominating activity after a short irradiation may be an element of large cross-section which is only a minor constituent or impurity in the actual material. One example illustrating this is the use of the Mn56 activity induced in technical aluminium to trace the aluminium; its own activity (Al28; T^ = 2. 3 min) decays much too rapidly to be of practical use [3j. One necessary condition here is, from the point of view of technical and general hygiene, that only a low percentage of longer-lived activities are induced together with the short-lived ones relied on for the measurement. Another important point is that the irradiated sample has to be chosen so RADIOISOTOPES IN INDUSTRIAL TRACING 441

TABLE I

RADIOISOTOPES ONLY RECENTLY AVAILABLE COMMERCIALLY [104]

Radioisotope Half-Life Remarks

Au199 3. 15 d Ça« 4. 53 d

Co58 71.3 d

Cu67 61 hr Hgl97 65 hr

K43 22 hr High spec, activity

Mg28 21.3 hr ï 30 mc/g

Mo99 67 hr Carrier -free

Mn52 5.7 d

Se58 1.8 d Carrier -free-, uc amounts

Cs129 30.7 hr Carrier-free

I124 4.0 d

Al28 2. 3 min Produced by 'milking' from parent activity

Ga68 68 min " jisz 2. 3 hr » Sr87m 2.8 hr » Tc"m 6. 0 hr •• 64 hr "

as to be representative of that fraction of a non-homogeneous material which one wants to study. Grain-size distributions, non-uniformities in composition and chemical or physical transformations which may lead to a re- distribution of the activated element(s) have to be watched so that the results obtained are not the consequence of a combined action of a number of physical and chemical mechanisms, all but one being irrelevant for the posed problem. Conversely, the use of a size-graded or in some other way classified tracer sample may add new information towards the understanding of certain types of process. Another method for obtaining a physical tracer is to adsorb a radionuclide on to the surface of the material studied. This surf ace-labelling technique has been used for cement, quicklime, aluminium powder and straw employing Aulyo [5], for silt and fly-ash also using Au190 [6J, for mud using 1131 [7], for sand using Cr01 and AgU°m [8, 9], and for pebbles using Ba140- La140 [10]. This technique seems to have a very wide applicability in those cases where a suitable nuclide cannot be induced in the process material or 442 TECHNICAL AND ECONOMIC SUMMARIES where its irradiation is precluded because of risk of degradation or other effects. The interpretation of the experimental data is, however, complicated by the fact that the activity measured is now proportional to the surface area of the material rather than to its mass and is thus dependent on the grain-size distribution. The radionuc.lide can alternatively be allowed to penetrate into the (porous) material to be labelled and subsequently be fixed to it by means of suitable treatment, e. g. heating. In this case a more or less uniform labelling of a surface layer of finite depth is obtained. The technique has been used to advantage for labelling bricks etc. with rare-earth metal salts in the study of the origin of non-metallic inclusions in steel [4]. Metallic surfaces can be labelled, isotopically or non-isotopically, by electrolytical or chemical plating. United States investigations show that Kr85 can be incorporated in solid substances, even metals, to serve as a physical tracer in wear studies and for temperature measurements. Mechanical tagging is sometimes resorted to when the substance to be followed is comprised of fairly large individual bodies. Wood chips have thus been tagged by means of small pieces of irradiated copper wire, inserted in holes drilled in the chips, in order to investigate the flow through continuous cooking equipment [11]. The transport rate through a cupola furnace for scrap-iron and coke has been studied with La140 as the oxide, enclosed in small iron containers inserted in holes in coke lumps and pieces of scrap-iron. The holes were then plugged with fire-clay [12], Pebbles have been labelled with Ta182 pellets, using a similar technique. Larger objects, such as "go-devils" for pipe-line cleaning, are tagged by means of the mechanical attachment of a radioactive source. A considerable number of tracer investigations have been carried out using artificial tracers, i. e. substances modelled to be physical imitations of the matter studied. Glass fibre, producing Na24 upon irradiation, has been used in numerous investigations to study the transport and mixing of cellulose fibre which in itself is .difficult to label by any method at a sufficient specific activity [12]. Plastic chips containing La140 or Na24 have been used for tracing wood chips through digesting equipment [13,12]. Glass ground to a particle size corresponding to that of natural sand has been used as a sand tracer in many instances. A suitable element like scandium or iridium is added in the manufacture of the glass so that, upon irradiation, a convenient specific activity of a medium half-life nuclide is produced [14,15]. In this particular case thorough investigations have been performed to establish whether the ground glass and genuine sand possess identical properties under experimental conditions. One further step has been to use a natural mineral of high ion-exchanging capacity onto which a suitable radionuclide, such as Sc46, is fixed [16]. Pellets of an aluminium-zinc alloy or an aluminium-cobalt alloy have been used for assessing the efficiency of con- centrators used in diamond beneficiation processes. By choosing the right proportion of the constituents the pellets could be given the same specific gravity as diamond [17]. Very convenient tracer substances containing a variety of radionuclides such as Y90, Cs134 and Lu117 can be made by fusing the element's oxide with montmorillonite clay, grinding the fused mixture and re-fusing it into beads of the proper size, which are subsequently irradiated [18]. To avoid inter- RADIOISOTOPES IN INDUSTRIAL TRACING 443

fering activities the clay is leached with ammonium nitrate solution to remove metallic cations. Another author has reported the making of tracer pellets by melting together lanthanum oxide and sodium phosphate 119J. These pellets have been used to study burden movement in roasting kilns. Another use of radioactive beads is to simulate the transport of catalyst beads, e. g. in cracking plants. By far the commonest way to accomplish physical labelling of a single chemical compound (or element) or a homogeneous phase is to use an element or compound which is soluble in it. This type of tagging can, of course, only be used when no changes of state of aggregate occur. Thus water or the aqueous phase in water-containing systems is often labelled with simple inorganic salts which are chosen for their small tendency to be sorbed or undergo chemical reactions. A range of half-lives is available by using salts containing one of the following nuclides as ions: Cl38 (T| = 37 min), Na24 (15 hr), Br82 (36 hr), Au 198 (65 hr), I*3* (8 d), Rb86 (19 d) or Cs134 (2 yr). Groundwater tracing can be carried out using several of the above-mentioned nuclides, e. g. Br82, I131 or Rb06. Because of the capacity of most soils to sorb efficiently even monovalent ions at low concentrations, considerable effort has been made to find other types of tracers, in particular such with a half-life of around one or a few months. Partly successful results have been achieved by using stable complex compounds, such as the EDTA-complexes of chromium (Cr51; T| = 28 d) or other metals, or the cyanide complex of cobalt (Co00; Tj = 5. 3 yr or, possibly Co00; T^ =71 d). All of these tracers are, however, restricted to use in moderately sized systems since it seems that carrier concentrations below 0. 001 ppm are not within reach because of sorption of the tracer. The ultimate tracer, tritiated water, which is isotopic, can be used but has disadvantages from the detection point of view and in its long half-life. Oils can be labelled non-isotopically with soluble compounds containing 82 124 58 60 46 S35 or P32 (beta-emitters) or Br , Sb , Co , Co or Sc (gamma- emitters). A kind of semi-chemical labelling can be made by adding I131 to unsaturated organic compounds. Gases are conveniently traced with the rare gas isotopes Xe133 and Kr85. Molten metals can be tagged with irradiated metals with low vapour pressure and low affinity for oxygen (Au198, Ir192 etc. ), while slags and other oxidic phases can be tagged with nuclides belonging to the rare-earth elements.

Interpretation of results

The correct interpretation of data obtained in tracer investigations for formulating a comprehensive description of the process studied is sometimes a formidable task. These difficulties stress the need for a theoretical model of the process studied — even if it has the character of a tentative approach — according to which the frequently large amount of data from tracer experiments can be processed and expressed in a small number of characteristic parameters for the system. There exists a fruitful mutual influence between the tracer experiment and the theoretical model — the tracer experiment will provide figures to fill the empty boxes of the model and eventually decide whether the adopted model was satisfactory or in- 444 TECHNICAL AND ECONOMIC SUMMARIES

correct at the same time as the model will give directions as to how new experiments should be best performed to gain new knowledge and critically test the validity of this assumed model. Most industrial tracer investigations are performed to answer fairly simple questions and hence no complicated theoretical models are needed, but for certain types of investigation it has been realized that full advantage cannot be derived from tracer experiments until the basic principles of the tracer method are fully understood. This has led to a renewed interest in the theory of the tracer method itself, not surprisingly emanating from the medical and biological side where the complexity of the systems studied makes the interpretation of experimental data very delicate and the need for workable models is strongly felt. The development of the compartment analysis technique for metabolic systems was a consequence of this need 120J. Recently a new theoretical approach has been developed in the "tracer dynamics" where the fundamental question is discussed under which conditions the kinetic behaviour of the.tracer can be used for drawing conclusions on the turnover of the "mother substance" in steady state [21, 22, 23], Theoretical work of this kind has a direct bearing on those industrial tracer investigations which are carried out in the pharmaceutical and chemical industries to establish the metabolism of drugs and agricultural chemicals, but it will also have an impact on the tracer methodology in general. Another approach to better understanding and utilization of data from tracer experiments has been made in chemical engineering science. Tracer investigations of the flow through process vessels and chemical reactors are as a rule made using a momentary or extended tracer addition in the inflow and registering the activity as a function of time in the outflow by means of a counter connected to a recorder. The outcome of the experiment is therefore a curve which directly shows the residence time distribution for the elements of flow passing through the vessel. This has to be compared, in the essential respects, to the corresponding function derived from the expected theoretical operating mode of the vessel. The concepts used at the present time to represent and evaluate residence time distributions have been developed and summarized by some authors [24, 25, 26]. Recent approaches to the analysis of residence time distributions include the use of, Laplace-transformations to establish the transfer function of the vessel [27,28] and intensity functions, adopted from statistical mathematics [29].

SURVEY OF INDUSTRIAL TRACING

The industrial applications of radioisotope tracing cover a wide range of chemical, physical and mechanical phenomena and they are to be found in practically all industrial branches. Somewhat arbitrarily, the applications can be classified into research applications, process operation control applications, product control applications and environmental applications. The lines between these categories cannot be drawn very distinctly for obvious reasons. The border-line between research and process operation control or product control is floating; one application regarded by one manufacturer as a product control application, e. g. testing of lubricants RADIOISOTOPES IN INDUSTRIAL TRACING 445

for anti-wear properties, may by another manufacturer, who is investigating wear in his machinery, be considered process operation control. The last category, the environmental applications, may be regarded as process operation control in a wider sense.

Research applications

Studies of chemical reactions and physico-chemical phenomena

Radioactive isotopes of an element have a fundamental application in studies of chemical reactions and physico-chemical phenomena in which the element is taking part. A considerable number of studies have concerned themselves with determinations of molecular structure and bond nature, atomic exchange reactions, determination of solubility and vapour pressure, and investigations into complex formation and structure of crystalline compounds. Reaction kinetics have been studied, and reaction paths and intermediate products have been elucidated. A large number of catalytic reactions have been studied with radioactive tracers. As the foremost example of such studies as regards industrial importance should be mentioned the investigations of the Fischer-Tropsch synthesis which have made a substantial contribution to the understanding of its mechanism [30], Petrochemical research has benefited considerably from studies of the catalytic oxidation of olefins to ethylene oxide, of the isomerization of cyclo- alkanes and of the conversion of naphthenes to aromatics. Further examples are investigations of the mechanism of polymerization; ion exchange studies; exchange reaction studies, e. g. of sulphur between cooking liquor and sulphonated lignin in pulp making [31]; and studies of the vulcanization of rubber. The electrochemical reactions which are essential for the function of accumulator cells [32] and in the chlorine-alkali electrolysis [33], for instance, have been studied.

Studies of metabolism

The effect of agricultural chemicals on plants, animals and human beings has been studied using radioisotopes as well as the uptake and fate of fertilizers. Tracer techniques have proved to be a powerful and by now indispensible tool for obtaining detailed knowledge of drug metabolism and effect, often required by the licensing authorities. In these studies, both the distribution of the radioactive element after administration of the labelled drugandits chemical state have to be determined. Some examples of studied substances are: vitamins, antibiotics, tranquillizers and analgetics. The résorption through the skin of various substances in medical or cosmetic use has also been studied. 446 TECHNICAL AND ECONOMIC SUMMARIES

Studies of diffusion

Isotopic tracers have acquired an important role in the measurement of diffusion coefficients, particularly for metals. The migration of the active component can be studied by autoradiography of sectioned specimens or by following the penetration of labelled surface layers into the metal. An invaluable advantage is that s elf-diffusion coefficients can also be measured in this way [34J. Important investigations on grain boundary diffusion have been made[34], Diffusion studies on silicates and related materials have provided information on sintering mechanisms and the formation of new compounds, which is of importance to the ceramic, cement, glass and refractory manufacturing industries. Diffusion phenomena in semiconductors have been investigated in numerous tracer studies. Diffusion through plastic membranes and penetration through protective films, including paints, has been studied.

Studies of surface reactions

A variety of reactions on surfaces has been studied. Among these are adsorption studies, e. g. for investigating the efficiency of flotation reagents [35, 36, 37], Surface area is determined by adsorption from a solution of radioactive ions or compounds. Other applications are related to studies of corrosion and electroplating and finishing of metallic surfaces. Some examples of corrosion research are the investigation of the formation of a passivating film on various metals (e. g. the protective effect of chromate on steel) [38], studies of iron phosphating [39], and the demonstration of the mechanism for aluminium corrosion in water [40], The cleaning efficacy of detergents etc. has been investigated in a similar manner.

Studies of wear and material transfer

The corrosion studies require measurement of very small amounts of matter, far less than monomolecular layers. Even moderately high specific activities give a sensitivity high enough for such measurements. This sensitivity can similarly be utilized for assessing very small amounts of matter transferred from surfaces by frictional wear. Basic studies of the mechanism of material transfer when metallic surfaces are sliding against each other have been made [41]. The necessity of such investigations is emphasized by the fact that there is no simple relation between measured frictional forces and material transfer. Again, the isotopic labelling, e. g. by means of irradiation of one metallic test piece, makes possible the study of the material transfer between surfaces of identical composition. The measurements have usually been supported with autoradiographic studies of the distribution of the transferred metal. RADIOISOTOPES IN INDUSTRIAL TRACING 447

Process operation control applications

Flow-rate measurements

The radioactive isotopes have revived a number of methods for the determination of flow rate of liquid and gaseous media. These methods are: (1) the peak-timing (isotope velocity) method; (2) the pulse-dilution method (having two versions, the total count and the total sampling or continuous sampling method); and (3) the steady-state dilution (isotope dilution) method. The first method is based on the timing of a pulse of tracer between two recording stations at a known distance from each other; knowing the cross- section of the stream, its volumetric flow rate can hence be calculated. This method can be used for accurate measurements only of flow in closed conduits., All the other methods are'based on the conservation-of-tracer principle; a simple balance equation for the tracer, added all at once or continuously, will contain the volumetric flow rate as the only unknown variable after appropriate calibrations. The total count method has added a new element, specific for radioactivity, since the required integration of a count-rate vs. time curve is accomplished by direct measurement with a sealer [42]. All dilution methods can be used for open streams as well as for closed conduits. The attainable accuracy in the flow-rate determination is somewhat better than 1%, and a great advantage is that the methods are absolute, i. e. require no calibration with known flow rates [43], These methods have been used for measuring water consumption of pulp and paper mills, for establishing water balances within plants, for measuring pipe-line flow, for measuring flow rate of cooling water in oil refineries, power stations and large marine diesel engines (to study flow-induced corrosion on the pipes), for determining flow rates of industrial waste water, community sewage and natural streams. An important use of these methods is in the calibration of installed continuously-reading flowmeters. Circulation within closed systems has been studied under extreme pressure and temperature conditions, e. g. in steam boilers [44], The methods are in frequent use in many countries participating in the survey.

Determination of transport velocity and through-flow characteristics

Transport velocities and distribution of residence times in process vessels and reactors of various types must be established experimentally in numerous industrial operations to prove that the equipment is used to capacity and that the product is uniform in quality. The experimental technique for and the interpretation of such experiments have been touched upon earlier. One application nearing research is the study of longitudinal dispersion in liquid flow through pipes, packed columns etc. Other applications are: studies of water and fibre flow through bleaching towers for pulp [45], of fibre flow in paper-making machines [46, 47], of circulation through sul- phite digesters [48], of flow through series-connected vessels for pulp bleaching [12], peat refining [2], electrolysis [33], and gold beneficiation processes [49J. Further instances are studies of flow through thickeners used in sugar refining [50, 51] and in the Bayer process [33]. 448 TECHNICAL AND ECONOMIC SUMMARIES

Flow distribution in a vacuum distillation column has been studied 152J, and small entrainments in a distillation unit have been located. The flow of solid material in fluidized beds [53] and of glass through glass furnaces has been studied [54,12]. The flow of material through rotary kilns has been investigated in the cement [2, 55] and fertilizer industries [56], as well as in the production of sulphur dioxide by roasting of pyrite [19]. The movement of coke and ore in blast furnaces has been studied with physical tracers [57, 58], as well as the movement of scrap iron, coke and limestone in a cupola furnace [12]. Gas flow in large fluidized catalyst regenerators in the petroleum industry has been investigated with rare gas isotopes [59]. The separation of impurities in the zinc rectification process has been studied using Cu64, Fe59, Cd115 and Zn69m as tracers [60], The removal of impurities from electrolytic baths has been checked [61]. The efficiency of filters, e. g. oil filters, and separators has been tested [62], Studies are reported on the formation of fertilizer granules and on the air flow through heaped fertilizers. Foaming problems in a phenol plant and in an extraction unit have been studied.

Wear determination in furnaces

The wear of the lining in blast furnaces and other metallurgical furnaces as well as in glass furnaces can be kept under observation if, at relevant points in the lining, gamma-emitting sources are mounted containing a nuclide with a rather long half-life. After the furnace has been put into operation it is possible to find out, by measuring the radiation intensity from outside the furnace, when the wear has reached the sources which will then disappear. The measurement can also be made on samples of metal taken from the furnace, since the dissolution of a source will render the metal active at a low level. This application is reported from many countries.

Localization of blockage in pipes

For cleaning pipe-lines, scrapers called "go-devils" are used. Some- times they will be caught in a pipe. It is difficult to locate the blockage, and in order to facilitate the search, "go-devils" are equipped with a Co60 — source. When a stop has occurred, a counter is carried along the pipe-line. It will rapidly find the location of the scraper [63]. Obstructions in pipes can be located by inserting special bodies tagged with a radioactive source which are caught at the constriction.

Localization of leaks

Radioactive tracing has been developed into a useful complement to other methods for detection and localization of leaks in closed vessels or RADIOISOTOPES IN INDUSTRIAL TRACING 449 pipes carrying liquid or gaseous flow. The most typical application is the leak localization in underground pipes. The leaking section is filled with a tracer solution, put under pressure for a suitable period of time and flushed, after which activity should only remain at the leak(s). If the depth is less than l m the detection can usually be made from ground surface (provided that hard gamma-emitters are used as tracers). Should the depth exceed l m other techniques are called for. The detector can, under favourable circumstances, be pulled through the pipe or through a parallel pipe. Miniature self-contained counters mounted with a wire-recorder in a water-proof housing have also been developed which can be forced through the pipe in much the same way as go-devils. By means of reference sources the signals appearing at the leaks can be located along the pipe [64]. Together with the location of pipe-line scrapers, leak detection is the most frequently reported application of radioactive tracers. Radioactive gases are used for detecting leaks and cross-connections in municipal gas mains [6, 65], as well as for the location of leaks in compressed-gas protected telephone cables [66]. Radioactive leak detection is also used extensively for finding fissures in heat exchangers, absorption columns and similar equipment.

Control of oil-field operation

Tracers are used in oil-field operation in order to study the efficiency of water flooding and gas injection intended for the stimulation of oil wells [67]. The effectiveness of acid treatment aiming at an increase of the porosity of certain oil-bearing strata can also be checked with radioactive tracers [67], Furthermore, tracers are used for controlling cement injections of bore-holes which are necessary to avoid losses of crude oil or contamination of the oil with brine [67].

Investigations of mixing

Batch mixing is usually controlled by means of determining one of the components with a suitable analytical method during the progress of the mixing operation. Sometimes, when closely related components or constituents of indefinite composition are to be mixed, all ordinary analytical methods fail. Chemical analysis also, generally speaking, requires time and labour for large series of samples. Radioactivity, on the other hand, is readily measured, and therefore radioactive tracers have come into use for establishing minimum mixing times and optimizing the conditions for a mixing operation. Complete mixing has been reached when the standard deviation of activity between samples taken at various points at the same time has reached a constant value which is compatible with the theoretically expected spread. Examples of mixing investigations are: mixing of material for Söderberg electrodes [68], of vitamin addition to flour, of carbon-black and quartz to rubber and of components for making light-weight concrete[3]. Control of the mixing properties of cement slurry basins has had industrial importance in some cases [2,45], 450 TECHNICAL AND ECONOMIC SUMMARIES

Studies of distribution

Numerous distribution studies using radioisotope tracers have been carried out in research and process control, mainly in the metallurgical field. The distribution between molten steel and slag has been studied for, among other elements, phosphorus, sulphur [69], arsenic and niobium [70], The distribution of alloying components, in particular as a result of segregation phenomena has been widely studied, e. g. in ingot solidification. Radioactive isotopes of sulphur, phosphorus and alloying elements, such as niobium and tantalum, have been used for these studies. Using gamma- emitting tracers and scintillation detectors, distribution studies can be made directly from the surface of ingots, and rolled billets and plates. Microscopic distribution of alloying components has been studied using autoradiography for the radiation detection. As examples, the determination of lead, phosphorus and carbon distributions in steel can be mentioned. The distribution and migration of sulphur and zinc in rubber have been investigated. The convection currents in the steel of a solidifying ingot has been studied by using Au198 as a tracer. In an analogous way the phase boundary in continuous casting of aluminium and steel has been located [71, 72, 73].

Investigations of material transfer and wear under operating conditions

As already mentioned tracer methods are extremely useful in studies of wear and material transfers. They have accordingly been employed in a very large number of wear investigations of tools used in industrial machining operations, or of moving parts of machinery. Cutting tools [74, 75], wire drawing dies [76], punches and dies for shearing [74], and grinding balls [78, 79] have been made subject to studies as have ball bearings [80], gear wheels, piston rings and cylinders of. combustion engines [74, 81, 82], electrical relay contacts [83], etc. The measurement of wear in combustion engines has become a widely accepted standard testing method for lubricants. The oil containing the metallic debris is circulated through a measuring chamber containing a radiation detector. This technique makes a continuous monitoring of the accumulated wear possible and also permits changes in wear rate to be immediately observed. Hence, unlike the conventional test bench method, the method is a differential one which makes changes in wear for changes in operating conditions, e. g. load, cooling, addition of antiwear agents, directly measurable. Miscellaneous wear studies have been made of car tyres, car wax, floor wax, varnish, etc. Losses of material and the fate of the released material can be established. Loss of catalyst metal, e. g. osmium and platinum, has been followed using this technique [68].

Investigation of sources and fate of impurities and defects

The appearance of non-metallic inclusions leads to costly rejections of high-quality steel. It has therefore become an urgent task for the metallurgical process operation to identify the sources of such inclusions RADIOISOTOPES IN INDUSTRIAL TRACING 451

and reveal the mechanism for their formation. To the degree that such inclusions are of an exogenic nature, i. e. emanates from slag, lining materials or similar sources, studies of their exact origin can be performed by the use of radioactive tracers which are either induced by irradiation of the suspected source material or by some form of physical labelling of it. A large number of such studies have contributed evidence, among other things, that the exogenic inclusions are of minor importance in killed steel, while they are mainly responsible for the inclusions found in rimming steel [4], The fate of surface defects of ingots has been studied by tagging the crack or flaw with thin radioactive threads of silver welded on both sides of it and measuring the activity distribution in the final product [84]. Similarly, radioactive inserts have been used in billets to study the de- formation of the metal during tube-making [85], The UK report mentions the marking of welds for identification after rolling of metal. Radioactive tagging has also been adopted for marking the location of wire-splices on endless wire [86].

Weighing by isotope dilution

By adding a radioactive substance, soluble in molten slag and remaining quantitatively in the slag phase, the total amount of slag in an open hearth furnace can easily be determined from the resulting dilution of the tracer after its uniform distribution [87], In the same way the amount of molten metals, e. g. steel in an electric furnace [88], or aluminium in an electrolytic cell [89], can be determined.

Product control applications

Tagging for identification and age determination

The origin of a product can be confirmed by a simple activity measurement if the product during a suitable stage of its manufacture is labelled with a radioactive tracer. This has been applied for the identification of products of special qualities needed for particularly critical installations or made for experimental purposes. This type of control has been applied for certifying that all tubes for the heat exchangers to a nuclear power station had the approved composition [90]. Rubber identification has been accomplished by vulcanization of S35 into it, as reported from the UK. A development of this tagging method permits age determination of the product to be made. For this purpose double labelling with two nuclides of widely different half-lives and easily distinguishable radiations are used [ 91].

Check of presence and position of vital parts

The presence or correct position of hidden parts, which are vital for the function of a machine, has been ascertained by tagging it radioactively and using a monitor at the end of the assembly line. 452 TECHNICAL AND ECONOMIC SUMMARIES

Leak testing of sealed products

Sealed products, e. g. electronic components, can be tested for leaks if a small percentage of a radioactive inert gas is added to the filling gas by means of subsequent activity measurement. Also the inverse technique can be used where the components after manufacture for some time are exposed to an atmosphere of radioactive gas and their content of radioactivity is thereafter tested [92, 93].

Environmental applications

Studies of ground and surface water

The movement of ground waters and surface waters has been the object of extensive investigations, made with the aid of radioactive tracers. In this way connections between water reservoirs and springs have been established and the magnitude and capacity of underground aquifers have been estimated [94]. The seepage of water under dam structures and from canals has also been measured [95,12]. Flow rates of natural water courses have been gauged [96, 97, 98].

Studies of pollution and flow patterns in natural waters

The dilution of industrial wastes or community sewage discharged into large receivers can be studied with tracer techniques. The tracer is added at the site of an existing or planned outlet and its subsequent transport and dilution are followed by in-site measurements from boats equipped with scintillation counters. From these measurements iso-concentration curves for the tracer at various times after release can be drawn. By integration of these curves, the steady-state dilution of any assumed continuous waste water outlet can be calculated [99]. Such measurements are essential for predicting the efficiency of new costly waste-water discharge tubes and also give information as to what degree of waste purification is necessary for any assumed stretch of the tube. The diluting efficiency of discharge tubes where the waste water is lead out at a depth of 10-20 m through a large number of small openings over a long stretch has been tested by means of continuous tracer addition and activity measurements of the resulting quasi-steady state tracer distribution [12].

Tracing of sand and silt movement '

Many countries, e. g. , Argentina, Australia, Denmark, Holland and Portugal, report the use of radioisotopes for studies of sand and silt movements along coasts and in harbours. Such studies contribute essential information on the mechanisms that control the silting up of estuaries and channels etc. [1, 14,15,100]. RADIOISOTOPES IN INDUSTRIAL TRACING 453

Studies of ventilation and air pollution

Radioactive gases have been used for various ventilation studies, e. g. of the mixing and dispersion times of gases in coal mines [101]. Ventilation in laboratories and houses has likewise been studied as well as the air leakage from railway cars. Air pollution has been studied using radioisotope methods [102, 103], The Danish report mentions a case where a non-active tracer was used for assessing air pollution from a foundry. The amount of tracer in samples taken was determined with activation analysis.

ORGANIZATIONS FOR TRACER WORK

In the majority of the countries participating in the survey, industrial tracing is carried out by units belonging to the national atomic energy organizations. In many highly industrialized countries, private industrial companies have established groups for tracer work within their own research and production. The number of such groups is especially notable-in Japan, where no less than 54 tracer laboratories are reported to exist in industry. Strong industrial tracing groups also exist in USA, UK and the Federal Republic of Germany. The UK reports that no less than 123 establishments were using radioactive tracers for investigations in 1961, most of which were made by the establishments themselves. The US Atomic Energy Commission established its Division of Isotope Developments in 1957, which allocates large sums annually for research and development work in the isotope field to private firms, research institutes and educational institutions. The Australian Atomic Energy Commission has an Industrial Research Group which has made considerable and successful efforts to introduce tracer methods in the Australian industry. The atomic energy authorities in the UK and France have established information bureaux giving free advice on isotope methods with a view to attracting enquiries regarding, among other matters, industrial and technical problems. An interesting organizational pattern is demonstrated by Poland, where seven major branch centres all have isotope divisions working with applications within that branch and reporting to the Isotope Development De- partment of the Central Atomic Energy Authority. In Canada, a strong centre exists within the Department of Mines and Technical Surveys which is responsible for all applications in its. own field, while the Atomic Energy of Canada Ltd. is entrusted with the remaining technical applications. In some countries, notably the USA, private firms engaged in isotope production, instrument manufacturing or similar work undertake tracer investigations on a consultative basis as well as activation and other nuclear analyses. A private enterprise, l'Atome Industriel, has been established in France devoting itself mainly to industrial tracing on a commercial basis. 454 TECHNICAL AND ECONOMIC SUMMARIES

Germany has an Isotopenstudiengesellschaft which collects and disseminates information on isotope applications and carries out experimental investigations for industry. In Austria, a similar role is played by the Studiengesellschaft für Atomenergie. The Scandinavian countries also show some interesting features in the organization of their industrial tracing. In Denmark an Isotope Centre has been formed within the Academy of Engineering Sciences which assists industry on a commercial basis with feasibility studies and experimental investigations, most of them using radioactive tracers, in addition to doing research and development work o-n methodology and instrumentation with support from general research funds. In Sweden, the Isotope Techniques Laboratory, which is supported by industry and the Technical Research Council, in a similar way concerns itself with research and development work beside the contractual work for industrial customers, which mainly comprises tracer investigations. In Finland, tracer investigations have been included in the activities of the Association for Power and Fuel Economy, a big consulting company in the heat, power and industrial engineering field. In Belgium, a recently established Radioisotope Bureau has as its objective to promote industrial radioisotope applications by an advice and information service. Within the Euratom organization, a special unit, Euroisotop, collects and disseminates information, makes studies of important fields of radioisotope applications and grants research contracts for development of isotope methods. Still another form of organization of tracer work exists: Industry sometimes approaches nuclear chemistry or nuclear physics departments of universities and requests assistance for carrying out a tracer study of some urgent problem. A considerable number of industrial applications have been realized in this manner. It is difficult to decide which way of organizing tracer work is the most efficient. An isotope applications .unit within a national atomic energy organization will have large resources at its disposal and will be able to engage itself in interesting projects even if they require a great deal of research and development. On the other hand it may meet administrative obstacles, being a small unit within a big organization, and sometimes difficulties in establishing the necessary intimate contacts with industry. Such a simple thing as charging the customers for the services provided may be very difficult to arrange under such circumstances, which is unfortunate since only the degree of willingness to pay the cost of an investigation is a true measure of its urgency from the industry's viewpoint. It has been proved that rather small organizations working in intimate contact with industry can reach a high degree of efficiency as consultants on industrial radioisotope tracing. These organizations suffer, however, from difficulties of arranging the economic support for the necessary general research and development work which is still required in this field in order to realize new applications. One way of introducing tracer methods into industry efficiently would probably be to encourage branch research institutes to develop tracer applications of general use within the technology of their branch. This way seems not to have been widely used. RADIOISOTOPES IN INDUSTRIAL TRACING 455

CONCLUSIONS

Although the present survey of tracer applications is by no means complete, it nevertheless demonstrates the wide variety of uses that radioisotope tracing has acquired in industrial production and research. The instances of application of the tracer method are virtually unlimited. But one fact is evident from this account of applications: the use of radioactive tracers is, with few exceptions, not a method employed on a routine basis. The few routine applications are found in the product control group and in analysis. The applications in the process operation control have been developed for either trouble-shooting or for occasional studies of the efficiency of production processes and equipment, the latter sometimes being repeated after the deficiencies found have been eliminated. The potential usefulness of the tracer method for process control, using continuous or intermittent tracer addition to obtain a concentration figure for the interesting component, has not yet been recognized in practice.

REFERENCES

[1] INMAN, D.L. and CHAMBERLAIN, T. K. , Proc. 2nd UN Int. Conf. PUAEJ19 (1958) 349. [2] ERWALL, L.G. and LJUNGGREN, K., Proc. 2nd UN Int. Conf. PUAE J19 (1958) 3. [3] BJERLE, I. and FORSBERG, H.G. : Production and Use of Short-Lived Radioisotopes from Reactors^, IAEA, Vienna (1963) 259. [4] FORSBERG. H.G., Jernkontorets Ann. 147 (1963) 1001. [5] PETERSEN, B.R., Production and Use of Short-Lived Radioisotopes from Reactors^, IAEA, Vienna (1963) 269. [6] WATT, J.S., Production and Use of Short- Lived Radioisotopes from Reactors _!_, IAEA, Vienna (1963)343. [7] ELLIS, W.R. and GARDNER, M.E., Australian Atomic Energy Report AAEC/E-9, Lucas Heights, New South Wales (1958). [8] PETERSEN, B. R.. Ingentfren (Int. Ed.) 4 (1960) 99. [9] GffiERT, A. et al.. Proc. 2nd UN Int. Conf. PUAE 19 (1958) 355. [10] SMITH, D.B. and EAKINS, J.D., Proc. 1st UNESCO Int. Conf. on Radioisotopes in Scientific Research, Paris 2 (1957) 619. [11] FINEMAN, O. , Svensk Papperstidn. 60 (1957) 425. [12] ERWALL, L.G., FORSBERG. H.G. and LJUNGGREN, K., Production and Use of Short-Lived Radioisotopes from Reactors^, IAEA, Vienna (1963) 229. [13] HAMILTON, R.P., Tappi 44 (1961) 647. [14] PUTMAN, J.L. and SMITH, D. B., Int. J. appl. Rad. Isotopes 1 (1956) 24. [15] CHABERT, J.E. et al., Radioisotopes in Hydrology, IAEA, Vienna, (1963) 133. [16] ARLMAN. J.J., SVASEK, J. N. and VERKERK. B., Philips Techn. Rev. 21 (1960) 157. [17] NESBITT, A.C., Application of Isotopes and Radiation, Natl. Conf. nucl. Energy (Pretoria April 3-8) (1963) 99. [18] STANG, L.G., Jr., Production and Use of Short-Lived Radioisotopes from Reactors^, IAEA, Vienna (1963) 3. [19] FRÜHAUF, K., Production and Use of Short-Lived Radioisotopes from Reactors_!, IAEA, Vienna(1963)249. [20] SHEPPARD, C. W., Basic Principles of the Tracer Method, John Wiley and Sons, New York (1962). [21] BERGNER, P.-E.E., J. theoret. Biol. 1 (1961) 120. [22] BERGNER. P.-E.E., J. theoret. Biol. 1 (1961) 359. [23] BERGNER, P.-E. E.. Acta radiol. Suppl. 210, Stockholm (1962). [24] GILLILAND. E.R. and MASON, E.A., Industr. Engng Chem. 41(1949) 1191. [25] GILLILAND. E.R. and MASON, E.A., Industr. Engng Chem. _44 (1952) 218. [26] DANCKWERTS, P.V., Chem. Engng Sei. ^(1953) 1. 456 TECHNICAL AND ECONOMIC SUMMARIES

[27] VAN DER LAAN, E. T. , Chem. Engng Sei. _7 (1958) 187. [28] WOLF, D. and RESNICK, W. , Industr. Engng Chem. Fundament. 2 (1963) 287. [29] NAOR, P. and SHINNAR, R. : Industr. Engng Chem. Fundament. 2 (1963) 278. [30] EMMET, P.H. and KUMMER, J. T. , Proc. 3rd World Petr. Congr., The Hague Sect. IV, 15 (May 1951). [31] REZANOWICH, A., ALLEN. G.A. and MASON, S.G. , Pulp Paper Mag. Canada 58,11(1957) 153. [32] ROWAN, R. and CLARK, G. L., J. Amer. chem. Soc. 63 (1941) 1299. [33] SAITO, T. , Proc. 2nd UN Int. Conf. PUAEJ19 (1958) 201. [34] SIMNAD, M.T., Int. J. appl. Rad. Isotopes J. (1956) 145. [35] PLAKSIN, I. N. , Proc. 2nd UN Int. Conf. PUAE JL9 (1958) 249. [36] EICHHOLZ, G.G. and ROBERTS, W.N. , Proc. 2nd UN Int. Conf. PUAE J.9 (1958) 240. [37] ER WALL, L.G., Proc. 2nd UN Int. Conf. PUAE J19 (1958) 107. [38] BRASHER, D. M. et al., Proc. 1st UNESCO Int. Conf. on Radioisotopes in Scientific Research, Paris _! (1957) 326. EISLER, S. L. and DOSS, J., Metal Finishing _52, 3(1954) 60. AZIZ, P.M. , J. electrochem. Soc. 101(1954) 120. [41] CAMPBELL. R.B. et al. , Radioisotopes in the Physical Sciences and Industry J., IAEA, Vienna (1962)355. [42] HULL, D.E., Int. J. appl. Rad. Isotopes 4 (1958) 1. [43] CLAYTON, G.G., Nucleonics JL8.7 (1960) 96. [44] CARLSON, R. . CEDERBERG, B. and LJUNGGREN, K. , Combustion 33,12 (1962) 25. [45] LUOTO, U.A. and ROTKIRCH, E.G., Proc. 2nd UN Int. Conf. PUAE .19 (1958) 28. [46] SANKEY, C.A. et al., Pulp Paper Mag. Canada^2,3 (1951) 136. [47] MASON. S.G. et al., Pulp Paper Mag. Canada^5,9 (1954) 97. [48] BURCHARDT, O. .LJUNGGREN, K. and STOCKMAN, L. , Svensk Papperstidn. 62 (1959) 345. [49] BASSON, J.K. , Application of Isotopes and Radiation, Natl. Conf. nucl. Energy (Pretoria April 3-8) (1963) 559. [50] WRAMSTEDT, S. , Socker U (1958) 113. [51] GREGORY, J. N. , Radioisotopes in the Physical Sciences and Industry I_, IAEA, Vienna (1962) 415. [52] HULL, D.E., Int. J. appl. Rad. Isotopes JL (1957) 305. [53] YAVORSKY, P.M. and GORIN, E. . Trans. Amer. nucl. Soc. 3 (1960) 197. [54] FISCHER, R., Silikattechn. _11(1960) 559. [55] COSTA, H. and PETERMAN, K. , Silikattechn. K> (1959) 253. [56] WILDBLOOD, A.M. , Chem. and Ind. (1957) 364. [57] GRUZIN, P.L. . AFANA'SEV, V. N. and ZEMSKII, S.V., Stal in English (Apr. 1959)251. [58] KOHN, A., Proc. 1st UNESCO Int. Conf. on Radioisotopes in Scientific Research, Paris, 1 (1957)302. [59] HANDLOS, A. E. , KUNSTMAN, R. W. and SCHISSLER, D.O., Industr. Engng Chem. _49 (1957) 25. [60] AKERMAN, K. et al., Production and Use of Short-Lived Radioisotopes from Reactors 1, IAEA, Vienna (1963) 305. [61] McFARLING, J. L. et al., Batteile Memorial Institute Report BMI-1553, Columbus (1961). [62] ELY, R. L., Jr. and PIER, J.R., Nucleonics 18,3 (1960) 130. [63] BALL, A.M., DAGLISH, J.C. and JEFFERSON, S., Brit. chem. Engng 4 (1959) 665. [64] PUTMAN, J. L. and JEFFERSON, S. , Proc. UN Int. Conf. PUAE _15 (1956) 147. [65] TELLER, C. , COURTOIS, G. and GASNIER, M., Production and Use of Short-Lived Radioisotopes from Reactors I_, IAEA, Vienna (1963) 357. [66] GUERON, J. , Nucleonics 9,5 (1951) 53. [67] CALDWELL, R. L. , Nucleonics _19,2 (1961) 58. [68] BEEN, U. and SA ELAND, E. , Proc. UN Int. Conf. PUAE _15 (1956) 170. [69] SAMARIN, A.M. , Proc. UN Int. Conf. PUAE JJ> (1956) 151. [70] SAZONOV, M. L. and SHV ARTS MAN, L.A. , Int. J. appl. Rad. Isotopes T. (I960) 311. [71] PUTMAN, J. L. , J. Inst. Metals £2 (1953/54) 414. [72] VARGA, C. and FODOR, J. , Proc. 2nd UN Int. Conf. PUAE_19 (1958) 235. [73] SPERNER. F. and PERSSON, G. , Stahl u. Eisen 82 (1962) 1099. [74] SNOW, A.J. and SKONECKE, H.L. , Atompraxis 3 (1957) 299. [75] POPOV, S. , Nucleonics^9,12 (1961) 76. [76] LINDSTRAND, E. , Jernkontorets Ann. 141 (1957) 837. [77] SATA, T. , ABE, K. and NAKAJIMA, K. , Radioisotopes in the Physical Sciences and Industry I_, IAEA, Vienna (1962) 387. RADIOISOTOPES IN INDUSTRIAL TRACING 457

[78] POBERESKIN, M. et al., Mining Engng j) (1957) 1356. [79] KEYS, J.D., EICHHOLZ, G.G., Radioisotopes in the Physical Sciences and Industry^, IAEA, Vienna (1962) 397. [80] LANDERGREN, U., Int. J. appl. Rad. fcotopes 2 (1958) 86. [81] GUMBLETON, J.J., GREEN, F. L. and MAYER, W.J.. Nucl. Sei. EngngJ (1959) 313. [82] HOWES, J. E., Jr., BRAUN, W.J. and SUNDERMAN, D. N., Radioisotopes in the Physical Sciences and Industry^, IAEA. Vienna (1962) 343. [83] LINDBERG, P.A.. Tele (1960) 4 365. [84] ISUPOV, P.F., SMIRNOVA, O.A. and SAAR, T. M., Stal in English (Sept. 1958) 841. [85] DAVISON, W. H. T., Radioisotopes in the Physical Sciences and Industry I_, IAEA, Vienna (1962) 251. [86] CLANCY, M.J. , Nucleonics ^9,3 (1961) 84. [87] ERWALL, L.G., Tekn. Tidskr. _88 (1958) 617. [88] SCHMITT, R. A. and S HARPE, R. A., General Atomic Report GA-1083, San Diego (1960). [89] BOZOKY, L. and VODROS. D., Proc. 2nd UN Int. Conf. PUAE _19 (1958) 237. [90] AMEEN, L. and FORSBERG, H. G., Tekn. Tidskr. 91 (1961) 671. [91] GREGSON, T. C. , WAISBROT, S.W. and GEHMAN, S.D., Nucleonics 19,6 (1961) 90. [92] BERRY, P.P., CAMERON, J.F. and WILSON, E.J., Radioisotopes in the Physical Sciences and Industry I, IAEA, Vienna (1962) 467. [93] CASSEN, B. and BURNHAM. D., Int. J. appl. Rad. Isotopes j) (1960) 54. [94] HARPAZ, Y. et al., Radioisotopes in Hydrology, IAEA, Vienna (1963) 175. [95] KAUFMAN, W.J. and TODD, O.K., Tritium in the Physical and Biological Sciences^, IAEA, Vienna (1961) 83. [96] CLAYTON, G.G. and SMITH, D.B., Radioisotopes in Hydrology, IAEA, Vienna (1963) 1. [97] GUIZERK, J. et al.. Radioisotopes in Hydrology. IAEA, Vienna (1963) 255. [98] TIMBLJN, L.O., Jr. and PETERKA, E.J., Radioisotopes in Hydrology, IAEA, Vienna (1963) 37. [99] BERG, O. and SOMER, E., Production and Use of Short-Lived Radioisotopes from Reactors I_, IAEA, Vienna (1963) 405. [100] GRIESSEIER. H. , Acta Hydrophys. j> (1960) 163. [101] HODKINSON, J.R., Int. J. appl. Rad. Isotopes 2 (1957) 97. [102] HAINES, G.F., Jr., HEMEON, W.C. and CEMBER, H. , J. Air Poll. Contr. Assoc. _7 (1958) 262. [103] TARRAS, §. and PIRTLE, O.L. , Trans. Amer. nucl. Soc. J5 (1962) 280. [104] STANG, L.G.., Jr. and RICHARDS, P., "Tailoring the Isotopes to fit the Need", Nucleonics^2,1 (1964) 46.

THE INDUSTRIAL USE OF ANALYTICAL TRACER METHODS

G.B. COOK DIVISION OF RESEARCH AND LABORATORIES IAEA, VIENNA

A very large number of industrial applications of radioisotopes can be regarded as essentially analytical in character. Most of these are, however, covered by other participants, so I am confining my remarks essentially to three methods. These are activation analysis, isotope dilution analysis and the use of radioactive reagents of various sorts. Firstly I shall consider activation analysis which is the best known of these methods, the most widely used and certainly the most powerful. It has now reached a stage where it must be considered as part of the normal armoury of the analytical chemist. Its development has been rapid, probably only surpassed by that of gas chromatography as an analytical method. How- ever, its character has changed appreciably over the last few years due to technical developments. In its early stages, samples were irradiated in a reactor with fluxes normally of the order of 1012-1013 n/cm2s. After irradiation, the samples were dissolved, carriers were added to the solution to allow the chemical separation and purification of the element sought and the radioactivity of the final sample was determined along with the yield of the chemical processing. The radioactivity was normally determined by Geiger-Müller or proportional counter, and at a later stage by scintillation counter and single-channel analyser. Radiochemical purity was checked by half-life determinations, by absorption curve characteristics and by gamma-ray energy determinations where possible. Clearly this procedure in general offered no particular advantage from the point of view of speed and the use of a reactor introduced an element of remoteness as there were appreciable delays caused by the dispatch, irradiation and return of the samples. Such difficulties were not serious to those working close to a reactor, but to an industrial concern this was a deterrent, even assuming they had personnel trained in radiochemistry. In spite of this, however, the overriding advantage of activation analysis, its great sensitivity, meant that it could not be ignored. Many elements could be determined with good accuracy in amounts of 10~8-10~9 g and in some cases even less, a sensitivity which could only in exceptional cases be offered by other methods. As this development coincided with an increasing industrial interest in very pure materials, in particular germanium and silicon semiconductors, industry had to use this method to obtain its analytical results. However, in the course of time methods were developed which could be used directly in the industrial laboratory for these very small traces, but such development was often based on the control possible through the results of activation analysis. In the late 1950's, however, the accent changed appreciably as workers started to develop another potent aspect of activation, the possibility of non-destructive analysis avoiding all chemical processing, an idea dear

459 460 TECHNICAL AND ECONOMIC SUMMARIES to the hearts of all chemists. Many radionuclides emit gamma rays which are very little attenuated in the irradiated sample. The determination of the intensity of a gamma ray, characteristic of the element sought, using a scintillation counter makes possible a quantitative estimation. Determi- nation of this type had been made earlier using a single-channel analyser and scintillation counter but undoubtedly the use of transistorized multichannel analyser has been responsible for the rapid development in the past few years. This development has been at the expense of a relatively small loss of sensitivity and, from the analyst's point of view, some loss of assurance, as gamma-ray energies are not as characteristics of a radioisotope as are for instance the lines in emission spectroscopy. Moreover, resolution is much poorer with gamma spectroscopy. However, half-life determinations and, where the gamma spectrum of a nuclide is not simple, the presence of the necessary associated gamma rays, can add to the assurance of identification. The freedom from the need for chemical processing has enabled analyses to be carried out much more rapidly than before and this is correspondingly cheaper. At the same time, it has enabled elements with radioisotopes of very short half-life to be determined and this has made an appreciable extension of the method. The use of short-lived activities however ties the analyst even more to the reactor, but the recent technical advance of small relatively cheap accelerators which can produce quite appreciable neutron fluxes is tending to ease this restriction, and several industrial concerns have such accelerators for routine industrial analysis. Although the neutron flux from these machines is appreciably smaller at the present time than is commonly available in reactors, some improvement is possible by the use of larger samples and the possibility of using a fast neutron flux which has certain advantages. I would like to turn now to a consideration of the National Reports. As analytical activities are not numerous I will supplement them with other examples from the literature. Only France, Denmark, Israel, Sweden and the United Kingdom specifically mention activation analysis although other countries mention analytical activities which probably include activation analysis. Denmark reports the determination of mercury containing pesticides in seeds and foodstuffs and a study of the segregation of impurities in large iron castings (presumably by dividing up the cast and irradiating various specimens). In France it is not widely used industrially although there is a vigorous school there whose work must presumably be classed as research. Sixteen uses have been reported of which fifteen have been irradiated in a reactor and one by accelerator. The samples included five of metals, one of semi-conductors, one of paper, and eight of various chemical products. The Israel report is short but they have a vigorous research programme. Mention is made of a study of trace elements of samples for forensic medical purposes with a possibility of extension into the field of criminology. While this is perhaps not an industrial activity, it may have some economic significance in saving analytical time. What has not been mentioned in this report is the extensive use of the reactor services for the analysis of uranium in geological specimens. Samples were irradiated with slow neutrons of the reactor and transferred rapidly to a neutron counting assembly, which ANALYTICAL TRACER METHODS 461

determined the delayed neutron activity of uranium (mainly the 22-s half- life). This reaction is unique for uranium-235 for naturally occurring material and allows an extremely rapid and sensitive determination, 10 fj.g of uranium can be determined to ±1% in about 2 min. Thorium can also be determined by this method but using the fast neutrons of the reactor. Al- lowance must be made for the presence of uranium, but the sensitivity for thorium is not so high as for uranium, about 1 mg can be determined -with a precision of about 2%. The analysis for uranium takes only 2-3 min, and using this method, it was possible to clear off a backlog of samples of six months in a couple of weeks. Sweden also reports a few cases of activation analysis of industrial samples but gives no examples. More extensive use is reported by the United Kingdom which gives figures of 56 applications from 38 establishments for all analytical activities, but it seems that the majority of these must be by activation. It is commented that "the technique is not widely used for process and product analysis because generally samples have to be sent to a reactor, but smaller and cheaper neutron generators could ease this". Samples include the determinations of uranium in environmental materials, of gold evaporated film on a vacuum, of trace elements in semiconductors, rubies and lasers, of sodium, barium and phosphorus in petroleum products and the analysis of oxygen in steel (using fast neutrons from an accelerator). The examples given of course make by no means an exhaustive list and from workers engaged in commercial activation analysis sources, one can complete a larger one which includes for example hafnium in zirconium, vanadium and other elements in oils, aluminium and calcium in greases, aluminium and magnesium in cracking catalysts, titanium, aluminium, chlorine and fluorine in plastics and synthetic rubbers, and pesticides in food and crop samples. The last example is possible because many of these compounds contain chlorine and bromine and can be extracted by hydrocarbon solvents, which can then be subject to activation analysis. How- ever, severe competition can be expected in this case from gas chromatography where amounts of the order of 10-9 g can be detected which compares very favourably with activation analysis. From an analyst's point of view, of particular interest are the determinations of nitrogen in organic compounds (limit about 100 ppm) fluorine in several materials and oxygen in hydrocarbons, metals and other materials, all with fast reactor neutrons. These latter determinations can be carried out also using fast neutrons from a small accelerator (as was mentioned in the United Kingdom report and has also been used in France and the United States of America). This method (i.e. using reactors or accelerators) offers the unique advantage for activation analysis of direct and rapid determination of oxygen down to about 10 ppm. The analysis must be very rapid because the product of the fast neutron reaction O16(n, p) N!6 has a half-life of only 7.4s. Easy determination is possible because the nuclide emits extremely high energy gamma rays of 6.13 and 7.12 MeV. Interference is possible only from fluorine and this is not serious with the small neutrons generating 14 MeV neutrons. The same reaction when carried out in a reactor is subject to more serious interference, however. The analysis of oxygen in this way has been applied 462 TECHNICAL AND ECONOMIC SUMMARIES

to metals and petroleum products routinely but is not of course the only possibility. Elements such as chromium, copper, fluorine, iron, nitrogen and silicon can be determined with limits of detection of the order of 10-20 ppm using a flux of 108n/cm2 s for a few minutes. Another situation which does not appear to have been reported is the use of accelerators to determine major constituents of samples (say 1% or more). Here the low flux (compared with a reactor) is no disadvantage and the use in difficult analytical situations such as arise in ceramics, refractories, ores and many alloys, offer some advantages of speed. To place the cost of these accelerators in proper perspective, the price of about $ 40000 for accelerator and multichannel analyser is lower than several analytical instruments such as double focus mass spectrometers (~$ 100000), and quantometers (~$ 50000). It is not greatly in excess of X-ray fluorescence assemblies (~$ 20000) or normal mass spectrometers ($20-30000).

Isotope dilution analysis

This technique was first reported using artificial isotopes in about 1946 and important variations of the method were published shortly afterwards. It is nearly always used in the context of organic or biochemical problems although some applications of it to inorganic substances are known. It has a good sensitivity, very high in some cases, but does not appear ever to have been widely used in industrial practice. To a large extent, this is possibly due to the development which took place at the same time of paper chromatography, which is more generally applicable, not so expensive and does not have the "mystique" of the use of radioactive materials. Never- theless, there are a few cases where isotope dilution maintains its position as a routine method, even in competition with several Chromatographie developments. Denmark reports the routine and daily analysis of weed-killing agents by isotope dilution. The chemical is, I believe, in this case chlorophen- oxyacetic acid; a chlorine-36 labelled tracer is used for the analysis. The determination of gamma hexachlorcyclohexane, a well-known insecticide was also reported some years ago by the isotope dilution method which was recommended as an official method. In this case also the radioactivenuclide was also Cl36. The United Kingdom also report the analysis of pesticide residues in crop plants by isotope dilution. It is often in complex biochemical processes and products that isotope dilution finds its main uses. One of these is in the determination of vitamin B-12, a complex cobalt-containing compound. This can be obtained labelled with cobalt-60 or cobalt-58 and is relatively widely used for the determination of this compound in fermentation broths and other mixtures by isotope dilution. The method is officially included in the United States Pharma- copaeia. Its usefulness can be judged by the claim of one manufacturer that is saved $ 64 000/yr compared with other methods of analysis and also the French Report mentions that its use represented a saving of Ffr. 500000 for a manufacturer in the year 1960-1. The United Kingdom also reports the use of this method. Isotope dilution determination of fermentation pro- ANALYTICAL TRACER METHODS 463 ducts etc. have also been reported by several industrial organizations for compounds such as penicillin, benzyl penicillin, gibberellic acid and stigmasterol. In the area of heavy industry, several more examples can be added to the list from the current survey. Poland reports the determination of liquid aluminium in electrolytic cells by a type of dilution analysis. Gold is added to the molten aluminium and allowed to mix completely. A sample is removed and the gold determined by activation. From the known amount of gold added and the final concentration, i.e. the dilution, the amount of molten aluminium can be assessed. It is well known that a similar application is used for the determination of the mercury content of chlorine-alkali electrolytic cells. The United Kingdom reports a more usual application in the determination of calcium in rock phosphate, and of hafnium in zirconium but no details are given.

Radioactive reagents

The use of radioactive reagents can be a method of great sensitivity when material of high specific activity is used, but the method is by no means widely used. A typical example is given in the United Kingdom report on the determination of additives in thin oil films. Radioactive tracers for the additives were prepared and added to the oil which was used to lubricate gears. The very small amounts of additives remaining on the gear teeth were determined by washing off the additive and measuring the radioactivity in the wash liquor. From the known specific activity of the compound, the amount could be estimated and it is difficult to imagine other methods which could be so sensitive and easy to use. Another example from the same report is the determination of the solubility of water in hydrocarbons using tritiated water. Parts per million could be determined readily and more accurately than by other methods. Switzerland reports the use of zinc-65 in the determination of traces of the element in metals of high purity. During the course of the analyses, losses of zinc occurred but which could readily be estimated from the radioactivity and the analyst claimed a very high precision and sensitivity.

Conclusion

The reported use of radioactive methods of analysis is on the whole disappointing although I feel sure that many research projects, which are not reported here, use such methods. The barrier to the routine use of activation analysis is the fact that usually the reactor is remote from the analyst, who likes to control and carry out his analyses in his own laboratory as far as is possible. However, the use of small and relatively cheap accelerators is changing this situation, bringing useful neutron fluxes to the laboratory, but one should not expect this to be a rapid development as there still remains the general suspicion of things radioactive, and also of course it must stand on its own feet economically compared with other techniques, and there is as yet little data available. 464 TECHNICAL AND ECONOMIC SUMMARIES

Isotope dilution analysis nearly always must compete with Chromato- graphie techniques at least in the organic and biochemical field, both in research and industry. Its use in the vitamin B-12 case is well established and other occasions may occur which offer similar advantages, but it is impossible to predict where and when, as so much depends on the details of a process. In inorganic analysis, there appear to be a few cases of interest and its use is favourable in those cases where complete precipi- tation takes a long time. ECONOMIC BENEFITS OF RADIOACTIVE TRACER METHODS

This summary will include both normal tracer methods and analytical applications of tracer methods, including activation analysis. While the techniques are quite different, the types of savings deriving from their use are the same. It must be stressed that the field of industrial tracing is enormous, and it is not as easy as in the gauging and radiography to transfer the economic information obtained in one case to another. Nevertheless, there are three principal and different applications of tracer methods: in research, in production (process) control, and in product control. This differentiation can of course be made for the other techniques covered by the survey, but in no other case is it so important to make the distinction. As the distinctions were not always clear in the national reports, Table I has been arranged to include all tracer users in each country for the period of the survey. Corresponding figures for the United States of America have been included.

PRINCIPLE METHODS FOR DETERMINATION OF SAVINGS

Research applications

Radioisotopes are frequently used in both basic and applied industrial research. The most direct estimates of savings can be made if a radioisotope method produces a result more cheaply than an alternative method. Here the direct savings obtained either from decreased labour costs or lower capital requirements are easy to account for. One can take a static view and say that by obtaining a result more quickly, the time spent in solving a particular problem can be saved. This is, however, only one side of the picture; the other, the dynamic one, takes into account that labour savings in research are rarely exploited as a decrease in research costs as the personnel are allocated to other projects. This leads to an increased overall efficiency of research which might have an impact on the development of new products. At present a heated discussion is taking place on the ultimate value of an investment in research. Some people have tried to obtain formulae with an overall validity for the research-progress ratio corresponding to those used for other investment-revenue cases. From the increasing number of new products that are introduced into the market every year, particularly by the chemical industry, it is evident that a large amount of money is going into research funds. If the amount of a research budget covering radioisotope methods were known, it would be possible to use the research-product formula and thus give credit to radioisotopes for producing benefits also in manufacturing and processing. This is, however, a highly theoretical argument, particularly as we do not know whether radioisotope methods are on the average more or less efficient than other research tools, and as, anyhow, most research projects never lead to an industrial product.

465 466 TECHNICAL AND ECONOMIC SUMMARIES

TABLE I THE NUMBER OF TRACER USERS IN VARIOUS INDUSTRIES

Country Broad product group

S 1 S CH (X X) SU a. ni Ü 49 o n) 5 m 'S •n§i U •§ S E 13 js o 1 8 1 'i a- •crsf U m

, Tobac c . Textil e , Cémen t , Petro l a . Machi n . Service : t identif y S i-H OJ co «0 c- oo 05 o

_ _ _ Argentina . . . . 2 . . 4 . 6 Australia - - - i - 2 1 1 1 1 3 2 12 Austria - - - - - 2 - 1 - - 2 - 5 Belgium - - - - - 5 - - 2 - - - 7 Canada* Czechoslovakia - - 3 i 3 6 4 4 8 6 3 - 38 Denmark 1 - - i 1 8 1 - - 2 - - 14 Finland* France* - 3 7 - 3 38 7 33 15 28 19 57 210 Federal Republic of Germany - - - - - 14 3 7 24 16 1 - 65 Japan - - 6 2 - 12 3 3 14 15 3 - 58 Netherlands* Norway - - 1 - - 2 - - - 1 1 - 5 Poland - - - - - 2 2 1 9 - 1 - 15 Portugal ------1 - - - 1 - 2 South Africa - - - - - 1 - - 8 - - - 9 Spain - - - - - 1 - - - - 1 - 2 Sweden - - - 7 - 6 1 - 8 3 3 - 28 United Kingdom 5 - 1 2 1 41 3 9 14 25 25 - 126 United States* 14 3 - 5 3 135 14 156 22 126 82 - 560 Yugoslavia 3 - 1 - - 6 - 2 4 6 - 6 28

Total " 23 6 19 19 11 281 49 219 129 229 149 65 1190 (9) (-) (12) (14) (5) (108) (19) (30) (92) (75) (48) (8) (420)

* Tracers not covered by the national survey + Accumulated number of applications * Number of applications in 1958 11 Figure in brackets is obtained when France and USA are excluded

None of the national bodies studied these questions, but limited themselves to the static savings. There are some cases where radioisotopes have enabled a company to obtain results that would not have been achieved in the same time by con- RADIOACTIVE TRACER METHODS 467

yentional methods. Thus, lacking radioisotope testing, a new product such as a pharmaceutical one would not have been marketed at a certain time. To be first in the market before competition begins to lower the prices normally means good profits, even if bare economic facts on costs and revenue are hidden as much as possible to prevent competitors from benefiting. The United States NICE report gives a number of examples of radioisotope applications where information from research was used to create savings in manufacturing and processing. These examples were dealt with in detail above and will be only briefly referred to in this context.

Process control applications

One of the most fruitful applications radioisotopes have found in industry is in process control. One or several tracer studies can often be used to determine the optimum working conditions for a plant, thereby minimizing the costs for the plant operation for a given output. It seems reasonable that the decrease in costs be credited as gross annual savings. Calculation is somewhat complicated in those cases where a tracer investigation has given information leading to the reconstruction of an existing plant or changes in working practice, but when the relevant operational data is known it should not be too difficult to evaluate savings or an increased output. Some of the methods of calculation discussed under gauging can often be applied; how- over, the cost of reconstruction must also be taken into account. Cases such as the calibration of existing meters will also approximate to gauging applications. A special instance of this use is "trouble-shooting". It is often economic to apply tracers for the rapid elucidation of troubles in production and to remedy the troubles; leak detection is a good example. The application of a tracer in an industrial plant to obtain information on the construction of new plants or units can be considered as research.

Product control applications

The problems in evaluating the economic benefits of tracer methods applied to product control are basically the same as arose during the discussions on radiography. Considerable time and money can be saved in product tagging, thereby avoiding analytical inspection of a large number of units. Leak-testing with Kr85 probably compares reasonably well with any other method, e.g. long- term testing. Finally, the part played by routine analytical methods must be included here. In the survey period their use was still limited, but this is a likely field for rapid development, and the savings recorded by the survey may be multiplied in the future.

EXAMPLES OF SAVINGS FROM THE NATIONAL REPORTS

Savings in research

The term research can be used in several meanings. In order to distinguish appropriately between the various radioisotope applications, its 468 TECHNICAL AND ECONOMIC SUMMARIES meaning .here will be limited to laboratory research and development of new processes and products. The use of radioisotopes to control the running of industrial plants and for final product control will be dealt with separately. This distinction follows in principle those made by Mr. Ljunggren in his paper on the use of radioisotopes in industrial tracing. Despite the number of scientific articles dealing with the applications of radioisotopes in laboratory research, very little is said abput the economic implications. In the report from the United States of America no less than 477 research applications were recorded, showing savings of $ 12.5 million/yr. The applications and the techniques used in evaluating the savings were dealt with in some detail in the description of the NICE report and need not be taken up again here. Nothing of a similar order of magnitude was reported from any other country. The report from the United Kingdom showed a very high response to the questions on annual cost for tracer applications in general: 97%. Only 22% of the cases submitted information on savings. Of the annual costs 85% could be attributed to research applications, while 70% of the savings derived from these. The total net savings were, however, only £53000. The contribution to the total figure from research savings would therefore be £35 000/yr for the sample; a simple up-scaling would not give more than £150000 (US $ 400 000) a year. This is a low figure, bearing in mind that the number of recorded applications in the survey period was as high as 237. It was confirmed, however, by a case study included in the report that individual applications might be beneficial. "One firm in the petroleum products industry provided a careful assessment of seven radioactive tracer investigations in progress in their research laboratories during the period of the survey. Although the main use of radio-tracers during 1961 was for the measurement of wear in engines fitted with radioactive piston rings, radio-tracer techniques were also found to be valuable in the investigations described below. Radioisotopes are particularly applicable to research on petroleum products because the most important chemical elements involved can all be conveniently labelled with useful isotopes, e.g. tritium, carbon-14, phosphorus-32, sulphur-35. These radioisotopes are all beta emitters and can be detected with high efficiency by the technique of liquid scintillation counting. Thus in research on petroleum products the use of radio-tracers has the advantage of high sensitivity of detection of the elements of interest. 1. The permeability of paint films to water was measured by the use of tritiated water. Measurement of microgram quantities of water transferred through detached films enabled results to be obtained much more quickly than by other techniques. 2. The solubility of water in hydrocarbons was measured by the use of tritiated water. Quantities of water in the parts per million range could be measured in hydrocarbons much more accurately than by other techniques. 3. Chemical reaction mechanisms involving petroleum products and additives were studied by the use of radio-tracers. By labelling specific hydrocarbons with radioisotopes their fate could be followed through various processes. RADIOACTIVE TRACER METHODS 469

4. The chemical analysis of thin films formed on metal surfaces by additives present in oils was made possible by labelling the additives with radioisotopes. By chemical treatment and radioactive assay, measurements could be made of the amounts of different types of compounds present on gear surfaces after lubrication with labelled oils. In this way information has been gained on the mechanisms of lubrication processes. 5. Corrosion studies were made of the effect of salt water on metals by labelling the salt with chlorine-36. After immersing metal specimens in the salt water and removing successive surface layers, the use of autoradiography allowed the detection of chlorine which had penetrated to various depths in the metal. The total investment was about £9 700, including £2400 in 1961, and the running costs of the research in that year amounted to £11 500. These considerable expenditures were well justified by the estimated savings in research alone, which amounted to £24000 in manpower for wear measurements in comparison with alternative, more cumbersome methods which would have had to be used. " The following question may be asked: "Are the research applications in the United States of a different pattern from those in the rest of the world?" The answer to this question is probably negative. The bulk of the research savings came from wear studies, investigation of chemical reactions, corrosion studies, and metabolism and uptake studies. It is, of course, clear that the position of the petroleum and automobile industries is much stronger in the United States than in other countries, but this is not sufficient to explain the enormous difference between the results in the United States and the rest of the world. Instead, it is much more likely that there is a difference in the attitude to research. It is believed that United States industry has much better internal accounting systems than that of other countries. Thus it is easier to study the research costs in detail and also obtain details on these costs and their variations in the United States than elsewhere. For instance, detailed statistics on industry's research costs are published yearly, while in other countries only rough estimates are given from time to time. This lack of information might have hampered considerably the response on research savings. The questionnaires used in the United States and the United Kingdom were much more detailed and hence easier to apply to such applications, than the simple questionnaire prepared by the Agency, which possibly made it difficult for industry to produce answers that could be treated and included in the national reports. In any case the low response for research is regrettable. The only consolation is that research workers in industry are open-minded, readily accepting new research tools wherever they appear. Therefore one should not foresee too many obstacles to the sound introduction of tracers in basic and applied industrial research because of the absence of economic evidence.

Savings in industrial processing

The response for the tracer applications in process control was somewhat better than for pure research, in so far as economic considerations 470 TECHNICAL AND ECONOMIC SUMMARIES were concerned. Case studies were also submitted in the national reports, and additional ones were presented at the Study Group Meeting on Radio- isotope Economics. As most of the examples from the national reports we re already given in the text, the case studies presented below will be taken from the records of the meeting only. Although Sweden did not fully participate in the survey, a number of firms known to use tracers for industrial investigation were contacted. The study of lining wear in Kaldo steel furnaces, where batches of pig iron of 30-100 t are blown with oxygen while rotating, is a valuable tracer application. Re-lining takes place frequently, normally once every week or ten days, although it causes a considerable loss of productivity, and therefore as many heats as possible must be treated between the re-lining periods. On the other hand, economic as well as safety considerations prohibit the use of the furnace for such a long period that the steel might break through the lining. By mounting a number of weak radioactive sources at various depths in the lining and measuring the activity of steel in each heat, a way was found to measure the wear-rate of the lining. The integrated wear was found to be a linear function of time from the very first batches, and the life of the lining could therefore be safely predicted from the wear of the first runs. With maintained safety, the number of heats between the re- linings could be increased by 50%, corresponding to a substantial increase in productivity. This application is probably the most valuable tracer application in Swedish industry. A corresponding type of application was used many years ago in blast furnaces. Here the time between the re-linings is very long, amounting to years, so that the economic benefits are less striking. It is very difficult to predict the wear in the lining in a big blast furnace, and the benefits (including the increased safety of the plant) from early indications of a possible break-through are very valuable. Twelve detailed case studies from the German steel industry were described at the Study Group Meeting (the technical details are already published [1], the economic details are shown in Table II). The following details are given in explanation: Case 4 concerned an experimental study on preparing the bottom of moulds to prevent contamination of ingots. The costs for the investigation were about US $600; the savings in research costs were almost US $ 30 000, to which could be added US $ 180 000/yr from reduced scrap because the pouring technique could be improved. Another example was the study of the solidification of ingots, which, when made without the radioisotope method, involved the scrapping of some of them. Using radioisotopes, the same information could be obtained without interfering with the production, so that US $ 2 300 was saved on the investigation (Case 12). Another example (Case 7) concerned the wear of refractory material in the channel by bottom-pouring of steel, an investigation which would have been impossible without the use of radioisotopes. The cost for this investigation was almost US $ 20000, but it gave a direct reward as the casting process could be modified giving US $ 117 000/yr in savings on less scrap. Table I illustrates the ways in which the savings can be calculated. For costs of no more than US $ 9000, gross savings of US $ 250000 in research and US $ 180000 in production costs were achieved. The total annual saving in production was more than US $400 000/yr from these 12 investigations. Single investigation Yearly investigation Research cost Savings Research cost Savings with with with with Case Research Production Research Production radioisotope other radioisotope other cost cost cost cost method methods method methods (DM) (DM) (DM) (DM) (DM) (DM) PM) (DM)

1. 2000 115340 113340 97200 - - - 97200 3500 34500 31000 - - - 54000 o 2. -- H 3. 1350 27000 25650 30000 - . - - 96000 4. 2550 125000 122450 360 000 - - - 720000 5. 3850 88500 84650 15000 - - - 30000 6. 9600 515400 505800 ....* - - - .... 7. - - - - 75000 + 75000 519 500 8. 8900 74190 65290 200 000 15000 41000 26000 .... 9. 600 10000 9400 - - - - 10. 500 18640 18140 - - - - 37000 11. 2000 2000 - - - - - 6000 12. 1200 10300 9100 - - - - ....

36050 1020870 984820 702 200 90000 41000 49000 1559700

* Figure too low, as savings were not completely realized + Investigation impossible without radioisotope method * Figure not used because of its insignificance 472 TECHNICAL AND ECONOMIC SUMMARIES

A tracer study from the cement industry was also referred to in the Swedish study. Transport of potassium was studied in a rotary kiln, and it was found that this element, which had been introduced with the raw material, re-circulated in the furnace because of evaporation in the hottest part of the kiln, causing certain operational problems. It was also found that dust was formed when the clinkers fell from a conveyor belt into the furnace. This had to be prevented, and on the evidence provided by the tracer investigation a costly reconstruction scheme was undertaken. This was successful, and the plant is now running with substantially increased yearly production, corresponding to gross sayings worth hundreds of thousands of dollars. It is probable that the chemical and related industries are the greatest users of tracers in pure research, but fairly valuable applications are also recorded in industrial production. "Trouble-shooting" in the petroleum industry was frequently mentioned in the United States report, as well as in other reports. In the French contribution to the survey is described an example of leak detection in a water-line in a chemical plant with the aid of tracers. For the cost of F.Fr. 1000 leaks were found that were causing loss of water to the extent of more than F. Fr. 500 a month. Important economic benefits were in several cases obtained from investigations into the dynamic character of process units in, e.g. the chemical and paper industries. Several firms manufacturing process equipment for these industries have taken up radioactive tracers to improve their products. If the tracer investigations show that the products are perfect the producer is pleased, but he gains no revenue, and has to pay for the investigations. When certain deviations are revealed in equipment re-design may be necessary. Compared with the alternative methods of testing the theoretical behaviour of process units, the tracer approach is probably in most- cases a very economic one. The intangible savings from the marketing of improved products are very important for the equipment manufacturer, and the buying industry has the choice of either improving the quality of its goods or lowering costs. Here an important aspect is appearing: the industrial customer's interest in obtaining the best possible equipment for his plant. When contracts for expensive units, such as power plants and paper machines, are signed the manufacturer has often to pledge himself to deliver a unit with, e.g. a given thermal efficiency, or hourly production rate, etc., and to demonstrate this by a test. Because of their accuracy and their applicability to dynamic problems, radiotracer methods have become valuable in such tests. At the Study Group Meeting on Radioisotope Economics these "guarantee tests" were frequently mentioned because of both their technical importance and inherent economic value. The accurate determination of water flow in power stations was an example quoted. The pumps for such units are constructed and built on the site, so there is no means of testing them before the station be gins to ope rate. Because the pumps may consume 3-4% of the electricity generated in the plant, it is important that they should be efficient, and their efficiency can be determined only by measuring the flow rate very precisely and here tracer methods have proved to be of importance. Tracer experiments are easy RADIOACTIVE TRACER METHODS 473 to perform compared with other tests, and thus savings can be obtained. In the United Kingdom, the Central Electricity Generating Board is arranging these tests in all power stations under construction by installing the necessary values, etc. Tracers are also being used to measure extremely high flow rates, e.g. through hydroelectric power stations. Other types of guarantee tests were reported from the Swedish paper industry, where the manufacturers had to offer units with very strictly determined mean residence times, mixing characteristics, etc. Testing with radioactive tracers by an independent body was stipulated in the contract. Another country reported that similar guarantees had to be included in the contract when mixing and extruding process units were ordered for the plastics industry. The participants in the study group meeting thought that not enough of these tests were performed, and that it would be useful for tracer methods to be included as accepted standards of testing. So far examples of this could be found only in gamma radiography and a few routine analytical applications of tracer methods. The establishment of standard tracer methods was important, because it would not only decrease the costs but would also increase the general interest in these methods, and thus contribute to the development of still more ingenious tracer applications.

Product control applications

The number of applications to product control is not as high as in the two applications already described, but almost every application seems to have high intrinsic economic value. Some examples of the economics of leak detection in ready-made products were given in the United States report, and similar applications were reported from other countries including Denmark, Japan, France and the United Kingdom. The economy of the application of tagging certain heats or batches of material was explained by the Swedish representative to the Study Group Meeting, who described the well-known application to steel. As it was necessary for each of several thousands of tubes to have an analysis certificate "regarding its composition, the standard material control was not applicable. There were possibilities: to analyse each tube for 8-10 elements, or to tag the heats with radioisotopes that could be detected many months afterwards. The later technique was much cheaper, the total cost for labelling being well below US $ 1000, and detection could be made by unskilled workers under certain supervision. Some of the more exciting examples of direct savings were in the analytical applications of tracer techniques (analytical is here used in the sense of determination of an element or a compound). Examples of vitamins were given in the report from the United States, and a similar case was referred to in the French report. In one plant it was estimated that the equivalent of six months' production had been saved after the introduction of an isotope dilution technique. As the price of this vitamin is about F. Fr. 500/g and production 1 - 2 kg per month, the benefits amounted to F.Fr.500000 (US $100000)/yr. 474 TECHNICAL AND ECONOMIC SUMMARIES

The most esteemed research tool of the analytical radioisotope technique - activation analysis - had few industrial applications in the period of the survey in which the savings could be estimated. One of the few examples available is the detection of impurities in semi-conducting materials. High savings were indicated, but the actual benefits were guarded with the utmost secrecy. The French report gives, as an example, the determination of boron in glass. For a cost of F. Fr. 25 000, savings of F.Fr. 10 000/yr were given. It was not clear whether this is an activation application or it should be treated as a "component analysis gauge". In any case, this type of apparatus represents interesting aspects, as there is increasing industrial interest in boron-containing materials.

Environmental applications

Radioactive tracers are being used increasingly in open-air investigations of hydrological and hydraulic problems. Three typical examples of such uses were analysed during the study group meeting. The first concerned the results obtained by investigations of silt movement in the River Thames in London, in the middle 1950's. It was found that the silt, dredged from the bottom of the river and dumped beyond its mouth in the estuary, moved back upstream with the tide. The efforts and costs for dredging were therefore much higher than necessary, and after studying the results of the tracer experiments, the authorities chose another dumping system. It was decided to use the silt to reclaim land on the river banks, and since 1962 the mud has been pumped directly from the river to the banks. This entailed new investment, but the system is cheaper to operate than the previous one. An additional benefit is, of course, that the reclaimed land will be very valuable; this benefit is intangible in this survey, but the costs of transporting mud downstream ceased, and the total demand for dredging in London's harbour will also probably decrease with time. The French report makes several references to the use of tracers in hydraulic models. For example, model studies for a harbour showed that it could be built much more cheaply than was estimated. Tracer experiments contributed considerably to the scaling-up of model results, and gave the necessary support for a decision. The cost for this particular experiment was F.Fr.l million, the direct cost of the tracer experiments representing only a small portion of it. The savings from the whole study were F.Fr. 8 million. The Danish Isotope Centre has established a radioactive tracer method to predict pollution from sewage outlets. The outlets along the Danish coast have to be arranged so that there is sufficient dilution of polluting agents and bacteria. This can be achieved either by erecting purification plants or by building long pipelines out into the open sea. Often a combination of both methods is chosen. Tracer injections where the pipes would end enable the dilution under different weather conditions to be calculated. The costs of purification and of building a pipe are known, so that the dilution data can then be used to design a project with minimum costs. Although a complete investigation is somewhat expensive (US $ 50 000 or more), the results can give savings out of all proportion to the cost. RADIOACTIVE TRACER METHODS 475

SUMMARY AND WORLD OUTLOOK

The national reports contain a large number of applications of tracer techniques, but in a few cases only are details of costs and savings obtainable. The diversity of the applications makes it impossible at this stage to establish reliable cost-benefit ratios for even the most frequent applications. Furthermore, most of the benefits, although tangible, cannot be easily found in the companies' accounts. In the United States and the USSR fairly high savings were shown, but the remaining countries were reluctant to attribute high savings to tracer methods. The national bodies decided to take a conservative attitude, taking account of those figures only that came from a few firms successfully applying tracer methods. In France, estimates of annual net savings were US $ 1-4 million, in Japan US $0.2-0.5 million, in Poland US $0.2-0.4 million, in Sweden US $0.1-0.5 million. When the tracing problem is analysed the actual savings to the industries must be much higher than the figures reported. If a figure for global savings is to be relevant each technique must be given its real value. Taking into account the types of tracer applications reported for each country, the structure of the country's industry, and the savings reported from individual applications in that and other countries, an attempt was made to reach a reliable minimum figure for each country. A table corresponding to the gauging and radiography table was constructed, but the Agency decided not to publish it. However, the minimum net annual savings for 21 participating countries (excluding the United States among others) was just above US $ 10 million. When looking at the range of estimates of the individual countries, it was decided that the high estimate should be put at four times the low level, i.e., US $40 million. For the United States, the figures given for 1963 on "research and development" and "manufacturing and processing" were accepted. The low estimate was US $27 million, the high US $48 million. For the USSR, the figure of US $58 million for all type of applications, except gauging, logging and gamma-radiography, was taken, although it was known to include the benefits of other techniques such as ionization methods. It could therefore be stated that the global net savings from tracer use are between US $ 95 million and US $ 146 million/yr.

MISCELLANEOUS INDUSTRIAL APPLICATIONS OF RADIOISOTOPES

H. G. FORSBERG DIVISION OF RESEARCH AND LABORATORIES INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA

The national reports originally contained a relatively high number of miscellaneous applications. A careful investigation revealed, however, that most of these could be reclassified into the other five techniques. For example this refers to a number of source-detector combinations for odd applications, which have been reclassified as gauges, logging devices (same group), activation analysis (tracers), scintillator scanning of refractories and reinforced concrete (gauging). The remaining cases are luminescent paints and light sources, nuclear batteries, sources for calibration or testing of nuclear detection devices, and homogeneity tests using alpha and beta radiography. These applications can be found in several national reports and some technical details will be given in the following paragraphs.

LUMINESCENT PAINTS AND LIGHT SOURCES

The property of nuclear radiation which, upon absorption causes excitation and ionization phenomena in solid materials is very important for detecting radiation. But the light emitted by certain materials, normally referred to as phosphors, upon exposure to relatively high radiation fields has found a few important applications, and this technique has even greater future possibilities. A thorough mixture of a nuclide emitting alpha or beta radiation and a phosphor, such as zinc sulphide, is commonly used for marking dials of watches or instrument panels to allow them to be read in darkness. Already in the 1920's radium and other nuclides occurring in nature were used, and their use has spread with time [1, 2] . However, as certain objections could be raised against the use of radium, particularly because of its high radio- toxicity and its emission of penetrating radiation, a demand for other nuclides arose. Besides radium, the following nuclides are now in regular use: tritium, C14, Sr90, Pm147 and Kr85. Nowadays, the relative importance is well illustrated by the Swiss import figures, contained in the national report to the survey. The economic figures are taken from another source [3] . Corresponding uses are reported from many of the other countries participating in the survey. No details are available on the economic significance of this but it is probably quite considerable and the total use must be approximately that of the Swiss, i.e. the annual cost of the radioactive material alone is several hundred thousand dollars. It is likely that the change from radium to other nuclides is also guided by economic considerations, as radium is relatively expensive and causes

477 478 TECHNICAL AND ECONOMIC SUMMARIES a certain destruction of the paints, which decreases the brightness with time. An interesting method of introducing the radioactive compound is to use Kr85 in the form of clathrate [4] , which is then mixed with the zinc sulphide or any other phosphor [5J . The other very important application of this principle is the preparation of nuclear light sources which can be seen over considerable distances. Of course, this necessitates much higher source strengths than those used in watches and instruments. In principle the sources can be made by mixing a radionuclide with a phosphor, but because of the short range of alpha and beta rays in solids and the absorption of the emitted light in the phosphor itself it is not a practical solution. Hence, other geometric configurations must be taken into account, and the best suggested so far is to make use of a radioactive gas inside an ampoule of transparent material, the walls of which are covered by a thin layer of phosphor. As the life-span of such a device must be long, the only practical gases are Kr05 and tritium. Brightness levels at the surface of the order of 1-3 millilamberts have been reported, and this enables visibility over 500 m or more in twilight. These sources contain Kr85. With tritium, which has certain advantages with regard to compactness and shielding, surface brightness values up to 0.5 millilamberts have been obtained [6, 7] . Numerous applications have been suggested for these light sources, such as: Safety markers in aircraft, mines or dark-rooms; Ship channel markers or buoys; Calibration sources for photoelectric equipment; Instrument dial and panel illumination; Comparison sources in light meters; Illumination of cross hairs in optical equipment; Colour identification of equipment used in darkness; Low level general illumination; Signalling equipment for use in life rafts; Activation of photocells [8] . However, out of the numerous suggestions, only a few have so far crystal- lized into practical application. These include railway signal lamps and emergency exit signs in aircraft. A description of the railway signal lamp indicates the heed of about 600 me Krbb, and the cost in the United States would be around $125. It competes with battery-operated devices or kerosene lamps and should be capable of lasting no less than 10 yr without maintenance costs if it is really to represent a saving. On the other hand, the radioactive lamps must be considered to offer a higher degree of reliability than the others, and hence they might be chosen even if they represent a somewhat increased cost. Concerning emergency exit signs, tritium can be very well made use of, as the distance over which the signs should be seen is not very large. A few curies in each would be sufficient. The cost is not prohibitive for its use [6] . It must be stated that, to our knowledge, not even these applications, of which the feasibility was demonstrated several years ago, have been de- MISCELLANEOUS INDUSTRIAL APPLICATIONS OF RADIOISOTOPES 479 velopéd for practical use. Anyhow, they are not found in the contents of the national reports.

NUCLEAR BATTERIES

The conversion of the energy of nuclear radiation into electrical energy is another application which has already been used, and has certainly a great future. Several principles can be used for the construction of small batteries: collection of beta particles from a source, use of contact potential between two electrodes of different materials between which the air is ionized from a radiation source, use of a semiconducting junction potential and use of photocells together with a luminescent source (see above) [9] . None of these principles has so far created a battery ready for industrial production and regular use. For several applications, there is a need for a reliable generator with a long life and an output'power of at least several watts, and careful investigations have been made as to whether a nuclear battery would meet this need. Research along these lines has been continuing for about 10 yr, primarily in the USA. The best-known programme here is the SNAP programme (this stands for Systems for Nuclear Auxiliary Power). All these generators make use of thermo-émission or thermo-electricity to convert the heat produced in absorption of nuclear particles from a strong source into electrical energy. The SNAP-3 series with 2-3 W output has been used for demonstration purposes and in satellites. The source material was Pu238. In later series, (SNAP-9 and SNAP-11) bigger sources were constructed giving an output of some 25 W. These are also used in space, and are very light. For terrestrial uses other sources have been designed, using Sr90 or Cs137. They are much heavier than the space systems, partly due to shielding, but are designed for longer duty periods. For 10 kc Sr90 about 2.5 W are obtained; the strongest source in use represents about 60 W output. These sources are useful for supplying power for signal lights in remote buoys and beacons and for operating instruments and relaying signals from arctic weather stations [10] . Still stronger outputs are reported using Ce144 as a source [11] . It should be pointed out that the national reports contain no information about these applications, except concerning research. The future value of this development is very high, although it is difficult to foresee any direct industrial applications of it.

CALIBRATION SOURCES

One application mentioned in some reports but disregarded in others is the possession by firms producing or using radioisotope devices of a number of sealed sources for calibration purposes. This is, of course, an absolute necessity for the firms concerned. In principle, it should be said that the TABLE I

SWISS IMPORT FIGURES

1959 1960 1961 1962 1963

Total import value 470 000 760000 540000 730000 (Swiss Francs) G Radium 202000 253 000 S Tritium 31000 144000 O Z Import O 502 16000 17250 s Luminescent paints (curies) n Tritium 500.6 16000 c« Not available G Carbon- 14 0.2 0.15 Not available Prometheum-147 52 Not available Radium 0.7 0.95 1.22 MISCELLANEOUS INDUSTRIAL APPLICATIONS OF RADIOISOTOPES 481 value of these sources is low, and that an economic evaluation of them is not very meaningful. Producers of photographic films, particularly for X-rays, also make great use of these sources.

HOMOGENEITY TESTS

Radiography need not only be performed with X-rays or gamma-ray sources. Less penetrating radiation (alpha and beta) has to be used for thin material. Although the literature covers several such applications [12, 13], they are contained in only two national reports, those from Denmark and the United Kingdom. In Denmark it is reported in use for measuring laundry wear, and in the United Kingdom in paper manufacturing [14] and the machinery industry, using Po210 and Co60 respectively.

EXCEPTIONAL APPLICATIONS

In international literature there occasionally appear descriptions of various applications of radioisotopes with industrial potential which are difficult to classify into any of the schemes described so far. Many hybrid cases are also known, but in the instructions for the survey the most appropriate classification of these in one of the other five groups was suggested. One odd application might, however, be worth mentioning, as it seems to have great economic importance. This use is quoted from the NICE survey [15] in the USA and refers to a company growing synthetic quartz crystals. Using a nuclear source on one side of the autoclave in which the crystal is grown and an X-ray film on the other side it was possible to watch how the crystal was being formed out of the process melt. A net saving of $35000 was reported because of a 25% reduction in bad runs.

REFERENCES

[1] WAHL, R., Industrie-Lackier-Betrieb 29 (1961) 101. [2] VUILIE, R. , Atome et Industrie lV/C/12 (1960) 16 pp. [3] HENRY, R., Neue Technik 6 (1964) 8. [4] CHLECK, D. J. and ZIEGLER, C. A., Nucleonics 17 9 (1959) 130. [5] WILSON, E.J. and HUGHES, J. D. H., British Patent 843, 838(1961). [6] Radiation - A Tool for Industry, Arthur D. Little Inc., Cambridge, Mass. (1959) 392 pp. [7] NOVATSKI, P. Y. et al. , Polish Academy of Sciences Report No. 175AlI(1959). [8] WALLHAUSEN, C. W. , Proc. UN Int. Conf. PUAE 15 (1956) 307. [9] THOMAS, A. , Nucleonics 13 11 (1955) 129. [10] CULWELL, J. P., Industrial Uses of Large Radiation Sources IL IAEA, Vienna (1964) 143. [11] MORSE, J. G. and HARVEY, D. G. , Nucleonics 19 4 (1961) 69. [12] ANIANSSON. G. and STEIGER, N. H. , Nature 170 (1952) 201. [13] WESTERMARK, T., Nature 164 (1949) 1086. [14] PUTMAN, J. L. , Proc. 2nd UN Int. Conf. PUAE 19 (1958) 125. [15] McMAHON, J. J. and BERMAN, A., Radioisotopes in Industry, USAEC Report NYO-2977. New York (1959) 115.

PRESENT RESEARCH THAT MIGHT AFFECT THE USE OF RADIOISOTOPES IN THE FUTURE

THE UNITED STATES ATOMIC ENERGY COMMISSION PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT AND ITS INDUSTRIAL IMPACT

E.E. FOWLER DIVISION OF ISOTOPES DEVELOPMENT UNITED STATES ATOMIC ENERGY COMMISSION, WASHINGTON 25 D.C.

The US Atomic Energy Commission's isotopes development programme is directed towards (a) encouraging development of beneficial applications of radioisotopes and radiation technology, particularly those designed to meet problems of urgent public interest; (b) accelerating the potential contribution of radioisotopes and radiation applications to the national economy and welfare, and (c) contributing to world development in the peaceful uses of atomic energy. The programme is administered by the Division of Iso- topes Development. The programme objectives are being achieved through a multiphase research and development programme including the following major elements (see Table I): (1) Radiation pasteurization of food, involving development of technology for low dose radiation processing of representative fruit and fishery products to extend their refrigerated shelf life. (2) Process radiation development, directed to fostering development of a broad technology leading to productive use of megacurie quantities of fission products and other radioisotopes for process radiation purposes. (3) Radioisotope technology development, directed to creating a broad base of new and improved technology required for extending and speeding up the application of radioisotopes in science and technology. (4) Radioisotope production and separation technology, directed to in- suring availability of radioisotopes to meet the changing needs of advancing science and technology in the United States of America. (5) Isotopic power and heat sources development, aimed at the development and production of isotopic fuels and fuel forms for a broad spectrum of thermal applications, including SNAP auxiliary electrical power devices. (6) Analysis and applications, whose objective is to identify and analyse radioisotope and radiation research and development activities in the United States of America and abroad; to establish channels of communication with science, government, and industry, and to encourage broad dissemination and productive utilization of the technology. It is considered there will be an industrial impact from each of the major categories above, namely: (I) Radiation pasteurization of food, (II) Process radiation development, (III) Radioisotope technology development, (IV) Radio- isotope production and separation technology, and (V) Isotopic power and heat sources development.

485 TABLE I

MAJOR ELEMENTS OF ISOTOPES DEVELOPMENT PROGRAMME (Division of Isotopes Development)

I. RADIATION PASTUERIZATION OF FOOD IV. RADIOISOTOPE PRODUCTION AND SEPARATION TECHNOLOGY 1. Preservation factors 1. Fission products 2. Acceptability factors 2. Neutron products 3. Packaging 3. Cyclotron products 4. Source and facility studies 4. Sealed-source safety testing 5. Wholesomeness* 5. Advanced technology

V. ISOTOPIC POWER AND HEAT SOURCES DEVELOPMENT II. PROCESS RADIATION DEVELOPMENT m Z A. Fuel forms development H 1. Exploratory processing systems 1. Fission products g 2. Advanced development systems GO 2. Plutonium-238 m 3. Radiation engineering 3. Polonium-210 4. Curium-242, Curium-244 5. Other neutron products III. RADIOISOTOPE TECHNOLOGY DEVELOPMENT B. Thermal systems 1. Isotope measurement systems 1. Space-propulsion systems 2. Advanced methods technology 2. Manned space life-support systems 3. Isotope analytical technology 3. Navigation aids 4. Low-level tracer technology 4. Component heaters 5. Applications safety testing

VI. ANALYSIS AND APPLICATIONS Transfer and use of isotopes and radiation technology in government, science and industry

* Programme cognizance by Division of Biology and Medicine USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 487

I. RADIATION PASTEURIZATION OF FOOD

Research on radiation processing of food is carried out in the United States of America through the joint efforts of the Department of Army and the Atomic Energy Commission. The Department of Army programme is concerned with radiation sterilization of food for long-term storage without refrigeration, and the Atomic Energy Commission programme with radiation pasteurization of perishable foods to extend their refrigerated shelf life. In the USA, industry's interest in radiation processing of food has increased notably since the US Food and Drug Administration (FDA) cleared radiation sterilized bacon for human consumption in February 1963. The FDA has also approved petitions for the clearance of radiation processing of wheat and wheat products. Additionally, the use of 5-MeV electrons for sterilizing bacon has been approved. Table II identifies petitions now pending or planned with FDA for clearance of other food products.

TABLE II

PETITIONS NOW PENDING OR PLANNED WITH FDA FOR CLEARANCE OF OTHER FOOD PRODUCTS

Product Sponsor Objective Status

Potatoes Army Sprout Pending inhibition Oranges, AEC/Army Shelf -life Pending lemons extension Flexible packaging AEC/Army Toxicity Pending materials clearance Peaches, nectarines, AEC/Army Shelf-life Planned -CY 1964 carrots extension Shrimp, haddock AEC/Army Shelf-life Planned -CY 1964 flounder, cod extension

The A EC research and development programme on radiation pasteurization of food is limited to selected fruit and fisheries products and empha- sizes factors such as storage and shelf-life dosage, quality-including or- ganoleptic effects, wholesomeness and packaging materials studies. In addition, continuing consideration is being given to marketing and consumer acceptance studies. (See Fig. 1 with respect to AEC food programme targets.) An important part of the radiation pasteurization of food programme has been devoted to the development of a family of radiation facilities. (See Appendix I.) Initial emphasis was on design and construction of research irradiators capable of supporting food irradiation studies. Three such units have already been installed at the Massachusetts Institute of Technology, the University of California (Davis) and the University of Washington. A fourth research irradiator is now being installed at the University of Florida. 488 PRESENT RESEARCH

PLAN OF THE LAYOUT OF THE MPDI

86 ft 0 in

Fig. l AEC food programme targets* Division of Isotopes Development * Calendar year

Current emphasis is on proto-commercial facilities intended to prove out laboratory data on a near commercial scale and to aid in the determination of the economics involved. Included in this category are mobile or transportable units on shipboard irradiators, bulk grain irradiators, and a Marine Products Development Irradiator (MPDI). The AEC is also actively exploring prospects of establishing a moderate semi-production plant in the State of Hawaii. Irradiation as a solution to quarantine control has shown very encouraging initial results. In general, the mobile units will be self-contained, will utilize up to 150000e Cobu, weigh in the neighbourhood of 50 to 701, and have a production capacity of up to 2000 Ib/hr of fruits irradiated to a dose of 250000 rad. The mobile irradiators will provide the necessary flexibility to optimize their uses to permit their movement from location to location at various harvest times during the year. The MPDI is designed to utilize a Co60 source of approximately 250000e with a capability of processing up to 1 t/hr of product at a 250 000-rad dose, or 1000 Ib/hr of product at a 500 000-rad dose. It is scheduled for completion in late summer of 1964. The MPDI is at present being designed and constructed at Gloucester, Massachusetts. This is a semi-production fixed facility. Its use is being USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 489

directed primarily towards supporting the programme on radiation pasteurization of marine products. Its capabilities will include processing large amounts of fish for shipping, storage and large-scale acceptability tests. The basic purpose of the MPDI is to demonstrate to the fishing industry the feasibility and advantages of radiation processing, and to aid in determining the economics of the process. In layout, the MPDI is a rectangular, one-storey facility of slightly under 4000 ft2, divided into a general building area and an irradiation cell. A floor plan is included to indicate specific areas and features. (See Fig. 2.)

I960 1961 1962 1963 1964 1965 1966 196? 1968 1969 1 RESEARCH AND DEVELOPMENT (a) FEASIBILITY

(b) PROGRAMMING

(c) MARKET ANALYSES (d) EXPERIMENTAL RESEARCH

FRUIT FISH (e) PACKAGING

(f ) WHOLESOMENESS* (9) PUBLIC EDUCATION

Ih) FIELD STUDIES

II EO.UIPMENT

a) IRRADIATOR DESIGN

b) RESEARCH IRRAOIATORS c) MOBILE IRRADIATOR

d) MPDI e) GRAIN BULK

If) HAWAIIAN IRRADIATOR

(9) ON-SHIP IRRADIATORS

III COMMERCIALIZATION (a) FDA PETITIONS

(b) INDUSTRIAL USE

'PROGRAMME COGNIZANCE BY DIVISION OF BIOLOGY AND MEDICINE

Fig. 2

Plan of the layout of the MPDI

The cobalt is in a rectangular array and normally stored vertically in a water-filled storage pool. In the irradiation position, the source is in a horizontal attitude, while packages being irradiated pass over and under. Fillet boxes of 10, 20 and 30-lb capacity will primarily by utilized, although there is sufficient flexibility to permit irradiation in other containers such as 6 in X24inX30 in, 100-lb packages. Ultimate success in the radiation pasteurization of food is dependent on consumer education, on a willingness to accept the final product, and on the establishment of commercial radiation facilities. In recognition of these aspects we are carrying out the following activities: (1) Consumer education We have a two-part contract with the US Department of Interior covering consumer education. The first part will determine and define, on the basis of interviews, actual attitudes of the consumers. The second part will result in the design of an educational plan to correct misimpressions, or mis- 490 PRESENT RESEARCH

apprehensions, if any. As a follow-up, the Department of Interior will implement any educational plan found necessary in the first part and developed in the second part of the contract. (2) Fruit products The US Department of Agriculture is working with the US Atomic Energy Commission not only in carrying out the technical work, but also in the shipping and test marketing aspects, and in making economic analyses. (3) Fishery products The US Atomic Energy Commission is working very closely with the US National Fisheries Institute, a trade association of fish processors. This institute has already established an industry advisory committee to serve as the mechanism by which the co-operation of US industry with the US Atomic Energy Commission will be engaged for the initial supply and stocking of fishery products, radiation treatment, their storage, shipping and test marketing. In this effort, the US Department of Interior is collaborating in the making of economic analyses. (4) Facilities for fruit and fisheries products Industrial architectural-engineering firms in the USA are active in designing, for specific purposes, facilities for radiation pasteurization of fruit and fisheries products, not only under contract to the USAEC, but also through expenditures of their own funds.

II. PROCESS RADIATION DEVELOPMENT

In contrast to the past decade's slow initial progress in the USA towards the industrial utilization of radiation for the manufacture of chemicals and chemical products, we are today witnessing new gains, new interests and new efforts in developing ionizing radiation for process purposes. In the USA today, the government, through the Process Radiation De- velopment Programme of the Atomic Energy Commission, is attempting to provide a productive, balanced effort on radiation processing in concert with that of private industry. The AEC's process radiation development programme is designed and directed towards: (i) Seeking original radiation reactions, thereby establishing a substantial scientific foundation leading utilmately to the production of unique radiation products; (ii) Establishing the technical feasibility of specific process radiation systems; (iii) Learning to design, construct and operate large kilowatt radiation processing facilities; (iv) Finding ways of cutting radiation costs; and (v) Developing large-scale requirements for fission products and other radioisotopes in the process radiation field. An estimated 120 kW of installed radiation power is now being used in the USA for commercial radiation purposes. The major part of this involves machine radiation sources. During 1963, Esso Research and Engineering Company announced the development of a radiation process for producing bio-degradable detergents. Previously, the first industrial use of radiation for bulk chemical manufacture in the USA had been announced in 1962 by USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 491 the Dow Chemical Company for commercially producing ethyl bromide, a low-volume but industrially-important chemical, using Co60 as the source of radiation energy. Other radiation produced products introduced into commerce in past years include radiation cross-linked polyethylene wrap and insulation, radiation-induced graft polymers, radiation-cured industrial coatings, radiation-modified semiconductors, and radiation-sterilized medical supplies. Current commercial processes, while still relatively limited in number and dollar value, nevertheless have shown that continued research and development on process radiation by both government and industry will broaden the range of productive radiation applications and thus contribute to the national economy and welfare. The AEC's process radiation development programme recognizes the appropriate limits to AEA-sponsored research on radiation processing and the beginning of private industry's commercial responsibilities. Thus, the AEC's process radiation development is not directed primarily towards specific product development, but rather to provide a foundation of radiation technology, not otherwise available, which is of general applicability and basic to the commercial development by private industry. Listed in Table III and Table IV are radiation processed products now being manufactured in the USA and those which appear to have a commercial potential in the reasonably near future. Trade sources place the process radiation business at about $20 000 000/yr. Important to the A EC programme on process radiation development is the High Intensity Radiation Development Laboratory (HIRDL), one of the world's most versatile and unique radiation facilities which is located at Brookhaven National Laboratory. Much of our work on radiation engineering and large source development is carried out at Brookhaven using this HIRDL facility. The handbook will contain information on basic radiation physics data being accumulated, source design and fabrication, computational pro- cédures, safety aspects, health physics, shielding calculations, and economic guidance. Thus, it will provide all the information essential for the engineering design and construction of both pilot-plant and commercial radiation facilities. A preliminary edition is scheduled to be published during 1964. Now follow three examples of advanced development work in which we are engaged under the process radiation development programme and which have important industrial interest.

( 1) Wood-plastic products

A new family of wood-plastic products has been developed in an Atomic Energy Commission sponsored programme. These materials offer advantages over natural wood in a wide variety of uses. The product is a wood-plastic combination produced by impregnating wood with a liquid plastic chemical (i. e. a monomer, such as methyl methacrylate) and then irradiating it with gamma rays from a Co60 source. The radiation polymerizes the plastic molecules and yields a solid-wood-plastic combination which: TABLE in

EXISTING COMMERCIAL RADIATION PROCESSES

Process Radiation source Company Volume

Production of ethyl bromide Co60 Dow Chemical 400 t/yr Polyethylene film Machine W.R. Grace 1500 t/yr Cross-linked polyethylene wire Machine Radiation Application, Inc. insulation, circuit boards etc. General Electric $15 million/yr Raychem (Redwood City, Calif.) Medical supply sterilization Machine Ethicon, Inc. Hospital Supply Co. 80<7o of US market Becton, Dickinson and Co. (sutures) Smith & Nephew, Ltd. (England) No estimate Goat-hair sterilization Co60 Westminster Carpet Co. 2250 t/yr (Australia) Sprout inhibition of potatoes Co60 Atomic Energy Commission, Ltd. 500 t/yr (Canada) Production of polyvinyl acetal resin Machine Toyo Rayon (Japan) No estimate Semiconductors Machine At least six of the larger 20 million units a year semi-conductor producers G Crt TABLE IV M O 3 NEAR-FUTURE COMMERCIAL RADIATION PROCESSES .O O

Process Probably radiation source Potential use m O Radiation curing of coatings Machine Plastic-coated plywood panels, paint primer curing c/5 O Textiles Machine Dyeability, mildew resistance, fire retardation, 3"O water resistance tn

Wood-plastic alloys Machine Wood construction, furniture, piling, sporting •iZ a Co60 equipment

Sterilization of medical supplies Co60 Bulk-packaged sutures, catheter kits, etc.

Food pasteurization Co60 Extension of shelf life (fish and fruit)

Semiconductor devices n-y flux Transistor, diodes, multi-functional devices w 60 Food sterilization Co Military rations (chicken, beef, pork, and ham) O

Bio-degradable detergents Co60 Commercial detergents

See Appendix III for Notes to Table IV.

CO CO 494 PRESENT RESEARCH

(1) Is harder than natural wood by several hundred per cent — thus more resistant to blows, scratches, etc.; (ii) Has a much higher compression strength; (iii) Absorbs moisture more slowly and therefore has more dimensional stability (resistance to warping and swelling); (iv) Has much improved static bending strength; (v) Retains the natural wood grain and colour; and (vi) Can be sawn, drilled, turned and sanded, giving a hard beautiful, satin- smooth finish. West Virginia University, under contract to the AEC, has developed testing methods for, and has tested various plastic combinations of, sugar, maple, white pine, birch, and white oak. Other woods can also be used. These new products are promising for these and other markets: Furniture (indoor and outdoor) Structural beams Floors Sporting goods Window frames, sills and doors Boat decks and fittings Tool handles Shoe lasts Decorative trim Dies and jigs. Process methods for the wood-plastic materials have been steadily improved under the past two-year development effort. Experience with impregnation techniques using various monomers (methyl methacrylate, hydroxy ethyl methacrylate and polyvinyl acetate), radiation doses and catalytic additives has disclosed several short-cuts having economic significance. For example, radiation doses to bring about the plastic hardening have been reduced by as much as 75% to about 0. 5 Mrad. The result is a product superior in many ways to the natural wood. It is expected that the process will be readily adaptable for volume production by industry.

(2) Semiconductors by neutron transmutation doping

A nuclear reactor at Oak Ridge, Tennessee, has been used for fabricating semiconductor electronic devices by a new process, called neutron transmutation doping, by Fundamental Methods Associates, Inc., of New York City. Silicon wafers were doped in controlled spatial patterns. Direct nuclear transmutation of the silicon took place using reactor neutrons, to produce p-n junctions in patterns whose typical dimensions are measured in thousands of an inch. These devices exhibited electrical properties, including rectification characteristics, comparable with those required in conventional semiconductor electronic equipment, the company reports. Process goals; According to the company neutron doping has potential economic importance as a simple, controllable, one-step process for making transistors and other devices by direct exposure of the semiconductor in a nuclear reactor. The fabrication of complex micro-electronic integrated circuits within a single chip of silicon appears to be within the capability of the process, possibly permitting significant cost reductions for specialized microcircuits, as well as for simpler devices. The term "neutron transmutation doping" derives from the fact that reactor neutrons produce the electronically active impurities which dope USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 495

the semiconductor by directly transmuting the atoms of the semiconducting material. In the case of silicon, phosphorus is produced by the neutron transmutation. Precise spatial control of the doping is attained by enclosing the semiconductor within a radiation die which is impervious to neutrons everywhere except through a previously prepared slit pattern. A one-week irradiation is required, followed by a one-month wait for radioactivity to decay. The final device has no residual radioactivity. The company is developing the process under AEC Isotopes Development Division contracts.

(3) Ethylene polymerization and co-polymerization

With the increase in yield indicated in recent studies of radiation induced ethylene polymerization, and with the steadily decreasing cost of Coou sources, it now appears that a radiation polymerization process can be made competitive with a conventional thermal-catalytic process. The following are some of the incentives indicating the desirability of pursuing further investigations to develop an industrial radiation chemical process for polyethylene: (i) There is still a large differential between the cost of raw material ethylene at 4^/lb and the market price of the premium-grade low-pressure polyethylene at 30-35^/lb. The main cost items in order of importance for the lower pressure processes are, (a) the cost of steam to remove and recover the solvent (cyclohexane), (b) the cost of losses of solvent and (c) the cost of loss of valuable catalyst. The radiation polymerization process promises a competitive situation in that no internal solvent or catalysts are used. Therefore, if a suitable intermediate or high-density polymer (one which is linear and has a low branching ratio) can be produced at pressures lower than 10000 lb/in2 with radiation, this process could possibly compete with the Phillips or the Ziegler-Natta Process. (ii) Polyethylene produced by radiation is of high purity and contains no catalyst impurity fractions, which is possible in the conventional thermal- catalytic processes. High purity polymer also implies improved electrical, thermal and nuclear properties of the material. (iii) The radiation process may be an inherently safer process. Since no internal initiator, such as peroxide, is utilized, there is less danger of initiating a runaway reaction leading to an explosive decomposition which commonly plagues the operation of the conventional processes, (iv) Because Co60 gamma radiation can produce initiating radicals independently of the thermal, pressure and fluid dynamic conditions of the ethylene, it is possible to envisage a single plant that could produce a variety of polyethylene grades (from low to high density) by merely adjusting the ethylene conditions. Thus, a very versatile plant could be constructed satisfying changes in market conditions. The control of grade could also be made more easily and conveniently, since one would not have to depend on the efficiency of mixing of catalyst with the ethylene and obtaining certain thermal conditions for producing radical species from a temperature dependent catalyst. Against the above advantages one must, of course, balance the problems involved in handling radiation. However, a polyethylene radiation process which would only capture 10% of the present market would be of large proportion, since this would amount to 250 million Ib/yr of material. The de- 496 PRESENT RESEARCH monstration of a radiation process for polyethylene, under the most competitive and severest process conditions, could be a significant economic contribution and could open up possibilities for other large-scale radiation processes. In recent years, an even more exciting development has emerged in polymer processing and this is the field of co-polymerization. By analogy co-polymerization can be compared to the field of alloying in metallurgy. Co-polymerization is used to improve the properties of polymers by com- bining the best properties of each of several homopolymers by producing one co-polymer. By means of co-polymerization, it is also possible to induce the polymerization of monomers which ordinarily do not easily homopolymerize. One co-polymer which has reached large-scale proportions on the market is EPR or ethylene-propylene co-polymer which is used as a rubber substitute for industry. Radiation induced co-polymerization of ethylene has received only scant attention in the past. A survey programme instituted in the Radiation Division at Brookhaven has indicated that it is possible to co-polymerize ethylene with each of twenty different other monomers, ranging from unsaturated hydrocarbons through halogenated hydrocarbons to the acrylates, acetates, acrylonitrile and carbon monoxide. The co-polymer of ethylerie and carbon monoxide shows particular po- tentiality. Data in the literature indicate that it can be produced only in low molecular weight waxes by conventional thermal-catalytic methods. The reason for this is believed to be due to a reversible reaction during the chain propagating step caused by the higher temperatures needed to produce the radical from the internal catalysts required for initiating the polymerization. It has been found that the radiation produced polymer at temperatures of 25-50°C, is of high molecular weight and can be formed into a tough plastic film. Carbon monoxide does not ordinarily homopolymerize. Carbon monoxide is a very cheap raw material. Thus, if it can be incorporated, in significant concentrations, into a polymer exhibiting useful properties, it can materially lower the cost of the polymer. The radiation produced polymer has been shown to be a high molecular weight polyketone, having concentrations of 50%, CO in ethylene, the cost of polymer material could conceivable be reduced by 2£/lb below that of polyethylene. The polyketone is a highly functional polymer which, under further chemical reactions, can be transformed to a polyalcohol, oxime or intrile, each of which in themselves has .a valuable market potential. Other radiation produced copolymers of ethylene with silicones and vinyl acetate, show interesting and exciting possibilities which further provide a. strong incentive for continuing this line of investigation.

III. RADIOISOTOPE TECHNOLOGY DEVELOPMENT

Singularly, isotopes represent the greatest potential from Atomic Energy for doing work of benefit to mankind whether it is economic gain, technological progress, or improvement in public health. While the basic principles of isotope use have been known for about 25 yr, and important progress has been made in certain areas of use, their broad application is, with limited exception, relatively unexplored. Therefore, it is the purpose of the USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 497

Isotopes Technology Development activity of the USAEC to create a broad base of new and improved technology so that use of isotopes in industry, agriculture, medicine, and research can be extended and accelerated. The research and development which is being sponsored to meet the purpose is of the applied type and has the specific goal of helping to solve problems important to the government and the public. We are not supporting work on specific industrial problems. However, much of the technology which we are developing can be used by industrial firms by supporting additional engineering development on their part. This we believe to be an important "spin off" of the radioisotope technology development programme. This area embraces five major research and development categories. These are: (a) Isotope measurement systems utilizing new types of radiation sensors essential to improving and extending applications in all fields, (b) advanced methods technology that develops and exploits new capabilities for utilizing isotopes, (c) isotope analytical technology for performing new and more sensitive measurements on materials, (d) low-Level tracer technology for making process measurements not permissible by conventional methods, and (e) applications safety testing for developing testing procedures and safety standards for isotope applications. In summary, we have some 46 technical projects active at the present time (See Appendix II), and these are being carried out under contract with 35 organizations. Here are four examples representative of the above activities.

(1) Development of Kr^s as a universal tracer — kryptonates

The inert gas radioisotope Kr85 has been stably incorporated into more than 80 different solids including elements, alloys, inorganic and organic compounds, in the form of powders, wires, foils, and fabricated pieces. To data all solids tested have collected some Kr^5 and retained this gas with time. The resulting solid sources, termed "kryptonates", are not only stable at room temperature but, following an initial fractional loss of activity, are remarkably stable at elevated temperatures up to the melting or decomposition point of the host solid. On being heated to a given temperature a kryptonate will lose a given fraction of its initial activity, which fraction is a function of that temperature. Further heating at or below this temperature yields no further loss in activity. Two important conclusions result: (a) kryptonates can be used to determine the maximum temperature attained at a surface or interface and (b) kryptonates can be stabilized for use at any elevated temperature. Kryptonates are now being evaluated for use in friction and wear studies. Electroplated nickel surfaces have been kryptonated and put in sliding motion with a harder surface of nickel-free tool steel.. Total wear was monitored by the chemical determination of removed nickel. This was correlated with Kr85 release. Preheated samples were then run to eliminate that portion of the Kr85 release due to frictional heating. Growing awareness of the value of the kryptonates is shown by the commitments of other organizations to the development of particular appli- 498 PRESENT RESEARCH cations. Jet Propulsion Laboratory is supporting continued study of the kinetics and mechanisms of the reactions of several solids with oxygen at elevated temperatures. The results are to be utilized in an air-oxygen detector of rigorous specifications. Measurement of oxygen concentrations over a range of 10 orders of magnitude has been shown feasible by a device capable of withstanding interplanetary travel conditions including preliminary sterilization. The United States Air Force is supporting development of detectors for hazardous vapours. Preliminary work with fluorine resulted in detection of concentrations to 1. 0 ppm. Study of the reactions of hydrogen with solid oxidants led to a simple, rugged, low-power system which has measured concentrations below 5 ppm. Industry has also seen the value of kryptonates. Kryptonation to indicate the surface temperatures attained by gas turbines blades is under study with Lycoming Division of AVCO Corporation. Kryptonates are also being used to test the wear experienced by parts of these engines. Other commercial concerns are utilizing kryptonated materials in the various application areas. In addition, graphite samples were kryptonated for use in a study of the diffusion of reactor by-product gases being conducted at the Pennsylvania State University.

(2) Application of large-volume detectors to radioisotope process control

Static tests were made on a number of large-volume gamma-scintillation detectors with designs based on recently developed optimum criteria. Re- sults show liquid detectors at present superior to commercially available plastic scintillators. For gamma energies below 1 MeV the best detector was an annular detector (axial length 8 in, outer diam. 16-in, and inner diam. or diameter of axial sample chamber 4. 5 in) filled with approximately 25 1 of 2. 5 g/1 Dimethyl-POPOP in toluene, argon flushed, and viewed by four 5-in-diam. phototubes equally spaced on one end. Current practice involves construction of the scintillator tank from polished stainless steel; the tank interior is then vacuum aluminized. For gamma energies above 1 MeV, the best detector was found to consist of two 5-in-diam, X4-in-thick Nal(Tl) crystals, opposed 180°C and view- ing a one-litre-volume, 5-in-diam. on-stream sample chamber. Figures of merit indicate this superiority despite higher cost compared to the large liquid detector. Static tests showed limits of detection on the order of 0. 2 to 1. 0 pc/ml (based on 0. 95 error in background for most of the detectors). During the coming year tests of the other large-volume scintillation detectors in the pilot-scale simulated unit-process system will continue. Also, during the coming year we plan to modify this system to control other unit processes using pH, mass flow, or other process variables as external set-points for the control loop. The industrial application of this basic technology on large volume detectors has already been demonstrated successfully in the potash mines of Texas Gulf Sulfur at Moab, Utah. USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 499

(3) Use of radioisotope techniques in the canning industry to help protect wholesomeness of food

The food canning and processing industry in the United State of America encounters contaminant problems mainly because of the high standards of food quality and purity that legally must be maintained. Such high quality demands the use of pesticides in the field and detergents in procès sing plants. Use of pesticides and detergents, in turn, bring their own cleansing problems which a National Canners Association-AEC joint programme has successfully attacked. Using basic isotopic research techniques, the canning industry has been provided with new information needed to solve these perplexing problems: (a) How to detect and measure low levels of detergent .and pesticide residues in foods being processed; (b) How best to wash, rinse, heat sterilize, steam blanch, and peel foods to reduce such residues; (c) How to cut water, detergent and caustic use-and-expense to a minimum; (d) How to transform food processing wastes from a troublesome disposal problem to usable animal feed by removing residues. It is emphasized that radioisotopes are not used in the actual commercial processing of food, but only in the laboratory to define improved methods. In this project, both radiotracer and neutron activation analysis techniques were used in laboratory studies of certain commonly-used pesticides and detergents. Various pesticides (DDT derivatives) were tagged with either carbon-14 or tritium and used in simulated field-growing experiments. Detergents were labelled with sulphur-35 and used in washing studies on sample food products to optimize the cleaning process. Results of research findings under this programme have already been applied by leading food processors with growing benefit to the consuming public. The National Canners Association is preparing an "NCA Handbook on Pesticide Residue Control and Methodology" which will be distributed in the near future for use by the entire canning and processing industry. NCA sees an almost limitless potential for the speedy and effective solution of food research and processing problems through the research use of radioisotopes in the years to come.

(4) Industrial use of nuclear techniques for coal analysis

The need for rapid instrumental analysis of the BTU value and ash content of coal has become prominent in the coal industry because of the advent of rapid mass transportation. In the new "Unitrain" method for lowering costs, a 100-truck train is loaded only with coal, high-balled to an electric generating station and dumped, within a period of 6 to 12 hr. All stops, sidetracking and uncoupling are avoided, keeping the train an integral coal carrier only. Present control analyses of the coal, are done by taking 500ib batch samples, tediously riffling these to a few representative grams, followed by laboratory determination of ash and BTU. Usually, results are not available until 24 hr after loading the coal. Thus, it is possible that the coal has been delivered and is even being combusted before the operators 500 PRESENT RESEARCH know its heating value or ash content. This can result in decreasing generating efficiency and even costly burner damage. This problem is being com- pounded by the building of extra-high-voltage power stations, with long transmission lines, at mine mouths, where there will be even less time between coal production and consumption. Past feasibility studies done by Texas-Nuclear Corporation have indicated that neutron reactions can be utilized to determine certain key elements in coal that are strongly related to the BTU and ash contents. In particular, empirical correlations have been shown to exist between the BTU value and the ratio C/Al+Si+O) as measured by neutron reactions. Also, (Al + Si + O) correlates with ash content. Carbon and oxygen are measured by inelastic neutron scattering (prompt gamma emission). Presently, instrumentation is being constructed by Texas-Nuclear for rapid assay of BTU and ash of coal as it moves on a conveyor belt, into coal trucks or barges. It is planned to install the nuclear instrumentation at the loading facilities of Consolidation Coal Company's Humphrey Mine and Preparation Plant near Morgantown, West Virginia, after complete assembly by Texas-Nuclear. This will probably be in the early spring of 1964. A neutron generator will irradiate the coal on the belt as it leaves the preparation plant. Here, a gamma-ray detector with two channels will measure carbon and oxygen in the coal by the prompt gamma emission during irradiation. Six hundred feet downstream on the conveyor belt will be another gamma detector with two channels to measure aluminium and silicon by delayed radioactivity or neutron activation. Suitable electronics will process and translate the primary elemental analyses into BTU and ash percentages on chart read-outs, by virtue of the pre-established empirical correlations.

IV. RADIOISOTOPE PRODUCTION AND SEPARATION TECHNOLOGY

In certain respects, the Atomic Energy Commission's work on radioisotopes and fission-product production and materials development in probably one of the most important of its activities. This is so since all its radioisotopes and radiation technology development effort must ultimately be based on a continuing availability of suitable radioactive materials in adequate quantities and at a reasonable price. . The changing needs of science and technology have presented a continuing challenge to our radioisotopes production programme. Already 137 individual radioisotopes are routinely available from the Atomic Energy Commission. On almost a day-to-day basis efforts are being directed to exploring the development of new radioisotopes and radiation sources, as well as improved production processes for existing radioisotopes. The latter is particularly important because many recent industrial and medical applications require ever increasing quantities of radioactive materials. For example, from 1 January 1963, Oak Ridge National Laboratory produced and distributed about 2. 1 million curies of radioactive materials during the entire 16 yr of the radioisotopes distribution programme. However, almost half of this amount or about one-million curies were distributed during the previous two years. This substantial growth in the requirements for radio- USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 501

active materials and associated services and equipment has also led to the development of a substantial private radioisotopes business in the United States of America. The market for privately produced basic radioisotopes, modified isotope products and devices in 1962 was in the $ 26-32 000 000 range. The following is a break-down according to product areas: Current sales of privately produced basic radioisotope product forms are in excess of $500000 annually; Current sales of labelled organic compounds are $ 3-4 000 000/yr. Growth rate is at a level of approximately 10-15%/yr; Current sales for radio-pharmaceuticals are at a $ 5 000000 level. Growth rate is at a level of approximately 25%/yr; . Sales of teletherapy units have reached the $ 2-3 000 000/yr level. Seven US manufacturers produced these devices; The market for radiographie equipment and commercial irradiation services has reached the $ 15-20 000 000/yr level.

V. ISOTOPIC POWER AND HEAT-SOURCES DEVELOPMENT

One of the most exciting new areas of radioisotopes application in recent years stems from the fact that when a radioisotope decays thermal energy is liberated at a rate and over a period of time that is characteristic of the isotope. This has given rise to the development of small nuclear power supplies, which derive their energy from radioisotope decay, for use in locations and in environments where more conventional sources of electric power are unsatisfactory. Already, isotopic power systems or SNAP (Systems for Nuclear Auxili- ary Power) devices as they are called, are being used to power navigational satellites in space, remote automatic weather stations near both the North and South Poles, navigational buoys and underseas electronic equipment. In the near future it is anticipated that other SNAP devices will power barge- mounted automatic weather stations, lunar scientific probes, communications and meteorological satellites and a host of additional terrestrial, marine and space systems. Present indications are that many electrical kilowatts of radioisotope power will be required annually by the latter part of this decade. Conse- quently, the Atomic Energy Commission programme has as its ultimate objective the yearly production of perhaps as much as 1000 kW(t) of radioisotope materials. Tables V,VI, and VII identify present and planned production goals of selected radioisotopes for isotopic power applications, as well as the properties of these isotopes. The incredibly large quantities of radioactive materials, possessing appropriate characteristics, which will be required to satisfy isotopic power needs have posed the most severe challenge to the AEC's materials development and production activity since its inception in 1946, as well as participation by private industry. Currently, isotopic power fuels are being produced by Commission con- tractors at AEC production and development sites. It is the policy of the TABLE V

RADIOISOTOPE PRODUCTION CAPABILITY FOR THERMAL APPLICATIONS

Isotope 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972

Sr90 (Me) 3 5 5 5 10 10 10 10 10 10

Cs137 (Me) 1 3.5 3.5 3.5 10 10 10 10 10 10

Ce144 (Me) 3.5 3.5 3.5 3.5 100 100 100 100 100 100

PmW7 (Me) 0.02 0.5 0.5 0.5 30 30 30 30 30 30

Pu238 (kg)» 3 6 13 18 24 32 36 42 47 51

244 Cm (kg) - 0.05 0.1 6 18 40 56 56 58 58

Cm242 (g) - 12 80 1000 1000 1000 1000 1000 1000 1000

Po21° (g) 20 50 100 100 1000 1000 1000 1000 1000 1000 TABLE VI m O THERMAL POWER AVAILABILITY FROM RADIOISOTOPES* O (kW/yr at fuel fabrication time) O

Fiscal years m O Isotope 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 Z

O Sr90 19 32 32 32 63 63 63 63 63 63 3

_ 137 Cs 5 17 17 17 48 48 48 48 48 48 Z „ 144 a Ce 25 25 25 25 700 700 700 700 700 700 147 a Pm 0.01 0.2 0.2 0.2 14 14 14 14 14 14 > 238 H Pu 1.5 3.0 6.0 0.5 11.5 15 17 20 23 25 O Z 244 a Cm - 0.1 0.2 14 41 92 129 129 134 134 m < 242 m Cm 1.5 9.5 120 120 120 120 120 120 120 - O _ 210 Po 3.0 7.0 14 14 140 140 140 140 140 140 m Z H

* Based on quantities of material in Table V on Radioisotope Production Capability for Isotopic Power Applications. TABLE VH

PROPERTIES OF RADIOISOTOPES FOR ISOTOPIC POWER APPLICATIONS

Specific thermal power Material requirement for mission Type of Half- Chemical Isotope decay life form W/kc W/g W/cm3 Mission Curies/Electrical life (yr) Watt

Sr90 Beta 28 yr Titanate 6.5 0.2 0.7 10 4000

Cs137 Beta 27 yr Glass 4.8 0.072 0.22 10 5500 Gamma

Ce144 Beta 285 d Oxide 7.9 2.3 13.8 1 7000 Gamma

Pm147 Beta 2.6yr Oxide 0.37 0.18 1.0 2.6 108000

238 Pu Alpha 89.6 yr Metal 34.5 0.48 9.3 10 625

244 Cm Alpha 18.4 yr Oxide 35.0 2.3 22.4 10 840

242 Cm Alpha 163 d Oxide 36.2 120 1170 0.5 1190

210 Po Alpha 138 d Metal 31.7 140 1320 0.5 1550 USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 505

AEC, however, to draw upon private industry, to the maximum extent possible, for future production of isotopic power materials. For example, the Commission has recently invited expressions of interest from industry concerning industrial participation in a large-scale fission-product recovery programme at AEC1 s Hanford Works near Richland, Washington. The programme is designed to recover fission products from wastes generated in the course of operation of the AEC Plutonium production reactors at Hanford. The Commission is hopeful that private industry will construct and operate the new facilities needed to process and encapsulate the fission products so that they may be produced and marketed on a completely commercial basis. It is expected such facilities will cost approximately 9 million dollars to construct. Our current schedule calls for the Hanford Fission Products Plant to begin routine operation some time during 1968. Based on current plans, the AEC will spend during the coming fiscal year 8 million dollars on the development of prototype isotopic power hardware for a variety of terrestrial, océanographie and space applications. Additionally, the Commission plans to spend in excess of 3 million dollars during the coming fiscal year on the development of isotopic power fuels technology and the production of prototype isotopic power fuels sources. Other US government agencies, such as the NASA and the Deparment of De- fense, also have development programmes related to isotopic power devices. We expect that these developmental programmes will give rise to a new and lucrative segment of the radioisotope industry. For example, it is estimated that the cost of isotopic power hardware after development, for space applications such as navigational, meteorological and communications satellites, will be approximately $1000 to $ 1500/W electrical. Since our fore- casts indicate a potential need for space use of several electrical kilowatts of isotopic power per year, the potential hardware market is of the order of millions of dollars annually. Similarly, isotopic power devices for terrestrial applications, such as automatic weather stations and navigational buoys, will probably cost on the order of $1000/W electrical. Again, the forecast requirements are in the range of kilowatts per year. Concomitantly, the production of fuels for these isotopic power systems should result, by the end of this decade, in revenues in excess of 10 million dollars annually. In the Division of Isotopes Development of the USAEC we see a continued and almost limitless potential for the speedy and effective solution of industrial research and processing problems through present research and development on radioisotopes, and thereby a continued and almost limitless impact of radioisotopes on industrial use in the future.

APPENDIX I

That portion of our programme related to irradiator development is proceeding well and generally on schedule. Appendix I summarizes the units which support the programme. 506 PRESENT RESEARCH

IRRADIATORS

Type Comments

Research On-site research Four units operating — University of support California. Massachusetts Institute of Technology. University of Washington, University of Florida, employ 30000 c CO««.

Mobile Feasibility'and large Semi-commercial scale. Under design scale demonstration; completion by spring, 1956. Initial use prove out lab parameters with fruits, West Coast area. Cost: $350000. employ 100000 c Co60.

On-ship Research One unit under construction. Small scale, 100 Ib/hr, for immediate processing at sea. Cost: $40000, employ 6500 c Co60.

Bulk grain Commercial prototype Under construction, location Savannah, Georgia. Bulk grain and packaged product capability. Cost $200 000; employ 20 000 c Co60.

Marine products Semi-production Under construction, location, Development marine products Gloucester, Mass. Up to 1 t/hr capacity. irradia tor Completion scheduled late summer 1964. Cost: $600000, employ 250000 c Co60.

Hawaiian Research, semi-production Proposed in FY-65 budget. Quarantine of tropical fruits control an important aspect of this research. $350000 requested. Employs 400000 cCo60.

ISOTOPE MEASUREMENT SYSTEMS

1. Radioisotope seeding of explosives and détection of clandestine bombs at airports. 2. Scintillation spectrometer measurements of capture gamma-rays — for measurement of impurities in important materials such as metals. 3. Study of the feasibility of using scintillating fibres for low-energy beta emitters — for use in measuring low levels of radioactivity in liquid samples. 4. Compilation of beta-excited X-ray source spectra. 5. Research and development of single-crystal high-resistivity cadmium telluride for use as a gamma-ray spectrometer. 6. Development of a radioisotope-activated diffractometer for analysis of powders and other solid materials. 7. Development of a tadioisotope-activa ted absorptiometer for analysis of liquid samples. 8. Spectrometry of neutron-deficient isotopes — for tracer use in problems involving neutron-abundant isotopes. 9. Investigations of computer-coupled activation analysis. USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 507

10. A study of fluorescence excitation using isotopic X-ray emission. 11. Use of radioisotopes as a source of X-rays to develop rayleigh scattering methods for analysis of heavy atoms in low "Z" media. 12. Development of a narrow band beta-excited X-ray detector for analysis of chemical elements in complex matrices. 13. Development of a microwave spectrometer to operate in the centimetre and submillimetre range. 14. Development of semi-conductor detectors for radioisotope applications.

ADVANCED METHODS TECHNOLOGY

1. A radioisotope powered underwater acoustic beacon. 2. Investigation of the use of radioisotopes as ground-water tracers — particularly their application in cross- well water-injection studies for improved oil recovery. 3. Short-lived radioisotope tracer system utilizing a portable neutron irradiator and gamma detector — for use as a mail depredations counter-measure. 4. Development of an isotope technique for re-location of land monuments. 5. Development of an ocean-bottom sediment density meter that works on the gamma-ray scatter technique. 6r Development of a methane ionization detector - as a safety control apparatus on mining machines. 7. Study of radiological mechanisms for use in geophysics research — now being applied to measurement of silt load in streams. 8. Development of engineering techniques for isotopic water tracing, sample preparation and radiation measurement. 9. Feasibility demonstration of a zero-gravity, propellant measurement system. 10. An investigation of the feasibility of using nuclear techniques for coal analysis. 11. Use of radioisotopes in measurement of snow-density profiles.

ISOTOPE ANALYTICAL TECHNOLOGY

1. Development of nuclear techniques for identification and characterization of material associated with crimes. 2. Identification of individuals by nuclear analysis of trace elements in human hair. 3. Development of rutherford (alpha) scatter technology — for use in the chemical analysis of solids. 4. Development of techniques for utilizing reactor fast neutrons for activation analysis. 5. Development of techniques for utilizing variable energy neutrons for activation analysis. 6. Development of neutron-activation techniques for identification of the origin of opium. 7. Ultra-sensitive measurements of mercury in wheat by neutron-activation techniques. 8. Development of a radioisotope activated dissolved-oxygen analyser. 9. Investigation of radiochemical separations and metastable isomers for use in activation analysis. 10. Application of radioisotope techniques in studying stream-pollution problems caused by the pulp and paper industry. 11. Exploration of potential application of Mössbauer effect to sensitive measurement problems.

LOW-LEVEL TRACER TECHNOLOGY

1. Development of a deep-water isotopic current analyser. 2. Evaluation of large-volume detectors and their application to isotope process control — particularly mineral bénéficiât!on operations in ore processing. 3. Adaptation of nuclear instrumentation to alpha and gamma spectroscopy of ocean deposits. 4. Investigation of radioisotope-tracer techniques to detect and measure both pesticide and detergent residues on washed food products, and to evaluate commercial food-washing practices, 5. Development of Kr85 as a universal tracer. 6. Development of a radio-release technique for measuring moisture in gases. 7. Radioisotope application to printed circuit-board technology. 508 PRESENT RESEARCH

8. Development of an isotope technique for gauging stream flow through turbines. 9. Use of radioisotopes for measuring movement of water through porous media.

APPLICATIONS SAFETY TESTING

NOTEi Safety evaluation and testing of the above techniques and devices are component parts of each project. 1. Fire resistance tests of shielded shipping containers.

APPENDIX III

NOTES TO TABLE IV

I. RESEARCH AND DEVELOPMENT

A. Feasibility

(1) Massachusetts Institute of Technology feasibility studies on radiation preservation of fish. (Completed.) (2) Stanford Research Institute studies on radiation feasibility of fruits and vegetables. (Completed.)

B. Programming

Massachusetts Institute of Technology and Stanford Research Institute studies on fish and fruit respectively. (Completed.)

C. Market analyses

(1) US Department of Interior study on market feasibility of fishery products 1960. (Completed.) (2) US Department of Agriculture market feasibility on radiation processing of fruits 1962-63. (In progress.) (3) US Department of Interior study on market feasibility of radiation processed fish 1962. (In progress.)

D. Experimental research

1. Fish (In progress) (a) US Department of Interior, Gloucester (haddock, clam, ocean perch, cod); (b) Massachusetts Institute of Technology (haddock) ; (c) US Department of Interior, Seattle (crab, flounder, halibut); (d) US Department of Interior, Ann Arbor (white fish, chub); (e) Louisiana State University (shrimp, oysters); (f ) Oregon State University (halibut).

2. Fruit (In progress)

(a) University of California, Davis (strawberries, peaches, oranges, nectarines, etc.); (b) University of Michigan (strawberries, peaches, cherries); (c) Florida State University (citrus, tomatoes, peaches); (d) US Department of Agriculture, Fresno (shipping tests variety of products) .

E. Packaging

Continental Can study 1961-62 to determine additional work required to successfully use packaging processes with radiation processed food. Extractives on packaging material culminating in petitions to Federal Drug Administration for appropriate use for Hazleton Laboratories, Inc. (Completed.) Petition submitted November, 1963. USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 509

F. Wholesomeness

Another important area of the programme is the wholesomeness and public health safety aspects of radiation processed foods. Contract work is being sponsored by the Division of Biology and Medicine and will be covered by Dr. Dunham of the Division of Biology and Medicine.

G. Public Education

Establishment of public education programme in 1964 by US Department of Interior, Washington, D.C., implementation by US Department of Interior and US Department of Commerce, beginning 1965. (In progress. )

H. Field Studies

Use of Atomic Energy of Canada Limited mobile irradiator 1963-64. Use of Marine Products Development Irradiator and Atomic Energy Commission mobile irradiator beginning latter 1964.

II. EQUIPMENT A. Irradiator design

Irradiator design development of design concept primarily by Brookhaven National Laboratory for equipment adequate to support food irradiation research - 1960-62. Design concepts of advanced irradiators including mobile and semi-production types 1963-64 by Brookhaven National Laboratory, Vitro, As- sociated Nucleonics. Further source and design studies as required through 1967.

B. Research irradiator

Installation of four research irradiators employing 30 000 c Cobu each at Massachusetts Institute of Techno- logy, University of California, University of Washington and University of Florida 1961-64.

C. Mobile irradiator

Completion of construction early 1965 for use in large-scale shipping tests with fruits. Costss $350000 - Employs 150000e Co60.

D. Marine products development irradiator

Completion scheduled for late summer 1964 at Gloucester, Mass, for semi-commercial scale production and shipping tests. Costs: $600 000 - Employs 250 000 c Co60. US Department of the Interior operation begins FY-68.

E. Bulk grain

Completion early 1965. Bulk grain capacity (5000 Ib/hr) as well as packaged product capability. Dis- infestation purposes. Costs: $200 00 — Employs 20 000 c CoS". US Department of Agriculture operation begins FY-67.

F. On-ship

A portable 12-t unit containing 20 000 c Co6", for use primarily aboard fishing vessels to process the catch as landed. Costs: $35000.

G. Hawaiian irradiator

Semi-production unit for (a) shelf-life extension of tropical fruits, and (b) quarantine control. $350000 requested for FY-65, completion by late FY-66. Employs 400000 c Co60. 510 PRESENT RESEARCH

III. COMMERCIALIZATION

A. Food and drug administration petitions

1963: Petition for radiation processed citrus submitted to Food and Drug Administration in September. A more detailed plan of petition action is outlined in Table II.

B. Industrial Use

Expected to begin in early 1965 for one or more products, increased industrial participation through end of programme.

DISCUSSION

A. PRADZYNSKI (Chairman): Thank you, Mr. Fowler, for your stim- ulating presentation. I was particularly interested to hear what you had to say about the food irradiation programme, for Poland is also a producer of fresh fruit and we are naturally interested to know that work is being done in the United States of America on the preservation of fresh fruits such as strawberries; in fact, we are engaged in a similar programme. J.L. PUTMAN: I should like to begin by expressing our appreciation of the masterly survey Dr. Fowler has given us of a very large programme. The high quality of the summaries prepared by our experts seems in fact to have become one of the most marked characteristics of this Meeting, and one might almost conclude that a useful way of getting scientists to describe the importance of their work clearly and thoroughly is to make them talk about economics. Perhaps, I might now comment on some of the ways in which we in the United Kingdom are approaching the question of present and future research. It is always difficult to predict the future, and this is one reason why we are filled with admiration at Dr. Fowler's convincing demonstration of some of the things which are almost bound to happen; and going beyond that, some of the things which may be foreseen, which are likely to happen in the more distant future. Since research into radioisotope techniques has now been going on for between 15 and 20 years in an increasing number of laboratories, it becomes more and more difficult for scientists in these laboratories to find really new ways of using radioactive material. Perhaps we could, for the sake of convenience, put research on and development of isotope techniques under three main headings. Firstly — and this is not really research at all — there is the provision of a service for industrial organizations which may be able to use existing techniques but are perhaps not fully aware of them or fully equipped to make use of them. Secondly, we must face a period of consolidation of techniques which have already been established in principle but not fully developed in practice; a great deal has been said at this Conference about the effects of such consolidation, which consists mainly in refining the established methods as much as possible and making some move towards automation. It is particularly noticeable in the field of radioisotope gauging, and is becoming apparent even in the field of analysis — at least, as we have heard, in the United States of America. And thirdly, we must always keep our eye on the possibility of further progress; USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 511

further breakthroughs through new techniques. In the United Kingdom our research effort was, until recently, largely concentrated in a small number of central establishments, of which the isotope research division at Wantage is perhaps the largest. There is now a tendency for it to spread to a greater number of research organizations, particularly through the Department of Scientific and Industrial Research, which has its own research laboratories in several parts of the country. In most of this research, and particularly the research being carried out at Wantage, we are concentrating on the three main headings mentioned above: service, 'consolidation and the attempt to make progress through new methods. Let me give two or three examples of progress that we can hope for through new methods. The development of X-ray fluoroscopy, about which we have heard something recently, seems to hold promise. Here it is not the technique itself that is new but rather the applications, which make use of radioactive materials and detectors sensitive to radiation energy. One obvious application, of importance in our own country, is the determination of ash in coal, and another is the determination of concentrations of metals in ores and ore concentrates. Another line of research which seems to promise completely new possibilities is the development of solid-state detectors. A number of countries are working on these detectors which, while having the advantage of being relatively small, allow us to discriminate in space between different points of rapidly-varying radiation fields; they also promise to give higher resolution in measuring energies, and this is becoming more and more important in isotope analytical processes. Yet another advance may come in autoradiography, particularly for metallurgical research. Some of my colleagues have recently developed a very high-resolution autoradiographic film, capable of resolutions of the order of 1 jum or less and incorporating a replica of a metal surface. This has opened the way for new tracer studies with greater resolution on alloys, and has solved many of the problems that existed in the past. But I must not go into too much technical detail at what is, after all, an economic conference. I agree entirely with Dr. Fowler that a fresh breakthrough is now most likely to come in the large-scale applications of radiation. We were very interested to hear of the ways in which these applications are being studied, and to learn that they may be put into use very soon in the United States of America. In our own country the emphasis is at present placed more on the sterilization of medical and surgical appliances than on food, although we are keeping a close watch on the future application of radiation to pasteurization, at first, and possibly later to the full sterilization of foods. There are now three main commercial plants in the United Kingdom using gamma radiation for the sterilization of surgical appliances; the first of these began operating in 1962. There is at present only one plant using accelerators on a large scale for sterilization — one reason for this being the limited penetration of the radiations, a matter which we discussed earlier at this Meeting. With regard to food, discussions are now in progress with our health authorities about legislation to cover the use of radiation for the pasteurization and sterilization of food for human consumption. One extremely interesting part of Dr. Fowler's paper concerned the legislation approved by the 512 PRESENT RESEARCH

Food and Drug Administration in 1963, authorizing the use of sterilized bacon for human consumption. I should like to end, if I may, by asking Dr. Fowler whether the sterilization in question is complete or whether it is aimed only at controlling the trichinae in the bacon, or at increasing its shelf life. We are particularly interested in this because we have a similar problem: that of controlling salmonella, one of the most common sources of food poisoning in our country. The doses required for its control are very similar to those needed for the control of trichina. E. FOWLER: The legislation approved by the Food and Drug Adminis- tration provides for fully-sterilized bacon (i.e. bacon exposed to a dose of about 4 million rad). None has been produced commercially so far, although I understand that the Department of the Army contemplates issuing a procurement order for certain quantities of it within the next year. W. J. SCHMIDT-KUESTER: Dr. Fowler, may I ask your opinion about the use of Cs137 instead of Co60? Also, what do you think about the possibility of using large accelerators — something like 3 MeV — as a source of secondary gamma-rays? E. FOWLER: Perhaps I could answer your second question first. I think it is much too early to reach any firm conclusion about the relative merits and efficiency of accelerators-versus-radioisotope sources for jobs such as processing food. The manufacturers of accelerators in the United States of America would naturally like to see them used for the processing of food. However, I think our experience with these machines and our knowledge of their operating characteristics, efficiency and reliability — and perhaps even their economics — are still insufficient, although the manufacturers might well disagree with me. As to the use of Cs*37 instead of Co60, it should be remembered that cobalt has certain advantages; it is a source of high efficiency, and is both convenient and economical to use. One would have to use about four times as much caesium to get the same radiation output. Even so, the difference in their half-lives might work in favour of caesium if one were thinking in terms of radiation availability over a longer period; this will be particularlv true when we have the large-scale production of fission products which we hope to achieve in the United States of America by 1968 or 1969, for then the price of caesium-137 is expected to go down to about $0. 10/c. So I think it still remains to be seen how effectively caesium can be used in comparison with cobalt. J.L. PUTMAN: May I ask two questions about Cs137, in which we are of course also very interested? Quite apart from the cost of the raw caesium there seem to be problems due to the difficulty of incapsulation. Is the cost of incapsulation likely to be reduced, bearing in mind that the specific activity is limited by the fact that Cs137 is a fission product? Secondly, for applications such as sterilization, where the dose must be kept uniform through the product in order to economize on radiation and avoid over- exposure, will caesium be able to compete with the more penetrating radiations from Co60, or possibly accelerators producing gamma rays, for purposes such as large-scale irradiation involving large containers? E. FOWLER: The most honest answer I can give is that we don't yet know. I think the problem of incapsulation is perhaps not so grave as the phrasing of your question suggests. For example, we recently recovered USAEC PROGRAMME ON ISOTOPES AND RADIATION DEVELOPMENT 513

a caesium source that had been prepared some ten years ago for medical therapy and examined the container for possible corrosion. We found the material completely clear and unaffected after such a long period of time. We think, therefore, that this is a manageable problem, and I would not expect the cost of incapsulation to delay the use of caesium for such purposes. As to the use of large caesium sources.for jobs such as sterilization, which raise problems of dose uniformity, efficient use of the radiation from a caesium source with relatively low specific activity, and so on: I can only say that we are studying these questions and hope to understand them better. A couple of-, months ago we fabricated a 200 000-c caesium source; this source has now been shipped to the Brookhaven National Laboratory where, as you may know, a great deal of work is being done on questions of radiation engineering and problems of facility design associated with process applications. The Brookhaven laboratory is also engaged in a broad research and development programme devoted to the general questions of geometry, configuration and containment of sources, as well as those of radiation efficiency. In the next few years we plan to study these matters and, with luck, we should soon be able to solve some of the problems they raise. I. DRAGANIC: I would like to ask you what may be an-awkward question. If I understood you properly, the accent in the United States isotope programme for the next ten years is to be placed on the application of large radiation sources. What, in fact, is the justification for your optimism regarding the use of large sources? If I may explain my.question a bit: in 1954 we heard, at the Oxford Isotope Conference, a very optimistic United States report about large radiation sources. Five years later, at the War- saw Conference in 1959, we again heard an optimistic description of the prospects, and today, it appears, a sanguine view is still — or again — being taken. Now, I most sincerely hope there are real grounds for this optimism — I am not a pessimist by conviction — but I should like to know what they are. E. FOWLER: Yes, about ten years ago there were these expressions of optimism with regard to the large-scale use of radiation for process purposes. The statements made then may well have been over-optimistic, particularly in view of the experience available to us ten years ago, which we know now to have been slight. Over the intervening years the optimism dwindled markedly, however, and if we have now returned to a more sanguine view, I think it is because we have profited by our experience and because we now firmly believe that large-scale radiation offers entirely new opportunities for radioisotope use. Obviously, we still have a lot to learn; the technology is highly complex and our task, therefore, will not be easy. Nevertheless, it seems fair to say that our background of experience is now much fuller, and that our assessment of future prospects is accordingly likely to be more accurate. The research and development programmes now being carried out, not only in my country but in other countries all over the world, are very much better conceived than they used to be; they are prosecuted with greater care and deliberation; and, of course, we are particularly on the watch for jobs which only radiation can do. We have made progress in all branches of radiation engineering and source design. Thus there has been, in the last two or three years in the United States of America, 514 PRESENT RESEARCH

this revival of optimism; or one might call it confidence among the industrial firms themselves — the people actually concerned with the application^of large sources. We do not know precisely what many of these companies are doing, because much of their information is of a proprietary nature and they are unwilling to divulge it. Still, we know that there is a great deal of activity going on and a lot of serious thought being given to these matters: firms often come to us as the supplier of radioactive material which they need either for pilot-scale or production-type operations, and the frequency of these approaches is of course suggestive. These, then, are the grounds for our fresh optimism, and for the conviction that large-scale radiation will mark a turning-point in the use of radioisotopes. A. DOLLINGER: I should like to ask Mr. Fowler a question that concerns the developing countries. Some of these radioisotope techniques are of direct interest to them, the sterilization of foodstuffs being a case in point. Is the United States of America trying at the present time to "export" any of these techniques to the developing countries, and secondly, are any technological simplifications foreseen which will make such techniques more easily applicable in the developing countries? If the answer is no, I wonder whether the United States of America is considering doing something along these lines for the developing countries in the near future. E. FOWLER: Clearly, both the information and the equipment required for the classical uses of isotopes — for gauging and other purposes — should be readily available, and I think they are in fact available to all countries interested in applying radioisotopes in those ways. With regard to the technology and equipment needed for jobs such as radiation processing of foods, I would say there is a clear desire to make them universally available. Apart from anything else, commercial firms are naturally interested in spreading the demand for their equipment and services. This is true not only of food processing but of other applications as well — the sterilization of medical supplies, for instance. Atomic Energy of Canada Ltd. have been active in this way, and there are companies in the United States of America with the same competence and the same interest. We are, of course, still improving the technology. When it becomes more highly perfected there will be a clearer industrial and commercial interest in getting it widely accepted, not only in the United States of America but in many other countries, too. We are well aware of the possible value of our research and development work in food processing to those countries of the world where food supply is a problem, and where the new techniques can, in all probability, be beneficially used. K. MIKAELSEN: I should like to add a few comments in connection with Mr. Dollinger's question. It would be unwise to assume that the new techniques can be usefully applied without taking into account the conventional standard of food technology in. a given country. The quality of the packing, for example, is immensely important. If food is poorly packaged, as it might well be in any country not having a good basic standard of food technology, the value of the new techniques would at best be doubtful. The irradiation process could not prevent subsequent infestation of the food. Now that I have the floor, perhaps I could add a few words to Mr. Fowler's reply to Mr. Draganic's question. After the first promising re- PRESENT RESEARCH 515

suits had been obtained with the irradiation of foodstuffs, the next question that arose was whether the product was edible, or whether it might present some danger for human consumption. There were once some accidents in feed trials; some of the test animals died — not, as it turned out, because they had eaten irradiated food but because they belonged to a diseased strain. Nevertheless, as one might expect, the deaths were immediately connected with the irradiated food. In 1961, FAO convened, in co-operation with WHO and IAEA, an international meeting* on the wholesomeness of irradiated foods. The results of that meeting did much to dispel the misconceptions that had arisen earlier and constitute, I think, one of the reasons for the new-found optimism to which Mr. Draganic has referred. Thus, the processes in question have now been cleared for commercial use in Canada and the United States of America, and it is to be expected that many other countries will follow suit.

* Technical Meeting on the Control of Wholesomeness of Irradiated Foods as a Basis for Legislation. Brussels, Belgium, 23-30 October 1961.

PANEL DISCUSSION

OBSTACLES TO AN INCREASED USE OF RADIOISOTOPES

CHAIRMAN: L. G. ERWALL (SWEDEN)

L. G. ERWALL (Chairman): The national surveys which we have been studying this week reveal how profitable investments in industrial isotope techniques are. As a matter of fact, they constitute massive documentary proof of the profitableness of such investments, and in view of this it is surprising that industry and the community at large are still neglecting to such a large extent the possibilities we offer them. Some speakers have said that in many cases we have to persuade industry to use isotope techniques, and during the discussions many obstacles to their increased use have been mentioned. I am sure that most if not all of us have met and tried to overcome these obstacles in different ways. And I think the collective experience of this Panel and the audience can help us to introduce and spread the use of many safe and beneficial isotope techniques, by providing us with arguments which will convince industry, and ideas as to how these arguments can be advanced most convincingly. To some extent these obstacles are based on facts — for instance, regulations concerning radiation protection. But in many cases they are based on nothing more than ignorance, prejudice or misunderstandings. We have compiled a list of such obstacles — both those based on facts and those which are more irrational — and I suggest that our discussion start with what might be classed as administrative obstacles. Let us first talk about regulations for protection against sealed sources. It is a fact that in many countries installations using these sources are hampered by too much red tape. International bodies such as the Agency have been successful in many cases in producing international regulations or recommendations governing the transport of radioisotopes; and I think this is the right place to discuss some recommendations for regulations to govern the use of sealed sources. Of course this is a matter of primary concern to the manufacturer of such sources, especially if he is working on an export market. S. MARGOLINAS: This is a subject very close to my heart. When we try to develop the use of isotopes in industry, we realize immediately what enormous difficulties are caused by the highly complex regulations and administrative modalities imposed within a single country — not to mention the fact that there are vast differences in the regulations from one country to another. I think we can divide the obstacles which inhibit the development of radioisotope uses into two groups. First of all there are the normal obstacles to the development of any new technique: ignorance, fear, a lack of knowledge of the possibilities and so on. Secondly there are the man-made obstacles, and here I will speak specifically of legislation. Laws on the subject vary greatly from country to country, and they tend to hinder the use of isotopes in two ways. Firstly, they restrict the free circulation of products

519 520 PANEL DISCUSSION over national boundaries when the relevant laws of different countries are in conflict. Secondly, they reinforce the psychological obstacles to the use of isotopes, for the mere existence of complex legislation seems to increase the fear in which such a novelty is held. This can have serious economic consequences. Therefore it is important that we should realize, when discussing the economic advantages of the use of isotopes, that one of the main obstacles isotope techniques must face is unduly harsh legislation, and the enormous differences between the laws of different countries. J. P. van GANS BERG HE: Mr. Chairman, if I clearly understood what Mr. Margolinas said, he hopes (and I must say I share his hope) that the Agency will take it upon itself to draft a code of practice for the use of radio- elements — a code which would break the subject matter down by types of application. This would be a laudable initiative, but let me stress that such a code must not only be drafted; we must also find a way of getting it applied in various countries. Otherwise we shall have a situation which is already too common: that of an international body publishing recommendations which remain a dead letter on the national plane. Some way should be found of making such codes of practice mandatory, and it would be well for the Agency to bear that in mind. H. SELIG MAN: We have been aware of these problems for a long time. All of us have suffered from them in our own countries; indeed, I should think there is hardly anybody here who has not had ten or more years' experience with such troubles. Once we realize how difficult it is to get a commonly accepted code of practice in our own countries, it is not hard to imagine how extraordinarily problematic an international code is. However, we are here not to make problems more difficult but to solve them. Let me say right at the outset that our Agency cannot do what Mr. van Gansberghe has just suggested as being desirable. We cannot enforce rules because we are not a world government. We are an international agency, financed by our Member States, and we can therefore only make recommendations; whether the individual Governments wish to accept our recommendations or not is up to them. We have made such recommendations in the legal field, as you may know, and not long ago we drafted some regulations on the safe transport of radioactive materials. But the detailed discussion of how to tackle these problems must be left to the experts. Our legal staff may find some way of going about it, although we realize that the problems before this Panel are far more complex and difficult to solve than those involved in transport. K. WOLFF: I should like to make a few remarks about the question of compulsory regulations issued by the Agency. As you know, the Agency deals with certain aspects of the peaceful uses of atomic energy in which the differences of national legislation afford quite a lot of scope for international co-operation. This proved to be true, for instance, in connection with civil liability for damage caused by nuclear installations. Now, as a general rule I would say this: even though the regulations or recommendations prepared by an organization such as our Agency may not be formally binding on Governments, they nevertheless exercise a kind of moral suasion (particularly when they have been accepted by some Governments); and insofar as they do that, they are of definite practical value. Thus from a prac- OBSTACLES TO AN INCREASED USE OF RADIOISOTOPES 521 tical, and even from a legal point of view, I should say that the smooth path of framing recommendations is to be preferred to the thorny path of trying to impose formal regulations, which normally are accepted only under very exceptional circumstances (as in the case of civil liability for nuclear damage, for instance). S. MARGOLINAS: I understand the difficulty of imposing regulations, and I believe that recommendations are highly desirable. The mere existence of a body of well-considered international recommendations would make the framing of reasonable national regulations easier. Countries in the process of drafting their own regulations — and there are many of these at the moment — would presumably follow the international recommendations, by and large, and in countries already possessing Draconian rules the international recommendations could be expected to militate in favour of more liberal legislation. It should be possible, among other things, to recommend standards for the application of specific regulations in specific cases. In France we have often adopted this method. At present negotiations are under way to obtain approval for the application of international regulations in the field of neutron accelerators, where development would be hampered if we had to apply without exception the regulations on tritium. This is a particular case. Thus one could begin, in each country, by asking for permission to apply international rules in specific cases. We all know what are the most important cases for industrial applications. C. G. CLAYTON: I think it is important to determine how often applications have had to be abandoned or withdrawn because the radiation levels were so high as to infringe the requirements of law. In the United Kingdom, as far as I know, there are examples of applications which existed before recent legislation and which have now been withdrawn: these were static eliminators and some level gauges. There are also many examples of gauges that had to be redesigned, at some expense, after the adoption of new legislation. The fresh design was made in every case, however, and I am fairly sure that no gauges have been withdrawn because the extra cost could not be borne by their users. Therefore I submit that, although strict legislation does create difficulties, the difficulties are not insurmountable in the United Kingdom. One quite understands the manufacturer's point of view: his is a competitive business, and the cost of the isotope device is related to the amount of material necessary for shielding; further, the technical usefulness of the device is often affected by its weight, bulk, and so on. Nevertheless, this is not, in my experience, a major difficulty. H. SELIGMAN: I think this is not quite the problem. The real problem arises not within a single country but when one wishes, say, to ship a piece of equipment from one country to another and encounters different regulations. We have given some thought to the matter, and I think perhaps Mr. Szasz of our Legal Division could outline for you what the Agency might possibly do in this field. Any comments you wish to make after his statement would be very helpful to us. P. C. SZASZ: I think you all know some of the difficulties involved in setting up standards for the use of isotopes, and of course framing international standards is more complicated than establishing national regulations. 522 PANEL DISCUSSION

At the national level, the problem is really one of co-ordinating the competent organs of government and deciding what has to be done. At the international level, one also has to get all the interested countries and international organizations to agree. Obviously, the first step in setting up any regulations or standards is to establish the scientific basis for them. Let me say here, from the lawyer1 s point of view, that we find the scientists are by no means always in agreement on the most fundamental issues. The question whether to measure the intensity of radiation at the surface or at a certain distance from the surface is a case in point; at one of last year's transport panels several scientists talked at great length about it. It is obviously not a legal issue. It is basically a scientific issue, and the first task is for scientists to decide what really is the proper practice. The Agency goes about this by convening panels, symposia and conferences, which we hope will evolve a kind of scientific consensus as to what should be done in the field in question — transport, packaging, the use of sealed and open sources, and so on. That is the first step, for without the scientific consensus no further step can be taken. The second step is to formulate the scientific consensus in terms of what might be called a code of practice: practical rules which permit the application of the scientific requirements to particular situations. At this stage the lawyers can start co-operating in order to make the rules clear. It is basic to the technical problem that they should be properly framed and readily intelligible. Now comes the third step. Given these codes of practice, what does the Agency do with them? In the first place it applies them to its own operations, in the widest possible sense — that is, not only to work done at Agency headquarters or in the Laboratory. Whenever we enter into a research contract, we ask the contractor to apply our code. Whenever we give technical assistance, we ask the technical assistance experts to hold themselves to our rules. Whenever we send round an isotope laboratory, or give assistance in setting up a reactor, we ask that our rules be applied or that we be able to check the national rules to see that they are at least equivalent. In this way we try to propagate our rules inoffensively but, we hope, effectively. Now comes the next possibility. Whenever we promulgate a set of rules or a code that we think is good, we recommend it to Member States for adoption as national legislation. As has been pointed out, many countries are new and have no national legislation on the subject; these countries will presumably be responsive to the Agency' s regulations, which are their best source for an impartial and up-to-date account of what such codes should be. As to those countries which already have established legislation —the United States of America, the United Kingdom, the USSR and most western European countries — the problem is of course more difficult because they have to change their laws. But we hope that as our recommendations gain a reputation for effectiveness, these countries too will come around and see the advantage of uniformity. Thirdly, we recommend our codes to other international organizations, again for their own use. For instance, if WHO and FAO use radioisotopes we hope that they will apply our codes of practice rather than other codes. OBSTACLES TO AN INCREASED USE OF RADIOISOTOPES 523

Furthermore, other international organizations are engaged in drafting regulations or treaties of various sorts. For instance, we recommended our transport regulations to the United Nations commission engaged in drafting international transport regulations. We have recommended our transport regulations to ICAO and IATA and have, in general, received positive re- sponses to these initiatives. Fourthly, the Agency itself can initiate the drafting of treaties incertain areas where we do not encroach on the prerogatives of some other international organization. Obviously, once we have established the scientific standards and drawn up codes on that basis, we can consider in what legal form we might wish to put these regulations. As Mr. Wolff pointed out, it would not do to try to impose these rules on Member States. We have no legislative authority over Member States. If we try to impose treaties that they do not like, we will either get no response or the provisions will be so watered down as to be almost worse than no international code at all. There is also a fifth possibility that I should mention briefly. Some international treaties, like the Convention on the High Seas, provide for 1 regulations the Agency might wish to make in their respective fields. The Convention on the High Seas has a provision enabling the Agency to frame regulations governing waste disposal into the sea. Similar clauses are to be included in other treaties. Naturally, whenever the Agency has a legitimate function related to the subject matter of any treaty, it also has an interest in seeing that it is mentioned and that the possibility of its either drafting regulations or securing the acceptance of existing Agency regulations is considered in the preparation of the instrument. That is the present situation. While the Agency1 s opportunities should not be overestimated, I think that in time we can and will do effective work in this field. E. FOWLER: Could you clarify whether the Agency is concerned only with standards or codes of practice governing the transport of materials from country to country, or whether it concerns itself also with codes of practice affecting, say, the use of sealed sources in particular countries? G. APPLETON: I have listened with some interest to the remarks about a lack of codes of practice in these fields; and yet such codes exist. The code on the safe handling of radioisotopes has existed since 1958. We have had a set of basic safety standards since 1962. And we recently revised the transport regulations so as to enable the free movement of radioisotopes between nations throughout the world. I suggest to you that one reason why we have perhaps had better success with the transport regulations than the basic safety standards or the regulations on safe handling of radioisotopes is because — as Mr. Szasz said — we invited the international transport organizations to sit in on our deliberations. These people are in the business for the money they can get out of it, and it is in their interest to promote the promulgation of international regulations. So, we find now that all the international organizations — and I say all — are going over to using the Agency's regulations. Shortly we shall find that an isotope produced in America can go, in its container, to the other end of the earth with no more trouble than the paper work accompanying the shipment. 524 PANEL DISCUSSION

As to the basic safety standards, which set down levels of exposure for different categories of people, and for the organizations or establishments using radioisotopes, I feel that this is a local problem. You, as isotope users, must educate your countrymen and urge them to adopt these standards. The standards exist, and they are subject to revision from time to time. My answer, therefore, is that we have got transport regulations, which are being adopted by all the international transport organizations. We have codes of practice relating to radiation exposure and basic safety standards for the handling of radioisotopes, too; but it is naturally more difficult to secure international acceptance of these. S. MARGOLINAS: I must express my disagreement with the last speaker. It is precisely because of the form in which such recommendations exist at the present time that we have all these differences (which go as high as a factor of 1000) of interpretation. It is because the recommendations are expressed in the form of cumulative doses. To take an example previously cited, an installation made in the United States of America can be transported to Belgium but may not be installed there, because the standards for fixed installations in a plant are entirely different. It is perfectly legitimate to write regulations in terms of annual cumulative doses, but an interpretation giving the dose rate in the neighbourhood of an installation is also needed. This is what we are asking for. P. C. SZASZ: Perhaps it is unfortunate that we have concentrated our remarks so much on the transport regulations. Actually the Agency has a whole range of codes, some of which Mr. Appleton has mentioned. Our first code was the Safe Handling of Radioisotopes. We now have the Basic Safety Standards and a manual entitled Safe Operation of Critical Facilities, and we are working on yet others. All these, of course, are meant to be applied in a given country in a given situation and have nothing to do with transport. Obviously they are interrelated. The regulations for safe transport are based on our concept of basic safety standards. As a matter of fact, all these codes are derived from the basic safety standards, which embody our notion of safe dose levels in various situations. Thus both the transport rules and those governing the handling of materials and equipment have their foundation in the basic standards. But it would be a mistake to think that the Agency is concerned only with regulations of international import such as those on civil liability, waste disposal in international waters and international transport. We are equally concerned with applications of atomic energy in a given place or a given situation, and we are drafting appropriate codes and regulations. Obviously it is more difficult to get a code of practice accepted where no international contacts are involved than where the reverse is true. Legislatures can be persuaded to accept a treaty on international transport, or international civil liability, or international waste disposal; but it is not so easy to persuade them to follow international rules in national practice. We are nevertheless trying to persuade them to follow international rules — not necessarily to give any formal undertaking, at first, but gradually to adapt their own laws to the international norms. E. FOWLER: I think an extremely important question is whether the Agency could undertake to draft a code of practice for the use of sealed sources. This may well be an area in which there are conflicts related to the manner in which radioactive devices are manufactured, the radiation OBSTACLES TO AN INCREASED USE OF RADIOISOTOPES 525

fields around particular devices, and the restraints which may exist in particular countries by virtue of their standards and regulations. Something which has not been discussed here and which is of vital concern for the use of sealed sources is the question of the type and frequency of testing that should be carried out on such sources. The main point of such tests is to determine any possible leakage of radioactive material from the source. For many years we have been trying to produce a suitable set of regulations for the testing of sealed sources; but so far, I feel, we have not found a sound technical basis for such regulations. The rules we now use are based on our best technical judgement, but are not necessarily backed up by sound technical data. Moreover, I think any new regulations on the testing of sealed sources should take into account the experience we have had with them. The fact that sources in use for many years (Sr90 foils, for example, ) have retained their radioactivity so well suggests that some relaxation of the testing requirements might be in order. L. G. ERWALL (Chairman): That could come under the Agency's Basic Safety Standards. I wonder whether this Study Group feels that the Agency should prepare specific recommendations as to how the Basic Safety Standards could be applied to sealed sources. G. APPLETON: I think what Mr. Margolinas wants is virtually impossible. One can establish a set of basic safety standards; but to prescribe dose levels at the surface or at a distance from any particular source used industrially one would have to make a time and motion study of the environment in which the source was being used. Do you want the Agency to do time and motion studies on all these installations? You cannot possibly set down a uniform level. It will not fit everywhere. You will be too restrictive in one case and not restrictive enough in another. That is why the Basic Safety Standards can do no more than quote maximum permissible annual exposures. In Safe Handling of Radioisotopes if you turn to the section dealing with sealed sources, you will find a general account of what must be taken into consideration in order that the radiation workers and non-radiation workers of your installation do not receive, in the course of a year, a dose in excess of that laid down in the Basic Safety Standards. We cannot be much more specific than that. I will give you another example. Contamination of the hands has been a vexing problem for nuclear energy authorities working with large amounts of unsealed radioactive materials. But it is almost impossible to prescribe maximum permissible levels for contamination of the hands in an international document, because habits in different countries vary so greatly. It must therefore be left to local legislation to lay down the specific rules required to ensure compliance with the more general rules recommended in international documents. G. ROBIN: There has been a great deal of discussion about the sealed sources used in gauges, but there is also an important problem with regard to tracers. If we wish to develop the use of tracers, a code of practice for the use of unsealed sources must be formulated. Here again we find ourselves with maximum permissible concentrations defined in terms of cumulative annual doses. It would therefore seem necessary to define, clearly 526 PANEL DISCUSSION and precisely, how on the basis of these data the risk inherent in a tracer experiment can be assessed, bearing in mind the half-life of the radionuclide used, its activity and the conditions of its dispersion; and also, in the long- run, the frequency of the operations to be carried out in the same place. From these data it should be possible to devise a method of calculation which would allow us to establish the limits in which tracer experiments might be authorized. L. G. ERWALL (Chairman): It should be remembered, of course, that tracing and gauging have much in common, although we intend to treat them separately here. S. MARGOLINAS: I am sorry for having to come back to the floor. I don't wish to engage in polemics. I must apologize to Mr. Appleton, but I cannot believe that his evaluation of the situation is valid. The best proof of this lies in the fact that national organizations have taken it upon themselves to spell out the detailed rules; and it is precisely because they have done so that we now have all these difficulties. Had they been content to stick with cumulative doses, saying merely that measures must be taken not to exceed them, there would be no problem. But each Government which dealt with the question felt obliged to specify an average in the interests of securing compliance with the maximum permissible cumulative doses. Thus , the enormous contradictions, with variations (as I have said) by a factor of as much as 2000. J. L. PUTMAN: From our discussions one thing has emerged, namely that there is a great deal of similarity in the use of radioactive materials, and particularly sealed sources, in different countries. I should have expected the diversity of modes of use of sealed sources in a single country to be greater than the differences between one country and another; and I find it a little difficult to understand the difficulty of deriving from national regulations on sealed sources some sort of international recommendations. Therefore, I think that Mr. Margolinas has, to some extent, made his point. It should not be so difficult to make international regulations if it is possible to make national ones at all. T. CLESS-BERNERT: I think one important point is very often over- looked in the national regulations. That is that a source does not necessarily constitute a danger, the degree of danger depending rather on the circumstances in which it is used. Thus it is a good idea to lay down standards for the maximum permissible dose, perhaps also taking into account the probability of the worker getting a certain dose. I tried to point this out when I was engaged in devising a system for calculating the risk involved in using radioisotopes. Much depends on the circumstances — particularly the shielding and other protection — in the individual case. P. TEMPUS: It is only fair to say that the Agency's recommendations were a great help in setting up the Swiss regulations for protection against radiation. We have adopted more or less all the general recommendations, although not some of the detailed ones. For the rest, we think that more elaborate regulations are no help at all if in industry, or wherever radioisotopes are applied, there is not the necessary discipline to follow them. One can formulate highly detailed rules as to what must be done, why and when; but the more detailed the rules one prescribes, the less likely they are to be followed conscientiously. OBSTACLES TO AN INCREASED USE OF RADIOISOTOPES 527

Thus we have the feeling that the general recommendations given by the Agency are sufficient; the rest must be done by educating people to use radioisotopes. We think that any changing of the regulations at the moment would be very difficult. Often too much national prestige is at stake in certain special questions. It will be easier to discuss the existing regulations and possibly change them in a few years' time, when practical results have been obtained. These discrepancies exist not only in the radioisotope field. For many years there have been conflicts among the national regulations on foodstuffs; serious difficulties have arisen because of the different standards, and it is only now that FAO has formed an international commission to work for co-ordination in this field. I should like to ask one question which someone here may be able to answer. A few years ago the International Organization for Standardization began working on standards for sealed sources and the testing of sealed sources. Can anybody say what has happened, and whether any substantial progress has been made? H. J. MARCINOWSKI: ISO is preparing a new standard for the testing of sealed sources and I believe it is to be finished this year. It is also hoped that the studies on testing of containers for transport will be completed this year. R. J. MOFFETT: There must, I think, be general agreement with the principle that each installation should be judged independently according to the circumstances that prevail in it; this of course means inspection. I agree with the Agency's conviction that it is impossible to legislate for every contingency. However, it is possible to legislate for the results which are required. Here we must come back to the problem of interpreting the regulations. In a business which I know fairly well, where inspections sometimes account for as much as 15% of production labour, we found that generally there were two sorts of inspectors. There is the man who knows nothing but the written regulations; he is a nuisance and should be fired. Then there is the good inspector who not only knows the written regulations but understands them as well, and who knows exactly how much variation from the norm is permissible in a given case. This is the type of man who, armed with suitable recommendations from the Agency, could remove most of these difficulties and also keep the rules to a minimum. To my mind, for instance, the requirement for a sealed source is that nothing should leak out of it. This is a general rule; a good inspector can then determine, perhaps with some assistance from recommendations on methods of inspection, whether the source leaks or not. There is no need for the regulations to prescribe exactly how the inspection should be carried out, or under what conditions. The inspection constitutes an adequate control, and the problem boils down to having a good man for the job. C. G. CLAYTON: There seems to i>e little doubt that we must have uniform regulations, and that lack of uniformity creates difficulties of economic concern. What I would like to know is exactly how great these difficulties are insofar as.they affect the use of sealed sources. R. CORNUET: On the whole I agree with Mr. Margolinas. I cannot see why serious difficulties should arise in framing the regulations which he 528 PANEL DISCUSSION would like to see adopted throughout the world. Indeed, I think the problem seems to be difficult because radioéléments are. still something of a novelty and public opinion regarding them has not as yet been sufficiently well educated. Even so, it is hard to believe that this problem is any more difficult than the one which arose when men first started building steam engines. I doubt whether anyone thought at that time of prescribing that not more than ten persons should be killed per year by explosions in boilers or steam engines. They determined maximum pressures by allowing for a certain safety factor between the operating pressure of a boiler and the pressure at which it .would burst. Similarly, in the case of electrical energy, I expect there was no difficulty in obtaining uniform laws to govern the insulation of plugs, for instance, and no one considered what should be the maximum amperage which a user of electricity could have available to him. With all due respect to Mr. Tempus1 views, I don't think this is something that affects national prestige. If we wish to set up regulations — and here we must consider the matter from the simplest viewpoint — it seems clear that the use of a thickness gauge should be governed by nearly identical rules in the United States of America, the United Kingdom, France and so on. We might wish to make provision for particular circumstances: for instance, that a person working at a certain distance from a gauge should not receive more than a certain dose. Health physics measurements would then be required. But I think we should not fail to see the forest for the trees. As Mr. Appleton said, it will be extremely difficult to get agreement from a group of experts on specific figures, but the mere difficulty of the problem cannot justify failure to convene a meeting of experts in an attempt to set such figures. E. FOWLER: I am not sure whether this Panel is supposed to make any specific recommendations, but I think it would be useful if the Agency examined the possibility of establishing standards for the use of sealed sources. I agree with Mr. Putman: it should not be impossible to do this sort of thing because, clearly, in individual countries it is being done. In the United States of America the approach is to define the characteristics of the device itself — the features twhich the apparatus and the sealed source must embody. Secondly, we deal with the question in terms of radiation fields, and in particular, areas of radiation use. Lastly, I am certain that all countries having regulations on the use of radioisotopes establish limits for the exposure of personnel to radiation. These are three ways of approaching the problem, and with them I think it should be possible to establish standards for the use of sealed sources. L. G. ERWALL (Chairman): I have a very strong feeling that all of us participating in this Study Group would welcome recommendations from the Agency concerning the application of its safety standards to the industrial uses of sealed sources. G. APPLETON: The Safe Handling of Radioisotopes is to be revised in the very near future. Even so, I must repeat my main point, namely that it would be quite impossible to establish international standards in the technical detail desired by Mr. Margolinas. The British laws on the subject can serve as an illustration: they prescribe permissible radiation levels for places accessible to the general public, and for areas frequented by radiation workers, but they do not attempt to prescribe limits in respect of the source itself. 529

P. PLATZEK: Perhaps it should be pointed out that EURATOM, like the Agency, has published recommendations on safety which were accepted by the Dutch authorities about a year ago. This is a useful first step, at least within the framework of the European community. S. MARGOLINAS: If I understood Mr. Appleton properly, he thinks the Agency should recommend countries not to limit dose rates around sources; at least this is what he seems to be saying, and I think we should try to be logical about it. The problem with the EURATOM standards — if I may reply now to Mr. Platzek — is that they are set out in the same way as the Agency's, i. e. in terms of cumulative annual doses rather than dose rates. L. G. ERWALL (Chairman): I suggest that we now turn to the next real obstacle, and that is the insurance question. We know that in some countries stringent insurance requirements are all but prohibitive to the increased use of certain isotope techniques. H. J. MARCINOWSKI: The question of insurance is also very complex, and I doubt therefore whether we can usefully enter into a detailed discussion of it. I shall mention only a few things that must be borne in mind. The difference between the insurance sum and the premium is often not sufficiently considered. The first is determined by the magnitude of the maximum credible accident, the second by the probability of its occurring. The product of these two figures gives the risk, and this risk can vary over a wide range. Separate calculation of the premium for a given risk often yields a higher premium, so that the special insurance prescribed in some countries against radiation damage is more expensive than insurance based on an overall calculation. Furthermore, we must not forget that many private users of radioisotopes are at a disadvantage in relation to governmental institutions, which are generally not affected by insurance legislation and therefore pay no premiums. The risk inherent in the use of radioisotopes is not only very different from the risk which reactors involve; there are also great differences in this regard among the different uses to which isotopes can be put. Very often, by using radioisotopes one can diminish some other risk so that the total risk is in fact less when nuclear energy is used than when it is not. This is often forgotten when the pros and cons -are weighed. After nearly twenty years of experience it is clear that nuclear techniques — thanks to the thorough safety measures that have been devised — are among the safest of industrial methods. I hope, therefore, that the Agency will be able to formulate appropriate recommendations to Governments in this matter, for I am convinced that unnecessarily stringent insurance laws can do much to hinder the further development of nuclear techniques; more, even, than the inflexible attitude of an inspector (the case to which Mr. Moffett referred) who does not comprehend the real purpose of the regulations which he is called upon to apply. K. WOLFF: If I understand your question correctly, it amounts to recommending that the Agency investigate the effect of insurance on the use of radioisotopes and consider whether recommendations on the subject could usefully be made to Governments. Let me point out, first of all, that the use of radioisotopes has not been considered so risky as to require their subjection to the kind of regime established by the Vienna Convention. Radio- isotopes are in fact exempted from coverage in Article I. 1. (g) of that Con- 530 PANEL DISCUSSION verition. This exemption, which is embodied in a definition of radioactive products or waste, reads as follows: " 'Radioactive products or waste'means any radioactive material produced in, or any material made radioactive by exposure to the radiation incidental to the production or utilization of nuclear fuel, but does not include radioisotopes which have reached the final stage of fabrication so as to be useable for any scientific, medical, agricultural, commercial or industrial purpose. " Thus, all radioisotopes of this kind are exempted from the terms of the Civil Liability Convention, regardless whether they are located inside or outside a nuclear installation. Now, this definition of having reached the final stage of fabrication means in practice that the radioisotopes are excluded at the moment when they are safely handed over to industrial operators. Of course the absence of an international regime governing civil liability in respect of the use, transport and so on of radioisotopes has both advantages and disadvantages. It has the advantage that the user of radioisotopes is not obliged to carry $5 million of insurance — the minimum amount under the Convention. It has the disadvantage that different national legislations may have to decide the question whether strict liability is to be applied in a particular case. These uses of nuclear energy have, however, been insured for'quite some time, and as far as we know no special problems have arisen. In view of this it is questionable, firstly, whether any real need exists for recommendations which could be made by the Agency in regard to some kind of uniform legal system for the use of radioisotopes; and secondly, whether such a system could or should include standards to govern insurance requirements. Possibly the Agency could work out some non-compulsory standards, in collaboration with representatives of the insurance companies, and of course in collaboration with governmental and scientific experts, if it is felt by this Panel that the insurance required for radioisotope applications constitutes a real obstacle to the free use and circulation of radioisotopes. H. J. MARCINOWSKI: I believe it would be a good idea to convene a symposium of insurance experts and experts in the use of radioisotopes. The real problem is to get a firm empirical basis for the calculation of premiums; calculations based on theory alone are complex and not well suited to the mentality of the insurance companies. E. SOMER: The first task is to make a survey of accidents that have resulted from the use of radioisotopes in industry/ There have been surveys, both international and national, of accidents and incidents in nuclear installations in general. However, these, surveys have covered all types of accidents in reactor installations, hot laboratories, installations where isotope sources are produced and installations where they are used. Insurance men and others who are not specialists in the field unfortunately make little distinction between these different installations, although the potential hazard of isotope applications in industry is less than that represented by the isotope production installation by a factor of more than a million. I think, therefore, that it would be very useful to conduct a survey exclusively on accidents in connection with isotope applications. It would have to be on an international scale to provide enough information for a really sound estimate of risks. It should be possible to persuade the national atomic energy authorities to make this information available; but not until it is assembled should we consider making recommendations in insurance. OBSTACLES TO AN INCREASED USE OF RADIOISOTOPES 531

G. ROBIN: Mr. Somer has ably said what I intended to say. In France, for instance, insurance for nuclear risk in respect of radioéléments is discussed with a pool of insurance companies which deal specifically with nuclear risks. Insurance companies in general do not know what risks exist and tend to assimilate the risks of isotopes to those represented by a nuclear power station. The premiums they demand are often very high at the outset, but after somewhat difficult and lengthy discussions we often arrive at premium rates which are not more than 1% of the original request. This just proves that the risks are not known, because it is not normal to set a premium and, after discussion, to reduce it by 99%. It would therefore be useful to have statistics on this type of accident. Perhaps the Agency could collect and collate reports on accidents which have occurred, in order to make available to insurance companies detailed information on the risks and dangers presented by the use of radioisotopes. P. TEMPUS: I want to give strong support to this suggestion. We know of no specific case in which the use of radioisotopes has been held up by insurance problems, but developments in some European countries are giving rise to the fear that this could happen. E. FOWLER: I would like to have a clearer idea how insurance can affect the use of radioisotopes. In the United States of America we have laws on insurance and indemnities associated with accidents that might occur in nuclear power plants or what we call production facilities, where the magnitude of the potential accident could give rise to enormous liability. These laws do not extend to the applications of radioisotopes, however, and I know of no case where a company using isotopes has been obliged to accept a high insurance premium. L. G. ERWALL (Chairman): This, then, appears to be another proposal on which the Study Group is in agreement: the Agency should conduct a survey of accidents involving isotope applications, assess the results and determine their implications for insurance. K. WOLFF : I think I made it plain that the Agency could do something about the insurance question if it is felt that insurance constitutes a severe obstacle to the free use and circulation of radioisotopes. However, it has been pointed out that in one country, at least, there are no problems with respect to insurance coverage. L. G. ERWALL (Chairman): Yes, but it has also been made quite clear that in some countries it does constitute a problem; so it seems the proper procedure would be for the Agency to conduct a survey, the results of which would indicate whether any follow-up was necessary. Am I right in this interpretation? G. ROBIN: Part of the insurance problem lies in the fact that we are obliged to take out special insurance for nuclear hazards or risks, including risks arising from the use of'radioéléments. Any normal insurance policy in France, be it for automobile insurance, civil liability or industrial risk, states quite clearly that nuclear risks are excluded. We must therefore take out special policies. This fact, even though the premium may be low, nevertheless gives rise to administrative difficulties which may represent an obstacle to the use of radioisotopes. K. MIKAELSEN: This survey of accidents should not be limited to the 532 PANEL DISCUSSION industrial uses of isotopes but should cover agricultural and medical uses as well. J. L. PUTMAN: One reason why insurance has not been found necessary in many countries that are using isotopes is that a great deal of the work has so far been done, and much of the advice on the use of radioisotopes has been given, by specialists from government departments or government- sponsored research organizations. Part of the responsibility is thus taken by a central government or government agency. If, as is to be expected, isotope techniques develop to the stage where they are used as commonly as other industrial techniques, it will be valuable for ordinary — that is, non-governmental — engineering consultants as well as universities and technical colleges to be able to give advice on the subject. One may assume that they would be deterred from doing so if there were no means of obtaining insurance at a reasonable price. L. G. ERWALL (Chairman): Perhaps we can now finish this discussion. The Study Group has at least made some general recommendations and we hope, of course, that the Agency will find it possible to follow them. There is a further point concerning legislation, one which has already been touched upon by Mr, Robin: in tracing work, how are the MPC values recommended by international bodies, for example, to be applied in specific cases? This might be worth discussing; but if you have no comments, as appears to be the case, it cannot be a very serious obstacle. E. FOWLER: If you mean tracing in the sense of introducing radioactive material into an industrial processing stream for control purposes, clearly we have standards in terms of concentrations permitted. In the United States of America these restrictions probably have slowed down the use of radioisotopes for tracing; they become particularly important when one considers the residual radioactivity that may be left in a manufactured product as a consequence of tracers having been used in the process stream. R. HOURS: I think the absence of special regulations to govern the use of isotopes with short half-lives does a lot to hinder the use of tracers in general. This is a matter which the Agency could profitably consider. In France there are certain special regulations (mainly in connection with hydrological applications) which, although rather conservative and restrictive, nevertheless enable short-lived isotopes to be used with relatively little fuss and bother. I regard them as provisional nevertheless; they should be reviewed so that these applications can eventually become routine. L. G. ERWALL (Chairman): Yes, there are of course quite a few standard tracer applications for which it should be possible to get standard — or at least widely accepted — regulations. In Sweden we were asked, several years ago, to perform an investigation in the sugar industry. This was done, and the sugar was later sold, after being stored for a couple of weeks. The attitude of the Swedish public and authorities towards these things has changed to some extent. Of course we have a food and drug act, like many other countries, and in general the radiation protection law is not applied if the food act can be. Our request for permission to make an investigation is sent through the radiation protection authorities to the food authorities — the legal authorities on the food side — and of course their view of these matters is somewhat irrational. 533

based on prejudice and ignorance. It is therefore extremely important that the factual hazards, expressed in mr/h, or the permissible concentrations, expressed in juc/cm3 for continuous exposure, should in some way be referred to these accidental exposures which occur, and to goods which are consumed by human beings. In quite a few cases recently we have been refused a licence to perform ground-water studies, for instance, or studies in the food industry. With regard to ground-water research especially, I think it would be valuable if we could hear what has happened in other countries, i. e. how the authorities look upon the introduction of radioactive material into ground water. E. SOMER: I think one should not even try to make the regulations on tracer applications completely uniform. More or less firm regulations could be applied to the techniques which have now become routine: leak detection, mixing studies, studies on metallurgical processes, and so on. In Denmark we have applied the Swedish regulations, which appeal to us because they enable us to get on with the work and to obtain the licences without any delay. However, in a field such as hydrology it would be awkward — and I think, therefore, inadvisable — to try to apply uniform regulations. The situation can vary enormously from one case to another; a project involving considerable risk might suggest the need for strict regulations which in another situation would be unduly restrictive and indeed quite unnecessary. It is impossible to generalize about hydrological applications as one can about leak detection and other industrial tracer studies. R. HOURS: We, The French representatives, might give the impression of being in a rather contradictory position, but it is only an appearance. I do agree with Mr. Margolinas who wants the regulations, now expressed in annual cumulative dose, to be translated into dose rate at a certain distance. On the other hand, when short-lived isotopes are used for tracer experiments, most people estimate the risk due to contamination of air or drink- able water by using the maximum permissible concentrations (MFC's); but these MFC's are computed for a permanent consumption or inhalation, which is practically never the case for these experiments. Therefore, it seems more logical to consider the cumulative dose delivered to the various organs during one experiment, which is generally easy to estimate in a pessimistic and conservative way. This method of computing the risk will emphasize the benefit, from the health point of view, of using a short-lived isotope rather than a long-lived one, and of performing a short-time experiment rather than a long-time one, a benefit that can completely disappear with the single MFC consideration. Then, one can introduce the notion of "temporary" MFC opposed to the usual "permanent" MFC. The greatest difficulty in this technique would be the frequency of the experiments themselves, although this should not be an insurmountable obstacle. We have proposed an analogous approach in connection with studies on moving sediments, but it has not yet been adopted as a regulation. The relevant study was performed by Mr. Courtois at Saclay. The matter is still under discussion, and I must say that it is very complex. We wanted to consider the total number of cases that might be expected to arise. At the 534 PANEL DISCUSSION moment the medical authorities do not have time for a project of that nature, but I still think that it is a marvellous initiative to have given them the preliminary calculations which they can eventually use for it. We have proposed certain rules for the frequency of the experiments which seemed to us logical and easy to apply while still being quite conservative. G. APPLETON: This is not a new technique by any means. I can only speak with certainty of my own country, but from what I have heard from the representatives of other countries, I believe it is widely used. Indeed, this method of assessing the potential hazard of a tracer experiment is already used in the United Kingdom on a day-to-day basis to evaluate the release of active wastes to the environment. A similar method is used by the authorities responsible for tracer experiments. The maximum permissible concentrations in air and water are based on a standard man and a standard period of exposure. Needless to say, the authorities must be taught to plan them sensibly. The MFC's for waste gases from a power reactor or production facility are based on concentrations averaged over a period of time; in other words the regulations do not attempt to prescribe that the waste should not exceed a certain level at any given moment, but rather that over a fixed period of time the average should not exceed the MPC. There is nothing new about this. I am confident that in the United Kingdom a tracer experiment would be dealt with similarly — straightforwardly and without any trouble at all. L. G. ERWALL (Chairman): There is the difference with regard to the period of exposure, though, isn't there? The MFC's are calculated, you said, for a standard period of exposure, and yet one would have to apply them to individual tracer studies. G. APPLETON: Yes, I did-say they were calculated for a standard period of exposure. However, one can integrate the short burst of exposure over a longer period of time. For instance, if for some reason one had an abundance of I131 and thought it would be better to be rid of it rather than store it in the plant, a case could be made for removing it all at once and thus "using up" — if I may use that phrase — three months' waste disposal allowance. The concentration would be averaged over the three months. That is what I meant. L. G. ERWALL (Chairman): Even so, I think the government authorities and the public in many countries must be educated to this way of thinking. Do you agree? G. APPLE TON: Yes, certainly. R. HOURS: I was pleased to hear what Mr. Appleton said. He proposes an intelligent use of the standards, and I think that is what we have been seeking from the very beginning of the discussion. One of the difficulties in the use of these standards is that they are not immediately applicable but require certain calculations in order to be adapted to circumstances. Of course, the use of tracers for short periods will continue to require authorization. In other words, we do not ask that any private company, for instance, should be allowed to use bromine-82 to locate a leak without authorization. The authorization will remain necessary, and it will be up to the competent authorities to calculate the dose in roentgen (not in roentgen per hour) for a particular locality. This naturally means extra work for the safety OBSTACLES TO AN INCREASED USE OF RADIOISOTOPES 535 services, and in France, at least, serious difficulties arise. These services are not sufficiently well staffed. Some of the most delicate problems are not solved, and as a result the authorization is postponed for months on end. This problem may be widespread, and I think it should perhaps be regarded as another obstacle to the use of isotopes. One does not like to increase the number of controllers or the number of civil servants, but it is precisely because they are in short supply that this difficulty has arisen. L. G. ERWALL (Chairman): Thank you. I cannot formulate any specific recommendation to the Agency on this point; but no doubt the Secretariat representatives have grasped what is at issue and will do all they can, in this connection too, to promote radioisotope applications in industry. H. SELIG MAN: The Agency can of course make some calculations by way of example, to show the national authorities how they should proceed. I think we cannot do more. When our booklet Safe Handling of Radioisotopes is revised we shall try to take into account everything that has been said here today. A. C. CASTAGNET: The seriousness of these obstacles varies according to the technical and economic development of a country, and it is precisely in developing countries like Argentina where they acquire the greatest importance. The difficulties can be divided into two major groups. First, there are problems relating to the introduction of new applications having direct interest to industry and, secondly, obstacles to the promotion in industry of already existing nuclear techniques and equipment. The first category, as thus defined, is proper to the highly industrialized countries. The second, however, is the one which prevails in our case. Our expedience has shown that the main obstacle is ignorance of such applications, their advantages and the savings they can bring; ignorance on the part of administrative personnel and the practical staff of a company rather than any legal or administrative impediments. For us the most gratifying result of this survey will be its contribution to the banishing of such ignorance. I am not sure whether this is the place to suggest further ways" of filling in the gaps in our knowledge. One way, however, would be for the Agency to create or assist national or regional training courses in the use of radioisotopes in engineering and in industry. Similarly, a conference on the subject in some Latin American country would do a lot to solve the problem. The courses could be organized in those developing countries which request them, the Agency's contribution being made in the form of laboratory equipment required for studies on the industrial applications of radioisotopes, and the sending of experts to speak on specialized subjects, such as tracers in the petroleum industry, hydrology, and so forth. These courses could be used to train the professors who would be responsible for ensuring continuity of knowledge. With regard to the conference, beneficial results could be expected because such meetings offer a unique opportunity for engaging direct contacts between specialists, and for making the public aware of the technical and economic benefits that can come from the use of radioisotopes in engineering and industry. E. FOWLER: Education and information are probably among the most important needs if the uses of radioisotopes are to be promoted. This has in fact been one of our major tasks for a great many years, and I think we 536 PANEL DISCUSSION have brought every conceivable argument to bear on industrialists to convince them of the value of radioisotopes and to show them the kinds of work they can do. Even so the job is far from done. I don't think this is any indictment of the programmes we have carried out; it merely shows that the task is an enormous one which is bound to take a lot of time. There is no magic formula which will allow the job to be finished in a hurry, but there are many different kinds of education and information activities which in the long run will prove useful. R. HOURS: With regard to the education of the public, I should like to make known a suggestion which is not mine, but which I share; it was put to me by one of my colleagues. The persons most exposed to the effects of radioisotopes are factory employees. "The majority of these workers have more trust in their shop-stewards than in their bosses, as the firm's profits may be gained at the risk of the workers. " The suggestion that was made to me concerns the training of shop-stewards, who represent the staff. When these men fully understand the risks to which the staff may be exposed; when they know that these risks are calculated, and that they are calculated in such a way as to make them no greater than the normal risks encountered in one's own garden; then, I think, one of the major obstacles to the use of radioisotopes, and one of the major sources of fear in the public mind, will be removed. I. DRAGANIC: I should like to pursue the discussion started by Mr. Castagnet and taken up by Mr. Fowler. However, I will go a bit further than they did and suggest even more work for the Agency. I do not know whether Mr. Seligman would agree with me when I say that a country such as my own is more likely to obtain technical assistance or co-operation in the building of a reactor or nuclear power station than in the application of tracers, but I think that the facts will bear me out. To some extent one can understand why this is so. Those who have developed new techniques are often reluctant to divulge their secrets. Furthermore, operations with radionuclides are not nearly so spectacular as nuclear reactors or power stations, and are therefore unlikely to command the same measure of political support. Co-operation in training programmes and courses is an excellent beginning, but it is not enough. If we are to overcome the obstacles that have been discussed here, and particularly the problems I mentioned a moment ago, the Agency must be prepared to do more. It must assist in organizing and carrying out co-operative isotope projects; projects in which interested countries can actively participate, from which they can learn and eventually develop their own human and physical resources. Such projects, along with training programmes and courses, would serve as a real spur to the use of radioisotopes. Thus, if we want the work of this Study Group Meeting to be of real assistance in promoting the industrial applications of radioisotopes, we should not delude ourselves into thinking that the bare documents presented here are sufficient in themselves. H. SELIGMAN: Joint projects in the applications of radioisotopes are rather difficult, although we have established successful relations in certain fields — in hydrology, for example, with our French colleagues. Thus there has been some collaboration in novel applications of isotopes, and the results of this work are being made available to all other States so that all can bene- OBSTACLES TO AN INCREASED USE OF RADIOISOTOPES 537 fit from them. I do not think we can go much further than that. Projects involve working in the field or in the laboratory; you can, of course, send your people to one of the laboratories where such work is done, say atSaclay or Wantage, and in that way you learn what is happening there. Similarly you can join in field experiments; we always welcome people who want to join us in the field. I do not see what more we can do. S. MARGOLINAS: All the obstacles we have heard mentioned — whether legal, psychological, or having to do with problems of insurance or international assistance — seem to have certain things in common. For one thing, the uses of isotopes seem to suffer everywhere from the incubus of distrust associated with nuclear energy in general and the bomb in particular. Un- educated public opinion fails to distinguish them as something relatively harm- less. Secondly — and perhaps this is inevitable — radioisotopes are considered by international bodies, and even by national bodies, as poor relations, because the investment they require is so much lower than that demanded by nuclear power or nuclear energy as a whole. These facts lurk behind all the obstacles we meet. Perhaps a greater effort should be made, from the psychological point of view, to separate isotopes from the rest of nuclear energy. This, again, is a question of educating the public and planning international co-operation. L. G. ERWALL (Chairman): Thank you, I think that is a very good point. I do not think there is any need to summarize what has been said. Quite a few suggestions have been made to the Agency, and of course we hope that the Agency will find it possible to act in accordance with them. I would like to thank you, Mr. Deputy Director General, members of the Agency, the Panel, and all our fellow members of the Study Group for your very active co-operation in this discussion. I doubt whether we have solved any real problems, but a good many ideas have been put forward and it is to be hoped that they will prove fruitful.

RESULTS OF AND CONCLUSIONS FROM THE SURVEY

In this volume, the results of the International Survey on the Use of Radioisotopes in Industry have been presented first country by country, then technique by technique. It remains to assess the results, to view their reliability, to compare the stage of radioisotope development in the various participating countries and to discuss whether the efforts made by the Inter- national Atomic Energy Agency and the national bodies were worthwhile and what implications the results of the survey may have on future development in the industrial radioisotope field.

RESULTS OF THE SURVEY

Table I shows the global savings from the industrial use of radioisotopes in the early 1960's estimated from the survey. In order to get any picture at all, it was necessary to take the data as they came, which means that, in some instances, the figures concern 1961, in others 1962, and in a few cases even 1963. However, the rate of development in the field is moderate so, in view of the margins of uncertainty given in Table I, it can be said that the influence from the time factor should be small. As far as gauging is concerned, the figures in the Table should be reliable. The distance between the low and high estimates does not reflect a high uncertainty in the primary values, but depends more on the method used in scaling up the primary results to national and global levels. One must bear in mind that the proportion of companies who submitted useful data was never very high; hence, it is hard to tell whether the group is a true sample or if it is biased in any way. For radiography the figures are somewhat less reliable, because fewer countries submitted useful information. Hence, the gap between the high and low estimate is greater than that for gauging. For ionization applications it was found that the economic importance was low. The estimate of the total savings is uncertain but, on the other hand, it will not seriously affect the final results of the survey. The industrial applications of tracer methods were the most difficult to assess, as economic information on this technique was very limited. While the figures for the United States of America and the Soviet Union were accepted directly, it was not possible to establish anything but an absolute minimum figure for the rest of the participating countries. For estimating the higher value a figure of four times the low level was chosen. Massive irradiation and miscellaneous applications had so far not created any savings of a comparable magnitude. However, it is quite clear that in both fields considerable economic results will come in the future. With these explanatory remarks, the global savings from the industrial applications of radioisotopes in the early 1960's can be presented as US $296-400 million/yr. At this stage, it is necessary to ask how reliable are the results of the survey. As will be shown below, the response rate to questions varied very

541 542 CONCLUSIONS FROM THE SURVEY

TABLE I GLOBAL SAVINGS FROM RADIOISOTOPE USE ($ million)

24 countries USA USSR Total (1961-63) (1963) (1961)

Gauging 26.7 - 43.4 35.2 - 50.4 100+ 162 - 194 Radiography 12.1 - 28.9 4.0 - 7.6 22 38 - 58 lonization 1-2 -* -* 1 - 2 Tracing ~10 - 40 27 - 48° 58+ 95 - 146 Massive irradiation - - - -

Total ~49 - 104 66 - 106 180 296 - 400

* Included in other groups 0 Includes also certain gauging and ionization applications + The exact distribution of savings in gauging and tracing is not known.

much from country to country. It also differed from one technique to another. In general, it can be said that it was best for gauging, medium for radiography, and rather low for the other techniques. However, where savings were given, they were correlated surprisingly well from one country to another. As already elaborated in the economic summaries, the deviations could be explained by such factors as plant size and degree of automation. It must be stressed here that the definition of a saving was very narrow and, in fact, the actual benefits to industry are considerably higher than the figures reported. One explanation for this is that the scaling-up operations performed by the national bodies or the Agency Secretariat included those which claimed that no savings or benefits existed. We know that these statements were often much too pessimistic. Also, cases where firms stated that savings existed, but the value could not be estimated, were frequently treated as if there were no savings when the national summaries were prepared. It is also possible that individuals were too enthusiastic, and thereby over-estimated the importance of radioisotope applications. However, knowing the attitude to surveys of this kind, one can be sure that the number of under-estimates far exceeds the over-estimates. Therefore, results are, for certain, low by an unknown factor. Detailed studies of the primary material for the national reports might reveal its magnitude; from the Agency's viewpoint it is completely impossible to assess even its order. In conclusion, it can be said that all evidence points to the amount of global savings being correct, and that these net savings can be used as a basis for estimating the total savings. CONCLUSIONS FROM THE SURVEY 543

If a more complete response had been obtained, it should have been possible to evaluate in detail the reported savings and compare the national differences in terms of savings. However, the response rate was low as shown in Table II which gives data on isotope-assisted output, costs and savings. TABLE II

RESPONSE TO QUESTIONNAIRE

Response to questionnaire (%) Total number Country of users Output Costs Savings

Argentina 44 - 90 5 Australia 57 ~100 ~100 ~100 Austria 34 - ~100 40. Belgium 75 - - - Canada 473 - - Czechoslovakia 85 - - - Denmark 50 - - - Finland 47 ~100 ~100 ~100 France 656 - -• - Germany, Federal Republic of 768 15 29 11 Japan 212 - 24 24 Netherlands 93 - - 59 Norway 74 43 51 19 Poland 166 - - - Portugal 13 - - - South Africa 56 27 50 18 Spain 37 16 16 11 Sweden 175 - 25 10 United Kingdom 721 75 88 31 United States of America 664 - 89 79 Yugoslavia 89 - -

Details for output were available from 7 countries. Average response 55%. Details for costs were available from 12 countries. Average response 80%. Details for savings were available from 13 countries. Average response 35%. 544 CONCLUSIONS FROM THE SURVEY

Of the 25 participating countries, 21 reported the actual number of users and this can be used for calculating response rates. Seven provided output details of replying-firms - the response rate ranged from 15% to around 100%. Twelve national reports permitted calculations of response rate on costs and thirteen on savings. In these cases the rates ranged from 16% to 100% and 5% to 100%. Those with 100% response rate were few and were obtained only by extremely laborious follow-up actions; in some of the cases the data on output and costs were calculated by the national bodies using sources of information other than the responding firms themselves. Hence, the international comparison can only be made in terms of the number of installations per thousand million dollars of industrial output. In Table III this comparison is made for gauging and radiography: for these two techniques sufficient economic details were provided in the national reports.

Gauging

In gauging a comparison can be made for 20 countries. The highest figure is reported from Canada with 112 gauges per 1 000 million dollars. It is followed by Sweden with 89, and by Denmark, Netherlands and the United Kingdom, each with around 60. Somewhat lower figures, around 40 to 55, are given by the Federal Republic of Germany, the United States of America, Norway, France, South Africa and Finland. For Belgium 30 gauges per thousand million dollars were reported. A considerable number of countries - Poland, Australia, Argentina, Yugoslavia and Japan - has around 20 gauges per thousand million dollars of industrial production. The lowest figures were reported by Spain (13), Austria (11) and Portugal (8). The variation can be interpreted in two ways: either it shows that the industrial structure varies considerably from country to country or the attitude to the introduction of radioisotope gauges differs. To give a true picture both interpretations should probably be combined. It is obvious that certain categories of industry (such as paper and plastics) are better suited to the introduction of thickness gauges than others. Hence, certain countries that are advanced in the paper trade, for example, would be expected to report a high number of thickness gauges which would affect the totals. If the percentage of paper thickness gauges is calculated it is also found that in Finland and Norway, for instance, these gauges pre- dominate (45% and 57% of all gauges, respectively), A rather high figure was also reported from Sweden (29%), but similar values were reported from other countries that do not produce paper to the same extent as the Scandi- navian countries: Austria had 47% of its gauges for controlling paper thickness, Belgium 29%, Denmark 32% and Portugal 42%. On the other hand, in Canada only 12% of the installed gauges were for paper thickness measuring. Another type of gauge that varies considerally in number from country to country is - as was pointed out earlier - the cigarette density gauge, most frequently found in Canada, the United Kingdom and USA. Exact figures are lacking for the USA, but in the other two they represented 37% and 44%, of the total number, respectively. As these installations are of a very special type and their economic importance is due to local factors such as taxation TABLE III

COMPARISON OF THE USE OF GAUGING AND RADIOGRAPHY IN VARIOUS COUNTRIES

Gauges Radiography Country Industrial production Number per Number Number per (million US $) Number of thousand of thousand devices million US $ sources million US $ n ni Argentina 1760 33 19 27 15 Australia 6000 125 21 50 8 Austria 3100 34 11 30 10 Belgium 4600 144 30 51 11 Canada 12400 1394 112 145 11 Czechoslovakia not available 115 - 168 - 8 Denmark 2600 174 67 21 8 Finland 1800 69 38 8 4 France 30800 1465 47 500 16 Germany, Federal Republic of 36400 2000 55 300 8 Japan 18600 341 16 170 9 Netherlands 4700 304 64 135 28 Norway 1700 84 48 16 9 Poland 9800 219 22 80 8 Portugal 950 ' 8 8 10 10 South Africa 2700 113 42 48 18 Spain 3100 41 13 17 5 Sweden 5400 480 89 80 15 United Kingdom 32000 2037 64 706 22 United States of America 157 000 8000 51 not available - Yugoslavia 2200 41 19 124 56 546 CONCLUSIONS FROM THE SURVEY

rules, one should not use them as a measure of the general level of gauging applications. Therefore, if cigarette density gauges are deducted from total numbers, these two countries will drop to 75 and 36 gauges per thousand million dollars value of industrial production. Also, three other countries that have a considerable number of installations in the tobacco industry, namely Denmark, Netherlands and South Africa, drop their comparative figures to 39, 52 and 20, respectively. For other countries the decrease is less considerable. In general, it would be expected that countries with advanced industrial operation in large plants would show a higher number of gauging installations than other countries. Small-scale industries do not offer the same opportunities for mechanizing and installing expensive instruments as do large units. There is, however, also an upper limit. Many gauging installations may control a varying production without a change in the number of devices and cost. Hence, the number of gauges per unit of production value would tend to decrease with increasing unit size. The relatively low number of gauges in US industry can partly be interpreted to that effect. After deducting cigarette density gauges and correcting for an unusually high proportion of paper thickness gauges, two general groups of countries are found - one with 40-60 gauges per thousand million dollars of production value and one with 10-20 gauges. The first group is headed by Canada and Sweden and includes the Federal Republic of Germany, Netherlands, France and Denmark. The United States of America, Finland and Norway also belong to this group in view of the importance of the paper industry in these countries. To the second group belong Argentina, Austria, Australia, Belgium, Japan, Poland, Portugal, South Africa, Spain and Yugoslavia. It is interesting to note that some of these countries also report a low industrial output per capita. The remainder must, however, be interpreted to the effect that their industry is more reluctant than that of other countries to instal radioisotope gauges. Hence, it is obvious that a considerable increase could be attained both in the number of gauges and in the savings from radioisotope usage. It is likely that the installation of gauges has not reached saturation point in the other countries either. The considerable variation in the number of level or density gauges indicates room for expansion in the use of well- established techniques. Also, by the fact that, for example, innovations were made in logging and in component-analysis, an increase in the number of installation can be anticipated in the future.

Radiography

Table III also contains the results from the enquiry about the number of gamma radiography sources used industrially, relating them to the industrial output of various countries. The order of countries is quite different from that found for gauging. In most of the countries for which useful information was available, there were 8 to 12 gamma radiography sources" per 1000 million dollars of industrial output. Finland and Spain showed a distinctly lower number, while a few other countries had a somewhat higher proportion than the average, 547 ranging from 15 to 22 sources per 1000 million dollars output. This latter group includes the United Kingdom, South Africa, France, Argentina and Sweden. Netherlands with 28 and Yugoslavia with 56 gamma radiography sources were well ahead of the others in the number of sources. Although exact information on the Czechoslovak industrial output is not available, there is no doubt that the relative number of gamma radiography sources is also very high. The most striking fact is that so many countries with a highly varying degree of industrialization show an almost identical extent of gamma radiography work, insofar as the number of sources is a measure of the activity. This is probably because the metal and machinery sector in all countries represent a very considerable proportion of the total output, and the requirements of final product testing are about the same in all countries. A complete survey should also have attempted to obtain further data on the importance of radiography, such as the number of films exposed each year, and the efficiency in the application of existing sources. Also, the extent of the application of other non-destructive testing methods should have been assessed. However, the similarity in the number of sources in various countries underlines the theory that gamma radiography has now almost reached its maturity. In those countries, such as Netherlands, the United Kingdom, South Africa and Sweden, where a higher proportion than the average is reported, the credit can be given to servicing organizations that operate testing services and extend gamma radiography services to firms which would normally not have considered the application of this technique. The anomaly of Yugoslavia is very interesting. The Yugoslav report stresses several times the importance of gamma radiography sources because external power supply is not needed. Hence, it is very likely that the high figure is partly explained by a favouring of gamma sources at the expense of X-rays.

Other techniques

The results obtained for the remaining four techniques as distinguished in the questionnaire are less suited for an international comparison. In ionization and the miscellaneous techniques the approach differed so much from country to country that a meaningful comparison is impossible. Massive irradiation, on the other hand, was so recently introduced into industrial practice that the available information was too limited. Concerning industrial tracing, it was possible to extract certain useful data from the national reports. However, the mere mention of the number of users in research or process control might be misleading, as the majority of tracer experiments in some countries are,in fact, not performed by the staff of the firms concerned, but by specialized organizations. The number of firms listed in the national reports may or may not include such cases. Also, the figures on the number of experiments performed annually given in some national reports is a doubtful measure for international comparison as the definition of an experiment does not imply whether a series of experiments performed in the same plant should be called one or several experiments. 548

It is obvious that the proportions of tracer experiments vary between the countries contributing to the survey. Most obstacles to a widespread application of radioisotope techniques, raised at the Panel Discussion at the Study Group Meeting on Radioisotope Economics, were applied to the use of tracers. There is evidence that tracer work could be multiplied in all countries if these obstacles were removed and more efforts were made to adapt these techniques to each country's industry. Some national reports can be taken as excellent studies on the variety of tracer applications that can be applied in one country - extremely good examples are the Danish and the United Kingdom reports. The results reported for tracing in this volume should therefore inspire all national authorities to devote more interest to this field. It is very likely that in the future the most rapid increase in savings will come from the use of tracers. Whilst gamma radiography has already reached a point where one can talk about saturation, and the rate of introduction of new gauging devices depends on the developing and marketing of new ideas, or extending the introduction of existing devices to a decreasing number of factories in each type of industry, the development of the adaption of new tracer techniques is limited only by the industrial processes themselves. It is common knowledge also that in those countries with a good reputation for extensive tracer use the proportion of firms that apply these techniques is still very low.

CONCLUSIONS

The implementation of the International Survey was complicated, particularly on the national level where the responsible bodies had to prepare the approach to industry, to evaluate the results obtained and to present the material to the International Atomic Energy Agency. Bearing in mind the often limited resources placed at the disposal of national organizations, the results obtained were in many respects spectacular and extremely well evaluated. When the first national reports reached the Agency it was obvious that they contained so much detailed information that they warranted the decision to reproduce and present in the Agency's summary report as much as possible of the original material. Hence, the Agency's evaluation of the original material was not exhaustive, but every reader wishing to study a particular aspect on industrial radioisotope'work should be able to find the basic material himself. The technical and economic summaries presented here stress only those aspects which were found most important by the responsible authors. The results of the survey will be most useful for the Agency's forth- coming activities in promoting the industrial applications of radioisotopes, particularly in developing countries. However, the international approach should be most valuable to the participating countries themselves. Those national bodies who took their task seriously and penetrated the problems concerned with industrial radioisotope applications can, by studying the results of the efforts of other countries and the international comparison, indicate the shortcomings of CONCLUSIONS FROM THE SURVEY . 549 their own industry to enlist national support for the dissemination of these methods. The Agency believes that the economic results of the survey, although incomplete, will be a strong argument in favour of increasing interest in this important means obtaining rapid returns from atomic energy. In presenting the results of the survey to the international public, the International Atomic Energy Agency wishes again to express its gratitude to the Governments of the participating countries, to the bodies responsible for the national surveys, and to the various experts who placed their experience and skill at its disposal.

VII

APPENDICES

APPENDIX I QUESTIONNAIRE DOC. No. 62-36/4 CONFIDENTIAL

INTERNATIONAL SURVEY ON THE USE OF RADIOISOTOPES IN INDUSTRY

Company's name and address of the establishment where the isotopes are used :

Please complete a separate questionnaire for each broad product group in the processing of which isotopes were used in 1961.

Name of broad product group:

P ART 11 Manufacturing sayings

1. (i) Total value of output in 1961 (ii) Value of isotope assisted output 1961

2. In what year did you first use radioisotopes in processing the product group mentioned ?

3. What was the cost (or if not available, the present book value) of all isotopes and related equipment and facilities at present in use ? (i) cost of isotopes (ii) cost of isotope equipment (such as gauges, counters, etc.) (iii) cost of health physics equipment (iv) cost of structures especially required for radioisotope use, including installation costs • (v) other

4. What was the cost of all isotopes and related equipment and facilities you installed or acquired in 1961 ?

5. What was the yearly cost of the maintenance of your isotope equipment in 1961, including health precautions (depreciations not included) ?

6. Show by ticks in appropriate boxes where cost savings have been achieved by radioisotope techniques. If possible, also give approximate amount of annual cost savings. *

(i) raw material CU (ii) product scrap d] (iii) labour CD (iv) other, including savings from lower capital costs or maintenance or increased productivity in general I I

* If costs have increased, show amount of increase, in brackets. If you can only give a total figure of savings, please indicate how this has been derived (e.g. as percentage of turnover). If you cannot give cost figures, kindly indicate the magnitude in terms such as tons of scrap, man-hours, etc. (Please use back page if necessary).

553 554

PART II : Cheek list of radio!sotop« techniques and benefits

Please indicate by ticks in the appropriate boxes the techniques yon employ, and the ways in which they are superior to previous methods.

TECHNIQUES BENEFITS (show cost savings in Part I, Item 6)

A. Radioisotope gauging

Thickness ..... Q] Density Product of better quality Level ...... | | Component analysis Closer control within tolerances Other, please specify: Saving of raw material | | Reduction of rejects Q^) Saving of scrap [__] The gauging is applied to : Saving of labour Is the use regular Others, please specify: occasional exceptional Sources: number, strength and nuciide:

B. Industrial radiography

Inspection of welds.... d]> castings Better control of raw materials f~l

materials to be machined Better control of products [~~1 Other, please specify : Reduced time for inspection Others, please specify: Is the use regular occasional exceptional Sources : number, strength and nuciide :

C. lonization applications

Static eliminators ...... Increased speed of production lonization sources in electron tubes, etc. . . . Reduced product scrap Other, please specify: - Reduced fire hazard

Others, please specify: Is the use regular ...... Q occasional ...... |_ _ ] exceptional ...... | | Sources : number, strength and nuciide : _ QUESTIONNAIRE 555

TECHNIQUES BENEFITS (show cost savings in Part I, item 6)

D. Radioactive tracers in research process and product control . n . n .... r— i . n r— i • en [n

Is the use regular • CD • CD Sources: rjnrlidps

E. Massive irradiation

Sterilization of medical and pharmaceutical Please state benefi ts : supplies CD Sterilization of foods CD Promotion of chemical reactions CD

Other, please specify :

Is the use regular CD occasional CD exceptional I I

Sources : number, strength and nuclide :

F. Miscellaneous applications

Luminescence CD Atomic batteries |~~| Please state benefits : Other, please specify:

Is the use regular CD occasional CD exceptional CD 556 APPENDIX I

PARTIE III. Description détaillée des expériences faites au moyen de radioisotopes Pour permettre la présentation de quelques exemples détaillés des avantages apportés par l'utilisation des radioisotopes, nous vous serions reconnaissants de bien vouloir décrire ci-dessous, plus en détail, les expériences que vous avez effectuées. Nous aimerions notamment savoir si les radioisotopes vous ont permis d'effectuer une opération qu'il n' aurait pas été possible de faire par une autre méthode.

PARTIE IV: Observations générales et renseignements complémentaires

Nom et fonctions de la personne Signature Date ayant rempli le questionnaire ^*g»uu«ic QUESTIONNAIRE 557

DOC. No. 62-36/5

CONFIDENTIEL

ENQUETE INTERNATIONALE SUR L'EMPLOI DES RADIOISOTOPES DANS L'INDUSTRIE

Nom de l'entreprise et adresse de l'établissement qui emploie les radioisotopes :

Prière de remplir un questionnaire distinct pour chaque catégorie de produits dans la fabrication desquels les radioisotopes étaient utilisés en 1961.

Catégorie de produits:

PARTIE I: Economies réalisées dans la fabrication

ii. Valeur de la production dans laquelle les radioisotopes étaient utilisés ..

2. En quelle année avez-vous utilisé pour la première fois les radioisotopes pour la production considérée ?

3. Quel a été le prix d'achat de tous les radioisotopes, appareillage et équipement s'y rapportant actuellement en service (ou, à défaut, leur présente valeur d'inventaire)

iv. Coût des ouvrages spécialement conçus pour l'utilisation des radioisotopes,

4. Quel a été le prix total des radioisotopes et de l'équipement correspondant acquis ou installé en 1961 ?

5. Quel a été le coût de l'entretien de l'équipement correspondant à l'utilisation des radioisotopes en 1961, y compris le coût des mesures de radioprotection (non compris l'amortissement) ?

6. Cocher la ou les cases correspondant aux économies réalisées au moyen des radioisotopes. Donner si possible le montant approximatif des économies réa- lisées dans l'année*

Matières premières CZÎ Déchets de fabrication C3] Main-d'œuvre CD iv. Divers, y compris l'abaissement du coût des investissements ou des frais d'entretien, ou l'augmentation de la productivité en général ...... F^

Si les coûts ont augmenté, indiquer le montant de l'augmentation entre crochets. Si vous ne pouvez donner que le total des économies, prière d'indiquer comment ce chiffre a été obtenu (par exemple, en pourcentage du chiffre d'affaires). Si aucun chiffre ne peut être donné, indiquer un ordre de grandeur en quantité de ma- tière (tonnes de déchets, etc.). (Au besoin, utiliser la page 5). 558 APPENDIX I

PARTIE II: Liste des techniques utilisées et des avantages obtenus

Prière de cocher les cases correspondant aux techniques que vous employez et aux avantages qu'elles ont montrés par rapport aux méthodes utilisées auparavant.

TECHNIQUES AUAKITAC-CC (indiquer les économies réalisées AVANTAGES danj s^ il a partie l,i paragraphi e ^o)\

A. Mesures faites au moyen de radioisotopes

Epaisseur Q, Densité Meilleure qualité du produit Q^) Niveau Q^l» Analyse qualitative Contrôle plus strict pour la précision demandée QH Autres (spécifier) Economie de matières premières [^ Diminution du nombre des rebuts Q] Economie de déchets [H Economie de main-d'œuvre | ] L'emploi est-il régulier Autres (spécifier) occasionnel exceptionnel

Sources: nombre, intensité et nucléide:.

EL Gammagraphie

Contrôle des soudures Meilleur contrôle des matières premières des coulées QD> pièces à usiner. Meilleur contrôle des produits Autres (spécifier) Diminution de la durée d'inspection Autres (spécifier)

L'emploi est-il régulier occasionnel exceptionnel

Sources : nombre, intensité et nucléide : -

C. Ionisation

Eliminateurs statiques Q^> sources ionisantes Accroissement du rythme de production dans les tubes électroniques, etc C3 Diminution des déchets Autres (spécifier) Réduction du danger d'incendie Autres (spécifier) L'emploi est-il régulier Q3 occasionnel Q3 exceptionnel C3

Sources: nombre, intensité et nucléide: QUESTIONNAIRE 559

Aw«ki-rAi-c:c (indiquer les économies réalisées TECHNIQUES AVANTAGES d(mg ja part;e ^ paragrapne 6)

D. Traceurs radioactifs dans la conduite et le contrôle de la fabrication

Etudes d'usure et de corrosion ...... CD Meilleure connaissance des procédés CD Etudes de débit et de localisation ...... CD Meilleur contrôle des opérations CD Détection des fuites ...... CD Meilleur contrôle des produits fabriqués CD Etudes des réactions chimiques ...... CD Réduction des frais d'analyse CD Analyse chimique ...... CD Meilleur rendement de l'installation CD

Autres (spécifier). Autres (spécifier)

L'emploi est-il régulier ...... CD occasionnel ...... [_ _ | exceptionnel ...... CD

Sources : nucléide _

E. Irradiations massives

Stérilisation de fournitures médicales et Prière d'indiquer les avantages : pharmaceutiques CD Stérilisation des produits alimentaires .... CD Chimie sous rayonnement CD

Autres (spécifier)

L'emploi est-il régulier CD occasionnel CD exceptionnel CD

Sources : nombre, intensité et nucléide :

F. Applications diverses

Luminescence.... CD Piles CD Prière d'indiquer les avantages : Autres (spécifier)

L'emploi est-il régulier CD occasionnel [ | exceptionnel CD 560

PART III: Further detailed description of exp«rlenee with radioltotope* In order to make possible presentation of some detailed case examples of how radioisotopes have been of benefit, we would appreciate any more detailed description of your experience you would care to present below. For example we would be interested to know whether radioisotopes have enabled you to do something not possible before.

PART IV: General comments and additional information

Name and title of official Signature Date 561

DOC. No. 62-36/7

Конфиденциально

МЕЖДУНАРОДНОЕ ОБСЛЕДОВАНИЕ ИСПОЛЬЗОВАНИЯ РАДИОИЗОТОПОВ В ПРОМЫШЛЕННОСТИ

Наименование компании и адрес учреждения, где используются изотопы:

Заполните, пожалуйста, отдельный вопросник по каждой основной группе продукции, в производстве которой были использованы изотопы в 1961 году.

Наименование основной группы продукции

ЧАСТЬ I : Производственная экономия

1. i. Общая стоимость продукции в 1961 году ii. Стоимость продукции, изготовленной в 1961 году при помоши изотопов

2. В каком году впервые использовались радиоизотопы в производстве продук- ции по указанной группе ?

3. Какова стоимость (за неимением укажите стоимость по книгам в настоящее время) всех изотопов и связанного с ними оборудования и технических средств, находящихся в настоящее время в использовании ? i. Стоимость изотопов ii. Стоимость изотопного оборудования (такого, как контрольно-измери- тельные приборы, счетчики и т.д.) Hi. Стоимость оборудования по радиационной безопасности iv. Стоимость устройств, специально предназначенных для использования радиоизотопов, и стоимость рабочей силы на установке v. Прочая стоимость

4. Какова стоимость всех изотопов и связанного с ними оборудования и тех- нических средств, которые вы установили или приобрели в 1961 году?

5. Каковы годовые эксплуатационные расходы на ваше изотопное оборудова- ние в 1961 году, включая меры по охране труда (без амортизационных расходов)

6. Отметьте значком "V" в соответствующих клетках, где была получена экономия средств благодаря применению радиоизотопных методов, Если можно, укажите примерную сумму ежегодной экономии средств:* i. Сырье Г~1 ii. Производственные отходы Г~1 ш. Рабочая сила Г~1 iv. Прочее, включая экономию в результате снижения капитальных затрат или экслуата - ционных расходов или увеличения производительности вообще Cj

* Если затраты увеличились, укажите в скобках сумму увеличения. Если вы можете привести только общую сумму экономии, то укажите, пожалуйста, каким образом она получена (например, в проценте с оборота). Если вы не можете привести цифр, то укажите, пожалуйста, размер увеличения техни- ческих цифр (тонны производственных отходов и т.д. ) При необходимости можно использовать обратную сторону страницы). 562

ЧАСТЬ II: Контрольный перечень радиоизотопных методов и получаемых выгод

Отметьте, пожалуйста, значком " V " в соответствующих клетках применяемые вами методы и укажите, почему они являются лучшими по сравнению с предыдущими методами.

МЕТОДЫ ПОЛУЧАЕМЫЕ ВЫГОДЫ (укажите экономию средств в Части I, пункт 6)

А. Измерение радиоизотопным методом

Толщины | I Плотности | | Продукция лучшего качества Уровня |~1 Компонентного анализа [~~] Более доступный контроль в пределах Укажите прочее допустимых отклонений Экономия сырья ...... |~1 Снижение брака ...... [~~| Измерение радиоизотопным методом приме- Уменьшение производственных отходов ...... | | няется к: Каково использование: Экономия рабочей силы ...... [~~] постоянное | ! Укажите прочее :_ _ в редких случаях £П в исключительных случаях [ | Источники: количество, мощность и изотоп: _

В. Промышленная радиография Технический контроль сварки | | Лучший контроль сырья Г~| Литья I I Предназначенных для меха- Лучший контроль продукции О нической обработки материалов Q Снижение времени на технический контроль .. .| | Укажите прочее Укажите прочее:

Каково использование: постоянное | | в редких случаях I I в исключительных случаях I I Источники: количество, мощность и изотоп:_

С. Применение ионизации Статические элиминаторы [П Увеличена ли скорость производства Г~1 Ионизационные источники в электронных Уменьшились ли производственные отходы Ц трубках и т.д СИ Уменьшилась ли опасность возникновения Укажите прочее пожара Г~1 Укажите прочее Каково использование: постоянное Г~1 в редких случаях О в исключительных случаях О Источники: количество, мошность и изотоп: _ 563

МЕТОДЫ ПОЛУЧАЕМЫЕ ВЫГОДЫ (укажите-экономию средств в Части I, пункт 6)

D. Радиоизотопные индикаторы в исследованиях, при контроле за производственным процессом или за продукцией Исследование износа и коррозии Q Более ясное понятие процессов Q Изучение производственного процесса Г~| Лучший контроль за производственным процессом Г~| Обнаружение течи I I Лучший контроль продукции О Исследование химических реакций О Более низкая стоимость анализа Г~1 Химический анализ I I Лучшая производительность установки О Укажите прочее Укажите прочее

Каково использование: постоянное Г~1 в редких случаях |~~1 в исключительных случаях О Источники: количество, мощность и изотоп: _

Е. Мощное облучение

Стерилизация медицинских и фармацевти- Укажите, пожалуйста, выгоды ческих материалов ...... I I Стерелизация пищевых продуктов ...... О Стимулирование химических реакций ..... О

Укажите прочее _

Каково использование : постоянное ...... f~] в редких случаях ...... ( | в исключительных случаях ...... | | Источники : количество, мощность и изотоп : .

F. Прочие виды применения

Люминесценция £2 Атомные батареи | I Укажите, пожалуйста, выгоды

Укажите прочее

Каково использование: постоянное О в редких случаях Г~1 в исключительных случаях I I 564

ЧАСТЬ III : Дальнейшее подробное описание опытов с радиоизотопами Для возможного представления более подробных примеров в отношении того, какую выгоду дает применение радиоизотопов, мы были бы признательны за подробное описание вашего опыта, который вы пожелаете привести ниже. Например, нас интересует, удалось ли вам сделать с помошыо радиоизотопов то, что ранее казалось невозможным.

ЧАСТЬ IV: Обшие замечания и дополнительная информация

nodnucT> Homo, 565

DOC. No. 62-36/6

CONFIDENCIAL

ENCUESTA INTERNACIONAL SOBRE EL EMPLEO DE RADIOISÓTOPOS EN LA INDUSTRIA

Nombre de la empresa y dirección del establecimiento en que se emplean los radioisótopos :

Rellénese un cuestionario distinto para cada grupo de productos en cuya fabricación se utilizaron radioisóto- pos en 1961.

Grupo de productos:,

PARTE I: Economías conseguidas en la fabricación

1. i. Valor total de la producción en 1961 ii. Valor de la producción en la que se emplearon radioisótopos

2. ¿En qué año se emplearon por vez primera radioisótopos en la fabricación de los productos del grupo indicado ?

3. Indíquese el costo de todos los radioisótopos, así como del equipo y medios auxiliares actualmente en servicio (de no conocerse, indíquese el valor actual en cuenta): i. Costo de los radioisótopos ii. Costo del equipo para empleo de los radioisótopos (por ejemplo, calibradores, contadores, etc.) iii. Costo del equipo de protección radiológica iv. Costo de las estructuras construidas especialmente para el empleo de los radioisótopos y de la mano de obra utilizada en la instalación v. Otros conceptos

4. ¿Cuál fue el costo total de los radioisótopos y del equipo y medios auxiliares adquiridos o instalados en 1961 ?

5. ¿Cuáles fueron los gastos anuales de conservación del equipo para empleo de radioisótopos en 1961, incluidos los correspondientes a las medidas de protec- ción radiológica (pero excluidos los de amortización) ?

6. Indíquense, marcando las casillas correspondientes, los conceptos en que se han conseguido economías gracias a los radioisótopos. De ser posible, indí- quese también la cuantía anual aproximada de esas economías* i. Materias primas C_l ii. Desechos de fabricación CU iii. Mano de obra C_- iv. Otras economías, incluidas las derivadas de una reducción de los gastos de capital o de conservación, o de un aumento de la produc- tividad en general CU

orden de magnitud en cantidades de material (toneladas de desechos, etc.) 566

PARTE II: LUta d« las tiénteos radioisotópicas empicadas y dt las ventajas obtenidas

Marqúense las casillas correspondientes a las técnicas radioisotópicas empleadas y a las ventajas que pre- sentan en comparación con los procedimientos anteriormente utilizados.

ueuTA i AC (indíquense las economías en la sec- VENTAJAS cioVódelaPartel)

A. Mediciones realizadas con radioisótopos

De espesores ... -CD De densidades CD Mejor calidad del producto CD De niveles | | Análisis cualitativo CD Control más estricto, dentro de los márgenes de tolerancia CD Otras mediciones (especifíquense) Ahorro de materias primas [~~] Disminución del número de productos rechazados CD Economía en los desechos de fabricación CD Las mediciones se aplican a: Economía de mano de obra CD Empleo regular CD Otras ventajas (especifíquense) ocasional CU excepcional \__j Fuentes: número, intensidad y nú elido:

B. Radiografía industrial

Inspección de soldaduras CD Mejor control de las materias primas CD de piezas de fundición CD Mejor control de los productos CD de materiales que han de mecanizarse CD Disminución del tiempo de inspección CD Otras (especifíquense) Otras ventajas (especifíquense)

Empleo regular CD ocasional CD excepcional CD Fuentes: número, intensidad y núclido:

C. Aplicaciones de la ionización

Eliminadores de electricidad estática CD Aumento del ritmo de producción CD Fuentes ionizantes en tubos electrónicos, etc. CD Disminución de los desechos de fabricación.... CD Otras (especifíquense) Disminución del riesgo de incendio CD Otras ventajas (especifi'qüense)

Empleo regular CD ocasional CD excepcional CD

Fuentes.: número, intensidad y núclido: 567

UCMTA IAC (indiquense las economías en la TÉCNICAS VENTAJAS secciót' n o£ uj_e li a Dran _*o ni/

D. Empleo de indicadores radiactivos en el estudio de procesos y control de calidad

Estudios de desgaste y corrosión

Otros (especifi'qiienfle)

CD ..CD

E. Irradiación masiva

Esterilización de productos médicos y Indíquense las ventajas: farmacéuticos ...... CD Esterilización de productos alimenticios. . . . CD Fomento de reacciones químicas ...... CD

Otras (especifíquense) _

Empleo regular ...... CD ocasional ...... CD excepcional ...... CD Fuentes : número, intensidad y núclido : _

F. Aplicaciones diversas

Luminiscencia .... CD Pilas CD Indíquense las ventajas: Otras (especifi'quense)

Empleo regular CD ocasional CD excepcional CD 568

PARTE III: Descripción detallada de la experiencia adquirida en el empleo de radioisótopos A fin de poder exponer algunos ejemplos detallados de casos en los que los radioisótopos han repor- tado ventajas, les agradeceríamos que nos facilitasen a continuación una descripción más detallada de la experiencia adquirida por ustedes. Por ejemplo, sería de interés saber si los radioisótopos les han permitido efectuar operaciones que no han podido llevarse a cabo aplicando otros métodos.

PARTE IV : Observaciones generales e información complementaria

Nombre y cargo de la persona . F- i ,,-; . . rFirma recna que retleno et cuestionano APPENDIX II

LIST AND EXPLANATION OF "BROAD PRODUCT GROUPS"

Originally, the division into 12 groups was made as shown below:

Group No. 1 Food: includes manufacture of dairy products, canning and preservation of fruit, vegetables, fish and meat, manufacture of grain mill, bakery and similar products, sugar refining and beverage industries. Group No. 2 Tobacco. Group No. 3 Textiles and foot-wear. Group No. 4 Wood and paper: includes manufacture of furniture, cork, pulp, paper, paper products and fibre boards and the printing industry. Group No. 5 Leather and fur. Group No. 6 Rubber. Group No. 7 Chemicals and plastics: includes also manufacture of fertilizers, paints, varnishes and lacquers, soaps etc. Group No. 8 Cement, glass and china. Group No. 9 Petroleum and coal. Group No. 10 Basic metals: includes melting, refining, rolling, drawing, alloying and manufacture of castings. Group No. 11 Machinery: includes all metal products, electrical machinery, apparatus, appliances and supplies, transport equipment, i.e. ships, motor and railroad vehicles and aircraft; also instruments and watches. Group No. 12 Services: includes construction and building of all kinds, electricity, gas, water and sanitary services.

When it was decided to widen the scope of the Survey, the following additions were made to the list:

In Group No. 7 Mining of phosphates and other raw materials for the chemical industry. In Group No. 8 Prospecting for and mining of potassium and other clay minerals. In Group No. 9 Prospecting for coal, lignite, peat and for petroleum and shale-oil; Mining of coal etc; Recovery of crude petroleum. In Group No. 10 Prospecting for ferrous, non-ferrous and precious metals; Mining them; Treatment of their ores. Further, the following comments have been made in the instructions concerning the handling of individual cases that are not readily classified into any particular broad product group.

569 570 APPENDIX II

Group 1 (Food) concerns all applications on an industrial scale but not the primary agricultural production itself. Thus, plant breeding research with the use of massive irradiation should not be included. Neither should research concerning the effects of fertilizers be included here, nor in Group 7. The use of radioisotopes in the production of fertilizers must, however, be accounted for in the latter group. The manufacture of drugs and Pharmaceuticals should be placed into Group 7. The manufacture of stone products such as bricks or light-weight concrete should be treated under Group 8. It is obvious that the border between Groups 10 and 11 is vague in many respects, owing to the integration of industry. It will be up to the national bodies to judge how to classify each application in the most appropriate way. Such economic activities as public services by railways, aircraft etc. will logically be included under Group 12. STUDY GROUP MEETING ON RADIOISOTOPE ECONOMICS

HELD IN VIENNA FROM 16 TO 20 MARCH, 1964

CHAIRMEN OF SESSIONS

Session 1 P. PLATZEK Netherlands Sessions 2 and 3 W.J. SCHMIDT-KUESTER Federal Republic of Germany Session 4 R.J. MOFFETT Canada Session 5 R. HOURS France Session 6 E. ROTKIRCH Finland Session 7 E. SOMER Denmark Session 8 A. PRADZYNSKI Poland (Panel Discussion) L.G. ERWALL Sweden Session 9 J.L. PUTMAN United Kingdom (Panel Discussion)

SECRETARIAT OF THE MEETING

Scientific Secretary: H.G. FORSBERG Division of Research and Laboratories (IAEA)

Editor: Monica KRIPPNER Division of Scientific and Technical Information (IAEA)

Records Officer: S.A. EDMINSTER Division of Languages (IAEA)

Conference Officer: F.W. HEROLD Division of Conference and General Services (IAEA)

571 LIST OF PARTICIPANTS

Name Institution Nominating State or Organization

Cabrai, J. M. P. Laboratôrio de Fisica e Engenharia Nucleares, Portugal Estrada Nacional 10, Sacavem

Castagnet, A.C. Comision Nacional de Energfa Atomica, Argentina Avda. Libertador Gen.San Martfn 8250, Buenos Aires

Clayton, C.G. United Kingdom Atomic Energy Authority, United Kingdom Wantage Research Laboratory (A. E.R. E. ), Wantage, Berks.

Cless-Bernert, T.Mme. Österreichische Studiengesellschaft für Austria Atomenergie GmbH, Lenaugasse 10, Vienna VIII.

Cornuet, R. C.E.N., Section d'Application des Radioéléments, France B. P. No. 269, Grenoble

Czeija, K. Engineering Office, Austria Zivilingenieur für technische Chemie, Gusshausstrasse 12, Vienna IV.

Dahl, J.B. Institut! for Atomenergi, Norway P.O.B. 175, Kjeller, Lilleström

DeWitt, J.E. Industrial Nucleonics Corporation, United States of America 650 Ackerman Rd., Columbus 2, Ohio

Dolak. E. Österreichische Mineralölverwaltung A. G., Austria Otto Wagner Platz 5, Vienna K.

Dollinger, A. European Office of the United Nations, United Nations Organization Palais de Nations, Geneva

Draganić, J. Federal Nuclear Energy Commission, Yugoslavia Kosanciéev Venae 29, P. 0. B. 353, Belgrade

Hering, J. Röntgen Technische Dienst N. V., Netherlands 144, Delftweg, Rotterdam 8

El Bakoush, M.S. Ministry of Industry, Libya Dept. of Research, Tripoli

Erwall, L.G. Isotope Techniques Laboratory, Sweden Drottning Kristinas v 45, Stockholm O

572 LIST OF PARTICIPANTS 573

Name Institution Nominating State or Organization Foa, E. Israel Atomic Energy Commission, Israel P.O.B. 7056, Hakirya, Tel-Aviv

Földiák, G. Hungarian Institute of Isotopes, Hungary Konkoly Thye ut, Budapest XII.

Fowler, E.E. Div. of Isotopes Development, United States of America USAEC, Washington 25, D. C.

Franco Netto, F.B. Permanent Mission of Brazil to IAEA, Brazil Josefsplatz 5, Vienna I.

Gansberghe van, J. P. Bureau Beige des Radioisotopes, Belgium 24, Rue du Luxembourg, Bruxelles 4

Garnum, E. Pulp and Paper Section, FAO Forest Industries Branch, Food and Agriculture Organization of the United Nations, Viale délie Terme di Caracalla, Rome

Good, F.H. 4228 Via Alondra, United States of America Palos Verdes Estates, Calif.

Hours, R. C.E.N. de Saclay, France B. P. 2, Gif-sur-Yvette (S et O)

Iliescu, C. Institute of Atomic Physics, Romania Bucarest lonescu, V. Permanent Mission of Romania Romanian People's Republic to IAEA

Kawashima, Y. Embassy of Japan, Japan Neuer Markt 1, Vienna I.

Komurka, M. Czechoslovak Atomic Energy Commission, Czechoslovakia Slezika 7, Prague

Lévêque, P. C.E.A., 69, rue de Varenne, Paris 7e France

Ljunggren, K. Isotope Techniques Laboratory, Sweden Drottning Kristinas v 45, Stockholm 0

Marcinowski, H.J. Isotopen-Studiengesellschaft E. V., Federal Republic of Postf. 16445, Frankfurt/M. Germany

Margolinas, -S. Société d'Applications Industrielles France de la Physique, 38, rue Gabriel-Crié, Malakoff-Seine 574 LIST OF PARTICIPANTS

Name Institution Nominating State or Organization

Martin del Campo, A. L. C.N.E.N., Mexico Apartado Postal 27 -190, Mexico, D.F.

Maydell, J. Biuro Urzadzen Techniki Poland Jadrowej, Krakow 23

Mayer, P. Österreichische Studiengesellschaft Austria für Atomenergie GmbH., Lenaugasse 10, Vienna VIII.

McKay, G. Industrial Nucleonics Corporation, United States of America 650 Ackerman Rd., Columbus 2, Ohio

Mikaelsen, K. Atomic Energy Branch, FAO Food and Agriculture Organization of the United Nations, Viale délie Terme di Caracalla, Rome

Moffett, R.J. Atomic Energy of Canada, Ltd., Canada Commercial Products Division, P.O.B. 93, Ottawa

Muenzel, F. INRESCOR International Research Co., Switzerland Schwerzenbach (Zch)

MUhlberger, F. Federal Ministry of Trade and Reconstruction, Austria Stubenring l, Vienna I.

O'Donnell, A.J. Permanent Mission of the United States United States of America of America to IAEA, Schmidgasse 14, Vienna VIII.

Pittori, S. C.N. E.N., Via Belisario 15, Rome Italy

Platzek, P. Isotope Division, Netherlands Central Laboratory TNO, 132 Julianalaan, Postbus 71, Delft

Pradzyftski, A. Office of the Commissioner of Government Poland for Nuclear Energy, Palac Kultury i Naukí, Warsaw

Propstl, G. Euroisotope Bureau, EURATOM European Atomic Energy Community, 51 - 53 Rue Belliard, Brussels

Putman, J.L. Isotope Research Division, United Kingdom Wantage Research Laboratory (A. E. R. E.), Wantage, Berks. 575

Name Institution Nominating State or Organization

Renner, R. Federal Ministry of Trade and Reconstruction, Austria Div. of Atomic Energy Matters in Industry, Stubenring l, Vienna I. i Robin, G. L'Atome Industriel, France 2, rue des Moulins, Paris 1

RotWrch, E. EKONO, S. Esplanadgatan 14, Finland Helsinki

Rudoe, W. Statistics Division, United Kingdom Board of Trade, 1, Victoria Street, London S.W. 1

Schmidt-Kuester, W.J. Federal Ministry of Scientific Research, Federal Republic of Luisenstrasse 46, Germany Bad Godesberg

Schwarz, K. R. Konsulat der Republik Guatemala, Guatemala Siebeneichengasse 2, Vienna XV.

Shigdar, H. Directorate General of Mineral Resources, Saudi Arabia Ministry of Petroleum and Mineral Wealth, Jeddah

Somer, E. Danish Isotope Centre, Denmark 2, Skelbakgade, Copenhagen V

Stremme, W. Frieseke & Hoepfner GmbH., Federal Republic of Postf. 72, Erlangen-Bruck Germany

Stuart, D. F. O. The Social Survey, United Kingdom Central Office of Information, Atlantic House, Holborn Viaduct, London E.G. 1

Tavares, H. L. Comissao Nacional de Energia Nuclear, Brazil Av. Almirante Barroso 82, 2°and., Rio-Guanabara

Tempus, P. Eidg. Institut für Reaktorforschung, Switzerland Würenlingen

Val Cob del, D.M. Seccion de Isotopos, Spain Junta de Energfa Nuclear, Apartado 3055, Madrid 3

Van der Eist, N. C.E.N. 31, rue Belliard, Belgium Bruxelles 4 576 LIST OF PARTICIPANTS

Name Institution Nominating State or Organization

Verbiest, A.J. Netherlands Reactor Centre, Netherlands Scheveningseweg 112, The Hague TECHNICAL DIRECTORY

RADIOISOTOPE APPLICATIONS IN INDUSTRY

A classification of industries and other economic activities in which radioisotopes have proved valuable, This publication is the basis for a survey of the international literature. Within each industrial category, the various applications of radioisotopes are listed in detail and provided with selected literature references. (STI/PUB/70; 132pp., 16X 24 cm, paper-bound - US «2.50; Elsewhere 15/-stg.)

PROCEEDINGS SERIES

PRODUCTION AND USE OF SHORT-LIVED RADIOISOTOPES FROM REACTORS

The complete proceedings of the Seminar on Practical Applications of Short-lived Radioisotopes produced in Small Research Reactors, held in Vienna, November 1962.

(STI/PUB/64; Vol. I: 432 pp., 16 X 24 cm, cloth-bound - US $8.50; Elsewhere: £2.11.0 Vol. II: 274pp., 16X24 cm, cloth-bound - US $5.50; Elsewhere £1.13.0)

RADIOISOTOPES IN THE PHYSICAL SCIENCES AND INDUSTRY

Proceedings of an IAEA Conference organized with the co-operation of UNESCO in Copenhagen, 1960. The subjects discussed include geophysics, metallurgy and solid-state physics, industrial applications of tracers, industrial applications of absorption and scattering, detectors and instrumentation, production etc. (STI/PUB/20; Vol.1: 542 pp., 16 X 24 cm, cloth-bound - US $8.00; Elsewhere £2.8.0 Vol. II: 554 pp., 16 X 24 cm, cloth-bound - US $8.00; Elsewhere £2.8.0 Vol.Ill: 633 pp., 16 X 24 cm, cloth-bound - US $8.00; Elsewhere £2.8.0) IAEA SALES AGENTS

Orders for Agency publications can be placed with your bookseller or any of our sales agents listed below :

AUSTRALIA ITALY Hunter Publications, Agenzia Editoriale Internazionale 23 McKillop Street Organizzazioni Universali (A.E.I.O.U.) Melbourne, C.I Via Meravigli 16 AUSTRIA Milan Georg Fromme & Co. JAPAN Spengergasse 39 Maruzen Company Ltd. Vienna V 6, Tori Nichome BELGIUM Nihonbashi Office international de librairie (P.O. Box 605) 30, avenue Marnix Tokyo Central Brussels 5 MEXICO BRAZIL Librarla Internacional Livraria Kosmos Editora Av. Sonora 206 Rua do Rosario, 135-137 Mexico 11, D.F. Rio de Janeiro Agencia Expoente Oscar M. Silva NETHERLANDS Rua Xavier de Toledo, 140- 1° Andar N.V. Martinus Nijhoff (Caixa Postal No. 5.614) Lange Voorhout 9 Säo Paulo The Hague BYELORUSSIAN SOVIET SOCIALIST REPUBLIC NEW ZEALAND See under USSR Whitcombe & Tombs, Ltd. CANADA G.P.O. Box 1894 The Queen's Printer Wellington, C.I Ottawa, Ontario NORWAY CHINA (Taiwan) Johan Grundt Tanum Books and Scientific Supplies Service, Ltd., Karl Johans gate 43 P.O. Box 83 Oslo Taipei PAKISTAN DENMARK Karachi Education Society Ejnar Munksgaard Ltd. Haroon Chambers 6 Nörregade South Napier Road Copenhagen K (P.O. Box No. 4866) Karachi, 2 FINLAND Akateeminen Kirjakauppa POLAND Keskuskatu 2 Osrodek Rozpowszechniana Helsinki Wydawnictw Naukowych FRANCE Polska Akademia Nauk Office international de Pafac Kultury i Nauki documentation et librairie Warsaw 48, rue Gay-Lussac Paris 5e SOUTH AFRICA Van Schaik's Bookstore (Pty) Ltd. GERMANY, Federal Republic of Libri Building R. Oldenbourg Church Street Rosenheimer Strasse 145 (P.O. Box 724) 8 Munich 8 Pretoria ISRAEL SPAIN Heiliger and Co. Libreria Bosch 3 Nathan Strauss Street Ronda de la Universidad 11 Jerusalem Barcelona SWEDECDEN UNITED KINGDOM OF GREAT BRITAIN C.E. Fritzes Kungl. Hovbokhande AND NORTHERN IRELAND Fredsgatan 2 Her Majesty's Stationery Office Stockholm 16 P.O. Box 569 London, S.E.I SWITZERLAND Librairie Payot UNITED STATES OF AMERICA Rue Grenus 6 National Agency for 1211 Geneva 11 International Publications, Inc. 317 East 34th Street TURKEY New York, N.Y. 10016 Librairie Hachette 469, Istiklâl Caddesi VENEZUELA Beyoglu, Istanbul Sr. Braulio Gabriel Chacares Gobernador a Candilito 37 UKRAINIAN SOVIET SOCIALIST REPUBLIC Santa Rosalia See under USSR * (Apartado Postal 8092) Caracas D.F. UNION OF SOVIET SOCIALIST REPUBLICS YUGOSLAVIA Mezhdunarodnaya Kniga Jugoslovenska Knjiga Smolenskaya-Sennaya 32-34 Terazije 27 Moscow G-200 Belgrade

IAEA publications can also be purchased retail at the United Nations Bookshop at United Nations Headquarters, New York, at the news-stand at the Agency's Headquarters, Vienna, and at most conferences, symposia and seminars organized by the Agency. In order to facilitate the distribution of its publications, the Agency is prepared to accept payment in UNESCO coupons or in local currencies. Orders and inquiries from countries where sales agents have not yet been appointed may be sent to :

Distribution and Sales Unit, International Atomic Energy Agency, Kärntner Ring 11, Vienna I, Austria

INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 1965 PRICE: USA and Canada: US $11.50 Austria and elsewhere: S 241.50 j (£3.9.0; F.Fr. 46,-; DM 40,25)