Analytical Chemistry of Nuclear Materials Held in Vienna, 17-21 September 1962

TECHNICAL REPORTS SERIES No. 18 » Analytical Chemistry of Nuclear Materials REPORT OF THE PANEL ON ANALYTICAL CHEMISTRY OF NUCLEAR MATERIALS HELD IN VIENNA, 17-21 SEPTEMBER 1962 INTERNATIONAL ATOMIC ENERGY AGENCY - VIENNA, 1963 ANALYTICAL CHEMISTRY OF NUCLEAR MATERIALS The following States are Members of the International Atomic Energy Agency: AFGHANISTAN ITALY ALBANIA JAPAN ARGENTINA REPUBLIC OF KOREA AUSTRALIA LEBANON AUSTRIA LIBERIA BELGIUM LUXEMBOURG BOLIVIA MALI BRAZIL MEXICO BULGARIA MONACO BURMA MOROCCO BYELORUSSIAN SOVIET SOCIALIST NETHERLANDS REPUBLIC NEW ZEALAND CAMBODIA NICARAGUA CANADA NORWAY CEYLON PAKISTAN CHILE PARAGUAY CHINA PERU COLOMBIA PHILIPPINES CONGO (LÉOPOLDVILLE) POLAND CUBA PORTUGAL CZECHOSLOVAK SOCIALIST REPUBLIC ROMANIA DENMARK SAUDI ARABIA DOMINICAN REPUBLIC SENEGAL ECUADOR SOUTH AFRICA EL SALVADOR SPAIN ETHIOPIA SUDAN FINLAND SWEDEN FRANCE SWITZERLAND FEDERAL REPUBLIC OF GERMANY SYRIAN ARAB REPUBLIC 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 AND ICELAND NORTHERN IRELAND INDIA UNITED STATES OF AMERICA INDONESIA URUGUAY IRAN VENEZUELA IRAQ VIET- NAM ISRAEL YUGOSLAVIA 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 29Julyl957. 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". Printed by the IAEA in Austria August 1963 TECHNICAL REPORTS SERIES No. 18 ANALYTICAL CHEMISTRY OF NUCLEAR MATERIALS REPORT OF THE PANEL ON ANALYTICAL CHEMISTRY OF NUCLEAR MATERIALS HELD IN VIENNA 17-21 SEPTEMBER 1962 INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 1963 ANALYTICAL CHEMISTRY OF NUCLEAR MATERIALS IAEA, VIENNA, 1963 STl/DOC/lO/18 FOREWORD The last two decades have witnessed an enormous development in chemical analysis. The rapid progress of nuclear energy, of solid-state physics and of other fields of modern industry has extended the concept of purity to limits previously unthought of, and to reach the new dimensions of these extreme demands, entirely new techniques have been invented and applied and old ones have been refined. Many determinations at the trace impurity level which 20 years ago were largely of academic interest only are today regularly present in the daily routine of the analytical laboratory. At the same time, a higher accuracy of macro-determinations is required from the chemists because of the high value of many of the materials handled. The importance of the control of the composition of the materials used in nuclear energy projects is obvious. The first step in such a programme consists almost invariably in geological prospecting and the exploitation of the natural resources of the country, and the correct analysis of ores and semi-elaborated materials is essential to its success. In a more advanced stage, the knowledge of the composition and purity of fuels, moderators, coolants and structural materials used in reactors is also of primary signi- ficance. Finally, the operation of reactors and the reprocessing of partially spent nuclear fuels depend also on the continuous control of chemical composition and sometimes pose real challenges to the analytical chemists as a consequence of the special conditions under which the analyses have to be performed. With about 200 reactors presently operating in the world and more projected, in development or under construction, the importance of these subjects increases every day. Recognizing these facts, the International Atomic Energy Agency convened a Panel on Analytical Chemistry of Nuclear Materials to discuss the general problems facing the analytical chemist engaged in nuclear energy development, particularly in newly developing centres and countries, to analyse the present situation and to advise as to the directions in which research and development appear to be most necessary. The Panel also discussed the analytical programme of the Agency's laboratory at Seibersdorf, where the Agency has already started a programme of international comparison of analytical methods which may lead to the establishment of international standards for many materials of interest. It was particularly fitting that this first panel on the analytical chemistry of nuclear materials should have been chaired by Professor Hans Malissa, President of the Analytical Section of the International Union of Pure and Applied Chemistry, which effectively ensured that the panel's work could proceed without fear of duplicating that of other international bodies. The papers presented to the Panel and a summary of its discussions and recommendations are included in this Technical Report, which it is hoped will be found useful by all chemists concerned with nuclear energy development. CONTENTS PART I. ANALYSIS OF URANIUM AND THORIUM 9 A. Report to the Panel by Dr. С. J. Rodden 9 B. Summary of Discussion 25 PART II. TRACE IMPURITY ANALYSIS IN NUCLEAR MATERIALS 33 A. Report to the Panel by Professor Dr. J. Minczewski 33 B. Comments by Professor Dr. I. P. Alimarin 43 C. Comments on Analyses of Nuclear Materials in Japan by Professor Dr. T. Somiya 48 D. Summary of Discussion 55 PART III. ANALYTICAL CHEMISTRY OF IRRADIATED NUCLEAR FUEL PROCESSING 61 A. Report to the Panel by Dr. F.J. Woodman 61 B. Summary of Discussion 74 PART IV. RECOMMENDATIONS OF THE PANEL 79 List of participants 81 PART I ANALYSIS OF URANIUM AND THORIUM A. REPORT TO THE PANEL BY DR. C. J. RODDEN INTRODUCTION Of the three nuclear fuels, uranium, thorium and plutonium, that are presently considered for use in nuclear reactors the one most commonly used is uranium. Of these three elements uranium is more readily determined by chemical analysis since it has valence states such that a change of two valence states can be readily utilized. Plutonium in general has only one valence-state change while thorium exists only in the tetravalent state and cannot be determined by oxidimetric-titration methods. The analysis of uranium and thorium is such an inclusive subject that it is felt a more restrictive discussion as applied to materials which are now being or may soon be exchanged on an international basis would be appropriate. With this in mind the present discussion considers concentrates, alloys, ceramics and compounds of uranium and thorium. There have been several review articles and books on the determination of uranium 11, 2, 3, 4, 5, 6] , which give certain methods of separation and determination which may be applicable for high uranium-containing materials. URANIUM The types of materials analysed will to a large degree indicate the method or methods that will be used. In the case of uranium fuels either in the form of alloys, ceramics or cermets the method should be as precise and accurate as possible, especially if one is analysing uranium with a high uranium-235 content, since the monetary value of the fuel is high. Inva- riably the knowledge of uranium-235 content is generally desirable and the chemist in many cases has this problem to answer. Since the international exchange of materials of high uranium content is increasing it is highly desirable that methods which are acceptable to all concerned be used. Although uranium in some instances may be determined without prior separation of interfering elements, in general some kind of separation is necessary. Uranium concentrates The uranium concentrates encountered in the uranium industry are generally of high grade, ranging from 60 to 90% U3O8, although an occa- sional low-grade concentrate may be obtained. A few randomly selected analyses of various types of concentrates are given in Table I. 9 t TABLE III (cont.) REPRESENTATIVE ANALYSIS OF URANIUM CONCENTRATES Origin V2O5 P2Os Na SO, Mo Fe Cu As в H20 C02 NHj u,o, 1 United States 0.07 0.03 2.19 0.31 <0.05 0.15 <0.10 <0.005 6.81 0.68 77.86 3 United States 2.42 0.22 1.81 1.75 0.09 1.84 <0.10 <0.005 0.36 - 87.46 16 United States <0.20 0.59 0.03 2.35 0.29 2.22 0.59 4.88 0.14 - 74.77 21 United States 0.25 0.61 1.71 4.62 0.13 0.34 - <0.10 <0.005 1.09 0.02 85 81 23 Canada <0.02 0.08 3.28 1.74 0.003 0.42 <0.01 <0. 01 0.006 - <0.08 79 39 26 Canada <0.02 0.08 <0.03 2.37 0.001 0.40 <0.01 <0.01 0.009 <0.08 77.83 28 South Africa <0.02 <0.08 <0.02 6.28 <0.001 0.61 - 0.06 0.004 0.12 <0.08 0.023 88.12 29 Australia 0.75 0.944 0.863 3.98 0.56 0.10 68.45 30 Belgian Congo 0.03 0.45 1.92 0.49 0.003 2.49 0.01 <0.01 0.03 0.35 74.07 " 31 South Africa 0.026 1.91 0.0007 0.40 92.00 As one can see certain elements that would interfere with a volumetric or gravimetric determination of uranium must be removed. In the concentrates analysed these interferences are mainly vanadium and iron and no serious problem of removing these impurities presents itself. One problem connected with certain types of uranium concentrates is the preservation of the samples. Many of these materials are adversely affected by changes in humidity and it has been found that the only way to preserve these samples in their original composition is to have them put in glass containers with vacuum sealed tops somewhat similar to those used for canning fruits and vegetables. By having the warm material placed in these containers, and then cooling, a vacuum tight seal is made.

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