Radioactive Wastes by Charles H. Fox

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U. S. ATOMIC ENERGY COMMISSION Division of Technical Information Understanding the Alum Series This booklet Is one of the "Understanding the Atom" Series. Comments are invited on this booklet and others in the series; please send them to the Division of Technical Information, U. S. Atomic Energy Commission, Washington, D. C. 20545. Published as part of the AEC's educational assistance program, the series includes these titles:

Accelerators Nuclear Propulsion for Space Animals m Atomic Research NHclea7 Reactors Atomic Fuel Nuclear Terms, A Brief Glossary Atomic Power Safety Our Atomic World Moms at the Science Fair Plowshare Atoms m Agriculture Plutonium Atoms, Nature, and Man Power from Radioisotopes Books on Atomic Energy for Adults Power Reactors in Small Packages and Children tiadioaclne Wastes The Understanding the Atom Series Careers m Atomic Energy Radioisotopes and Life Processes Computers Radioisotopes m Industry Controlled Nuclear Fusion Radioisotopes m Medicine Nuclear energy is playing a vital role in the life of every Cryogenics, The Uncommon Cold Rare Earths Direct Com ersion of Energy Research Reactors man, woman, and child in the United States today. In the Fallout From Nuclear Tests SNAP, Nuclear Space Reactors Food Preservation by Irradiation Sources of Nuclear Fuel years ahead it will affect increasingly all the peoples of the Genetic Effects of Radiation Space Radiation Index to the VAS Series Spectroscopy earth. It is essential that all Americans gain an understanding Lasers Synthetic Transuranium Elements Microstructure of Matter The Atom and the Ocean of this vital force if they are to discharge thoughtfully their Neutron Actwation Analysis The Chemistry of the Noble Gases Nondestructive Testing The Elusive Neutrino responsibilities as citizens and if they are to realize fully the Nuclear Clocks The First Reactor myriad benefits that nuclear energy offers them. Nuclear Energy for Desalting The Natural Radiation Environment Nuclear Power and Merchant Shipping Whole Body Counters The United States Atomic Energy Commission provides Nuclear Power Plants Your Body and Radiation this booklet to help you achieve such understanding. A single copy of any one booklet, or of no more than three different booklets, may be obtained free by writing to:

. /Q-a«fc«-"»«-«*->~T' USAEC, P. 0. BOX 62, OAK RIDGE, TENNESSEE 37830

Edward J. Brunenkant, Director Complete sets of the series are available to school and public librarians, and to teachers who can make them Division of Technical Information available for reference or for use by groups. Requests should be made on school or library letterheads and indi­ cate the proposed use. Students and teachers who need other material on spe­ cific aspects of nuclear science, or references to other UNITED STATES ATOMIC ENERGY COMMISSION reading material, may also write to the Oak Ridge address. Requests should state the topic of interest exactly, and the use intended. Dr. Glenn T. Seaborg, Chairman In all requests, Include "Zip Code" in return address. James T. Ramey Wilfrid E. Johnson Dr. Theos J. Thompson Dr. Clarence E. Larson Printed m the United States of America USAEC Division of Technical Information Extension, Oak Ridge, Tennessee Radioactive Wastes by Charles H. Fox

CONTENTS

MEN AND ASHES 1 THE NATURE OF RADIOACTIVE WASTES 3 Sources of Radioactive Waste 4 Levels of Radioactivity 11 Potential Effects of Radioactivity 12 WASTE MANAGEMENT 14 Liquid Waste Management: Low and intermediate Level . . .15 PHOTO CREDITS Gaseous Waste Management 20

Cover courtesy the General Electric Company Solid Waste Management 22 Figure 3 The Anaconda Company High-level Waste Management 24 Figure 4 Oak Ridge National Laboratory (OKNL) Figure 6 Union Carbide Corporation RESEARCH AND DEVELOPMENT 28 Figure 7 ORNL High-level Waste Processing 29 Figure 8 Savannah River Plant Low-level Waste Processing 36 Figure 9 BroolAaven National Laboratory Figure 11 ORNL Intermediate-level Waste Processing 37 Figure 13 E. I. Du Pont de Nemours & Company Environmental Studies 38 Figure 16 ORNL APPENDIX I Figure 17 ORNL Figure 18 ORNL Naturally Occurring Radioisotopes Encountered in Mining, Figure 19 Hanford Plant Milling, and Fuel Preparation in Uranium Fuel Cycle . . .40 APPENDIX II Principal Fission-product Radioisotopes in Radioactive Wastes 41 APPENDIX III Principal Activation-product Radioisotopes Produced by Neutron Irradiation of Nonfuel Materials 42 APPENDIX IV List of Firms Licensed to Receive and Dispose of Radioactive Wastes 43 SUGGESTED REFERENCES 44

United States Atomic Energy Commission Division of Technical Information Library of Congress Catalog Card Number: 66-60724 1966; 1969 (rev.)

46 THE COVER Radioactive Waste Management, W. G. Belter and D. W. Pearce, Reactor Te c hno logy (Selected Revieifs~1965) (TID-8541), pp. 149-248, 1966, $3.00. Management oj Radioactive Wastes at Nuclear Power Stations (ORNL-4070), J. O. Blomeke and F. E. Harrington, 1968, 102 pp., ys.oo. The main corridor of the Carey Salt Lou Level Radioactive Wastes: Their Treatment, Handling, and Company Mine in Lyons, Kansas, 1000 Disposal, Conrad P. Straub, produced by the AEC's Division of feet below the surface of the earth. The Technical Information and available from the Superintendent of ceiling height in the corridor is 14 feet. Documents, U. S. Government Printing Office, Washington, D. C. The Oak Ridge National Laboratory has 20402, 1964, 430 pp., $1.50. carried out a radioactive waste disposal experiment in this mine to determine heat and radiation effects on salt from Motion Pictures high-level solidified wastes and to dem­ onstrate radioactive waste handling Available for loan without charge from the AEC Headquarters Film techniques in this environment. Results Library, Division of Public Information, U. S. Atomic Energy Com­ of these tests show that this may provide safe and efficient storage mission, Washington, D. C. 20545, and from other AEC film li­ for high-level radioactive wastes. (See page 33 and Figure 16 for braries. more information on this research.) Living with Radiation, 28 minutes, sound, color, 1958. Produced for the AEC's Idaho Operations Office by Lookout Mountain Air Force Station. This film documents the AEC radiation safety program by using procedures at the National Reactor Testing Station in Idaho as illustrative examples. It includes waste stor­ age and disposal, personnel-protection methods, and other rele­ vant topics. Isotopes, 20 minutes, sound, color, 1959. Produced by the AEC's Oak Ridge National Laboratory. This film explains radioactivity and methods for producing radioisotopes, including separation of THE AUTHOR isotopes from high-level wastes. Regulation of Atomic Radiation, 28'/2 minutes, sound, color, 1963. Produced by the AEC. This film surveys AEC work in the li­ censing and regulation of the uses of nuclear materials. It shows the control of radioactive materials from the time they leave the mine until they become waste. CHARLES H. FOX is a consultant Reactor Fuel Processing, 20 minutes, sound, color, 1958. Pro­ in nuclear er^ineering with many duced by the AEC's Oak Ridge National Laboratory. This film years' experience in industry, much covers the chemical processing of irradiated reactor fuels and of it with The Martin Company, waste-disposal operations. where he was Chief, Advance De­ Atoms on the Move: Transportation of Radioactive Materials, 24 sign, and later program manager minutes, color, 1966. Produced by Bennie Korzen Productions for the PM-3A nuclear power plant, for the AEC. Ores, reactor fuel, weapons, radioisotopes for now operating in the Antarctic. medicine, industry, research, and atomic wastes are shown in Mr. Fox won the Eshbach Award transit. Safety aspects, including accident research, and re­ as the outstanding graduate of the sponsibilities of federal agencies are discussed. Technological Institute, Northwest­ Working with Radiation, 29 minutes, black and white, 1962. Pro­ ern University, where he obtained duced by the AEC's Argonne National Laboratory. Precautions his degree in chemical engineering. He served as an instructor and various methods for handling radioactive materials including in nuclear engineerii^ at Martin and for several years was a wastes are illustrated. member of the Advisory Committee on Nuclear Education at the Drexel Institute of Technology. He has frequently addressed high school groups and civic clubs on nuclear energy.

45 SUGGESTED REFERENCES Radioactive Wastes Popular Level The Hazards of Atomic Wastes, Alton Frye, Public Affairs Press, By CHARLES H. FOX 419 New Jersey Avenue S. E., Washington, D. C. 20003, 1962, 45 pp., $1.00. Radioactive Wastes, W. G. Belter, International Science and Tech­ nology, 12: 42 (December 1962). Annual Report to Congress of the Atom.ic Energy Comm.ission for 1964, Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20402, 1965, 443 pp., $1.75. The Management of Radioactive Wastes Produced by Radioisotope Users, Safety Series No. 12, International Atomic Energy Agency, available from National Agency for International Publications, Inc., 317 East 34th Street, New York 10016, 1964, 58 pp., $1.50. Background Information on Mom.ic Power Waste Handling, John F. Hogerton, James G. Cline, Robert W. Kupp, and Charles B. Yulish, Atomic Industrial Forum, Inc., 850 Third Avenue, New York 10022, 1965, 48 pp., $1.50. Management of Radioactive Wastes, Atomics, 18: 8 (May/June 1965). MEN AND ASHES Technical Level Radioactive Wastes: Their Treatment and Disposal, John Collins An archaeologist kneels in the Mexican valley of Te- (Ed.), John Wiley & Sons, Inc., New York, 1960, 239 pp., $8.00. huacan, gently brushing the dirt from crude artifacts dis­ Processing of Radioactive Wastes, C. A. Mawson, International carded thousands of years before. Fragments of earthen­ Atomic Energy Agency publication No. 18, available from Na­ tional Agency for International Publications, Inc., 317 East 34th ware and chipped stones in the ashes of ancient fires tell Street, New York 10016, 1961. 44 pp., $1.00. their story. They are wastes from the first human culture Industrial Waste Disposal Hearings Before the Joint Com.m.ittee on on the North American Continent. Atomic Energy of the 86th Congress, 1959, summary analysis of the hearings available from the Office of the Joint Committee on Today, in the wheat fields of Kansas, tons of straw left Atomic Energy, Congress of the United States, Senate Post Of­ behind by threshing machines must be disposed of each fice, Washington, D. C. 20510, 40 pp., free. year by baling for later use or by burning. Wastes of straw may never be seen by archaeologists of the future, The following reports are available from the Clearinghouse for Federal Scientific and Technical Information, 5285 Port Royal but other wastes of our time will intrigue them—^piles of Road, Springfield, Virginia 22151. slag from steel mills, city dumps under tons of soil, and U. S. Operational Experience in Radioactive Waste Management mountains of rusted automobiles. 1958-1963 (A/CONF.28/P/869), W. G. Belter, International Almost every act of man leads to wastes of one sort or Conference on the Peaceful Uses of Atomic Energy, 1964, 16 pp., another—hunters' ejected cartridges, smoke from power- $3.00. Advances in Radioactive Waste Management Technology and Its plant chimneys, wastepaper in schoolrooms, or the curls Effect on Future U. S. Nuclear Power Industry (A/CONF.28/P/ of childhood lost forever on the barbershop floor. 868), W. G. Belter, International Conference on the Peaceful The nuclear industry is no exception. Managers of nu­ Uses of Atomic Energy, 1964, 18 pp., $3.00. clear installations are concerned with the handling, pro­ Proceedings of the Sym.posium on the Solidification and Long- cessing, and disposal of wastes. In many ways this activity Term Storage of Highly Radioactive Wastes (CONF-660208), W. H. Regan (Ed.), February 14-18, 1966, Richland, Washington, is comparable to other disposal processes, but it is dif­ 1966, 900 pp., $3.00. ferent in a few important respects.

44 1 The most significant difference between nuclear wastes APPENDIX IV and those of other industries is that nuclear wastes are radioactive, and this accounts for the special methods re­ List of Firms Licensed to Receive and quired for their disposal. The highly radioactive wastes Dispose of Radioactive Wastes from spent nuclear fuels, in particular, pose a challenging problem. They cannot be piled in open fields or dumped 1. Firms Licensed by U. S. Atomic Energy Commission into rivers or the ocean. Another problem exists because Allied-Crossroads Nuclear Corp. New England Tank Cleaning Co. 201 Victory Road 135 First Street of the millions of gallons of water containing traces of Dorchester, Massachusetts 02122 Cambridge, Massachusetts 02138 radioactivity that must be disposed of each year. The The Walker Trucking Company management of radioactive wastes is, indeed, a complex 1283 East Street and interesting activity. New Britain, Connecticut 06050 Since 1942, when the first self-sustaining chain reaction 2. Firms Licensed by AEC and Agreement States* was achieved, the nuclear industry has grown vigorously. California Salvage Company Laboratory for Electronics, Inc. 700-745 North Pacific Avenue Tracerlab Division Over 300 operating reactors are now in use.* In addition, San Pedro, California 90731 1601 Trapelo Road radioactive materials are increasingly regarded as im­ Waltham, Massachusetts 02154 Nuclear Engineering Company, Inc portant tools for research, medicine, and industry. As the Box 594 Laboratory tor Electronics, Inc. Walnut Creek, California 93002 Tracerlab Division 2030 Wright Avenue California Nuclear, Inc. Rlchmon, California 94804 2323 South Ninth Street Lafayette, Indiana (HQ) 47905 Long Island Nuclear Services Corp. Station Road Nuclear Engineering Company, Inc. Bellport, New York 11713 Box 146 Burns Building Radiological Service Co., Inc. Morehead, Kentucky 40351 35 Urban Avenue Westbury, New York 11590

3. Firms Licensed Entirely by Agreement States'^ Consolidated American Services, U. S Nuclear Corporation Inc. 801 North Lake Street 12600 South Daphne Avenue Burbank, California 91502 Hawthorne, California 90250 William Wayne Electronics Nuclear Fuel Services, Inc. Hastings Radiochemical Works Box 124 Box 60448 West Valley, New York 14171 Houston, Texas 77060

•States which have sufficient interest and which develop adequate con­ trols and regulations may, by agreement with the AEC Division of Li­ censing and Regulation, assume control of waste-handling activities within their boundaries. Licensing by the AEC is required for interstate activi­ ties. tThis list may not be complete. Current information can be obtained from the Department of Health of the particular state involved. The fol­ lowing states have entered into agreements for control by state regulation: Figure 1 The Dresden Nuclear Power Station near Chicago, Illi­ Arkansas, California, Florida, Kansas, Kentucky, Mississippi, New York, North Carolina, Texas, Oregon, and Tennessee. nois, is an example of America's groiving nuclear industry.

*For more about nuclear reactors, see Nuclear Reactors and Research Reactors, companion booklets in this series.

2 43 APPENDIX 111 nuclear era continues, there will obviously be more radio­ active waste. Clearly the methods used for the control and Principal Activation-product Radioisotopes Produced disposal of wastes must not only be appropriate to a wide­ by Neutron Irradiation of Nonfuel Materials spread, lusty endeavor but also be safe and economical. In the U. S, nuclear program, the Atomic Energy Com­ Radiation Atomic Source and mission (AEC) has the function of protecting the public Radioisotope number reaction* Half-life emittedt against the hazards of radioactive materials. Regulations Air and Water have been developed through research to ensure effective Tritium (H-3) 1 2H (n,y) 12.3 yr iS, r control without unduly restricting the growth of nuclear Carbon-14 6 "N (n,p) 5700 yr ^ industry. The AEC also directs research to develop new Nitrogen-16 7 '''O (n,p) 7.3 sec /3, r methods of radioactive waste management. Much remains Nitrogen-17 7 "O (n,p) 4.1 sec /3 Oxygen-19 8 '''O (n,r) 30 sec /3,y to be done, but the work already promises that disposal of Argon-41 18 ^OA (n,r) 1.8 hr &,y radioactive wastes will not erect economic barriers to our nuclear future. Sodium

Sodium-24 11 23Na (n,y) 15 hr /5, Y Soaium-22 11 ^^Na (n,2n) 2.6 yr /3+, y THE NATURE OF RADIOACTIVE WASTES Rubidium-86 37 85Rb (n,y) 19.5 hr /3, y- (impurity in (IT)I K, y Many kinds of radioactive wastes are produced by the sodium coolant) 1 min nuclear industry,* AEC licensing procedures and regula­ Alloys tions deal with more than 900 radioisotopesf of 100 ele­ Aluminum-28 13 27A1 (n,y) 2.3 min /3, y ments. Wastes containing these isotopes may be in the Chromium-51 24 sOCr (n,y) 27 days /?+. K, y form of gases, liquids, or solids, may be soluble or in­ Manganese-56 25 s^Fe (n,p) 2.6 hr ^, y soluble, and may give off various types of radiation at Iron-55 26 5^Fe (n,y) 2.9 yr K many energy levels. Although many radioisotopes decay Iron-59 26 59Co (n,p) 45 days /3, y Copper-64 29 63Cu (n,y) 12.8 hr i3, y, /3+, K rapidly, some require hundreds of years to decay to safe Zinc-65 30 •^^Zn (n,y) 250 days /3+, e-, y levels. Tantalum-182 73 *"Ta (n,y) 115 days /3, y The hazards of radioactive materials stem from their Tungsten-187 74 18«W (n,y) 24 hr /3, y Cobalt-58 27 s^Ni (n,p) 71 days /3+, y basic characteristics. Radiation cannot be detected by the Cobalt-60 27 ^^Co (n,y) (also 5.3 yr /3, y senses (except in massive doses); its effects are often purposeful cumulative and may not be evident for some time; and it irradiation) Phosphorus-32 15 ^»P (n,y) 14.3 days /3 can damage both an individual and, by impairing his (purposeful reproductive cells, future generations of his descendants. irradiation) Fortunately the nature of radioactivity also makes it pos­ *(n,y): absorbs neutron, emits gamma. (n,p): absor bs neutron. sible to detect its presence with certainty and remarkable emits proton. accuracy. t/3: beta particle, an electron, y: gamma ray, similar to X rays. jS*: positively charged electron. K: orbital electron capture into *For a discussion of the nature, measurement, and control of nucleus. e~: internal electron conversion. radioactivity at nuclear power plants, see Atomic Power Safety, tIT: isomeric transition, internal. another booklet in this series. tRadioisotopes are radioactive forms of elements. For defini­ tions of unfamiliar words, see Nuclear Terms, A Brief Glossary, a companion booklet in this series.

42 3 One final point—radioisotopes are immune to outside APPENDIX II influence. Each isotope decays at its own particular rate Principal Fission-product Radioisotopes regardless of temperature, pressure, or chemical environ­ ment and continues to do so no matter what is done to it. in Radioactive Wastes Allowing radioisotopes to decay naturally is the only Atomic Radiation practical means of eliminating their radioactivity. All Radioisotope number Half-life emitted* processing, storing, and use of radioisotopes must there­ fore be considered as an intermediate step leading finally Krypton-85 36 4.4 hr (IT)1 (3, y, e- —/3,y to disposal by decay. -* 9.4 yr Strontium-89 38 54 days fi Strontium-90 38 25 yr a Sources of Radioactive Waste Zirconium-95 40 65 days /3, y Niobium-95 41 90 hr (IT) e~ - )3, y Radioactive wastes are created wherever radioactive — 35 days Technetium-99 43 5.9 hr (IT) e", y - /? materials are used. By far the greatest source of wastes — 5 X 10^ yr is the nuclear fuel cycle: The mining, milling, and prepara­ Ruthenium-103 44 39.8 days /3, y tion of fuel for reactors and weapons produce wastes Rhodium-103 45 57 min e~ containing natural radioisotopes; and fuel irradiation and Ruthenium-106 44 1 yr P subsequent processir^ produce wastes rich in fission Rhodium-106 45 30 sec /3, y Tellurium-129 52 34 days (IT) e-,/3-/3, y products. Additional wastes are produced by irradiation of — 72 min nonfuel materials in and around reactors. Let us consider Iodine-129 53 1.7 X 10^ yr /3, y these sources. Iodine-131 53 8 days /3, y Xenon-133 54 2.3 days (IT) e-, /3 - /?, y NATURAL RADIOACTIVITY refers to the radioactivity of -* 5.3 days materials found in nature. These materials are present in Cesium-137 55 33 yr /?,y uranium and thorium ores, nature's nuclear fuels. Wastes Barium-140 56 12.8 days /3, y from mining, ore milling, and fuel fabrication therefore Lanthanum-140 57 40 hr /3, y contain this natural radioactivity, which consists primarily Cerium-141 58 32.5 days /3,y Cerium-144 58 590 days /5,y of the natural radioisotopes of uranium, thorium, radon (a Praseodymium-143 59 13.8 days /3, y gas), and radium (see Figure 2, page 6, and Appendix I). Praseodymium-144 59 17 min /3 Most mines are in dry formations, but some must be Promethium-147 61 2.26 yr /3 kept dry by pumping out hundreds of gallons of water per *(3: beta particle, an electron, y: gamma ray, similar to minute. This water contains only traces of radioisotopes X rays. e~: internal electron conversion. and poses no significant health hazard. In uranium ore- tIT: isomeric transition, internal. concentrating mills, liquid wastes are discharged to ponds or lagoons at a rate of 300 to 500 gallons per minute (for an average mill processing 1000 tons of ore per day). There are over 20 such mills in the United States. Radium is the principal radioisotope in mill wastes and is in­ corporated in the solid residues, called "tailings", in an insoluble form. In "feed" preparation, the next step in the fuel cycle, ore concentrates are taken from the mills and chemically

4 41 APPENDIX I purified. This produces uranium salts, or feed, for the gaseous-diffusion plants (for separation of uranium-235 Naturally Occurring Radioisotopes Encountered from other isotopes of uranium); or it converts concen­ in Mining, Milling, and Fuel Preparation trates to metallic uranium or uranium oxide for fuel ele­ in Uranium Fuel Cycle ments. For each ton of uranium processed, approximately 1000 gallons of liquid wastes are produced. Percent found in The purified uranium used in the fabrication of fuel Atomic natural Radiation elements has extremely low activity because the radium, Radioisotope number uranium Half-life emitted* thorium, and several radioactive decay products have been removed in earlier steps of the cycle. Liquid wastes from Uranium- -238 Decay Chain fuel fabrication plants are of small volume and very low Uranium-23 8 92 99.28 4.5 X 10^ yr a, y radioactivity. Contaminated scrap is also produced at Thorium-234 90 1 X 10-8 24.1 days /3. y fabricating plants, Protactinium- 234 91 5 X 10-" 1.14 min /3, y Uranium-234 92 6 X 10-3 2.5 X 105 yr a, y FISSION PRODUCTS produced during the irradiation of Thorium-230 90 2 X 10-3 8 X 10^ yr a, y Radium-226 88 4 X 10-5 1622 yr a, y nuclear fuels in reactors are by far the largest source of Radon-222 86 2 X 10-" 3.8 days a radioactive waste in terms of contained radioactivity. When Polomum-218 84 1 X 10-13 3.1 min a each uranium atom fissions, it breaks into two major X 10-12 Lead-214 82 1 26.8 min /3, y fragments appropriately called fission products. Fission Bismuth-214 83 8 X 10-13 19.7 min /3, y Polonium-214 84 1 X 10-15 ~10-* sec a products are radioactive; they undergo one or more steps Lead-210 82 5 X 10-1 22 yr P,y of radioactive decay before reaching a stable, harmless Bismuth-210 83 3 X 10-10 5 days /3 condition (see Appendix 11). Valuable fuel material remains Polonium-210 84 8 X 10-s 138 days a, y Lead-206 82 Stable in the irradiated fuel along with the accumulated fission products; so recovery of this fuel is important. Chemical Uranium- -23. 5 Decay Chain processing of irradiated nuclear fuels is, therefore, an Uranium-235 92 0.71 7.1 X 10^ yr a, y inescapable part of the nuclear industry. The processing Thorium-231 90 3 X 10-12 25.6 hr i3, y creates highly radioactive wastes consisting not only of Protactinium- 231 91 3 X 10-5 3.4 X 10^ yr a, y fission products but also of some activated reactor ma­ Actinium-227 89 2 X 10-8 27 yr a, /3, y Thorium-227 90 5 X 10-11 18.6 days a, y terials, chemicals, and corrosion products.* Radium-223 88 3 X 10-11 11.2 days a, y Radon-219 86 1 X 10-1" 3.9 sec a, y Chemical processing of irradiated fuel is presently done Polonium-215 84 6 X 10-2" ~ 10-3 gee a at AEC plants, but private industry will enter this field as Lead-211 82 7 X 10-1^ 36.1 min 13, y the nuclear industry grows. Already the first commercial Bismuth-211 83 4 X 10-15 2.1 min a, y plant is under construction in the state of New York by Thallium-207 81 9 X 10-15 4.8 min /3, y Lead-207 82 Stable Nuclear Fuel Services, Inc. (see Appendix IV). A number of solvent-extraction processes are used to *a: alpha particle, a helium nucleus. y: gamma ray, similar to X rays. jB: beta particle, an electron. separate remaining fuel from waste products in used fuel elements. From 1 to 100 gallons of highly radioactive liq­ uid result from each kilogram of uranium processed—1 to

*For more about fuels and fuel processing, see Atomic Fuel, another booklet in this series.

40 5 -1 Type of waste radioactivity Source of waste Form of waste

Solids Mining of Liquids uranium ores Gases and dusts Natural activity Solids Fuel fabrication Liquids (acid) plants Figure 18 Taking core samples of bottom sediments m the Clinch Dusts River m Tennessee.

Solids (from purposeful solidification) Fuel Liquids Fission-product irradiation (with strontium and isotopes and the resulting dosages to human and animal activity and cesium removed) processing life in the area. Studies such as these are essential to our understanding Gases of the effects of released radioactive wastes. This under­ standing must be thorough because no significant mecha­ nism for the dispersal of radioactive materials and pos­ Solids Reactor sible subsequent exposure of the public can be overlooked. materials Liquids Mankind needs the tremendous energy represented by nu­ Activation- unavoidably (dissolved material) product irradiated clear fuels, but their use will create vast quantities of activity during operation radioactive wastes. Disposal of these must never be al­ Gases lowed to harm man, his environment, or his natural Purposeful resources. Radioactive waste management is dedicated to irradiation this objective. to produce Solids useful isotopes

Figure 2 Typical radioactive wastes and disposal methods. See ap- Figure 19 Equipment disposal tunnel at the 10 gallons m processing natural or slightly enriched* Hanford Plant m Rich­ uranium and 10 to 100 gallons m the case of highly enriched land, Washington. Ra­ uranium. Up to now, most of the fuels processed have been dioactive chemical pro­ cessing equipm.ent, too natural-uranium fuels from the AEC's plutonium-production large to be buried con­ veniently, is loaded onto •Enriched uranium is uranium m which the proportion of flatcars and pushed into uranium-235 has been increased by putting the natural element the 1700-foot tunnel. through an isotope-separation process, such as gaseous diffusion. The tunnel will then be See Appendix I for natural-uranium content of uranium-235. covered with earth.

6 39 or by shaped charges of explosive. A mixture of water, Typical Type of waste, and cement is pumped into the formation at high isotopes radiation Disposal methods pressure; this cracks the rock and allows the mixture to move out in horizontal sheets that solidify in place. Uranium-23 8 ca, y Pile in open Oak Ridge National Laboratory workers made test in­ Thorium-230 a, y Seep into ground jections of material containing radioactive tracers in 1960. Radon-222 a Ventilate mine Later, core drilling provided information on the extent and Uranium-23 8 a, y Decontaminate thickness of the solidified material. Results were favor­ Uranium-235 able, and early in 1964 a hydrofracturing plant was com­ Uranium-23 8 Neutralize, concentrate, and a,y pleted for injection of actual wastes. Approximately Uranium-235 bury residue 250,000 gallons of intermediate level waste concentrate is Uramum-238 Ventilate, filter, and a, y now being disposed of routinely each year using this tech­ Uranium-23 5 disperse to air nique. Strontium-90 Encase in container and Environmental Studies Cesium-137 (3, y store permanently (~600 years) An important part of waste-management research is the Technetium-99 /3, Store in tanks for several Ruthenium-103 /3, y years; then solidify in study of environments surrounding atomic energy installa­ Cerium-144 i3,y place tions. Objectives are to determine the fate of radioactive Iodine-131 P,y React with chemicals to bind materials released to waterways, to determine the mecha­ in solid, e.g., silver iodide nisms of their dispersion, to evaluate the hazards as­ Krypton-8 5 /3, y Disperse to air sociated with disposal practices, to evaluate the usefulness Aluminum-28 i3, y Package and ship for land of waterways for disposal, and to recommend appropriate Manganese-56 /3, y burial long-term environmental-monitoring procedures. Evaporation or ion-exchange; Cobalt-58 /3+, y The principal studies in the United States have been bury residue made of the Clinch-Tennessee River system below Oak Hold for decay (very short life); Nitrogen-16 Ridge, Tennessee; the Columbia River below Richland, /3, y then disperse to air Washington; and the Savannah River below Aiken, South Ship for burial when no longer Cobalt-60 Carolina. Similar studies have been made of the Ottawa /3, y useful (long life) River in Canada, the Thames River in England, and the Store for decay to safe levels Phosphorus-32 Rhone River in France, For example, the comprehensive /3 (short life) investigation on the Clinch and Tennessee Rivers is a multiagency effort to evaluate physical, chemical, and pendices for more detail and explanation. biological effects caused by the disposal of low-level radioactivity (see Figure 18). Water-sampling stations reactors, but increasing amounts of fuel from nuclear- have been established at seven sites, located as far as powered electric plants will have to be processed in the 125 miles below Oak Ridge, future. Studies have included dispersion tests with dyes and Predictions vary on the amount of high-level waste that radioactive tracers, determination of the distribution of will be produced by chemical processing of fuels from radioactivity in bottom sediments, methods of incorpora­ nuclear power plants. Current estimates are that some tion of radioactivity into the bottom sediments, and detailed 100,000 gallons will be produced in 1970 and that the amount analyses of the biological distribution of released radio- will increase to about 6 million gallons per year by the

38 7 THE FOAM-SEPARATION PROCESS for final decontamina­ tion of the filtered solutions from the scavenging-precipi­ tation process just described is also under study. In this method foam is produced by adding detergent to the waste solution and bubbling air through it. The foam rises to the top of a column. Most of the radioisotopes cling to the surface of the bubbles and rise with the foam. The foam is drawn off the top and collapsed; it yields a small amount of liquid. The bulk of the waste solution, having been cleaned by the foam passing through it, is drawn from near the bottom of the column. So far, however, this appears to be less simple and less efficient than the use of ion-exchange resins.

Intermediate-level Waste Processing A number of treating processes can be used for both low-level and intermediate-level liquid wastes. One of the Figure 3 Open-pit mme m New Mexico is a source of uranium ore that initiates the nuclear fuel cycle. most interesting studies, however, is one dealing with direct disposal of intermediate-level waste into shale or end of the century. Large quantities of less radioactive other suitable geologic wastes also will be produced; some 4 billion gallons have formations. The technique been produced and disposed of over the past 20 years. is called hydraulic frac­ Large as these quantities are, they are small in comparison turing and has been bor­ to the volumes of waste processed in other industries, such rowed from the oil indus­ as paper mills, chemical plants, and sewage-disposal try. It has been under plants. study for the past three ACTIVATION PRODUCTS are produced during the irradia­ years (see Figure 17). tion of nonfuel materials located near the fuel in nuclear The method requires the reactors. Structural materials are activated (made radio­ drilling of a well, followed active) by the absorption of neutrons, as are impurities in by lateral cuts through the the coolant* and often the coolant itself. Traces of iron, well casing into the rock nickel, and other corrosion products, for example, are formation, which are ac­ carried along with the coolant in some types of reactors complished by jets of and irradiated as they pass through the reactor. Appendix III a sand —water mixture lists typical activation-product radioisotopes.

* Coolant is a term identifying the fluid that flows through a re­ Figure 17 Facilities for dis­ actor to remove or transfer heat. Water is most commonly used, posal of intermediate-level but air, carbon dioxide, oils, sodium, and potassium also have been liquid wastes by injection used. into shale formations 1000 feet below ground level.

8 37 the top layers of earth. Each of these barriers is con­ Waste management operating experience at six American sidered to be an adequate shield in itself. Since they would nuclear power plants—Dresden-I m Illinois, Big Rock be encountered in succession, there is an ample factor of Point in Michigan, Humboldt Bay in California, Elk River safety. Studies are now under way on how to remove and in Minnesota, Indian Point-I in New York, and Yankee in transfer wastes from the present storage tanks. Massachusetts — has recently been assessed. The waste volumes handled in nuclear plants are not large in com­ Low-level Waste Processing parison with wastes from many other industries and the When the nuclear industry was small, low-level wastes total radioactivity is quite small. Radioactivity concentra­ could be discharged to the environment without raising tions in power plant effluents have been well below per­ background radiation significantly. This will be less pos­ missible release limits. sible in the future because of the growth of the industry. The irradiation of reactor coolant produces larger It is important to develop more efficient methods for treat­ quantities of low-level waste liquid at the AEC's plutonium- ing these large-volume wastes. production installations, particularly the Hanford Plant in Although normal chemical processing of low-level wastes Richland, Washington. Hanford personnel have the problem can remove approximately 90% of the contained radio­ of disposing of great amounts of water from the Columbia activity in a single treatment, multistage treatment is River that is used directly for reactor cooling. At the complex and costly. For this reason work is under way to AEC Savannah River Plant in Aiken, South Carolina, river develop more efficient and economical methods. water is also used, but it does not enter the reactors and A specific goal is to decontaminate low-level wastes to does not become irradiated; the reactor coolant is a an extent that would even permit direct consumption of the separate, relatively small quantity of water. Intermediate liquids by humans. Two treatment methods are being de­ veloped. Both involve scavenging-precipitation, but one is followed by an ion-exchange process and the other by a foam-separation process. THE SCAVENGING-PRECIPITATION ION-EXCHANGE PROCESS has demonstrated that it can produce wastes of signifi­ cantly lower residual activity than the lime-soda treatment now used. The low-level feed is adjusted to an alkaline condition in a mixing vessel, and a coagulant is added. The solution then flows to a slightly agitated tank (called a flocculator) in which insoluble materials agglomerate into large particles containing most of the fission products. The mixture then flows to another vessel (called a clari- fier) and passes up through a layer of sludge that is con­ tinuously removed and packed for disposal. The clarified water then passes through a filter and is pumped through ion-exchange columns for removal of the remaining fission products, principally cesium-137 and strontium-90. Over a five-month period, the process treated 600,000 gallons of low-level waste, removing 99.99% of the strontium and Figure 4 A "hot cell" worker at the AEC's Oak Ridge National Laboratory in Tennessee uses mechanical hands to separate useful 99.7% of the cesium. fission products from nuclear wastes.

36 9 Photo B. Cannisters containing radioactive material are lowered Figure 5 Face of plutonium-production reactor at the Hanjord down the shaft to a specially designed trailer coupled to a conven­ Plant in Richland, Washington. tional two-wheel tractor, which carries them to the experimental area shown m photo C. This machinery was assembled inside the mine. heat exchangers separate the coolant from the river water, and so the problem of quantity disposal does not arise. Some activation products are gaseous. In water-cooled reactors gaseous products arise from the irradiation of the water as well as from irradiation of any air in the coolant. The gases are mostly short-lived radioisotopes, such as nitrogen-16 or argon-41, but tritium (hydrogen-3) has a half-life* of more than 12 years. Air-cooled reactors produce argon-41, the major examples of this type being the large research reactors operated for many years at Brookhaven and Oak Ridge National Laboratories. Control and disposal of gases is an important aspect of radioactive waste management even though it involves a minor portion of the total radioactivity produced by nuclear industry. MISCELLANEOUS SOURCES OF RADIOACTIVE WASTES are the more than 4000 establishments making or using nuclear products in the United States. The radioactivity of this

*A half-life is the time required for half a radioisotope to be­ Photo C. Holes, 12 feet deep and lined with stainless steel, in the come stable; a period of two half-lives would reduce the quantity salt mine floor are used to contain radioactive fuel assemblies. of radioactivity to one-quarter the original amount. The room is 30 feet wide, 60 feet long, and 14 feet high.

10 35 great variety of wastes originates in one of the ways we have just discussed—from naturally occurring radioiso­ topes, fission products, or activation products. These may be in many forms, including chemicals, solids collected in evaporators, resins, and contaminated equipment and ma­ terials. Laboratories in hospitals, universities, and private industry produce waste solutions, contaminated gloves and clothing, and broken glassware. Even when sealed radio­ isotope devices are used, there eventually is need for disposal when the radioactivity has decayed below useful levels. IN SUMMARY, the four basic sources of radioactive waste materials are: 1. Mining, milling, feed-preparation, and fuel-manufac­ turing activities, involving naturally occurring radioiso­ topes. (See Appendix I.) 2. Irradiation and processing of nuclear fuel, involving fission-product radioisotopes. (See Appendix 11,) 3. Irradiation of nonfuel materials, involving activation- product radioisotopes, which include several radioisotopes purposely produced for their usefulness, (See Appendix III.) 4. The use of radioisotopes produced in one of the three preceding source categories. Figure 16 The Carey Salt Company Mine m Lyons, Levels of Radioactivity Kansas, is the scene of a radioactive waste disposal Radioactive wastes vary widely in the concentration of experim.ent conducted by radioactive materials. It is convenient to classify them the Oak Ridge National Laboratory. according to their potential hazard, as indicated by their level of activity. Three levels have been defined, some­ what arbitrarily, as follows: LOW-LEVEL WASTES have a radioactive content suffi­ ciently low to permit discharge to the environment with reasonable dilution or after relatively simple processing. They have no more than about 1000 times the concentra­ tions considered safe for direct release. In liquid form low-level wastes usually contain less than a microcurie* of Photo A. A 30-ton lead radioactivity per gallon. cask IS m.aneuvered into position over the 1000-foot *A microcurie is one millionth of a curie. A curie is a measure waste charging shaft. This of the number of atoms undergoing radioactive disintegration per provides shielding for per­ unit time and is 37 billion disintegrations per second, or about sonnel. the rate of decay in 1 gram of natural radium.

34 11 INTERMEDIATE-LEVEL WASTES have too high a concentra­ groundwater sources. The ability of salt to change shape tion to permit release after simple dilution, yet they are under pressure causes rapid closure of fractures. Salt is produced in relatively large volumes. Their radioactivity sufficiently strong that large cavities formed by mining is approximately 100 to 1000 times higher than that of low- will not collapse. Salt deposits underlie some 400,000 level wastes. In liquid form they may contain up to a curie square miles of the United States. And the estimated of radioactivity per gallon. volume of high-level waste solids to be produced in the HIGH-LEVEL WASTES contain several hundred to several year 2000 would occupy less than 1% of the volume of salt thousand curies per gallon in liquid form and result from now being mined each year. chemical processing of irradiated nuclear fuels. High-level An Oak Ridge National Laboratory program includes wastes pose the most severe potential health hazard and studies of possible effects of radiation on salt—on its the most complex technical problems in management. physical properties, the possible production of chlorine, and the effects on movement under pressure and plastic Potential Effects of Radioactivity flow when heated. This information is necessary before actual disposal facilities are designed. Man has always been exposed to the natural radioactivity in his environment. It is in the soil, in the water we drink, A 19-month demonstration disposal of high-level radio­ and even in our bodies. This natural "background" level of active waste solids was carried out in a salt mine at Lyons, radioactivity is quite low: The amount of radiation received Kansas. Spent reactor fuel was used in lieu of actual in one dental X ray is 10 to 100 times that received in a solidified wastes. During the field demonstration, the fea­ year from natural background activity. A cardinal principle sibility and safety of handling highly radioactive materials in an underground environment were demonstrated; the stability of salt under the effects of heat and radiation was shown; and data were obtained on the creep and plastic flow characteristics of salt for use in the design of an industrial salt disposal facility. Further engineering studies are now being carried out to determine the location and possible establishment of such a facility. 2. Bedrock Storage—In some cases it may not be necessary to reduce high-level wastes to solid form. At the AEC's Savannah River Plant, a study is under way for disposal of aged wastes in underground tunnels cut into bedrock. Underlying the plant at approximately 1000 feet is dense, crystallized bedrock. Exploratory drilling has provided information on the hydrology and geology of this formation and has verified the compatibility of the rock with the wastes to be stored. A layer of clay overlays the bedrock and separates it from the top layer of loose water-bearing sediment. Three principal mechanisms delay the migration of wastes from the bedrock tunnels: the low rate of natural Figure 6 Research to determine the effects o/ irradiated soil on water movement, the impermeability and ion-exchange cotton plants. properties of the clay, and the ion-exchange properties of

12 33 heated pot. There the calcination is completed and forms m waste management has been to preserve this low radia­ a powdery or molten residue, depending on the waste ma­ tion level m our environment — not to add to it. terial. In an experimental program numerous successful Any discharge of radioisotopes to our environment tests with high-level waste have been completed. This launches a series of interrelated physical and biological system handles many kinds of wastes, reduces vaporization events because of the movement of released materials and loss of certain fission products, and eliminates foaming through the atmosphere and underground water and their and heat-transfer problems. retention in soil and living organisms. Some of these 3. Phosphate-glass Fixation—For the past several processes may result m the concentration of radioisotopes years, Brookhaven National Laboratory personnel have that were originally released m very dilute form—^thus been working on a continuous process for incorporating fish may concentrate phosphorus-32 m their tissues, and waste fission products into phosphate glass. This process oysters may accumulate zinc-65, offers the possibility of a continuous process m an ail- The growth of nuclear industry emphasizes the need for liquid system and would allow easy heat control, removal complete understanding of natural processes affecting re­ of decomposition gases, mixing of ingredients, and general leased radioisotopes. Not only the concentration but also handling. The mam parts of the plant are a feed-mixing the amount of radioactive material is important; care must tank, an evaporator, a high-temperature furnace with a be taken not to exceed the capacity of the environment. platinum-lined crucible, and a gas processing system. Extensive research is being performed at large atomic The glass melt from the crucible is discharged into burial energy installations to insure that no unsuspected en­ containers. vironmental effects will result from the carefully con­ Three solidification processes have been undergoing pilot- trolled release of radioactivity. plant demonstration at full radioactivity level at Pacific Equally important is the intensive study of the long-term Northwest Laboratory since November 1966. The demon­ effects of radiation on man himself. Radiation can affect stration program is scheduled to be completed m 1970 with an exposed individual directly (somatic effects) by damage a series of engineering reports being made available to to body cells, or it can affect his descendants (genetic industry as separate phases of the program are completed. effects) by damage to reproductive cells. Somatic effects HIGH-LEVEL WASTE STORAGE m natural geologic forma­ are reduced when a given radiation exposure is spread over tions IS being investigated. The production of stable solids a long time. Although there is some evidence that the same that are insoluble and noncorrosive reduces the volume of principle applies m the case of genetic effects, it is not waste to be stored and increases the safety of the storage conclusive. activities. But what is the best way to store these solidified The isotopes of greatest concern are generally those wastes'? Remember that hundreds of years will be required with the longest half-lives, such as strontium-90 and for the natural decay of these wastes to harmless levels. cesium-137. It is also necessary to consider how each Simple burial or disposal m the sea is not a suitable radioisotope is taken mto the body and how it behaves, once answer. Fortunately there are a number of natural geologic there. Iodme-131, for example, is passed efficiently through formations that might be suitable for permanent storage — food chains — from the air to grass, thence to cows, and they are well removed from man and free of groundwater via milk to man, where it is concentrated m the thyroid that might otherwise leach and carry off some of the radio­ gland. Radioactive lodme therefore requires stringent con­ active material to areas of possible human access. trol even though its haK-life is a relatively short eight days 1. Salt Deposits—At present salt appears to be the best The type and energy of emitted radiation and the chemi­ disposal medium. Salt formations are usually dry, are cal properties of radioisotopes are other factors that were impervious to water, and are not associated with usable considered m establishing maximum permissible concen-

32 13 trations for the various radioisotopes. These safe limits The WCF has, during the past A^ years, processed ap­ are published in the Code of Federal Regulations, which proximately 1,500,000 gallons of high-level liquid waste to controls management of radioactive waste materials. a solid form. It can process 1400 gallons of liquid waste per day. WASTE MANAGEMEMT The bulk volume of the solid particles is about one-tenth Radioactive waste management consists of the various that of the liquid wastes from which they are made. The steps necessary for the safe disposal of radioactive wastes AEC plans to store the solid product underground in vented and the control and direction of these measures. Each type stainless-steel bins within concrete vaults. Heat from the of waste requires its own methods for control and disposal. radioactivity of the product will be removed by air flowing There are, however, two basic principles that are broadly past the outer walls. The solid oxide particles from this applied: process could also be glazed, coated, incorporated into a Concentrate and Contain. Radioactive materials can be metal or salt matrix, or converted to glasslike material by stored safely in permanently controlled reservations, but addition of appropriate chemicals at high temperature. the volume of stored wastes would be prohibitively great if These methods are being thoroughly investigated. they were not first concentrated. Even high-level wastes Waste Solidification Engineering Prototype. There are 3 can be concentrated or solidified for long-term storage. promising solidification processes to be demonstrated in Dilute and Disperse. Wastes of appropriately low ac­ the Waste Solidification Engineering Prototype (WSEP) tivity may be reduced to permissible levels for release by installation at the Pacific Northwest Laboratory at the dilution in air or in waterways. Wherever materials are to Hanford Plant, beginning early in 1966. The processes are be released to the environment, the amount of radioactivity the Oak Ridge National Laboratory pot-calcination process, that can be safely dispersed into that particular environ­ the Hanford spray-calcination process, and the Brookhaven ment is determined quantitatively for each specific radio­ National Laboratory phosphate glass-fixation process. isotope. 1. Pot Calcination — This process involves evaporation In the application of these principles, two considerations of wastes to dryness followed by calcination of the residues are important: at temperatures of 700 to 900°C. Calcination is the process Evaluate Each Case Individually. Each factor affecting of making dry, granular solids by heating. The tempera­ waste management must be evaluated for each facility. ture used is not high enough to melt the material. The last These factors include accurate data on the specific radio­ step is done in a pot, which then becomes the final storage isotopes, their chemical form and concentration, their container. When filled with calcined solids, the pot is maximum allowable concentrations for release, and the sealed and shipped to permanent storage. This process detailed characteristics of the environment. Suitable treat­ offers versatility in processing several types of waste, ment and disposal methods then can be chosen and detailed produces a minimum amount of gases, and eliminates the operating standards established. need for packaging the product. Check Results. It is important to make certain that 2. Spray Calcination—Over the past four years, per­ operating standards for waste management are met. This sonnel of the Pacific Northwest Laboratory have been requires constant checking on the amount and level of investigating the merits of converting liquid wastes to sol­ activity handled and released. If conditions change at a ids by spray calcination in a heated tower. Liquid wastes site, operating standards must be reexamined and changed are forced through a nozzle into the top of a tower, the if necessary. sides of which are heated to about 800°C. As the droplets Conscientious application of these considerations has fall, they are first subjected to evaporation, then drying, been responsible for the success, safety, and economy of and finally calcination. The resulting powder falls into a

14 31 Figure 7 View oJ the Pro­ cess Waste Treatment Plant ponds at Oak Ridge National Laboratory. A workman checks liquid level.

waste-management activities in this country. There have been no harmful effects to the public or their environment. The cost of waste handling and processing facilities at nuclear power plants averages only 3 to 5% of the total plant cost; the cost of managing high-level wastes from fuel processing is expected to be 1% or less of the total fuel-cycle cost.

Liquid Waste Management: Low and Intermediate Level Liquid wastes of low and intermediate radioactivity generally have low solids content but vary considerably in chemical and radioisotope content. Treatment and disposal methods differ among nuclear installations, depending both on the waste content and the environment. Let us consider methods in industry and science, SMALL LABORATORIES, such as educational, industrial, hospital, and medical laboratories, generally produce liquid wastes of low activity. They typically contain only traces of a few isotopes. They are produced in modest quantities and can usually be released by dilution, treated by filtration

30 15 \ or ion exchange,* or retained for shipment to sites equipped and in spite of the many different reactor types foreseen for their disposal. Though the amount of waste from these for future uses. laboratories is small, all agencies licensed for use of radioactive materials must meet disposal standards. High-level Waste Processing URANIUM MINES AND ORE MILLS produce relatively large The disadvantages of tank storage for hundreds of years quantities of low-level liquid wastes requiring minimal have resulted in vigorous search for more practicable treatment. Where mine pumping is required, as in the methods for the ultimate disposal of high-level wastes. Ambrosia Lake area in New Mexico, the radioactivity is Two general approaches have been dominant. The first so low that the wastes are allowed to seep into nearby seeks to convert aged wastes to solid form. The second desert soil. seeks to store these solids deep in geologic formations to The liquid wastes from ore-refining mills are also reduce future handling and the possibility of leaks to man's dispersed into the environment. Solids are settled out in environment. large retention ponds, and the liquid overflows to streams CONVERSION-TO-SOLID-FORM METHODS include use of flu- or percolates into the ground. In some locations, mills idized beds, heated pots, and radiant-heated spray columns first remove dissolved radium by chemical treatment. to form solid granules. The addition of glass-forming Uranium-mill waste treatment and control have improved materials to produce stable, glassy, insoluble products is substantially in the past five years, also under study. FUEL FABRICATION PLANTS produce modest quantities of Fluidized-bed Calcining. Studies began at Argonne Na­ low-level acid wastes that are diluted, neutralized, stored tional Laboratory, Argonne, Illinois, in 1955 in the use of to permit decay, and then discharged to waterways. Some fluidized beds for the reduction of liquid wastes to solid industrial fuel manufacturers collect the wastes and ship form. These studies led to the construction of the Waste them elsewhere for disposal. All shipments must conform Calcining Facility (WCF) at the Idaho Chemical Processing to Interstate Commerce Commission regulations, and ap­ Plant near Idaho Falls, Idaho. This plant processes highly proved containers must be used. enriched fuels and produces acid wastes requiring storage tanks constructed of stainless steel; thus the storage ex­ NATIONAL LABORATORIES OF THE AEC produce many kinds pense is somewhat higher than that for other facilities. of wastes. The methods used to manage them differ in The WCF was the first full-scale unit in the world for detail but are similar in many respects. In general, liquid reduction of high-level liquids to solids (see Figure 15). wastes from the laboratories range in concentration from Waste solutions are injected into a 4-foot-diameter vessel less than a hundredth of a microcurie to several hundred called a calciner that contains a heated bed of granular microcuries per gallon. Treatment usually includes several solids, fluidized with air. A fluidized bed is obtained when of the following steps: filtration, chemical precipitation, gas moves up through a bed of solid particles with enough ion exchange, evaporation, solidification in concrete, or force to raise them and move them about. The heat boils absorption in porous materials such as vermiculite. off the liquid and breaks down salts to oxides that deposit Chemical precipitation is a process of adding chemicals in layers on the bed particles. Gaseous products are drawn that combine with dissolved radioactive materials to form from the calciner. As solids accumulate, they are drawn off—about half are removed from the lower part of the calciner and half are carried off with the gases, from *Ion exchange, a process also used in home water softeners, re­ which they are removed in a series of cyclone separators. moves dissolved minerals from liquids. In this system air is used to transport the solids.

16 29 LONG-LIVED FISSION PRODUCTS have been in increasing solid particles.* The solids are then separated from the demand since 1960 for many different uses. At first glance liquid and disposed of by packaging and burial. Chemical it would seem that separation and use of these radioiso­ precipitation is 60 to 75% effective in removing mixed topes might offer a means of waste disposal or result in fission products from low-level laboratory wastes. Ion- reduced waste-disposal costs. Although some saving can exchange resins remove 90 to 99.99% of the contained be realized by combining waste management and fission- Figure 8 Engineers at the Sa­ product recovery, the ultimate disposal problem will not vannah River Plant developed this be appreciably affected, because final disposal is only by remotely controlled wall thick­ the natural decay of radioactive materials. The separation ness tester shown at left to detect corrosive thinning of the steel of isotopes must be self-supporting in terms of the value walls of underground tanks con­ of the separated isotopes. taining highly radioactive wastes. An operator at the surface lowers the foot-long "bug" through an RESEARCH AND DEVELOPMENT access hole on the tank perimeter. The nuclear industry is producing increasing amounts of Its magnetic wheels grip the steel all types of radioactive wastes. Furthermore, it is likely wall, and the carriage is then rolled up or down to the desired there will be need to locate new plants in less ideal spots position. A solenoid-actuated air than present sites. Environmental restrictions for long- cylinder on the carriage presses term management of wastes could be quite rigid in some a small ultrasonic transducer to the wall; water is jetted over the areas. It cannot be expected that methods adequate for an contact area, providing the nec­ infant industry will be sufficient to cope with the problems essary coupling. The transducer of its robust future. then emits an ultrasonic pulse Long-term management of radioactive wastes requires that penetrates the wall and is reflected from its inner surface. the solution of two principal problems. The first is de­ velopment of improved methods for processing and dis­ posing of high-level wastes in solid form. The second is radioactivity. Evaporation of low-level waste retains some improved treatment of large volumes of low-level and 99.99% of the activity in evaporator concentrates. intermediate-level wastes to reduce the amount of radio­ Waste-management operations at Brookhaven National activity released to the environment. Laboratory in Upton, New York, illustrate some current A number of research activities have begun on these two methods, Brookhaven is located near the center of Long problems, plus search for more complete understanding of Island, with farm and residential areas just beyond its the long-term effects of released radioactivity on man. boundaries. Several villages are close by. Most of the Although there is still much to be learned, it is worth Brookhaven liquid wastes are generated at the research noting that the hazards and behavior of radioactive ma­ reactor, the "hot"t laboratory, and the cyclotron building. terials probably are already better understood than are the hazards of conventional industry and that the safety record *The precipitation process is often demonstrated to chemistry of the nuclear industry is without parallel. classes by adding a weak silver nitrate solution to a sodium chlo­ We already know that proper management of radioactive ride (table salt) solution; a fine white powder, silver chloride, wastes can be accomplished without hampering the economic immediately forms and precipitates (settles) to the bottom of the container, growth of the nuclear industry — in spite of the millions of tTheterm "hot" is applied to radioactive materials or facilities. curies of radioactivity involved, in spite of the hundreds of The term "clean" is often used to indicate an absence of radio­ years of controlled storage required for high-level wastes, activity.

28 17 Low-level wastes are produced in most of the other labo­ of the liquid. "Self-heating" wastes, on the other hand, ratories. How are these wastes handled? will be separated into two fractions. The first fraction First, wastes are separated at their source by collection containing the long-lived heat-producing radioisotopes will of concentrated wastes in containers. In addition, the re­ be absorbed on ion-exchange beds and stored in stainless- actor and hot laboratory facilities have a separate liquid steel cylinders; the remainder will become "low-heating" waste system, and release from this to the general labo­ waste after several years and can be solidified in place in ratory system is rigorously controlled. The general labo­ the underground tanks. Figure 14 shows the planned in- ratory system, in turn, is monitored* to ensure control; release from this system to the environment is by way of WASTE INTAKE AIR INTAKE a filtering system. Wherever excess activity may accumulate, " hold-up tanks" are provided^ and evaporation reduces the stored volume. Some of the concentrate from evaporation is mixed with concrete, solidified, and handled as solid waste. The bulk of the low-level liquid waste, however, is discharged via a separate sewage system to a settling tank that re­ moves most of the solid material. From there the re­ maining liquid is discharged through a large sand filter, collected in an underlying tile field, chlorinated, and finally discharged to a small stream. (a) EVAPORATINQ PERIOD Samples are collected at key points in both the internal system and the nearby environment. These are monitored to assure control. Only several curies of activity are re­ SROUND LEVEL leased to the environment annually. The amount of radioactivity in purified wastes like these has been reduced in recent years. Oak Ridge National Laboratory in Tennessee, for example, in three years re­ duced the activity released m its low-level wastes to one- tenth the former amount. (b) COOUNS PERIOD NUCLEAR POWER PLANTS that generate electric power process low-level liquid wastes through treatment and Figure 14 Proposed m-tank solidification of high-level wastes at storage systems, such as evaporators, ion exchangers, gas the Hanford Plant. More waste can be added as tank level drops filtration, decay holdup tanks, incineration and fixation of during evaporation, (a) Evaporation process; (b) cooling. solids and liquids in concrete. In many cases, liquid wastes are processed by decay storage without any other treat­ tank solidification process. Heated air (800°C) both heats ment. The quantities of radioactivity discharged from and circulates the waste, and most of the water is boiled nuclear power plants have been well below permissible re­ off. Upon cooling, the remaining wastes form a massive lease limits. Most reactor installations control their wastes salt cake that no conceivable material failure or natural phenomenon could expose to living plants or animals. Other * Monitoring involves measurement of radioactivity with radia­ methods of solidifying high-level wastes also are under tion-detection instruments. intensive investigation.

18 27 array sits on a heavy steel "saucer" that extends upward 5 feet at the edges; the saucer, in turn, rests on a concrete slab. Access openings are provided for insertion of instru­ ments, inspection, sampling, and withdrawal of gases. Tank storage of liquid wastes has proved to be both safe and practical. To extend this for hundreds of years will require periodic replacement of tanks, however, and no valid basis yet exists for accurately predicting tank service life. Experience indicates a reasonable tank-life expecta­ tion of several decades, however. Extensive research and development is being carried out to convert highly radioac­ tive liquid wastes to a solid form. The cost of constructing waste storage tanks has varied from $0.50 to $2.70 per gallon of capacity. The cost de­ pends on size, the acidity of the expected waste, and the need for heat-removal equipment. Most tanks hold from 300,000 to 1,330,000 gallons. The largest ones are for alkaline, low-heating wastes at Savannah River, and they have the lowest unit cost. The total cost of storage, of course, includes construc­ tion of future replacement tanks and annual operating costs; annual expenses range from about '^/^o to 3% of the original capital cost. It is estimated that the total will be Figure 9 Monitoring residues from liquid wastes. A technician is about $100 per gallon for storage over the 600 or more placing a container of powdered material in a shielded i?istru)nent years of storage expected to be needed, assuming a 20- where radiation will be measured by a Geiger counter. year tank life. Some installations reduce storage requirements by con­ in accord with the strict standards applying to unidentified centrating wastes, and improved fuel processing has re­ mixtures rather than less stringent ones for individual duced waste volumes from several thousand to several radioisotopes. hundred liters per ton of spent fuel. No liquid wastes are released into the ground at reactor In spite of these improvements, continuous surveillance installations. The waste systems do use decay hold-up of stored liquid wastes is mandatory, as is the need for tanks, evaporators, ion-exchange systems, filtration, and, transfer of the wastes from tank to tank over periods of in some cases, steam stripping (to remove gases). In a hundreds of years. These are compelling reasons to search typical water-cooled reactor power plant, there are two for ways to reduce wastes to solid form. sources of liquid waste: the reactor coolant itself and IN-TANK SOLIDIFICATION plans at the Hanford Plant call drainage from supporting laboratories and facilities. When for solidification of "nonheating" wastes* by evaporation necessary, contaminated liquids are processed in evapora­ tors or ion exchangers. The evaporator concentrates and *"Nonheating" wastes produce less than 0.2 British thermal used ion-exchange resins are then retained for later ship­ units per hour per gallon. (One Btu is the amount of heat energy needed to raise the temperature of 1 pint of water by 1 degree ment from the site. Ion exchange is typically used for Fahrenheit.) continuous cleansing of reactor coolants, but discharged

26 19 reactor water must nonetheless be retained m tanks to levels; during all this time they must be stored away from allow radioactive decay, or be processed further man and his environment, At the Shippmgport Atomic Power Station m Pennsylvania, TANK STORAGE has been used since high-level waste discharged reactor-coolant water is not treated by evapora­ management first began years ago at the plutonium- tion or ion exchange but is stored m underground tanks for production facilities at the Hanford Plant, Since then a month or more, to permit radioisotopes to decay, before engineers and scientists of installations at Savannah River, being released to the Ohio River. South Carolina, and at the National Reactor Test Site, HANFORD PRODUCTION FACILITIES of the AEC, which pro­ Idaho, also have used tanks. Almost all such wastes are duce Plutonium, have environmental conditions more favor­ stored m some 200 underground tanks at the three sites (see able than most power-plant and laboratory sites. Hanford Figure 13). The newest type of tank at Savannah River has IS relatively remote from towns and is adjacent to the a steel Imer encased m concrete and concrete support­ Columbia River, with its high volume of flow. ing pillars between tank compartments. The whole tank The three reactors presently used for plutomum pro­ duction are cooled by a single pass of river water, which has been treated by coagulation,* settling, and filtration. A fourth reactor is cooled by recirculating water The water emerging from the single-pass reactors contains activated impurities and corrosion products and must be held m large basins or tanks for 1 to 3 hours; here natural decay reduces the activity by 50 to 70%. The basin water is then released to the Columbia, where it is immediately diluted by the streamflow If the basin water acquires unusual radioactivity because of leaks of fission products from fuel elements, it is dis­ charged to trenches and seeps into the ground. This percolation is very effective since the soil retains the radionuclides. The water table at Hanford is 200 to 600 leet below the surface. Some mtermediate-level liquid wastes are also dis­ charged into the ground through trenches or underground cribs at Hanford (see Figure 10). These include wastes from chemical processing of irradiated fuel, condensed vapors from these processes and from waste storage tanks Gaseous Waste Management Gaseous wastes may contain natural radioactivity, fission- product activity, or materials activated by neutron ab­ Figure 13 Large concrete-encased steel tanks under construction sorption, at tlie Savannah River Plant will store high-level wastes Note forms for prestressmg concrete on unfinished tank at left, finished •Coagulation and settling are used the world over for water tanks at right, and size of m.an m center foreground. There are treatment Added chemicals form a sticky, gelatinous precipitate now 80 million gallons of high-activity liquid wastes stored m AEC that removes suspended solids as it settles facilities.

20 25 wastes and hold surface radiation levels so low that ex­ posure for a full year would result in less radiation than results from a typical medical fluoroscopic examination. MONITORING WELLS Higher activity solids are often buried in concrete-lined wells or stored to permit decay of the activity prior to RARE EARTHS- disposal. STRONTIUM —

High-level Waste Management CESIUM - High-level wastes from processed nuclear fuels create the most challenging problem in waste management. These wastes produce substantial amounts of heat for a number of years (see Figure 12). Furthermore, their long-lived radioisotopes require hundreds of years to decay to safe

- — _^ ^^"^^^ TOTAL FISSION PRODUCT ENERGY Figure 10 Disposal oj liquid wastes into the ground at the Hanjord Plant using an underground crib. The various materials jound in 10 \ \ these wastes are retained in the soil as shown. \ \ \ \ RARE EARTHS—~\ \ In the mining, milling, and fabricating of uranium into 1 _ \ \ \ - fuel elements, airborne radioactivity consists of natural \ radioisotopes in dusts or gaseous radon. These typically STRONTIUM —1 occur in low concentrations. Normal ventilation of the work

01 area gives adequate protection. Air discharged from mine CESIUM —/ \ ventilation systems usually contains radon-222 and its \ short-lived decay products; the quantity released to the \ atmosphere is much less than that naturally given off by 0 01 — r rocks of the earth's crust. \ The generation of gaseous radioactive wastes at nuclear \ 0 001 power plants is different for each type of reactor, but the wastes have been effectively managed m all types of

1 5 20 reactors. In general, gaseous wastes are held for an ap­ YEAR YEARS YEARS propriate period of decay and then are released through a 0 0001 1 1 1 1 1 1 1 10 100 1000 10 000 high stack after filtration. TIME DAYS Radioiodine is often present in gaseous reactor wastes. Figure 12 Heat production in high-level wastes from spent fuel Its presence usually determines how the wastes are man­ processing. After five years strontium and cesium account for aged. Activated charcoal can remove up to 99.9%) of the most of the heat production. Note that removal of these isotopes radioiodine, but the charcoal's effectiveness soon may be bejore several years oj aging would have little effect on heat pro­ duction oj the remaining mixture. reduced by surface contamination.

24 21 Fuel-processing plants control the discharge of radio­ are carefully selected, and arrangements must be made to iodine by a combination of methods. First, the spent (used) control wastes over a period of many years after they are fuel is stored from 90 to 120 days to allow natural decay of buried. Only AEC-supervised sites were used until 1963; most of the iodine. Second, most remaining iodine is then the first state-owned burial sites were established for vaporized during the fuel processing and is removed from disposal operations by private industry. Burial sites have other gases by activated charcoal or a chemical-reaction now been established in Nevada, Kentucky, New York, system that converts the iodine into a solid. Illinois, and Washington by private companies. Burial of solid radioactive waste at AEC burial sites is Solid Waste Management about 1.5 million cubic feet per year since 1963. This waste Most solid radioactive wastes are of moderately low level volume requires approximately 20 to 25 acres of land an­ and are disposed of by burial. As with liquids and gases, nually. they may contain natural, fission-product, or activation- The volumes of low-level solid waste available for product radioactivity. commercial burial are estimated at 1 million cubic feet Solid refuse from mining operations contains only a by 1970, 2 miUion by 1975, and 3 million by 1980. fraction of 1% of uranium oxide. It is usually piled near Land requirements for waste burial have averaged about mine portals; no hazard is involved because of its low 1 square foot of ground for 1.5 cubic feet of waste. Solid radioactivity. Solid refuse from ore-refining mills, called wastes are now being pressed in standard baling machines tailings, is of greater concern because it contains most of before burial, however, to reduce the waste volume 2 to the radium from the ore. The tailings are usually held in 10 times. controlled areas to prevent dispersal to the environment. The wastes are generally buried in unlined pits and This is more economical than chemical treatment to re­ trenches (see Figure 11). Several feet of earth cover the move the radium from the large quantities involved. How best to dispose of tailings actually remains an unanswered question for the present. Solid wastes from feed-material and gaseous-diffusion plants contain only small amounts of natural radioisotopes. They are disposed of by burial in supervised reservations. Some are first treated to remove uranium, especially if it is enriched uranium. Moderately radioactive solid wastes from laboratories and reactor installations are similar. They consist mostly of residues (used ion-exchange resins or evaporator con­ centrates) and contaminated equipment and materials (worn- out clothing, filter elements, glassware, blotting paper i and other debris). Some establishments burn them to re­ 1 duce their volume before disposal. Most, however, simply bale and bury them. LAND BURIAL has been used for about two-thirds of all solid waste produced in the United States through 1963 at Figure 11 Land burial trench at the Oak Ridge National Laboratory five atomic energy reservations—amounting to approxi­ reservation. Each day's accumulation of waste containers is buried mately 30,000 to 50,000 cubic meters per year. Burial sites by 3 or more feet of earth.

22 23 Fuel-processing plants control the discharge of radio­ are carefully selected, and arrangements must be made to iodine by a combination of methods. First, the spent (used) control wastes over a period of many years after they are fuel is stored from 90 to 120 days to allow natural decay of buried. Only AEC-supervised sites were used until 1963; most of the iodine. Second, most remaining iodine is then the first state-owned burial sites were established for vaporized during the fuel processing and is removed from disposal operations by private industry. Burial sites have other gases by activated charcoal or a chemical-reaction now been established in Nevada, Kentucky, New York, system that converts the iodine into a solid. Illinois, and Washington by private companies. Burial of solid radioactive waste at AEC burial sites is Solid Waste Management about 1.5 million cubic feet per year since 1963. This waste Most solid radioactive wastes are of moderately low level volume requires approximately 20 to 25 acres of land an­ and are disposed of by burial. As with liquids and gases, nually. they may contain natural, fission-product, or activation- The volumes of low-level solid waste available for product radioactivity. commercial burial are estimated at 1 million cubic feet Solid refuse from mining operations contains only a by 1970, 2 million by 1975, and 3 million by 1980. fraction of 1% of uranium oxide. It is usually piled near Land requirements for waste burial have averaged about mine portals; no hazard is involved because of its low 1 square foot of ground for 1.5 cubic feet of waste. Solid radioactivity. Solid refuse from ore-refining mills, called wastes are now being pressed in standard baling machines tailings, is of greater concern because it contains most of before burial, however, to reduce the waste volume 2 to the radium from the ore. The tailings are usually held in 10 times. controlled areas to prevent dispersal to the environment. The wastes are generally buried in unlined pits and This is more economical than chemical treatment to re­ trenches (see Figure 11). Several feet of earth cover the move the radium from the large quantities involved. How best to dispose of tailings actually remains an unanswered question for the present. Solid wastes from feed-material and gaseous-diffusion plants contain only small amounts of natural radioisotopes. They are disposed of by burial in supervised reservations. Some are first treated to remove uranium, especially if it is enriched uranium. Moderately radioactive solid wastes from laboratories and reactor installations are similar. They consist mostly of residues (used ion-exchange resins or evaporator con­ centrates) and contaminated equipment and materials (worn- out clothing, filter elements, glassware, blotting paper and other debris). Some establishments burn them to re­ duce their volume before disposal. Most, however, simply bale and bury them. LAND BURIAL has been used for about two-thirds of all solid waste produced in the United States through 1963 at Figure 11 Land burial trench at the Oak Ridge National Laboratory five atomic energy reservations — amounting to approxi­ reservation. Each day's accumulationoj waste containers is buried mately 30,000 to 50,000 cubic meters per year. Burial sites by 3 or more jeel oj earth.

22 23 wastes and hold surface radiation levels so low that ex­ posure for a full year would result in less radiation than results from a typical medical fluoroscopic examination. Higher activity solids are often buried in concrete-lined wells or stored to permit decay of the activity prior to disposal.

High-level Waste Management High-level wastes from processed nuclear fuels create the most challenging problem in waste management. These wastes produce substantial amounts of heat for a number of years (see Figure 12). Furthermore, their long-lived radioisotopes require hundreds of years to decay to safe

~ ~ -~. ^^'^<-—TOTAL FISSION PRODUCT ENERGY Figure 10 Disposal of liquid wastes into the ground at the Hanford Plant using an underground crib. The various materials found m 10 these wastes are retained in the soil as shown. \ \ RARE EARTHS— In the mining, milling, and fabricating of uranium into 1 — fuel elements, airborne radioactivity consists of natural

STRONTIUM —J radioisotopes in dusts or gaseous radon. These typically \ \ occur in low concentrations. Normal ventilation of the wort? 01 area gives adequate protection. Air dischaiged from mme CESIUM -J \ ventilation systems usually contains radon-?22 ar.. iS \ short-lived decay products; the quantity it^-ifised to !1 •> 0 01 — \ atmosphere is much less than that naliirally > i>'eii -/ ' ,, \ \ rocks of the earth's crust. \ The generation of gaseous radioactive wastes at nuci'= u- \ 0 001 — power plants is different for each type of reactor, but the wastes have been effectively managed m all types of

1 5 20 reactors. In general, gaseous wastes are held for an ap­ YEAR YEARS YEARS propriate period of decay and then are released through a 0001 1 1 III 1 100 high stack after filtration. TIME DAYS Radioiodine is often present in gaseous reactor wastes. Figure 12 Heat production in high-level wastes from spent fuel Its presence usually determines how the wastes are man­ processing. After five years strontium, and cesium account for aged. Activated charcoal can remove up to 99.9% of the most of the heat production. Note that removal of these isotopes before several years of aging would have little effect on heat pro­ radioiodine, but the charcoal's effectiveness soon may be duction of the remaining -mixture. reduced by surface contamination.

24 21 reactor water must nonetheless be retained in tanks to levels; during all this time they must be stored away from allow radioactive decay, or be processed further. man and his environment. At the Shippingport Atomic Power Station in Pennsylvania, TANK STORAGE has been used since high-level waste discharged reactor-coolant water is not treatedby evapora­ management first began years ago at the plutonium- tion or ion exchange but is stored in underground tanks for production facilities at the Hanford Plant. Since then a month or more, to permit radioisotopes to decay, before engineers and scientists of installations at Savannah River, being released to the Ohio River. South Carolina, and at the National Reactor Test Site, HANFORD PRODUCTION FACILITIES of the AEC, which pro­ Idaho, also have used tanks. Almost all such wastes are duce Plutonium, have environmental conditions more favor­ stored in some 200 underground tanks at the three sites (see able than most power-plant and laboratory sites. Hanford Figure 13). The newest type of tank at Savannah River has is relatively remote from towns and is adjacent to the a steel liner encased in concrete and concrete support­ Columbia River, with its high volume of flow. ing pillars between tank compartments. The whole tank The three reactors presently used for plutonium pro­ duction are cooled by a single pass of river water, which has been treated by coagulation,* settling, and filtration. A fourth reactor is cooled by recirculating water. The water emerging from the single-pass reactors contains activated impurities and corrosion products and must be held in large basins or tanks for 1 to 3 hours; here natural decay reduces the activity by 50 to 70%. The basin water is then released to the Columbia, where it is immediately diluted by the streamflow. If the basin water acquires unusual radioactivity because of leaks of fission products from fuel elements, it is dis­ charged to trenches and seeps into the ground. This percolation is very effective since the soil retains the radionuclides. The water table at Hanford is 200 to 600 feet below the surface. Some intermediate-level liquid wastes are also dis­ charged into the ground through trenches or underground cribs at Hanford (see Figure 10). These include wastes from chemical processing of irradiated fuel, condensed vapors from these processes and from waste storage tanks. Gaseous Waste Management Gaseous wastes may contain natural radioactivity, fission- product activity, or materials activated by neutron ab­ Figure 13 Large concrete-encased steel tanks under construction sorption. at the Savannah River Plant will store high-level wastes. Note forms for prestressing concrete on unfinished tank at left, finished * Coagulation and settling are used the world over for water tanks at right, and size of man in center foreground. There are treatment. Added chemicals form a sticky, gelatinous precipitate now 80 million gallons of high-activity liquid wastes stored in AEC that removes suspended solids as it settles. facilities.

20 25 array sits on a heavy steel "saucer" that extends upward 5 feet at the edges; the saucer, in turn, rests on a concrete slab. Access openings are provided for insertion of instru­ ments, inspection, sampling, and withdrawal of gases. Tank storage of liquid wastes has proved to be both safe and practical. To extend this for hundreds of years will require periodic replacement of tanks, however, and no valid basis yet exists for accurately predicting tank service life. Experience indicates a reasonable tank-life expecta­ tion of several decades, however. Extensive research and development is being carried out to convert highly radioac­ tive liquid wastes to a solid form. The cost of constructing waste storage tanks has varied from $0.50 to $2,70 per gallon of capacity. The cost de­ pends on size, the acidity of the expected waste, and the need for heat-removal equipment. Most tanks hold from 300,000 to 1,330,000 gallons. The largest ones are for alkaline, low-heating wastes at Savannah River, and they have the lowest unit cost. The total cost of storage, of course, includes construc­ tion of future replacement tanks and annual operating costs; annual expenses range from about ^/^o to 3% of the original capital cost. It is estimated that the total will be Figure 9 Monitoring residues from, liquid wastes. A technician is about $100 per gallon for storage over the 600 or more placing a container of powdered material in a shielded instrum.ent years of storage expected to be needed, assuming a 20- where radiation will be measured by a Geiger counter. year tank life. Some installations reduce storage requirements by con­ in accord with the strict standards applying to unidentified centrating wastes, and improved fuel processing has re­ mixtures rather than less stringent ones for individual duced waste volumes from several thousand to several radioisotopes. hundred liters per ton of spent fuel. No liquid wastes are released into the ground at reactor In spite of these improvements, continuous surveillance installations. The waste systems do use decay hold-up of stored liquid wastes is mandatory, as is the need for tanks, evaporators, ion-exchange systems, filtration, and, transfer of the wastes from tank to tank over periods of in some cases, steam stripping (to remove gases). In a hundreds of years. These are compelling reasons to search typical water-cooled reactor power plant, there are two for ways to reduce wastes to solid form. sources of liquid waste: the reactor coolant itself and IN-TANK SOLIDIFICATION plans at the Hanford Plant call drainage from supporting laboratories and facilities. When for solidification of "nonheating" wastes* by evaporation necessary, contaminated liquids are processed in evapora­ tors or ion exchangers. The evaporator concentrates and •"Nonhealing" wastes produce less than 0.2 British thermal used ion-exchange resins are then retained for later ship­ units per hour per gallon. (One Btu is the amount of heat energy needed to raise the temperature of 1 pint of water by 1 degree ment from the site. Ion exchange is typically used for Fahrenheit.) continuous cleansing of reactor coolants, but discharged

26 19 Low-level wastes are produced in most of the other labo­ of the liquid. "Self-heating" wastes, on the other hand, ratories. How are these wastes handled? will be separated into two fractions. The first fraction First, wastes are separated at their source by collection containing the long-lived heat-producing radioisotopes will of concentrated wastes in containers. In addition, the re­ be absorbed on ion-exchange beds and stored in stainless- actor and hot laboratory facilities have a separate liquid steel cylinders; the remainder will become "low-heating" waste system, and release from this to the general labo­ waste after several years and can be solidified in place in ratory system is rigorously controlled. The general labo­ the underground tanks. Figure 14 shows the planned in- ratory system, in turn, is monitored* to ensure control; release from this system to the environment is by way of WASTE INTAKE a filtering system.

Wherever excess activity may accumulate, " hold-up EXHAUST FAN • tanks" are provided, and evaporation reduces the stored volume. Some of the concentrate from evaporation is mixed GROUND LEVEL with concrete, solidified, and handled as solid waste. The Trr?77777777777777r^rr77: bulk of the low-level liquid waste, however, is discharged SUPPLY via a separate sewage system to a settling tank that re­ moves most of the solid material. From there the re­ maining liquid is discharged through a large sand filter, collected in an underlying tile field, chlorinated, and finally discharged to a small stream. (a) EVAPORATING PERIOD Samples are collected at key points in both the internal system and the nearby environment. These are monitored GROUND LEVEL to assure control. Only several curies of activity are re­ -'/y/'^^|i|-' leased to the environment annually. //////^///^ SUPER SATURATED -^ The amount of radioactivity in purified wastes like these LIQUOR \^ f*^^ MU^ has been reduced in recent years. Oak Ridge National t • -^ Laboratory in Tennessee, for example, in three years re­ SALT , r.. ";;- duced the activity released in its low-level wastes to one- h tenth the former amount. (b) COOLING PERIOD NUCLEAR POWER PLANTS that generate electric power process low-level liquid wastes through treatment and Figure 14 Proposed in-lank solidification oj high-level wastes at storage systems, such as evaporators, ion exchangers, gas the Hanford Plant. More waste can be added as tank level drops filtration, decay holdup tanks, incineration and fixation of during evaporation, (a) Evaporation process; (b) cooling. solids and liquids in concrete. In many cases, liquid wastes are processed by decay storage without any other treat­ tank solidification process. Heated air (800°C) both heats ment. The quantities of radioactivity discharged from and circulates the waste, and most of the water is boiled nuclear power plants have been well below permissible re­ off. Upon cooling, the remaining wastes form a massive lease limits. Most reactor installations control their wastes salt cake that no conceivable material failure or natural phenomenon could expose to living plants or animals. Other *Monitoring involves measurement of radioactivity with radia­ methods of solidifying high-level wastes also are under tion-detection instruments. intensive investigation.

18 27

» LONG-LIVED FISSION PRODUCTS have been in increasing solid particles.* The solids are then separated from the demand since 1960 for many different uses. At first glance liquid and disposed of by packaging and burial. Chemical it would seem that separation and use of these radioiso­ precipitation is 60 to 75% effective in removing mixed topes might offer a means of waste disposal or result in fission products from low-level laboratory wastes. Ion- reduced waste-disposal costs. Although some saving can exchange resins remove 90 to 99.99% of the contained be realized by combining waste management and fission- product recovery, the ultimate disposal problem will not Figure 8 Engineers at the Sa­ vannah River Plant developed this be appreciably affected, because final disposal is only by remotely controlled wall thick­ the natural decay of radioactive materials. The separation ness tester shown at left to detect of isotopes must be self-supporting in terms of the value corrosive thinning of the steel of the separated isotopes. walls of underground tanks con­ taining highly radioactive wastes. An operator at the surface lowers RESEARCH AND DEVELOPIVIENT the foot-long "bug" through an access hole on the tank perimeter. The nuclear industry is producing increasing amounts of Its magnetic wheels grip the steel all types of radioactive wastes. Furthermore, it is likely wall, and the carriage is then there will be need to locate new plants in less ideal spots rolled up or down to the desired position. A solenoid-actuated air than present sites. Environmental restrictions for long- cylinder on the carriage presses term management of wastes could be quite rigid in some a small ultrasonic transducer to areas. It cannot be expected that methods adequate for an the wall; water is jetted over the infant industry will be sufficient to cope with the problems contact area, providing the nec­ essary coupling. The transducer of its robust future. then em.its an ultrasonic pulse Lor^-term management of radioactive wastes requires that penetrates the wall and is the solution of two principal problems. The first is de­ reflected from its inner surface. velopment of improved methods for processing and dis­ posing of high-level wastes in solid form. The second is improved treatment of large volumes of low-level and radioactivity. Evaporation of low-level waste retains some intermediate-level wastes to reduce the amount of radio­ 99.99% of the activity in evaporator concentrates. activity released to the environment. Waste-management operations at Brookhaven National A number of research activities have begun on these two Laboratory in Upton, New York, illustrate some current problems, plus search for more complete understanding of methods, Brookhaven is located near the center of Long the long-term effects of released radioactivity on man. Island, with farm and residential areas just beyond its Although there is still much to be learned, it is worth boundaries. Several villages are close by. Most of the noting that the hazards and behavior of radioactive ma­ Brookhaven liquid wastes are generated at the research terials probably are already better understood than are the reactor, the "hot"t laboratory, and the cyclotron building. hazards of conventional industry and that the safety record of the nuclear industry is without parallel. *The precipitation process is often demonstrated to chemistry classes by adding a weak silver nitrate solution to a sodium chlo­ We already know that proper management of radioactive ride (table salt) solution; a fine white powder, silver chloride, wastes can be accomplished without hampering the economic immediately forms and precipitates (settles) to the bottom of the growth of the nuclear industry — in spite of the millions of container. fTheterm "hot" is applied to radioactive materials or facilities. curies of radioactivity involved, in spite of the hundreds of The term "clean" is often used to indicate an absence of radio­ years of controlled storage required for high-level wastes, activity.

28 17 or ion exchange,* or retained for shipment to sites equipped and in spite of the many different reactor types foreseen for their disposal. Though the amount of waste from these for future uses. laboratories is small, all agencies licensed for use of radioactive materials must meet disposal standards. High-level Waste Processing URANIUM MINES AND ORE MILLS produce relatively large The disadvantages of tank storage for hundreds of years quantities of low-level liquid wastes requiring minimal have resulted in vigorous search for more practicable treatment. Where mine pumping is required, as in the methods for the ultimate disposal of high-level wastes. Ambrosia Lake area in New Mexico, the radioactivity is Two general approaches have been dominant. The first so low that the wastes are allowed to seep into nearby seeks to convert aged wastes to solid form. The second desert soil. seeks to store these solids deep in geologic formations to The liquid wastes from ore-refining mills are also reduce future handling and the possibility of leaks to man's dispersed into the environment. Solids are settled out in environment. large retention ponds, and the liquid overflows to streams CONVERSION-TO-SOLID-FORM METHODS include use of flu- or percolates into the ground. In some locations, mills idized beds, heated pots, and radiant-heated spray columns first remove dissolved radium by chemical treatment. to form solid granules. The addition of glass-forming Uranium-mill waste treatment and control have improved materials to produce stable, glassy, insoluble products is substantially in the past five years, also under study. FUEL FABRICATION PLANTS produce modest quantities of Fluidized-bed Calcining. Studies began at Argonne Na­ low-level acid wastes that are diluted, neutralized, stored tional Laboratory, Argonne, Illinois, in 1955 in the use of to permit decay, and then discharged to waterways. Some fluidized beds for the reduction of liquid wastes to solid industrial fuel manufacturers collect the wastes and ship form. These studies led to the construction of the Waste them elsewhere for disposal. All shipments must conform Calcining Facility (WCF) at the Idaho Chemical Processing to Interstate Commerce Commission regulations, and ap­ Plant near Idaho Falls, Idaho. This plant processes highly proved containers must be used. enriched fuels and produces acid wastes requiring storage tanks constructed of stainless steel; thus the storage ex­ NATIONAL LABORATORIES OF THE AEC produce many kinds pense is somewhat higher than that for other facilities. of wastes. The methods used to manage them differ in The WCF was the first full-scale unit in the world for detail but are similar in many respects. In general, liquid reduction of high-level liquids to solids (see Figure 15). wastes from the laboratories range in concentration from Waste solutions are injected into a 4-foot-diameter vessel less than a hundredth of a microcurie to several hundred called a calciner that contains a heated bed of granular microcuries per gallon. Treatment usually includes several solids, fluidized with air. A fluidized bed is obtained when of the following steps: filtration, chemical precipitation, gas moves up through a bed of solid particles with enough ion exchange, evaporation, solidification in concrete, or force to raise them and move them about. The heat boils absorption in porous materials such as vermiculite. off the liquid and breaks down salts to oxides that deposit Chemical precipitation is a process of adding chemicals in layers on the bed particles. Gaseous products are drawn that combine with dissolved radioactive materials to form from the calciner. As solids accumulate, they are drawn off—about half are removed from the lower part of the calciner and half are carried off with the gases, from *Ion exchange, a process also used in home water softeners, re­ which they are removed in a series of cyclone separators. moves dissolved minerals from liquids. In this system air is used to transport the solids.

16 29 Figure 7 View oJ the Pro­ cess Waste Treatment Plant ponds at Oak Ridge National Laboratory. A workman checks liquid level.

waste-management activities in this country. There have been no harmful effects to the public or their environment. The cost of waste handling and processing facilities at nuclear power plants averages only 3 to 5% of the total plant cost; the cost of managing high-level wastes from fuel processing is expected to be 1% or less of the total fuel-cycle cost.

Liquid Waste Management: Low and Intermediate Level Liquid wastes of low and intermediate radioactivity generally have low solids content but vary considerably in chemical and radioisotope content. Treatment and disposal methods differ among nuclear installations, depending both on the waste content and the environment. Let us consider methods in industry and science, SMALL LABORATORIES, such as educational, industrial, hospital, and medical laboratories, generally produce liquid wastes of low activity. They typically contain only traces of a few isotopes. They are produced in modest quantities and can usually be released by dilution, treated by filtration

30 15 \ trations for the various radioisotopes. These safe limits The WCF has, during the past A^ years, processed ap­ are published in the Code of Federal Regulations, which proximately 1,500,000 gallons of high-level liquid waste to controls management of radioactive waste materials. a solid form. It can process 1400 gallons of liquid waste per day. WASTE MANAGEMEMT The bulk volume of the solid particles is about one-tenth Radioactive waste management consists of the various that of the liquid wastes from which they are made. The steps necessary for the safe disposal of radioactive wastes AEC plans to store the solid product underground in vented and the control and direction of these measures. Each type stainless-steel bins within concrete vaults. Heat from the of waste requires its own methods for control and disposal. radioactivity of the product will be removed by air flowing There are, however, two basic principles that are broadly past the outer walls. The solid oxide particles from this applied: process could also be glazed, coated, incorporated into a Concentrate and Contain. Radioactive materials can be metal or salt matrix, or converted to glasslike material by stored safely in permanently controlled reservations, but addition of appropriate chemicals at high temperature. the volume of stored wastes would be prohibitively great if These methods are being thoroughly investigated. they were not first concentrated. Even high-level wastes Waste Solidification Engineering Prototype. There are 3 can be concentrated or solidified for long-term storage. promising solidification processes to be demonstrated in Dilute and Disperse. Wastes of appropriately low ac­ the Waste Solidification Engineering Prototype (WSEP) tivity may be reduced to permissible levels for release by installation at the Pacific Northwest Laboratory at the dilution in air or in waterways. Wherever materials are to Hanford Plant, beginning early in 1966. The processes are be released to the environment, the amount of radioactivity the Oak Ridge National Laboratory pot-calcination process, that can be safely dispersed into that particular environ­ the Hanford spray-calcination process, and the Brookhaven ment is determined quantitatively for each specific radio­ National Laboratory phosphate glass-fixation process. isotope. 1. Pot Calcination — This process involves evaporation In the application of these principles, two considerations of wastes to dryness followed by calcination of the residues are important: at temperatures of 700 to 900°C. Calcination is the process Evaluate Each Case Individually. Each factor affecting of making dry, granular solids by heating. The tempera­ waste management must be evaluated for each facility. ture used is not high enough to melt the material. The last These factors include accurate data on the specific radio­ step is done in a pot, which then becomes the final storage isotopes, their chemical form and concentration, their container. When filled with calcined solids, the pot is maximum allowable concentrations for release, and the sealed and shipped to permanent storage. This process detailed characteristics of the environment. Suitable treat­ offers versatility in processing several types of waste, ment and disposal methods then can be chosen and detailed produces a minimum amount of gases, and eliminates the operating standards established. need for packaging the product. Check Results. It is important to make certain that 2. Spray Calcination—Over the past four years, per­ operating standards for waste management are met. This sonnel of the Pacific Northwest Laboratory have been requires constant checking on the amount and level of investigating the merits of converting liquid wastes to sol­ activity handled and released. If conditions change at a ids by spray calcination in a heated tower. Liquid wastes site, operating standards must be reexamined and changed are forced through a nozzle into the top of a tower, the if necessary. sides of which are heated to about 800°C. As the droplets Conscientious application of these considerations has fall, they are first subjected to evaporation, then drying, been responsible for the success, safety, and economy of and finally calcination. The resulting powder falls into a

14 31 heated pot. There the calcination is completed and forms m waste management has been to preserve this low radia­ a powdery or molten residue, depending on the waste ma­ tion level m our environment — not to add to it. terial. In an experimental program numerous successful Any discharge of radioisotopes to our environment tests with high-level waste have been completed. This launches a series of interrelated physical and biological system handles many kinds of wastes, reduces vaporization events because of the movement of released materials and loss of certain fission products, and eliminates foaming through the atmosphere and underground water and their and heat-transfer problems. retention in soil and living organisms. Some of these 3. Phosphate-glass Fixation—For the past several processes may result m the concentration of radioisotopes years, Brookhaven National Laboratory personnel have that were originally released m very dilute form—^thus been working on a continuous process for incorporating fish may concentrate phosphorus-32 m their tissues, and waste fission products into phosphate glass. This process oysters may accumulate zinc-65, offers the possibility of a continuous process m an ail- The growth of nuclear industry emphasizes the need for liquid system and would allow easy heat control, removal complete understanding of natural processes affecting re­ of decomposition gases, mixing of ingredients, and general leased radioisotopes. Not only the concentration but also handling. The mam parts of the plant are a feed-mixing the amount of radioactive material is important; care must tank, an evaporator, a high-temperature furnace with a be taken not to exceed the capacity of the environment. platinum-lined crucible, and a gas processing system. Extensive research is being performed at large atomic The glass melt from the crucible is discharged into burial energy installations to insure that no unsuspected en­ containers. vironmental effects will result from the carefully con­ Three solidification processes have been undergoing pilot- trolled release of radioactivity. plant demonstration at full radioactivity level at Pacific Equally important is the intensive study of the long-term Northwest Laboratory since November 1966. The demon­ effects of radiation on man himself. Radiation can affect stration program is scheduled to be completed m 1970 with an exposed individual directly (somatic effects) by damage a series of engineering reports being made available to to body cells, or it can affect his descendants (genetic industry as separate phases of the program are completed. effects) by damage to reproductive cells. Somatic effects HIGH-LEVEL WASTE STORAGE m natural geologic forma­ are reduced when a given radiation exposure is spread over tions IS being investigated. The production of stable solids a long time. Although there is some evidence that the same that are insoluble and noncorrosive reduces the volume of principle applies m the case of genetic effects, it is not waste to be stored and increases the safety of the storage conclusive. activities. But what is the best way to store these solidified The isotopes of greatest concern are generally those wastes'? Remember that hundreds of years will be required with the longest half-lives, such as strontium-90 and for the natural decay of these wastes to harmless levels. cesium-137. It is also necessary to consider how each Simple burial or disposal m the sea is not a suitable radioisotope is taken mto the body and how it behaves, once answer. Fortunately there are a number of natural geologic there. Iodme-131, for example, is passed efficiently through formations that might be suitable for permanent storage — food chains — from the air to grass, thence to cows, and they are well removed from man and free of groundwater via milk to man, where it is concentrated m the thyroid that might otherwise leach and carry off some of the radio­ gland. Radioactive lodme therefore requires stringent con­ active material to areas of possible human access. trol even though its haK-life is a relatively short eight days 1. Salt Deposits—At present salt appears to be the best The type and energy of emitted radiation and the chemi­ disposal medium. Salt formations are usually dry, are cal properties of radioisotopes are other factors that were impervious to water, and are not associated with usable considered m establishing maximum permissible concen-

32 13 INTERMEDIATE-LEVEL WASTES have too high a concentra­ groundwater sources. The ability of salt to change shape tion to permit release after simple dilution, yet they are under pressure causes rapid closure of fractures. Salt is produced in relatively large volumes. Their radioactivity sufficiently strong that large cavities formed by mining is approximately 100 to 1000 times higher than that of low- will not collapse. Salt deposits underlie some 400,000 level wastes. In liquid form they may contain up to a curie square miles of the United States. And the estimated of radioactivity per gallon. volume of high-level waste solids to be produced in the HIGH-LEVEL WASTES contain several hundred to several year 2000 would occupy less than 1% of the volume of salt thousand curies per gallon in liquid form and result from now being mined each year. chemical processing of irradiated nuclear fuels. High-level An Oak Ridge National Laboratory program includes wastes pose the most severe potential health hazard and studies of possible effects of radiation on salt—on its the most complex technical problems in management. physical properties, the possible production of chlorine, and the effects on movement under pressure and plastic Potential Effects of Radioactivity flow when heated. This information is necessary before Man has always been exposed to the natural radioactivity actual disposal facilities are designed. in his environment. It is in the soil, in the water we drink, A 19-month demonstration disposal of high-level radio­ and even in our bodies. This natural "background" level of active waste solids was carried out in a salt mine at Lyons, radioactivity is quite low: The amount of radiation received Kansas. Spent reactor fuel was used in lieu of actual in one dental X ray is 10 to 100 times that received in a solidified wastes. During the field demonstration, the fea­ year from natural background activity. A cardinal principle sibility and safety of handling highly radioactive materials m an underground environment were demonstrated; the stability of salt under the effects of heat and radiation was shown; and data were obtained on the creep and plastic flow characteristics of salt for use in the design of an industrial salt disposal facility. Further engineering studies are now being carried out to determine the location and possible establishment of such a facility. 2. Bedrock Storage—In some cases it may not be necessary to reduce high-level wastes to solid form. At the AEC's Savannah River Plant, a study is under way for disposal of aged wastes in underground tunnels cut into bedrock. Underlying the plant at approximately 1000 feet •- • / is dense, crystallized bedrock. Exploratory drilling has provided information on the hydrology and geology of this formation and has verified the compatibility of the rock I. with the wastes to be stored. A layer of clay overlays the bedrock and separates it from the top layer of loose \k water-bearing sediment. K Three principal mechanisms delay the migration of wastes from the bedrock tunnels: the low rate of natural Figure 6 Research to determine the effects of irradiated soil on water movement, the impermeability and ion-exchange cotton plants. properties of the clay, and the ion-exchange properties of

12 33 great variety of wastes originates in one of the ways we have just discussed — from naturally occurring radioiso­ topes, fission products, or activation products. These may be in many forms, including chemicals, solids collected in evaporators, resins, and contaminated equipment and ma­ terials. Laboratories in hospitals, universities, and private industry produce waste solutions, contaminated gloves and clothing, and broken glassware. Even when sealed radio­ isotope devices are used, there eventually is need for disposal when the radioactivity has decayed below useful levels. IN SUMMARY, the four basic sources of radioactive waste materials are: 1. Mining, milling, feed-preparation, and fuel-manufac­ turing activities, involving naturally occurring radioiso­ topes. (See Appendix I.) 2. Irradiation and processing of nuclear fuel, involving fission-product radioisotopes. (See Appendix II.) 3. Irradiation of nonfuel materials, involving activation- product radioisotopes, which include several radioisotopes NEW MINING LEVEL purposely produced for their usefulness. (See Appendix EI.) '] fl ABOVE EXISTING MINE FLOOI 4. The use of radioisotopes produced in one of the three preceding source categories. Figure 16 The Carey Salt Company Mine in Lyons, Levels of Radioactivity Kansas, is the scene of a radioactive waste disposal Radioactive wastes vary widely in the concentration of experiment conducted by radioactive materials. It is convenient to classify them the Oak Ridge National Laboratory. according to their potential hazard, as indicated by their level of activity. Three levels have been defined, some­ what arbitrarily, as follows: LOW-LEVEL WASTES have a radioactive content suffi­ ciently low to permit discharge to the environment with reasonable dilution or after relatively simple processing. They have no more than about 1000 times the concentra­ tions considered safe for direct release. In liquid form low-level wastes usually contain less than a microcurie* of Photo A. A 30-ton lead radioactivity per gallon. cask is maneuvered into position over the 1000-foot *A microcurie is one millionth of a curie. A curie is a measure waste charging shaft. This of the number of atoms undergoing radioactive disintegration per provides shieldtngfor per­ unit time and is 37 billion disintegrations per second, or about sonnel. the rate of decay m 1 gram of natural radium.

34 11 Photo B. Cannisters containing radioactive material are lowered Figure 5 Face of plutonium-production reactor at the Hanjord down the shaft to a specially designed trailer coupled to a conven­ Plant in Richland, Washington. tional two-wheel tractor, which carries them to the experimental area shown m photo C. This machinery was assembled inside the mine. heat exchangers separate the coolant from the river water, and so the problem of quantity disposal does not arise. Some activation products are gaseous. In water-cooled reactors gaseous products arise from the irradiation of the water as well as from irradiation of any air in the coolant. The gases are mostly short-lived radioisotopes, such as nitrogen-16 or argon-41, but tritium (hydrogen-3) has a half-life* of more than 12 years. Air-cooled reactors produce argon-41, the major examples of this type being the large research reactors operated for many years at Brookhaven and Oak Ridge National Laboratories. Control and disposal of gases is an important aspect of radioactive waste management even though it involves a minor portion of the total radioactivity produced by nuclear industry. MISCELLANEOUS SOURCES OF RADIOACTIVE WASTES are the more than 4000 establishments making or using nuclear products in the United States. The radioactivity of this

*A half-life is the time required for half a radioisotope to be­ Photo C. Holes, 12 feet deep and lined with stainless steel, in the come stable; a period of two half-lives would reduce the quantity salt mine floor are used to contain radioactive fuel assemblies. of radioactivity to one-quarter the original amount. The room is 30 feet wide, 60 feet long, and 14 feet high.

10 35 the top layers of earth. Each of these barriers is con­ Waste management operating experience at six American sidered to be an adequate shield in itself. Since they would nuclear power plants—Dresden-I in Illinois, Big Rock be encountered in succession, there is an ample factor of Point in Michigan, Humboldt Bay in California, Elk River safety. Studies are now under way on how to remove and in Minnesota, Indian Point-I in New York, and Yankee in transfer wastes from the present storage tanks. Massachusetts — has recently been assessed. The waste volumes handled in nuclear plants are not large in com­ Low-level Waste Processing parison with wastes from many other industries and the When the nuclear industry was small, low-level wastes total radioactivity is quite small. Radioactivity concentra­ could be discharged to the environment without raising tions in power plant effluents have been well below per­ background radiation significantly. This will be less pos­ missible release limits. sible in the future because of the growth of the industry. The irradiation of reactor coolant produces larger It is important to develop more efficient methods for treat­ quantities of low-level waste liquid at the AEC's plutonium- ing these large-volume wastes. production installations, particularly the Hanford Plant in Although normal chemical processing of low-level wastes Richland, Washington. Hanford personnel have the problem can remove approximately 9C^ of the contained radio­ of disposing of great amounts of water from the Columbia activity in a single treatment, multistage treatment is River that is used directly for reactor cooling. At the complex and costly. For this reason work is under way to AEC Savannah River Plant in Aiken, South Carolina, river develop more efficient and economical methods. water is also used, but it does not enter the reactors and A specific goal is to decontaminate low-level wastes to does not become irradiated; the reactor coolant is a an extent that would even permit direct consumption of the separate, relatively small quantity of water. Intermediate liquids by humans. Two treatment methods are being de­ veloped. Both involve scavenging-precipitation, but one is followed by an ion-exchange process and the other by a foam-separation process. THE SCAVENGING-PRECIPITATION ION-EXCHANGE PROCESS has demonstrated that it can produce wastes of signifi­ cantly lower residual activity than the lime-soda treatment now used. The low-level feed is adjusted to an alkaline condition in a mixing vessel, and a coagulant is added. The solution then flows to a slightly agitated tank (called a flocculator) in which insoluble materials agglomerate into large particles containing most of the fission products. The mixture then flows to another vessel (called a clari- fier) and passes up through a layer of sludge that is con­ tinuously removed and packed for disposal. The clarified water then passes through a filter and is pumped through ion-exchange columns for removal of the remaining fission products, principally cesium-137 and strontium-90. Over a five-month period, the process treated 600,000 gallons of low-level waste, removing 99.99% of the strontium and Figure 4 A "hot cell" worker at the AEC's Oak Ridge National Laboratory in Tennessee uses mechanical hands to separate useful 99.7% of the cesium. fission products from nuclear wastes.

36 9 THE FOAM-SEPARATION PROCESS for final decontamina­ tion of the filtered solutions from the scavenging-precipi­ tation process just described is also under study. In this method foam is produced by adding detergent to the waste solution and bubbling air through it. The foam rises to the top of a column. Most of the radioisotopes cling to the surface of the bubbles and rise with the foam. The foam is drawn off the top and collapsed; it yields a small amount of liquid. The bulk of the waste solution, having been cleaned by the foam passing through it, is drawn from near the bottom of the column. So far, however, this appears to be less simple and less efficient than the use of ion-exchange resins.

Intermediate-level Waste Processing A number of treating processes can be used for both low-level and intermediate-level liquid wastes. One of the Figure 3 Open-pit mme m New Mexico is a source of uranium ore that initiates the nuclear fuel cycle. most interesting studies, however, is one dealing with direct disposal of intermediate-level waste into shale or end of the century. Large quantities of less radioactive other suitable geologic wastes also will be produced; some 4 billion gallons have formations. The technique been produced and disposed of over the past 20 years. is called hydraulic frac­ Large as these quantities are, they are small in comparison turing and has been bor­ to the volumes of waste processed in other industries, such rowed from the oil indus­ as paper mills, chemical plants, and sewage-disposal try. It has been under plants. study for the past three ACTIVATION PRODUCTS are produced during the irradia­ years (see Figure 17). tion of nonfuel materials located near the fuel in nuclear The method requires the reactors. Structural materials are activated (made radio­ drilling of a well, followed active) by the absorption of neutrons, as are impurities in by lateral cuts through the the coolant* and often the coolant itself. Traces of iron, well casing into the rock nickel, and other corrosion products, for example, are formation, which are ac­ carried along with the coolant in some types of reactors complished by jets of and irradiated as they pass through the reactor. Appendix III a sand —water mixture lists typical activation-product radioisotopes.

* Coolant is a term identifying the fluid that flows through a re­ Figure 17 Facilities for dis­ actor to remove or transfer heat. Water is most commonly used, posal of intermediate-level but air, carbon dioxide, oils, sodium, and potassium also have been liquid wastes by injection used. into shale formations 1000 feet below ground level.

8 37 or by shaped charges of explosive. A mixture of water, Typical Type of waste, and cement is pumped into the formation at high isotopes radiation Disposal methods pressure; this cracks the rock and allows the mixture to move out in horizontal sheets that solidify in place. Uranium-23 8 ca, y Pile in open Oak Ridge National Laboratory workers made test in­ Thorium-230 a, y Seep into ground jections of material containing radioactive tracers in 1960. Radon-222 a Ventilate mine Later, core drilling provided information on the extent and Uranium-23 8 a, y Decontaminate thickness of the solidified material. Results were favor­ Uranium-235 able, and early in 1964 a hydrofracturing plant was com­ Uranium-23 8 Neutralize, concentrate, and a,y pleted for injection of actual wastes. Approximately Uranium-235 bury residue 250,000 gallons of intermediate level waste concentrate is Uramum-238 Ventilate, filter, and a, y now being disposed of routinely each year using this tech­ Uranium-23 5 disperse to air nique. Strontium-90 Encase in container and Environmental Studies Cesium-137 (3, y store permanently (~600 years) An important part of waste-management research is the Technetium-99 /3, Store in tanks for several Ruthenium-103 /3, y years; then solidify in study of environments surrounding atomic energy installa­ Cerium-144 i3,y place tions. Objectives are to determine the fate of radioactive Iodine-131 P,y React with chemicals to bind materials released to waterways, to determine the mecha­ in solid, e.g., silver iodide nisms of their dispersion, to evaluate the hazards as­ Krypton-8 5 /3, y Disperse to air sociated with disposal practices, to evaluate the usefulness Aluminum-28 i3, y Package and ship for land of waterways for disposal, and to recommend appropriate Manganese-56 /3, y burial long-term environmental-monitoring procedures. Evaporation or ion-exchange; Cobalt-58 /3+, y The principal studies in the United States have been bury residue made of the Clinch-Tennessee River system below Oak Hold for decay (very short life); Nitrogen-16 Ridge, Tennessee; the Columbia River below Richland, /3, y then disperse to air Washington; and the Savannah River below Aiken, South Ship for burial when no longer Cobalt-60 Carolina. Similar studies have been made of the Ottawa /3, y useful (long life) River in Canada, the Thames River in England, and the Store for decay to safe levels Phosphorus-32 Rhone River in France, For example, the comprehensive /3 (short life) investigation on the Clinch and Tennessee Rivers is a multiagency effort to evaluate physical, chemical, and pendices for more detail and explanation. biological effects caused by the disposal of low-level radioactivity (see Figure 18). Water-sampling stations reactors, but increasing amounts of fuel from nuclear- have been established at seven sites, located as far as powered electric plants will have to be processed in the 125 miles below Oak Ridge, future. Studies have included dispersion tests with dyes and Predictions vary on the amount of high-level waste that radioactive tracers, determination of the distribution of will be produced by chemical processing of fuels from radioactivity in bottom sediments, methods of incorpora­ nuclear power plants. Current estimates are that some tion of radioactivity into the bottom sediments, and detailed 100,000 gallons will be produced in 1970 and that the amount analyses of the biological distribution of released radio- will increase to about 6 million gallons per year by the

38 7 Type of waste radioactivity Source of waste Form of waste

Solids Mining of Liquids uranium ores Gases and dusts Natural activity Solids Fuel fabrication Liquids (acid) plants Figure 18 Taking core samples of bottom sediments in the Clinch Dusts River in Tennessee.

Solids (from purposeful solidification) Fuel Liquids Fission-product irradiation isotopes and the resulting dosages to human and animal activity and (with strontium and processing cesium removed) life in the area. Studies such as these are essential to our understanding Gases of the effects of released radioactive wastes. This under­ standing must be thorough because no significant mecha­ nism for the dispersal of radioactive materials and pos­ Solids Reactor sible subsequent exposure of the public can be overlooked. materials Liquids Mankind needs the tremendous energy represented by nu­ Activation- unavoidably (dissolved material) product irradiated clear fuels, but their use will create vast quantities of activity during operation radioactive wastes. Disposal of these must never be al­ Gases lowed to harm man, his environment, or his natural Purposeful resources. Radioactive waste management is dedicated to irradiation this objective. to produce Solids useful isotopes

Figure 2 Typical radioactive wastes and disposal methods. See ap- Figure 19 Equipment disposal tunnel at the 10 gallons in processing natural or slightly enriched* Hanjord Plant in Rich­ uranium and 10 to 100 gallons in the case of highly enriched land, Washington. Ra­ uranium. Up to now, most of the fuels processed have been dioactive chemical pro­ cessing equipment, too natural-uranium fuels from the AEC's plutonium-production large to be buried con­ veniently, is loaded onto * Enriched uranium is uranium in which the proportion of flatcars and pushed into uranium-235 has been increased by putting the natural element the 1700-foot tunnel. through an isotope-separation process, such as gaseous diffusion. The tunnel will then be See Appendix I for natural-uranium content of uranium-235. covered uith earth.

6 39 APPENDIX I purified. This produces uranium salts, or feed, for the gaseous-diffusion plants (for separation of uranium-235 Naturally Occurring Radioisotopes Encountered from other isotopes of uranium); or it converts concen­ in Mining, Milling, and Fuel Preparation trates to metallic uranium or uranium oxide for fuel ele­ in Uranium Fuel Cycle ments. For each ton of uranium processed, approximately 1000 gallons of liquid wastes are produced. Percent found in The purified uranium used in the fabrication of fuel Atomic natural Radiation elements has extremely low activity because the radium, Radioisotope number uranium Half-life emitted* thorium, and several radioactive decay products have been removed in earlier steps of the cycle. Liquid wastes from Uranium- -238 Decay Chain fuel fabrication plants are of small volume and very low Uranium-23 8 92 99.28 4.5 X 10^ yr a, y radioactivity. Contaminated scrap is also produced at Thorium-234 90 1 X 10-8 24.1 days /3. y fabricating plants, Protactinium- 234 91 5 X 10-" 1.14 min /3, y Uranium-234 92 6 X 10-3 2.5 X 105 yr a, y FISSION PRODUCTS produced during the irradiation of Thorium-230 90 2 X 10-3 8 X 10^ yr a, y Radium-226 88 4 X 10-5 1622 yr a, y nuclear fuels in reactors are by far the largest source of Radon-222 86 2 X 10-" 3.8 days a radioactive waste in terms of contained radioactivity. When Polomum-218 84 1 X 10-13 3.1 min a each uranium atom fissions, it breaks into two major X 10-12 Lead-214 82 1 26.8 min /3, y fragments appropriately called fission products. Fission Bismuth-214 83 8 X 10-13 19.7 min /3, y Polonium-214 84 1 X 10-15 ~10-* sec a products are radioactive; they undergo one or more steps Lead-210 82 5 X 10-1 22 yr P,y of radioactive decay before reaching a stable, harmless Bismuth-210 83 3 X 10-10 5 days /3 condition (see Appendix 11). Valuable fuel material remains Polonium-210 84 8 X 10-s 138 days a, y Lead-206 82 Stable in the irradiated fuel along with the accumulated fission products; so recovery of this fuel is important. Chemical Uranium- -23. 5 Decay Chain processing of irradiated nuclear fuels is, therefore, an Uranium-235 92 0.71 7.1 X 10^ yr a, y inescapable part of the nuclear industry. The processing Thorium-231 90 3 X 10-12 25.6 hr i3, y creates highly radioactive wastes consisting not only of Protactinium- 231 91 3 X 10-5 3.4 X 10^ yr a, y fission products but also of some activated reactor ma­ Actinium-227 89 2 X 10-8 27 yr a, /3, y Thorium-227 90 5 X 10-11 18.6 days a, y terials, chemicals, and corrosion products.* Radium-223 88 3 X 10-11 11.2 days a, y Radon-219 86 1 X 10-1" 3.9 sec a, y Chemical processing of irradiated fuel is presently done Polonium-215 84 6 X 10-2" ~ 10-3 gee a at AEC plants, but private industry will enter this field as Lead-211 82 7 X 10-1^ 36.1 min 13, y the nuclear industry grows. Already the first commercial Bismuth-211 83 4 X 10-15 2.1 min a, y plant is under construction in the state of New York by Thallium-207 81 9 X 10-15 4.8 min /3, y Lead-207 82 Stable Nuclear Fuel Services, Inc. (see Appendix IV). A number of solvent-extraction processes are used to *a: alpha particle, a helium nucleus. y: gamma ray, similar to X rays. jB: beta particle, an electron. separate remaining fuel from waste products in used fuel elements. From 1 to 100 gallons of highly radioactive liq­ uid result from each kilogram of uranium processed—1 to

*For more about fuels and fuel processing, see Atomic Fuel, another booklet in this series.

40 5 One final point—radioisotopes are immune to outside APPENDIX II influence. Each isotope decays at its own particular rate Principal Fission-product Radioisotopes regardless of temperature, pressure, or chemical environ­ ment and continues to do so no matter what is done to it. in Radioactive Wastes Allowing radioisotopes to decay naturally is the only Atomic Radiation practical means of eliminating their radioactivity. All Radioisotope number Half-life emitted* processing, storing, and use of radioisotopes must there­ fore be considered as an intermediate step leading finally Krypton-85 36 4.4 hr (IT)1 (3, y, e- —/3,y to disposal by decay. -* 9.4 yr Strontium-89 38 54 days fi Strontium-90 38 25 yr a Sources of Radioactive Waste Zirconium-95 40 65 days /3, y Niobium-95 41 90 hr (IT) e~ - )3, y Radioactive wastes are created wherever radioactive — 35 days Technetium-99 43 5.9 hr (IT) e", y - /? materials are used. By far the greatest source of wastes — 5 X 10^ yr is the nuclear fuel cycle: The mining, milling, and prepara­ Ruthenium-103 44 39.8 days /3, y tion of fuel for reactors and weapons produce wastes Rhodium-103 45 57 min e~ containing natural radioisotopes; and fuel irradiation and Ruthenium-106 44 1 yr P subsequent processir^ produce wastes rich in fission Rhodium-106 45 30 sec /3, y Tellurium-129 52 34 days (IT) e-,/3-/3, y products. Additional wastes are produced by irradiation of — 72 min nonfuel materials in and around reactors. Let us consider Iodine-129 53 1.7 X 10^ yr /3, y these sources. Iodine-131 53 8 days /3, y Xenon-133 54 2.3 days (IT) e-, /3 - /?, y NATURAL RADIOACTIVITY refers to the radioactivity of -* 5.3 days materials found in nature. These materials are present in Cesium-137 55 33 yr /?,y uranium and thorium ores, nature's nuclear fuels. Wastes Barium-140 56 12.8 days /3, y from mining, ore milling, and fuel fabrication therefore Lanthanum-140 57 40 hr /3, y contain this natural radioactivity, which consists primarily Cerium-141 58 32.5 days /3,y Cerium-144 58 590 days /5,y of the natural radioisotopes of uranium, thorium, radon (a Praseodymium-143 59 13.8 days /3, y gas), and radium (see Figure 2, page 6, and Appendix I). Praseodymium-144 59 17 min /3 Most mines are in dry formations, but some must be Promethium-147 61 2.26 yr /3 kept dry by pumping out hundreds of gallons of water per *(3: beta particle, an electron, y: gamma ray, similar to minute. This water contains only traces of radioisotopes X rays. e~: internal electron conversion. and poses no significant health hazard. In uranium ore- tIT: isomeric transition, internal. concentrating mills, liquid wastes are discharged to ponds or lagoons at a rate of 300 to 500 gallons per minute (for an average mill processing 1000 tons of ore per day). There are over 20 such mills in the United States. Radium is the principal radioisotope in mill wastes and is in­ corporated in the solid residues, called "tailings", in an insoluble form. In "feed" preparation, the next step in the fuel cycle, ore concentrates are taken from the mills and chemically

4 41 APPENDIX 111 nuclear era continues, there will obviously be more radio­ active waste. Clearly the methods used for the control and Principal Activation-product Radioisotopes Produced disposal of wastes must not only be appropriate to a wide­ by Neutron Irradiation of Nonfuel Materials spread, lusty endeavor but also be safe and economical. In the U. S, nuclear program, the Atomic Energy Com­ Radiation Atomic Source and mission (AEC) has the function of protecting the public Radioisotope number reaction* Half-life emittedt against the hazards of radioactive materials. Regulations Air and Water have been developed through research to ensure effective Tritium (H-3) 1 2H (n,y) 12.3 yr iS, r control without unduly restricting the growth of nuclear Carbon-14 6 "N (n,p) 5700 yr ^ industry. The AEC also directs research to develop new Nitrogen-16 7 '''O (n,p) 7.3 sec /3, r methods of radioactive waste management. Much remains Nitrogen-17 7 "O (n,p) 4.1 sec /3 Oxygen-19 8 '''O (n,r) 30 sec /3,y to be done, but the work already promises that disposal of Argon-41 18 ^OA (n,r) 1.8 hr &,y radioactive wastes will not erect economic barriers to our nuclear future. Sodium

Sodium-24 11 23Na (n,y) 15 hr /5, Y Soaium-22 11 ^^Na (n,2n) 2.6 yr /3+, y THE NATURE OF RADIOACTIVE WASTES Rubidium-86 37 85Rb (n,y) 19.5 hr /3, y- (impurity in (IT)I K, y Many kinds of radioactive wastes are produced by the sodium coolant) 1 min nuclear industry,* AEC licensing procedures and regula­ Alloys tions deal with more than 900 radioisotopesf of 100 ele­ Aluminum-28 13 27A1 (n,y) 2.3 min /3, y ments. Wastes containing these isotopes may be in the Chromium-51 24 sOCr (n,y) 27 days /?+. K, y form of gases, liquids, or solids, may be soluble or in­ Manganese-56 25 s^Fe (n,p) 2.6 hr ^, y soluble, and may give off various types of radiation at Iron-55 26 5^Fe (n,y) 2.9 yr K many energy levels. Although many radioisotopes decay Iron-59 26 59Co (n,p) 45 days /3, y Copper-64 29 63Cu (n,y) 12.8 hr i3, y, /3+, K rapidly, some require hundreds of years to decay to safe Zinc-65 30 •^^Zn (n,y) 250 days /3+, e-, y levels. Tantalum-182 73 *"Ta (n,y) 115 days /3, y The hazards of radioactive materials stem from their Tungsten-187 74 18«W (n,y) 24 hr /3, y Cobalt-58 27 s^Ni (n,p) 71 days /3+, y basic characteristics. Radiation cannot be detected by the Cobalt-60 27 ^^Co (n,y) (also 5.3 yr /3, y senses (except in massive doses); its effects are often purposeful cumulative and may not be evident for some time; and it irradiation) Phosphorus-32 15 ^»P (n,y) 14.3 days /3 can damage both an individual and, by impairing his (purposeful reproductive cells, future generations of his descendants. irradiation) Fortunately the nature of radioactivity also makes it pos­ *(n,y): absorbs neutron, emits gamma. (n,p): absor bs neutron. sible to detect its presence with certainty and remarkable emits proton. accuracy. t/3: beta particle, an electron, y: gamma ray, similar to X rays. jS*: positively charged electron. K: orbital electron capture into *For a discussion of the nature, measurement, and control of nucleus. e~: internal electron conversion. radioactivity at nuclear power plants, see Atomic Power Safety, tIT: isomeric transition, internal. another booklet in this series. tRadioisotopes are radioactive forms of elements. For defini­ tions of unfamiliar words, see Nuclear Terms, A Brief Glossary, a companion booklet in this series.

42 3 The most significant difference between nuclear wastes APPENDIX IV and those of other industries is that nuclear wastes are radioactive, and this accounts for the special methods re­ List of Firms Licensed to Receive and quired for their disposal. The highly radioactive wastes Dispose of Radioactive Wastes from spent nuclear fuels, in particular, pose a challenging problem. They cannot be piled in open fields or dumped 1 Firms Licensed by U S Atomic Energy Commission into rivers or the ocean. Another problem exists because Allied Crossroads Nuclear Corp New England Tank Cleaning Co 201 Victory Road 135 First Street of the millions of gallons of water containing traces of Dorchester, Massachusetts 02122 Cambridge, Massachusetts 02138 radioactivity that must be disposed of each year. The The Walker Trucking Company management of radioactive wastes is, indeed, a complex 1283 Fast Street and interesting activity. New Britain, Connecticut 06050 Since 1942, when the first self-sustaining chain reaction 2 Firms Licensed by AFC and Agreement States* was achieved, the nuclear industry has grown vigorously. California Salvage Company Laboratory for Electronics Inc 700-745 North Pacific Avenue Tracerlab Division Over 300 operating reactors are now m use.* In addition, San Pedro, Cahfornia 90731 1601 Trapelo Road Waltham, Massachusetts 02154 radioactive materials are increasingly regarded as im­ Nuclear Fngineering Company, Inc portant tools for research, medicine, and industry. As the Box 594 Laboratory for Electronics Inc Walnut Creek, California 93002 Tracerlab Division 2030 Wright Avenue Cahfornia Nuclear, Inc Richmon, California 94804 2323 South Ninth Street Lafayette, Indiana (HQ) 47905 Long Island Nuclear Services Corp Station Road Nuclear Engineering Company Inc Bellport, New York 11713 Box 146 Burns Building Radiological Service Co , Inc Morehead, Kentucky 40351 35 Urban Avenue Westbury New York 11590

J Firms Licensed Entirety by Agreement States'^ Consolidated American Services U S Nuclear Corporation Inc 801 North Lake Street 12600 South Daphne Avenue Burbank, California 91502 Hawthorne California 90250 William Wayne Electronics Nuclear Fuel Services, Inc Hastings Radiochemical Works Box 124 Box 60448 West Valley New York 14171 Houston, Texas 77060

•States which have sufficient interest and which develop adequate con trols and regulations may by agreement with the AEC Division of Li censing and Regulation, assume control of waste-handling activities within their boundaries Licensing by the AEC is required for interstate activi­ ties fXhis list may not be complete Current information can be obtained from the Department of Health of the particular state involved The fol­ lowing states have entered into agreements for control by state regulation Figure 1 The Dresden Nuclear Power Station near Chicago, Illi­ Arkansas, California Florida, Kansas, Kentucky Mississippi, New York, nois, is an example of Am,erica's growing nuclear industry. North Carolina Texas, Oregon, and Tennessee

*For more about nuclear reactors, see Nuclear Reactors and Research Reactors, companion booklets m this series.

2 43 SUGGESTED REFERENCES Radioactive Wastes Popular Level The Hazards of Atomic Wastes, Alton Frye, Public Affairs Press, By CHARLES H. FOX 419 New Jersey Avenue S. E., Washington, D. C. 20003, 1962, 45 pp., $1.00. Radioactive Wastes, W. G. Belter, International Science and Tech­ nology, 12: 42 (December 1962). Annual Report to Congress of the Atom.ic Energy Comm.ission for 1964, Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20402, 1965, 443 pp., $1.75. The Management of Radioactive Wastes Produced by Radioisotope Users, Safety Series No. 12, International Atomic Energy Agency, available from National Agency for International Publications, Inc., 317 East 34th Street, New York 10016, 1964, 58 pp., $1.50. Background Information on Mom.ic Power Waste Handling, John F. Hogerton, James G. Cline, Robert W. Kupp, and Charles B. Yulish, Atomic Industrial Forum, Inc., 850 Third Avenue, New York 10022, 1965, 48 pp., $1.50. Management of Radioactive Wastes, Atomics, 18: 8 (May/June 1965). MEN AND ASHES Technical Level Radioactive Wastes: Their Treatment and Disposal, John Collins An archaeologist kneels in the Mexican valley of Te- (Ed.), John Wiley & Sons, Inc., New York, 1960, 239 pp., $8.00. huacan, gently brushing the dirt from crude artifacts dis­ Processing of Radioactive Wastes, C. A. Mawson, International carded thousands of years before. Fragments of earthen­ Atomic Energy Agency publication No. 18, available from Na­ tional Agency for International Publications, Inc., 317 East 34th ware and chipped stones in the ashes of ancient fires tell Street, New York 10016, 1961. 44 pp., $1.00. their story. They are wastes from the first human culture Industrial Waste Disposal Hearings Before the Joint Com.m.ittee on on the North American Continent. Atomic Energy of the 86th Congress, 1959, summary analysis of the hearings available from the Office of the Joint Committee on Today, in the wheat fields of Kansas, tons of straw left Atomic Energy, Congress of the United States, Senate Post Of­ behind by threshing machines must be disposed of each fice, Washington, D. C. 20510, 40 pp., free. year by baling for later use or by burning. Wastes of straw may never be seen by archaeologists of the future, The following reports are available from the Clearinghouse for Federal Scientific and Technical Information, 5285 Port Royal but other wastes of our time will intrigue them—^piles of Road, Springfield, Virginia 22151. slag from steel mills, city dumps under tons of soil, and U. S. Operational Experience in Radioactive Waste Management mountains of rusted automobiles. 1958-1963 (A/CONF.28/P/869), W. G. Belter, International Almost every act of man leads to wastes of one sort or Conference on the Peaceful Uses of Atomic Energy, 1964, 16 pp., another—hunters' ejected cartridges, smoke from power- $3.00. Advances in Radioactive Waste Management Technology and Its plant chimneys, wastepaper in schoolrooms, or the curls Effect on Future U. S. Nuclear Power Industry (A/CONF.28/P/ of childhood lost forever on the barbershop floor. 868), W. G. Belter, International Conference on the Peaceful The nuclear industry is no exception. Managers of nu­ Uses of Atomic Energy, 1964, 18 pp., $3.00. clear installations are concerned with the handling, pro­ Proceedings of the Sym.posium on the Solidification and Long- cessing, and disposal of wastes. In many ways this activity Term Storage of Highly Radioactive Wastes (CONF-660208), W. H. Regan (Ed.), February 14-18, 1966, Richland, Washington, is comparable to other disposal processes, but it is dif­ 1966, 900 pp., $3.00. ferent in a few important respects.

44 1 THE COVER Radioactive Waste Management, W. G. Belter and D. W. Pearce, Reactor Technology (Selected Revleivs-1965) (TID-8541), pp. 149-248, 1966, $3.00. Management of Radioactive Wastes at Nuclear Power Stations (ORNL-4070), J. O. Blomeke and F. E. Harrington, 1968, 102 pp., 83.00. ; _ --_ The main corridor of the Carey Salt Lou Level Radioactive Wastes: Their Treatment, Handling, and y'l'f -. Company Mine in Lyons, Kansas, 1000 Disposal,Conrad P. Straub, produced by the AEC's Division of feet below the surface of the earth. The Technical Information and available from the Superintendent of ceiling height in the corridor is 14 feet. Documents, U. S. Government Printing Office, Washington, D, C. The Oak Ridge National Laboratory has 20402, 1964, 430 pp., $1.50. carried out a radioactive waste disposal experiment in this mine to determine heat and radiation effects on salt from Motion Pictures Ift'if^ 1 high-level solidified wastes and to dem­ onstrate radioactive waste handling Available for loan without charge from the AEC Headquarters Film Library, Division of Public Information, U. S. Atomic Energy Com­ techniques in this environment. Results mission, Washington, D. C. 20545, and from other AEC film li­ of these tests show that this may provide safe and efficient storage braries. for high-level radioactive wastes. (See page 33 and Figure 16 for more information on this research.) Living uith Radiation, 28 minutes, sound, color, 1958. Produced for the AEC's Idaho Operations Office by Lookout Mountain Air Force Station. This film documents the AEC radiation safety program by using procedures at the National Reactor Testing Station in Idaho as illustrative examples. It includes waste stor­ age and disposal, personnel-protection methods, and other rele­ vant topics. Isotopes, 20 minutes, sound, color, 1959. Produced by the AEC's Oak Ridge National Laboratory. This film explains radioactivity and methods for producing radioisotopes, including separation of THE AUTHOR isotopes from high-level wastes. Regulation of Atomic Radiation, 28'/2 minutes, sound, color, 1963. Produced by the AEC. This film surveys AEC work in the li­ censing and regulation of the uses of nuclear materials. It shows the control of radioactive materials from the time they leave the mine until they become waste. CHARLES H. FOX is a consultant Reactor Fuel Processing, 20 minutes, sound, color, 1958. Pro­ in nuclear engineering with many duced by the AEC's Oak Ridge National Laboratory. This film years' experience in industry, much covers the chemical processing of irradiated reactor fuels and of it with The Martin Company, waste-disposal operations. where he was Chief, Advance De­ Atoms on the Move: Transportation of Radioactive Materials, 24 sign, and later program manager minutes, color, 1966. Produced by Bennie Korzen Productions for the PM-3A nuclear power plant, for the AEC. Ores, reactor fuel, weapons, radioisotopes for now operating in the Antarctic. medicine, industry, research, and atomic wastes are shown in Mr. Fox won the Eshbach Award transit. Safety aspects, including accident research, and re­ as the outstanding graduate of the sponsibilities of federal agencies are discussed. Technological Institute, Northwest­ Working with Radiation, 29 minutes, black and white, 1962. Pro­ ern University, where he obtained duced by the AEC's Argonne National Laboratory. Precautions his degree in chemical ei^ineering. He served as an instructor and various methods for handling radioactive materials including in nuclear engineerii^ at Martin and for several years was a wastes are illustrated. member of the Advisory Committee on Nuclear Education at the Drexel Institute of Technology. He has frequently addressed high school groups and civic clubs on nuclear energy.

45 Radioactive Wastes by Charles H. Fox

CONTENTS

MEN AND ASHES 1 THE NATURE OF RADIOACTIVE WASTES 3 Sources of Radioactive Waste 4 Levels of Radioactivity 11 Potential Effects of Radioactivity 12 WASTE MANAGEMENT 14 Liquid Waste Management: Low and intermediate Level . . .15 PHOTO CREDITS Gaseous Waste Management 20

Cover courtesy the General Electric Company Solid Waste Management 22 Figure 3 The Anaconda Company High-level Waste Management 24 Figure 4 Oak Ridge National Laboratory (OKNL) Figure 6 Union Carbide Corporation RESEARCH AND DEVELOPMENT 28 Figure 7 ORNL High-level Waste Processing 29 Figure 8 Savannah River Plant Low-level Waste Processing 36 Figure 9 BroolAaven National Laboratory Figure 11 ORNL Intermediate-level Waste Processing 37 Figure 13 E. I. Du Pont de Nemours & Company Environmental Studies 38 Figure 16 ORNL APPENDIX I Figure 17 ORNL Figure 18 ORNL Naturally Occurring Radioisotopes Encountered in Mining, Figure 19 Hanford Plant Milling, and Fuel Preparation in Uranium Fuel Cycle . . .40 APPENDIX II Principal Fission-product Radioisotopes in Radioactive Wastes 41 APPENDIX III Principal Activation-product Radioisotopes Produced by Neutron Irradiation of Nonfuel Materials 42 APPENDIX IV List of Firms Licensed to Receive and Dispose of Radioactive Wastes 43 SUGGESTED REFERENCES 44

United States Atomic Energy Commission Division of Technical Information Library of Congress Catalog Card Number: 66-60724 1966; 1969 (rev.)

46 This booklet Is one of the "Understanding the Atom" Series. Comments are invited on this booklet and others in the series; please send them to the Division of Technical Information, U. S. Atomic Energy Commission, Washington, D. C. 20545. Published as part of the AEC's educational assistance program, the series includes these titles:

Accelerators Nuclear Propulsion for Space Animals m Atomic Research NHclea7 Reactors Atomic Fuel Nuclear Terms, A Brief Glossary Atomic Power Safety Our Atomic World Moms at the Science Fair Plowshare Atoms m Agriculture Plutonium Atoms, Nature, and Man Power from Radioisotopes Books on Atomic Energy for Adults Power Reactors in Small Packages and Children tiadioaclne Wastes The Understanding the Atom Series Careers m Atomic Energy Radioisotopes and Life Processes Computers Radioisotopes m Industry Controlled Nuclear Fusion Radioisotopes m Medicine Nuclear energy is playing a vital role in the life of every Cryogenics, The Uncommon Cold Rare Earths Direct Com ersion of Energy Research Reactors man, woman, and child in the United States today. In the Fallout From Nuclear Tests SNAP, Nuclear Space Reactors Food Preservation by Irradiation Sources of Nuclear Fuel years ahead it will affect increasingly all the peoples of the Genetic Effects of Radiation Space Radiation Index to the VAS Series Spectroscopy earth. It is essential that all Americans gain an understanding Lasers Synthetic Transuranium Elements Microstructure of Matter The Atom and the Ocean of this vital force if they are to discharge thoughtfully their Neutron Actwation Analysis The Chemistry of the Noble Gases Nondestructive Testing The Elusive Neutrino responsibilities as citizens and if they are to realize fully the Nuclear Clocks The First Reactor myriad benefits that nuclear energy offers them. Nuclear Energy for Desalting The Natural Radiation Environment Nuclear Power and Merchant Shipping Whole Body Counters The United States Atomic Energy Commission provides Nuclear Power Plants Your Body and Radiation this booklet to help you achieve such understanding. A single copy of any one booklet, or of no more than three different booklets, may be obtained free by writing to:

. /Q-a«fc«-"»«-«*->~T' USAEC, P. 0. BOX 62, OAK RIDGE, TENNESSEE 37830

Edward J. Brunenkant, Director Complete sets of the series are available to school and public librarians, and to teachers who can make them Division of Technical Information available for reference or for use by groups. Requests should be made on school or library letterheads and indi­ cate the proposed use. Students and teachers who need other material on spe­ cific aspects of nuclear science, or references to other UNITED STATES ATOMIC ENERGY COMMISSION reading material, may also write to the Oak Ridge address. Requests should state the topic of interest exactly, and the use intended. Dr. Glenn T. Seaborg, Chairman In all requests, Include "Zip Code" in return address. James T. Ramey Wilfrid E. Johnson Dr. Theos J. Thompson Dr. Clarence E. Larson Printed m the United States of America USAEC Division of Technical Information Extension, Oak Ridge, Tennessee Radioactive Wastes by Charles H. Fox

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U. S. ATOMIC ENERGY COMMISSION Division of Technical Information Understanding the Alum Series