Disposal of Low-Level Radioactive Wastes William R. Hendee The generation of low-level radioactive waste is a natural consequence of the societal uses of radioactive materials. These uses include the application of radioactive materials to the diagnosis and t r e a t m e n t of human disease and to research into t h e causes of human disease and their prevention. Currently, low level radioactive wastes are disposed of in one of three shallow land-burial disposal sites located in Washington, Nevada, and South Carolina. W i t h the passage in D e c e m b e r 1980 of Public Law 96-573, " T h e Low-Level Radioactive W a s t e Policy A c t , " the disposal of low-level wastes generated in each state
was identified as a responsibility of the state. To fulfill this responsibility, states w e r e encouraged to f o r m interstate compacts for radioactive waste disposal. At the present time, only 37 states have entered into compact agreements, in spite of the clause in Public Law 9 6 - 5 7 3 that established January 1, 1986, as a target date for implementation of state responsibility for radioactive wastes. Recent action by Congress has resulted in postponement of the implementation date to January 1, 1993. 9 1986 by G r une & S t r a t t o n , Inc.
ADIOACTIVE WASTE is a natural conseR quence of the societal uses of radioactive materials for generation of electicity, identifica-
addition to fissionable material orginally comprising the fuel rods, spent fuel rods contain many fission products and transuranic elements, including plutonium. Spent fuel rods are extremely radioactive; currently, they are stored in temporary quarters pending the development of a high-level radioactive waste repository. Reprocessing of the fuel rods to recapture the unused nuclear fuel and plutonium is a promising alternative to direct disposal that would greatly reduce the volume and radioactivity of the waste material. However, an indefinite deferral of the chemical reprocessing of spent nuclear fuel materials was initiated in 1977 and is still in effect. High-level waste. This classification of radioactive waste includes the residue remaining after separation of uranium and plutonium from spent nuclear fuel rods during chemical reprocessing. Disposal of this highly radioactive residue in solid form would require a geologic repository identical to that for disposal of spent nuclear fuel. Transuranic wastes. This type of radioactive waste, consisting of elements above uranium in the periodic table, is also a by-product of reprocessing nuclear fuel. Although relatively low in radioactivity, some components of this waste product have very long half-lives and would require disposal in a geologic repository similar to that for spent nuclear fuel and high-level waste. Mine and mill tailings. These radioactive wastes are by-products of uranium mining and milling. They consist of large quantities of lowlevel radioactivity, including radium and its decay product gaseous radon. Mill tailings can be handled by placement in relatively secluded
tion of petroleum deposits, detection and treatment of disease, verification of structural integrity of construction materials, production of nuclear weapons, and application of radioactive substances for various other civilian and military purposes. As the uses of radioactive materials have grown in number and magnitude, their waste products also have increased, so that today the disposal of radioactive wastes is a significant national challenge. This challenge is exacerbated by the public perception of radioactive waste disposal as an intractable situation that creates a legacy of unsolved problems for future generations. This perception exaggerates the magnitude of technical problems associated with radioactive waste disposal; nevertheless, it creates severe difficulties for the nation in the identification of socially acceptable solutions to the waste disposal problem. TYPES OF RADIOACTIVE W A S T E S
Radioactive wastes can be separated into five categories according to the origin of the wastes, their level of radioactivity, and their potential hazard. 1 Spent fuel. This category of radioactive waste consists of nuclear fuel rods nearing the end of their useful life in a nuclear reactor. In
From the American Medical Association, Chicago. Address reprint requests to William R. Hendee, PhD, Vice President for Science and Technology, American Medical Association, 535 North Dearborn St, Chicago, IL 60610. 9 1986 by Grune & Stratton, Inc. 0001-2998/86/1603-0008505.00/0
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DISPOSAL OF RADIOACTIVE WASTES
areas with enough soil cover to impede the escape of radon. Low-level waste. To qualify as low-level waste, radioactive materials must satisfy three criteria2: (1) they must not be high-level waste, including spent fuel; (2) they must contain less than 10 nCi/g of transuranic elements; and, (3) they must not be mine or mill tailings. Low-level wastes can be solid, liquid, or gaseous radioactive products from a variety of medical, commercial, and industrial processes. These wastes include routine waste products (eg, paper, filters, piping, tools, rags, and glass) contaminated with small amounts of radioactivity. They can be buried in shallow land-burial sites at remote locations with controlled access. A shallow land-burial disposal site for lowlevel wastes resembles a sanitary landfill. Trenches with sloping sides are constructed so that water flows to each side along the bottom of the trench. Standpipes along the sides of the trench permit sampling of water for radioactivity. Trenches are dug in areas of low permeability to water migration. Radioactive wastes deposited in the trench are covered daily with dirt; when the trenches are filled, they are capped with soil and possibly with clay or plastic covers. The trenches are identified with a permanent marker describing the location, types, and volumes of radioactive materials contained therein. A buffer zone and fence are used to control access to the disposal site, and periodic surveys are conducted to detect the migration of radioactivity into surface and ground water, soil, vegetation, ambient air, and wildlife. Operation of a typical site is planned for 20 to 30 years, with surveillance anticipated for at least 300 years. At the time the site is closed, ambient radiation should be essentially at background levels. An intruder who lives on, grows food on, and derives drinking water from the site beginning 100 years after closure should receive less than 500 mrem/yr as a result of these activities. 3 Low-level radioactive waste encompasses all of the waste products of a typical nuclear medicine clinical or research laboratory. Hence, disposal of these wastes constitutes the major waste disposal concern for persons working in nuclear medicine. Commercial suppliers of radiopharmaceuticals (but not most clinical users or biomedical researchers) may generate other, more
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radioactive, types of waste as a by-product of the use of a nuclear reactor or particle accelerator to produce radioactive nuclides. HISTORY OF LOW-LEVEL RADIOACTIVE WASTE DISPOSAL
The generation of substantial quantities of radioactive wastes began with the introduction of reactor-produced radioactive materials into the civilian sector following the end of World War II. Initially, all radioactive wastes were handled at federal sites for radioactive waste disposal. The volume of low-level wastes increased steadily during the late 1940s and throughout the 1950s. In the early 1960s, several commercial sites were opened for the shallow land-burial disposal of low-level wastes. With one exception, these sites were operated by private firms on land leased from state governments; the exception was the site at Richland, Wash, where the land was leased from the federal government. Of the six disposal sites opened in the 1960s, three have been closed for the following reasons: (1) West Valley, NY: closed because of improper rainwater drainage; (2) Maxey Flats, Ky: closed because of an excessive state surcharge that made continued operation uneconomical; and, (3) Sheffield, Ill: closed when its licensed capacity was reached and expansion was denied by Illinois. The three remaining sites, all of which currently accept radioactive wastes are Barnwell, SC, Richland, Wash, and Beatty, Nev. These sites handle all low-level radioactive wastes generated by private and governmental sources, with the exception of low-level wastes generated by facilities operated by the Department of Energy. In 1980, 90,928 m 3 of low-level waste was buried in the three functioning commercial sites for radioactive waste disposal. The Barnwell site received 54,723 m 3 (60%) of this waste, and the remainder was distributed between Richland (26%) and Beatty (14%). Slightly more than half of the waste was produced by the nuclear power industry, with industry and institutions (principally hospitals and research centers) contributing about equally to the remainder. In 1979, the governors of Washington and Nevada, citing infractions of packaging and transportation regulations, temporarily closed the Richland and Beatty sites. In addition, South Carolina imposed a limit on the amount of waste
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Table 1. Currently Existing Interstate Waste Disposal Compacts Northwest
Southeast
Rocky Mountain
Central States
Central Midwest
Midwest
Northeast
Idaho Washington Oregon Utah Alaska Hawaii Montana
Georgia Florida Tennessee Alabama N. Carolina S. Carolina Mississippi Virginia
Colorado Nevada New Mexico Wyoming
Kansas Oklahoma Nebraska Arkansas Louisiana
Illinois Kentucky
Wisconsin Indiana Iowa Ohio Michigan Minnesota Missouri
Connecticut New Jersey Maryland Delaware
Reprinted by permission, Current Concepts in Diagnostic Nuclear Medicine, Vol. 2, No. 4, Winter, 1985. s
to be received each year at the Barnwell facility. These activities, together with congressional hearings and recommendations of an Interagency Review Group, resulted in the formation of a State Planning Council on Radioactive Waste Management in early 1980. The deliberations of the Council, together with those of the N a t i o n a l Governors Association and the National Conference of State Legislators, led to passage in December 1980 of Public Law 96573, "The Low-Level Radioactive Waste Policy Act." This Act states that (1) every state is responsible for disposal of low-level radioactive wastes generated within its boundaries, except for wastes resulting from activities of federal defense, research, and development activities; (2) states are encouraged to enter into interstate compacts for the purpose of discharging their responsibility for low-level waste disposal; (3) after January 1, 1986, state and regional compacts are authorized by federal statute to exclude from their disposal sites any and all wastes generated outside the state or region; and (4) operation of an interstate compact agreement requires prior approval of Congress and a 5-year congressional review. CURRENT STATUS OF INTERSTATE COMPACTS
Although simple in concept, interstate compacts for the disposal of low-level radioactive wastes have been difficult to implement in practice. By January 1, 1986, only seven compacts encompassing a total of 37 states had been formed (Table 1). These states account for 74% of the total national volume of low-level wastes and 47% of the total national waste activity) The compacts vary greatly in the amount of radioactive wastes falling under their jurisdiction. For example, the Southeast Compact encompasses 37% of the national volume of waste, whereas less than 1% is included under the
Rocky Mountain Compact. Several states, including some generating considerable radioactive waste, are currently not part of a compact agreement. In the near future, California is expected to ratify an agreement with Arizona to form the Western Compact, and Pennsylvania and West Virginia probably will form the Appalachian Compact) Late in 1985, the seven compact agreements were ratified by Congress. Ratification was granted with the provision of a transition period extending the access to existing disposal sites from January 1, 1986, until January 1, 1993. This extension was provided with the understanding that certain steps would be taken, including (1) achievement of specific objectives toward development of new disposal sites in a timely fashion between 1986 and 1993; (2) implementation of a ceiling on the volume of low-level waste accepted by each existing disposal site; and (3) imposition of a surcharge for handling waste from facilities outside the compact region sent to each existing disposal site. The governors of the three states with existing disposal sites for low-level radioactive wastes have indicated that actions to close the sites will be taken if the conditions of ratification and deadline extension are not followed. REFERENCES
1. Russ GD Jr: Nuclear Waste Disposal: Closing the Circle. Bethesda,Md, AtomicIndustrial Forum, Inc, 1984 2. Hendee WR: Management of radioactive wastes, in Hendee WR (ed): Health Effects of Low-LevelRadiation. Norwalk, Ct, Appleton-Century-Crofts,1984 3. Olsen JO: Low-LevelRadioactiveWaste Management: Status and PotentialImpactof MedicalPracticeand Biomedical Research.Columbus,Ohio, OhioState University, 1984 4. Department of Energy: Low-LevelRadioactiveWaste Management Handbook Series. An Introduction. DOE/ LLW-13Ta. Idaho Falls, Idaho, EG&G Idaho, Inc, 1983 5. Briner WH: Low-levelrad waste compacts:An update. Curr Concepts Diag Nucl Med 2:18, 1985