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Posted on April 21st, 2014, by

Today it is impossible to imagine a highly developed country without the use of nuclear power because of the lack of conventional power resources and high demands on the use of electric power in industry. The number of nuclear power plants in the world is constantly increasing. However, the stringent environmental laws have brought to the forefront the existing problem of the safe disposal of radioactive wastes in the USA and in other countries of the world, including not only uranium mining and fuel processing, but also the whole cycle of power production and the reprocessing of spent fuel (Dlouhý, 2004). The statistics show that 90% (or 32 million cubic meters) of the total nuclear waste volume can be defined as radioactive byproduct waste (Werner, 2002, p. 481).

Nuclear Waste Disposal

            It is known that the term nuclear waste is used to denote all types of residues from the utilization of radioactive materials, including the use in medical and industrious purposes. It has been found that the most dangerous radioactive materials are the spent fuel and wastes from commercial nuclear reactors as well as reactors that produced plutonium for nuclear weapons, according to David Bodansky (2004, p. 231). These materials are highly radioactive, while other materials have lower levels of radioactivity and can cause less harm, although the sites of the waste disposal of these materials cause public concern in the USA. The statistics show annually nearly 200.000 cubic meters of low- and intermediate level waste and about 10.000 cubic meters of high-level waste are generated and stored worldwide from nuclear power production (Werner, 2002, p. 481). These volumes are constantly increasing because each year more and more nuclear power units are put into operation.

The Handford Reservation is one of the main waste disposal sites in the USA. This site was established in 1943. Today a great variety of radioactive industrial wastes are generated by reactors and chemical laboratories. According to James Werner, high-level waste and spent fuel comprise only a small portion of the volume of radioactive waste that has been buried or being stored, they represent more than 95% of the radioactivity in nuclear waste (2002, p. 481).

Disposal of Low and Intermediate Level Wastes

            Low-level waste includes the products that contain low level of short-lived radioactivity generated from medicine and industry (clothing, tools, paper, filters, and others). Intermediate-level waste products contain higher level of radioactivity (chemical products, resins, sludge, nuclear fuel cladding, and other products). High level waste products are generated in the nuclear reactors and contain radioactive fission products and transuranic elements. Low-level waste must be stored until its decay and then it can be disposed of as trash.

It is known that liquid waste can be classified as low level, intermediate level and high level wastes. Low level wastes contain less level of radioactivity (5×10-5 uCi/ml), while intermediate level waste between 5×10-5 uCi/ml and 100 uCi/ml of radioactivity. Low and intermediate level liquid radioactive wastes are loaded into special containers, cribs and kept in swamps, dry wells, trenches, etc. The cribs are used for disposal of low and intermediate level wastes that cause damage to the environment. The first cribs at the Handford reservation were special underground timbered structures with graded gravel (Leeden et al., 1996).

Solid radioactive wastes produced from different nuclear reactor operations and from handling, processing and disposal of spent fuel are also categorized as low-, intermediate- and high-level wastes(Sabol et al., 1995, p. 228).As a rule, low-level wastes that arise in the form of contaminated protective materials used in the power plants and intermediate-level wastes that are produced in such forms as in-reactors components, evaporator concentrates, etc. , contain a considerable amount of radioactivity concentrations, but they do not generate heat at the high rate. Both low and intermediate wastes can be disposed of by shallow burial, including trenches, reinforced concrete vaults, and monoliths in pits (Sabol et al., 1995, p. 228). Although low-level radioactive waste is considered to be less radioactive than high-level radioactive waste, it may include high levels of radionuclides that are similar to high-level radioactive waste.

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