Spent-fuel wastes

The fast reactor high level waste is accumulated at the reprocessing plants and retains its toxicity for only a few hundred years, rather than the tens of thousands of years ofthe spent fuel wastes from our present reactors,. Thus, the nuclear waste disposal problems are minimal and arrangements for disposal could be made on a global basis. 

Spent-fuel wastes is a term sometimes used to describe wastes from nuclear power plants consisting of spent fuel rods. 

SPILKER, H., HOGGENBERG, R. The German Cask Concept for Intermediate and Final Storage of Spent Fuel. Waste Management 95, Tucson, 26.02. - 2.03.1995... 

The historical plan (that discussed in the 1950s and 1960s) for managing the spent fuel waste discharged from LWRs operating in a once-through fuel cycle was to reprocess it by partitioning it into three products ... 

Compared to the investigations described above for SLMs in processing actinides from spent fuel wastes, studies devoted to ELMs are very limited. ELM transport of U(VI) from a solution which was 0.01 M in nitric acid and 2 M in sodium chloride with an emulsion of 2.5 M phosphoric acid in 0.1 M DEHPA-dodecane is practically quantitative (Table 9) and equivalent to 66 stages of extraction with the DEHPA in dodecane (55). 

By-Products. The PUREX process is efficient at separating uranium and plutonium from everything else in the spent fuel. Within the high level waste stream are a number of components which have, from time to time, been sufficiendy interesting to warrant their recovery. The decision to recover a particular isotope is usually based on a combination of market incentives and desired waste reduction. 

Classification of wastes may be according to purpose, distinguishing between defense waste related to military appHcations, and commercial waste related to civiUan appHcations. Classification may also be by the type of waste, ie, mill tailings, high level radioactive waste (HLW), spent fuel, low level radioactive waste (LLW), or transuranic waste (TRU). Alternatively, the radionucHdes and the degree of radioactivity can define the waste. Surveys of nuclear waste management (1,2) and more technical information (3—5) are available. 

The safety record for transport of radioactive materials including spent fuel and wastes is excellent. Information about transportation of radioactive materials including waste is managed by DOE. Codes such as RADTRAN that can calculate pubHc radiation dose owing to the passage of shipments have been developed. The maximum dosage from such shipments is a very small fraction of the typical annual radiation dose from all other sources. 

The disposal of radioactive waste is governed by rules of the NRC and the EPA (19). NRC regulations differ for low level waste and for high level waste, including spent fuel (20). 

The geologic aspects of waste disposal (24—26), proceedings of an annual conference on high level waste management (27), and one from an annual conference on all types of radioactive waste (28) are available. An alternative to burial is to store the spent fuel against a long-term future energy demand. Uranium and plutonium contained in the fuel would be readily extracted as needed. 

Funding for developing commercial waste disposal faciUties is to come from the waste generators. In the case of spent fuel disposal, a Nuclear Waste Fund is accumulating based on an assessment of one mill per kilowatt-hour of electricity. For low level wastes, surcharges on waste disposal and direct assessments of utiUties have been imposed. 

Integrated DataBase for 1993 U.S. Spent Fuel and Raidioactive Waste Inventories, Projections, and Characteristics, DOE/RW-0006, Rev. 9, Oak Ridge National Laboratory, Oak Ridge, Term., Feb. 1994. 

The primary issue is to prevent groundwater from becoming radioactively contaminated. Thus, the property of concern of the long-lived radioactive species is their solubility in water. The long-lived actinides such as plutonium are metallic and insoluble even if water were to penetrate into the repository. Certain fission-product isotopes such as iodine-129 and technicium-99 are soluble, however, and therefore represent the principal although very low level hazard. Studies of Yucca Mountain, Nevada, tentatively chosen as the site for the spent fuel and high level waste repository, are underway (44). 

Some spent fuel is also stored at two off-site storage faciHties, one in Illinois and one in upper New York State (which no longer accepts waste). The water in these holding pools acts as a shield preventing release of radioactivity. At some plants, waste is beginning to be stored dry in heavily shielded,... 

The increasing number of atomic reactors used for power generation has been questioned from several environmental points of view. A modern atomic plant, as shown in Fig. 28-3, appears to be relatively pollution free compared to the more familiar fossil fuel-fired plant, which emits carbon monoxide and carbon dioxide, oxides of nitrogen and sulfur, hydrocarbons, and fly ash. However, waste and spent-fuel disposal problems may offset the apparent advantages. These problems (along with steam generator leaks) caused the plant shown in Fig. 28-3 to close permanently in 199T. 

The main drawback to nuclear power is the production of radioactive waste. Spent fuel from a nuclear reactor is considered a high-level radioactive waste, and remains radioactive for a veiy long time. Spent fuel consists of fission products from the U-235 and Pu-239 fission process, and also from unspent U-238, Pu-240, and other heavy metals produced during the fuel cycle. That is why special programs exist for the handling and disposal of nuclear waste. 

In 1976 the Swedish government stipulated that no new nuclear reactors should be charged until it had been shown how the radioactive waste products could be taken care of in an "absolutely safe manner" (8). Consequently, the nuclear power industry (through their joint Nuclear Fuel Supply Co, SKBF) embarked on a program referred to as the Nuclear Fuel Safety (KBS) Project (8). In one of the schemes (9) a repository for spent nuclear fuel elements in envisaged at a depth of 500 m in granitic bedrock. The repository will ultimately contain 6000 tonnes of uranium and 45 tonnes of plutonium. The spent fuel elements will be stored in copper cylinders (0.8 m in diameter and 4.7 m in length) with a wall thickness of 200 mm the void will be filled with lead. 

The Clinton Administration believes that the overriding goal of the Federal Government s high-level radioactive waste management policy should be the establishment of a permanent geologic repository - essential not only for the disposal of commercial spent fuel, but also for... 

The fact that spent fuel reprocessing and recycle are essential components ofgood nuclear non-proliferation and radioactive waste management practices. These actions are needed so that more efficient use can be made offissionablc materials, and unwanted radioactive fission products can be disposed of without need for permanent safeguards. In addition, potential weapons usable materials are destroyed through beneficial use. 

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