Waste from commercial nuclear fuel

Ewest, E., and H. W. Levi Evaluation of Products for the Solidification of High-Level Radioactive Waste from Commercial Reprocessing in the Federal Republic of Germany, Proceedings of the Mane ement of Radioactive Wastes from the Nuclear Fuel Cycle, vol. 2, International Atomic Energy Agency, Vienna, 1976, p. 15. 

HLW comprises most of the radioactivity associated with nuclear waste. Because that designation can cover radioactive waste from more than one source, the term spent nuclear fuel (SNF) will be used to discuss HLW originating from commercial nuclear reactors. LLW comprises nearly 90 percent of the volume of nuclear waste but little of the radioactivity. Nuclear power reactors produce SNF and most of the nation s LLW, although there are approximately 20,000 different sources of LLW. The name SNF is a bit of a misnomer because it implies that there is no useful material left in the fuel, when in fact some fissionable material is left in it. 

High-level waste (HLW) from spent nuclear fuel from nuclear power plants is generally stored in water basins at the plants where it was used. At present, nearly 30,000 metric tons of spent nuclear fuel is stored at commercial reactors (53). E>ry storage and wet basin storage are designed as temporary solutions. The need for a long-term storage repository is acute and is under study and development. 

HLW has yet been built. The only operating geological repository to date is the Waste Isolation Pilot Plant (WIPP) in the USA. In addition to WIPP, good progress has been made in several countries on repositories for HLW or spent fuel from commercial nuclear power plants. 

In summary, management of HLW and long lived low and intermediate level waste has made considerable progress. Spent fuel and stored HLLW, at least from the commercial nuclear fuel cycle, remain under control and containment. There have been, however, serious problems with HLW from military reprocessing. Solving these problems remains a major challenge. 

Nuclear Waste. NRC defines high level radioactive waste to include (/) irradiated (spent) reactor fuel (2) Hquid waste resulting from the operation of the first cycle solvent extraction system, and the concentrated wastes from subsequent extraction cycles, in a faciHty for reprocessing irradiated reactor fuel and (3) soHds into which such Hquid wastes have been converted. Approximately 23,000 metric tons of spent nuclear fuel has been stored at commercial nuclear reactors as of 1991. This amount is expected to double by the year 2001. 

Inclusion of NARM waste in the same classification system with radioactive waste that arises from operations of the nuclear fuel cycle would require a change in the scope of AEA, because management and disposal of commercial NARM waste cannot be regulated under AEA. 

High-level waste thus includes the concentrated wastes that arise from reprocessing of commercial or defense nuclear fuel that contain virtually all the fission products and transuranium radionuclides (except plutonium) in spent fuel. However, the definition does not mention the constituents of the waste, and it is only qualitative because concentrated is not quantified and the minimum fuel burnup that would yield high-level waste is not specified. Although the definition given above referred only to liquid (aqueous) waste, it is clear from further discussions in 10 CFR Part 50, Appendix F (AEC, 1970), that AEC intended that high-level waste also would include concentrated solid waste derived from liquid high-level waste that was suitable for permanent disposal. 

The third fact is that spent nuclear fuel is not waste. Spent nuclear fuel contains 2% to 3% waste, but is about 97% recoverable uranium and plutonium. Each bundle has the potential electric energy equivalent of more than 10 million barrels of oil. High-level nuclear wastes consist of fission products and actinides that are extracted from spent fuel, but not saved for commercial use or research. Spent fuel may be temporarily stored until it is reprocessed to separate the waste from the valuable plutonium and uranium. The remaining glassified waste will then be permanently entombed. 

It is considered a form of HLW because of the uranium, fission products, and transuranics that it contains. HLW includes highly radioactive liquid, calcined or vitrified wastes generated by reprocessing of SF. Both SF and HLW from commercial reactors will be entombed in the geological repository at Yucca Mountain —100 mile (1 mile = 1.609344 km) northwest of Las Vegas, Nevada. Disposal of spent nuclear fuel and HLW in the US is regulated by 40 CFR Part 191 (US EPA, 2001) and 10 CFR Part 60 (US NRC, 2001). It is discussed in more detail in a later section of this chapter. 

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