Reprocessing, domestic spent nuclear fuel

The Purex process is the only one with commercial-scale operating history. This military technology has been modified to treat domestic spent nuclear fuel. The focus of international commercial efforts to reprocess domestic spent fuel is to recover uranium and plutonium in the spent fuel. 

The pyrochemical coprocessing of spent nuclear fuel by the Salt Transport Process appears to be a potentially viable reprocessing method, not only as an "exportable proliferation resistant technology," but as a domestic reprocessing operation. All operations are nonaqueous and waste generation is in solid form, thus requiring no conversion from aqueous solutions to solids. 

Due to the low current costs of natural uranium and enrichment, the use of uranium oxide fuel with the spent nuclear fuel (SNF) storage at NPP site and postponed reprocessing is economically justified for SVBR-75/100. The duration of such storage depends on the available uranium resources and the scale of nuclear power. Anyway, the existing uranium resources are sufficient to realize a realistic scenario of nuclear power development till the year 2050. It can be expected that the costs of natural gas at the domestic market will increase more intensively than the costs of natural uranium. This will ensure the competitiveness of NPPs even in the case of a considerable increase of uranium prices, because the structure of electricity costs for NPPs and HPPs is essentially different. 

All the components of the nuclear-fission power system are fully operational except for ultimate waste disposal. However, spent fuel is not reprocessed in the United States because there is currently an adequate supply of natural uranium and enrichment services availab 1 e domestically and from other countries at a 1 ower cost than that of the recovered fissionable material from spent fuel. Also, the United States unilaterally declared a moratorium on reprocessing in the early 1980s in an attempt to reduce the spread of nuclear weapons. Current economics do not favor a return to reprocessing and fuel recycling in the United States at this time in as much as it does dramatically increase the amount of interim and final waste storage capacity that is required. 

Nuclear power plants in the United States use light water moderated nuclear reactors (LWR) that produce the steam to generate electricity. The fuel elements for boiling water reactors and pressurized water reactors (PWR) are nearly the same. The fuel is uranium dioxide enriched with 3 % and this produces a nearly uniform spent fuel, which would be the feed for domestic fuel reprocessing. 

The extended radiation time for the domestic fuel increases the quantity of fission products and the higher actinides. Pure plutonium product poses nuclear weapons proliferation risk and is the primary reason reprocessing is not practiced in the United States. The modified PUREX process has been practiced on an industrial scale in Europe and supports the production of mixed uranium-plutonium fuel. Blended UO2 and PUO2 powder is compacted and sinter to form the mixed oxide (MOX) fuel pellets much like the enriched UO2 fuel. Natural and depleted uranium can be used to prepare MOX fuel and is the demonstrated option to recover fuel values from spent fuel. 

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