METHOD OF PREPARING REDUCED-ENRICHMENT URANIUM HEXAFLUORIDE FROM HIGH- ENRICHMENT GUN URANIUM Russian patent published in 2004 - IPC

FIELD: nuclear fuel technology. SUBSTANCE: high-enrichment uranium metal is oxidized into oxides, which are then fluorinated. Resulting high- enrichment uranium hexafluoride is diluted and reduced-enrichment uranium hexafluoride is desublimated into containers. Content of minor isotopes in high-enrichment uranium is reduced in a series of gas centrifuges simultaneously with purification of high-enrichment uranium from chemical impurities. Operation conditions for the series of gas centrifuges are determined by restrictions for level of minor isotopes in high-enrichment uranium expressed by relationship: where m denotes mass number of minor uranium isotope; A_m is limiting level of minor uranium isotope in high-enrichment uranium, %; B_m is content of minor isotope in diluent, %; C_m is required amount of minor isotope in reduced-enrichment uranium hexafluoride, %; A₂₃₅, B₂₃₅, C₂₃₅ are contents of U-235 in high-enrichment uranium, diluent, and reduced-enrichment uranium, respectively, %. EFFECT: enabled preparation of high-quality reduced-enrichment uranium hexafluoride with elevated level of minor isotopes, in particular U-234. 1 dwg, 3 tbl