METHOD OF PREPARING REDUCED-ENRICHMENT URANIUM HEXAFLUORIDE FROM HIGH-ENRICHMENT ARMS URANIUM Russian patent published in 2007 - IPC C01G43/06 B01D59/20 

FIELD: nuclear fuel technology.

SUBSTANCE: invention relates to nuclear fuel cycle and can be used in manufacturing of nuclear reactor fuels by processing high-enrichment uranium removed from dismantled nuclear ammunition and having elevated content of minor uranium isotopes. Method of invention comprises conversion of high-enrichment arms uranium in its hexafluoride, which is then purified by removing chemical impurities in sorption-desorption cycle on metal fluorides. Isotope composition of high-enrichment uranium is adjusted on condition of restricting level of minor isotope in high-enrichment uranium by their limiting values on a rectangular-stepped cascade of gas centrifuges at ratio of numbers of steps in heavy and light fraction branches of the cascade 1:(8÷26). High-enrichment uranium hexafluoride is then mixed with diluting uranium hexafluoride enriched in uranium-235 isotope above its natural level, which was prepared from commercial natural material. Withdrawn light fraction of high-enrichment uranium cascade is diluted with refuse stream from uranium-diluent manufacture.

EFFECT: reduced irreversible loss of U-235, minimized separation means to manufacture high-enrichment uranium diluent, and reused isolated minor uranium isotopes.

4 cl, 1 dwg, 2 ex