METHOD FOR ISOTOPE RECOVERY OF REGENERATED URANIUM Russian patent published in 2019 - IPC G21C19/42 

FIELD: nuclear physics and equipment.

SUBSTANCE: invention relates to closure of nuclear fuel cycle and can be used for return of uranium extracted from spent nuclear fuel (SNF) into fuel cycle of both light-water reactors and other types of reactors operating on enriched uranium. Method for isotopic recovery of regenerated uranium involves high content of isotope ²³⁵U to 3–5 wt% in regenerated uranium with reduction of absolute and / or relative concentration of even uranium isotopes, with separation of raw uranium regenerate raw material isotopes at installation of two successive gas-centrifugal cascades. Moreover, the raw uranium regenerate is enriched in the fissile isotope uranium-235 in the first gas centrifugal cascade to content of 5–15 wt%. ²³⁵U, for production of commercial isotopic mixture, second stage cascade containing 5–14 wt%. ²³⁵U is mixed with low-enriched uranium-diluent of natural origin and concentration ²³⁵U 3–5 wt%, and the second cascade selected flow is enriched by ²³⁵U up to 20 wt% is directed into storage container. After holding and radiochemical cleaning, the next batch at the inlet of the first gas centrifuge cascade is mixed with the recovered uranium.

EFFECT: technical result is elimination of hazardous high concentrations of fissile isotope ²³⁵U is not more than 20 % by isotope ²³⁵U at any stages of the process, providing complete recovery of regenerated uranium in fuel reproduction due to the absence of unused regenerate directed to long-term storage.

1 cl, 1 tbl, 1 dwg