Double Cascades for Purification of Reprocessed Uranium Hexafluoride from ^{232, 234, 236}U Isotopes

The paper offers a double-cascade scheme for reducing the concentration of ^{232, 234, 236}U isotopes in reprocessed uranium hexafluoride. The greatest decrease of the ratio between the masses of ²³⁶U and ²³⁵U is provided in the product of the first ordinary cascade enriched by ²³⁵U at the concentration of less than 20%. For this purpose, a special mode of stages operation is determined. Enrichment by ^232, 234U is performed in the second ordinary cascade, which is fed by the product of the first cascade. After being purified from ^{232, 234}U, the waste flow is diluted till the concentration of ²³⁵U is less than 5%. This paper describes the methodology for calculating the parameters of cascades with the stage separation factors correlating with gas centrifuges. This methodology served as a basis for a computational experiment. It is demonstrated that the output gained after the dilution meets the requirements of the American Society for Testing and Materials C996-20 specification for the commercial grade of low-enriched uranium hexafluoride in terms of ^232, 234U isotopes. The content of ²³⁶U in it is several times less than during the direct enrichment of reprocessed uranium hexafluoride.