Today in the world there is a whole range of projects to complete thermal neutron reactors, which require closing the fuel cycle with the reuse of fissile materials obtained from spent nuclear fuel. use. However, according to experts, all options for enriching regenerative uranium have their own set of disadvantages.
The problem is that in the process of enriching regenerated uranium under repeated recycling conditions, in addition to the usual waste of depleted uranium, a portion of the mixture of regenerated uranium is also produced that does not participate in the enrichment process. , or a mixture of uranium contaminated with artificial even isotopes, which is very difficult for uranium enrichment plants to handle.
“After conducting computer modeling based on the programs developed at NRNU MEPhI to calculate and optimize the sequence of centrifuges. We have proposed a new variant based on the use of a three-stage enrichment scheme,” said NRNU MEPhI Associate Professor Andrei Smirnov.
Research scientist at Uranium enrichment plant. (Photo: RIA).
The presence of the artificial isotope 232˒236U and the elevated content of 234U in the isotopic composition of regenerated uranium, as the scientists point out, significantly complicates the secondary enrichment process. Along with that, repeated recycling significantly increases the content of harmful isotopes.
“Our project allows to obtain a product that meets the restrictions for all even isotopes of uranium, even if their content is elevated in the original mixture. Furthermore, in the stationary mode of operation, our scheme produces no wastes, except that depleted uranium is a natural and unavoidable by-product,” said Andrei Smirnov.
According to the scientists, the application of this scheme is to ensure the minimization of abnormal wastes in the enrichment of regenerated uranium. Currently, the scientists continue to improve the method’s characteristics through additional variations, aiming to reduce the power used for the enrichment and reduce the loss of the valuable isotope 235U.