METHOD FOR RECOVERY OF URANIUM ISOTOPE MIXTURE BURNT-OUT IN NUCLEAR REACTOR Russian patent published in 1998 - IPC

FIELD: nuclear fuel production. SUBSTANCE: method involves decreasing or increasing concentration of fissionable uranium-235 isotope to desired values in burnt-out mixture of uranium isotopes at the same time reducing concentration of harmful isotopes, such as uranium-232, uranium-234, uranium-236. Three components of uranium oxide powders are mixed up, this procedure being followed by their dissolving in nitric acid. During mixing, uranium isotope concentrations are checked and adjusted to desired values. Upon extraction and re-extraction of uranium salts, the latter are separated from liquid, filtered off, dried out, and recovered in hydrogen oven to uranium dioxide at 600-800 C. EFFECT: improved (high) concentration of fissionable nuclides at low concentration of harmful isotopes; increased homogeneity of fissionable isotope distribution. 3 cl, 1 dwg