METHOD OF CORRECTING ISOTOPIC COMPOSITION OF PLUTONIUM USING FAST NUCLEAR REACTOR WITH SODIUM COOLANT Russian patent published in 2024 - IPC G21C1/02 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of correcting isotopic composition of plutonium using a fast nuclear reactor with a sodium coolant. Method involves loading nuclear fuel into the active zone of a fast nuclear reactor, irradiating nuclear fuel with a stream of fast neutrons with flow of 3 × 10¹⁵ to 8 × 10¹⁵ neutrons/(cm² × c) during campaign 465 effective days and unloading irradiated nuclear fuel from fast nuclear reactor. Fuel assemblies of the first and second types are loaded into the core, wherein in the assemblies of the second type, which are designed to ensure criticality of the reactor, a mixture with mass fraction of plutonium oxide 0.17–0.35% and uranium oxide 0.65–0.83% is used. Weight fraction of plutonium oxide in fuel assemblies of the first type, intended for correction of plutonium isotopic composition, is determined by empirical ratio: X = (A/B)⁵ × F × τ × k, where X is weight fraction of plutonium oxide in fuel assemblies of the first type, in %; A is fraction of fissile isotopes in plutonium used in fuel assemblies of the first type, in %; B is fraction of fissile isotopes in plutonium with corrected isotopic composition, in %; F is the average neutron flux in the active zone, neutron/(cm² × c); τ is duration of fast reactor nuclear fuel campaign, in days; k = 1.21 × 10^-24 is an empirical coefficient, in cm². In fuel assemblies of the first type, the total relative fraction of fissile isotopes of plutonium 239 and plutonium 241 in plutonium for correcting isotopic composition corresponds to the range of permissible values from 0.30 to 0.60%.

EFFECT: obtaining plutonium oxide with an increased fraction of fissile isotopes suitable for reuse in PWR-type reactors.

1 cl, 1 dwg