METHOD FOR MANUFACTURING NUCLEAR FUEL PELLETS

摘要

FIELD: nuclear power engineering; pelletized nuclear fuel manufacture. SUBSTANCE: method for manufacturing nuclear fuel pellets by mixing up source powders having different concentration of uranium- 235 and high concentration of uranium-234 and uranium-236, and also by using reconditioned powdered nuclear fuel includes mixing up powders with different content of uranium-235 to attain desired uniformity and desired uranium-235 content which are stored in their respective reservoirs and by compressing nuclear fuel pellets. Uranium-235 content in mixture is calculated in advance from expression , where Ri is uranium-235 content in reservoir i; mi is powder mass taken from reservoir i for mixture; M is mixture mass, kg; n is total number of reservoirs in first and second groups. Then compensating value DELTAR depending on amount of thermal neutrons absorbed by uranium-234 and uranium-236 is found whereupon powder mass DELTAm, to be added to mixture from reservoir holding maximum uranium-235 content is calculated to ensure precise content of uranium-235 desired for the purpose. In this way desired content of uranium-235 is easy to control and adverse effect of uranium-234 and uranium-236 isotopes is compensated for. EFFECT: reduced deviation of mixture mass from desired value; enlarged range of source powders used. 5 cl, 9 tbl, 5 ex