METHOD OF PRODUCING PELLETED URANIUM DIOXIDE-BASED MODEL NUCLEAR FUEL Russian patent published in 2015 - IPC G21C3/28 

FIELD: atomic physics.

SUBSTANCE: invention relates to nuclear power engineering, particularly to production of uranium dioxide-based model nuclear fuel, which includes fission product imitators. The method of producing pelleted model nuclear fuel includes preparing and dry mixing powdered uranium dioxide and fission product imitators, preparing a mixture, pressing and sintering. The fission product imitators are divided into groups according to chemical state in uranium dioxide and premixing is carried out within each group, after which all groups are combined and mixed with double the weight of uranium dioxide. The obtained mixture is combined with the remaining mass of uranium dioxide in several steps, including intermediate mixing. Sintering is carried out in a vacuum. Sintering temperature is raised in several steps until gas release at each step ceases, wherein for fission product imitators with a melting point lower than 800°C, ageing is carried out at temperatures of 0.8 times the melting point thereof, and for the other fission product imitators at temperatures of 0.5 times the average melting point.

EFFECT: reduced volume inhomogeneity and improved uniformity of distribution of fission product imitators in the model fuel.

4 cl, 3 dwg, 1 tbl