WO2017082772A3 - Method of manufacturing nuclear fuel particles - Google Patents

Abstract

The invention relates to the field of nuclear engineering, and more particularly to the production of nuclear fuel particles. A method of manufacturing nuclear fuel particles which includes the successive deposition of protective coating layers on spherical fuel elements by the pyrolysis of a mixture of gases in a fluidized bed, in which a layer of low-density pyrolytic carbon is deposited by the pyrolysis of a mixture of acetylene and argon, an intermediate layer and an outer layer of high-density isotropic pyrolytic carbon are deposited by the pyrolysis of a mixture of gases consisting of 26.0 wt% acetylene, 22.0 wt% propylene and 52.0 wt% argon, and a strengthening layer of silicon carbide is deposited on the intermediate layer of high-density isotropic pyrolytic carbon, is characterized in that a layer of silicon carbide, which acts as an oxygen getter, is pre-deposited on the spherical fuel elements by the pyrolysis of a mixture of gases consisting of 96 wt% argon and 4 wt% methylsilane, the layer of low-density pyrolytic carbon is deposited by the pyrolysis of acetylene with a concentration of 55-65 wt% in a mixture with argon, and the strengthening layer of silicon carbide is deposited from the following mixture of gases: 8.5-9.5 wt% methyltrichlorosilane, 0.5 wt% propylene, and the remainder (90-91 wt%) hydrogen. The oxygen getter layer is deposited at a temperature of 1090-1110°С, and the protective coating layers are deposited at the same pyrolysis temperature of 1290-1310°С. The technical result is an increase in process efficiency, and more specifically: a reduction in the duration of the process and in the consumption of gases during pyrolysis, as well as a simplification of the method of producing nuclear fuel particles and an increase in the service life of spherical fuel elements.