COATED FUEL PARTICLE OF NUCLEAR REACTOR AND METHOD FOR ITS PRODUCING Russian patent published in 2008 - IPC G21C3/28 G21C3/62 

FIELD: nuclear energetics; microspheric fuel.

SUBSTANCE: the coated fuel particls of the nuclear reactor contains the fuel microsphere from (U,Th)O₂ and the multilayer protective coating where the first layer, starting from the fuel microsphere, is made of the low-density pyrocarbon, the second layer - of the high-density isotropic pyrocarbon, the third layer - of sialon containing Si₃Al₃O₃N₅ composition. The method for producing the coated fuel particls of the nuclear reactor with the three-layered protective coating includes the sequential precipitation of the coating layers on the fuel microspheres in the boiling layer where the first layer of the low-density pyrocarbon is precipitated by acetylene pyrolisis with the concentration in argon mixture 50 volume percent at 1450°C, 95-97% of the second layer of the high-density isotropic pyrocarbon is precipitated by acetylene pyrolisis with the concentration in argon mixture 40.0-43.0 volume percent and propylene with the concentration in argon mixture 30.0-27.0 volume percent at 1300°C, and 5-3% of the second layer precipitated by propylene pyrolisis with the concentration in argon mixture 20.0 volume percent with supplement of 1.0-2.0 volume percent of oxygen; the precipitation of the third layer of Si₃Al₃O₃N₅ is performed by SiCl₄-NH₃-AlCl₃-O₂ pyrolisis at molar correlation (2.5-3.0):(3.0-4.0):(2.5-3.5):(1.5-3.0).

EFFECT: service life of coated fuel particles of nuclear reactor is increased due to increased corrosion resistance of coatings.

2 cl