Preparation of the coated nuclear fuel particle using the fluidized bed-chemical vapor deposition (FB-CVD) method

摘要

The tristructural-isotropic (TRISO) type coated fuel particle, which has been commonly used in the current high temperature gas-cooled reactor consists of a microspheric UO2 fuel kernel surrounded by four coated layers: a porous buffer pyrolysis carbon layer (buffer PyC), an inner dense pyrolysis carbon layer (IPyC), a silicon carbide layer (SiC) and an outer dense pyrolysis carbon layer (OPyC). The fluidized bed-chemical vapor deposition (FB-CVD) method was selected for preparing the coated nuclear fUel particle. In this paper, the special design for FB-CVD process is given. The gas distributors with multi-ring inclined holes and the coating furnace with vertical inhomogeneous heating design are developed. Based on experimental study, the TRISO coated nuclear fuel particle has been successfully prepared, and the appropriate parameters in the coating process are obtained.