The silicon carbide (SiC) layer in tristructural isotropic (TRISO) coated fuel particles is a critical and essential layer for hydrogen production using high temperature gas cooled reactor (HTGR) since it is a protective layer against diffusion of metallic and gaseous fission products and provides mechanical strength for the fuel particle. In this study, SiC layers were deposited using a high temperature and high pressure horizontal hot wall chemical vapor deposition (CVD) system as an application of fluidized bed chemical vapor deposition (FB-CVD). Before the actual experiment, we performed computational simulations of the gas velocity, temperature profile and pressure in the reaction chamber with various process conditions. The simulation showed that the change of reactant states affects the growth rate at each position on the susceptor. As the deposition temperature increased, the microstructure, chemical composition and growth behavior changed and deposition rate increased. The simulation results were in good agreement with the experimental results.

Keywords: TRISO; SiC; simulation; CVD