Oxidation behavior of SiC layer of TRISO particles with the presence of NaF

In the present work, the oxidation behavior of the SiC layer of TRISO particles in NaF salt at concentrations of 0.2–2 % and at temperatures ranging between 800 and 1400 °C was studied. The results showed that the oxidation rate was accelerated with the increase in temperature and fluoride concentration, while the effect of fluoride concentration on oxidation rate was much greater than that of the temperature. This could be due to the reaction of fluoride with SiC/SiO2 and the dissolution of silicon oxide by the alkaline silicate formed during the oxidation process, which accelerated the diffusion of oxygen.