2022 年 8 巻 p. 22-00315
To improve the heat removal efficiency from the core and achieve the higher power density operation in High Temperature Gas-cooled Reactor, the use of a sleeveless SiC matrix fuel compact shall be proposed. In the present study thermogravimetric test on polycrystalline reaction-sintered SiC and IG-110 graphite was performed to evaluate the oxidation behavior under conditions of air ingress accident. The results showed that graphite oxidation in air was a severe weight loss reaction under elevated temperature. On the contrary, SiC was found to follow passive oxidation mode with a slight weight gain process up to 1400 ℃. Therefore, SiC is suggested as a preferable candidate in comparison to graphite because of its stable anti-oxidation property. The measured reaction rates were well fitted to Deal-Grove model, thus, ideal SiC passive oxidation kinetic was observed. Moreover, the activation energy was determined as 323 kJ/mol for polycrystalline reaction-sintered SiC.
