Characterization of oxidation behaviour of boron-doped graphite

Sumita, Junya ; Osaki, Hiroki*; Kunimoto, Eiji*; Yamaji, Masatoshi*; Konishi, Takashi*

Graphite materials are used for the in-core components of High Temperature Gas-cooled Reactor (HTGR) which is a graphite-moderated and helium gas-cooled reactor. The HTGR is particularly attractive due to capability of producing high temperature helium gas, and its passive and inherent safety features. It is required for core support graphite structure, which support the core, to have oxidation resistance in the case of air ingress accident in order to maintain the core arrangement and cool the core from a viewpoint of ensuring high safety of HTGR. Boron-doped graphite is one of candidate materials for oxidation-resistant graphite. It was reported that BO, which was generated by oxidation of BC, prevented boron-doped graphite from oxidation. To apply boron-doped graphite to core support graphite structure of HTGR, it is necessary to understand oxidation mechanism of boron-doped graphite. This study reports evaluation results of oxidation mechanism of boron-doped graphite on the basis of oxidation test, bending strength test and surface observation.