Multiphysics behavior in HTGRs with high power density, 2; Feasibility study

Takamatsu, Kuniyoshi  ; Okita, Shoichiro  ; Tachibana, Yukio ; Nishimura, Yosuke*; Okamoto, Koji*

In this study, accident analyses of high-power density HTGRs adopting SiC-matrixed fuel compacts and feasibility study were conducted. Specifically, for the feasibility study, rapid depressurization accidents were analyzed using the two-dimensional unsteady heat transfer analysis code for safety evaluation of HTGRs. As a result of the rapid depressurization accident analyses, the fuel temperature and RPV temperature distributions in the HTGRs with high-power density were clarified, and it was confirmed that the maximum fuel temperature does not exceed 1400C. In other words, even if a rapid depressurization accident occurs, the high-power density HTGRs adopting SiC-matrixed fuel compacts will be able to have excellent passive safety features.