A comparison study on mechanical models for TRISO fuel particle in HTGR

Abstract TRISO fuel performance is crucial for the safety of High Temperature Gas-cooled Reactor (HTGR). In the engineering design process of HTR-PM by Institute of Nuclear and New Energy Technology (INET), PANAMA code was adopted to evaluate the mechanical performance and failure probability of TRISO coated particle fuels. However, PANAMA results are quite conservative compared with the recent HTR-PM fuel irradiation experiment. INET develops a new TRISO fuel performance code FRAT that employs more delicate models involving internal gas pressure buildup, mechanical stress analysis as well as temperature and burnup effects. In this paper, we use FRAT code and do a comparison study of mechanical analysis model of TRISO fuel particle. Results yield a high sensitivity of calculated TRISO fuel failure probability to mechanical models adopted in TRISO fuel performance. This work helps to further understand the mechanical models of TRISO fuel particle.