Implementation of Reliability Evaluation Into JSME Fast Reactor Codes: 2 — Development of a Code Case for Seismic Buckling Evaluation Based on LRFD

Abstract

In a previous study, we proposed an evaluation method of seismic buckling probability of a reactor vessel considering seismic hazard and showed seismic load had the most significant impact on buckling probability among the random variables considered in the evaluation. It means that more rational design of vessels can be realized by taking account of seismic load variation. The load and resistant factor design (LRFD) method enables us to determine design factors corresponding to target reliability by considering variations of random variables and it is used widely in civil engineering. Therefore, in this study, we have developed a draft code case of the rule for preventing buckling of vessels in JSME fast reactor codes based on LRFD. The equation in the draft code case is almost the same as the original but every random variables, seismic load and yield stress, have their own design factors. In addition, mean or median values are used for evaluation instead of design values including conservativeness. This is the first attempt to develop a code case based on reliability evaluation and is expected to lead further implementation of reliability evaluation into JSME fast reactor codes.