Validation study of SAS4A code for the unprotected loss-of-flow accident in an SFR

Abstract

Sodium-cooled Fast Reactor (SFR) core is not in the most reactive configuration and relocation of core materials may lead recriticality and generate energetics. Therefore, Core Disruptive Accident (CDA) has been considered as one of the important safety issues from the beginning of SFR development history. In the evaluation of CDA, the whole sequence is categorized into some phases (Suzuki et al., 2015), e.g., Initiating Phase (IP), Transition Phase (TP), and Post-Accident Material Relocation/Post-Accident Heat Removal (PAMR/PAHR) phase, and the most appropriate method for each phase has been developed to precisely analyze event progressions. In IP which is the earliest stage of CDA, damaged core regions are inside wrapper tubes and materials relocate mainly in axial direction. SAS4A code

Study on initiating phase of core disruptive accident (Validation study of SAS4A code for the unprotected transient overpower accident)

“…て PIRT(Phenomena Identification and Ranking Table )手法 を適用し，信頼性向上と妥当 性が確認されている (Ishida et al, 2020) Kondo, S., Konishi, K., Morita, K., Shimakawa, N. and Furutani, A., Fuel-coolant…”