B241 軽水炉の安全性向上に資する熱水力技術戦略マップ(OS3 軽水炉・新型炉・原子力安全(6))

Abstract

New version of the Thermal-Hydraulics Safety Evaluation Fundamental Technology Enhancement Strategy Roadmap (TH-RM) was developed by the Atomic Energy Society of Japan (AESJ) for LWR safety improvement and development. The 1st version of TH-RM was prepared in 2009 under collaboration of utilities, vendors, universities, research institutes and technical support organizations (TSO) for regulatory body. The revision was made by three sub-working groups (SWGs) by considering the lessons learned from the Fukushima Daiichi Accident. The "safety assessment" SWG pursued development of computer codes for safety assessment. The "fundamental technology" SWG pursued safety improvement and risk reduction via accident management (AM) measures by referring the technical map for severe accident (SA) established by the "severe accident" SWG. Phenomena and components for counter-measures and/or proper prediction are identified by going through SA progression in both reactor and spent-fuel pool of PWR and BWR. Twelve important technology development subjects were identified, which include melt coolability enhancement to maintain integrity of containment vessel. Fact Sheet was developed to describe each of identified and selected R&D subjects. External hazards are also considered how to cope with from thermal-hydraulic safety point of view. This paper summarizes the revised TH-RM with several examples and future perspectives.