Based on the basic policy for introduction of Risk Informed Regulation (RIR) expressed by the Nuclear Safety Commission (NSC) of Japan in 2003, NSC set up the taskforce in April 2004 to take an initiative for coordinated collaboration of related organizations for developing scheme of RIR. Since then the taskforce has reviewed the efforts of related organizations and discussed the issues on further utilization of risk information in Japan. According to the final report prepared by the taskforce in September 2007, the risk consideration in related organizations has made a progress in line mostly with the NSC’s basic policy. For example, the regulatory guide for seismic design was revised in 2006 including combination of deterministic and probabilistic approaches. The regulatory body will start a new inspection system in 2008 that considers the risk informed safety classification of structures, systems and components. However, the followings were identified as important issues in the future: i) promotion of advanced and preliminary trials, ii) comprehensive applications using PSA results for both of the representative and individual plants, iii) preparation of acceptance guidelines for safety and performance goals in risk informed decision making, iv) improvement of PSA quality, v) revision of regulatory guides considering risk information, vi) comprehensive evaluation and promotion by NSC for further utilization of risk information, vii) enhancement of infrastructure such as PSA experts and database, viii) promotion of safety research, ix) application to seismic design, x) Introduction of risk informed approaches into nuclear fuel cycle facilities, and xi) promotion of risk communication, etc.
Fuel utilization improvements in a once-through PWR fuel cycle. Final report on Task 6