PRACTICAL LESSONS LEARNED AND CHALLENGES IN CONTEMPORARY PRA DEVELOPMENT AND APPLICATIONS

摘要

Since the issuance of Generic Letter 88-10, PRA of NPPs (Nuclear Power Plants) has been used for both mandatory and voluntary applications. This paper describes lessons learned and challenges from internal events, internal flooding, selected external events (fires, earthquakes, and floods) from both the technical and management perspectives for contemporary PRA development and deployment. The impact of Reg. Guide 1.200 Revision 2 on the management of PRA programs is described. Recent experience with the role of fire PRA and lessons learned from NFPA 805 are presented with special emphasis on the multi-disciplinary nature of the fire PRA tasks and ramifications. Other applications of PRA technology to integrated assessment for floods and seismic hazards, MR a(4), Technical Specifications, and SDP are also discussed. Contemporary PRA practitioners and managers require a comprehensive knowledge of scientific and engineering disciplines. An effective PRA practitioner in the new era post-Fukushima will need to reinvigorate the holistic thinking beyond the conventional wisdom or standards. It can be an exciting time for those with a questioning and open-mind to go beyond guidance which only provides high-level or does not address specific configuration of interest. The PRA as a discipline would be more useful viewed from a process standpoint than as a product. The mathematics and the framework for PRA remain robust; however, the input and the applications are increasingly more dynamic and demanding than prior to the Fukushima accident. A new paradigm consisting of a collaborative, non-adversarial, constructively critical, and holistic approach to resolving the challenging issues of common interest to all stakeholders is needed to make PRA an indispensable discipline for the sustainable safe and cost-effective nuclear power generation.