Exelon's Approach to NRC's Near Term Task Force Recommendation 2.1-Seismic Hazards

摘要

Exelon Generation's nuclear fleet comprised of ten nuclear power plants (NPPs) with a total of seventeen reactors is the largest nuclear fleet in the United States. As such, Exelon has a potential for considerable resource impacts from the Nuclear Regulatory Commission's Near Term Task Force (NTTF) Recommendation 2.1 for Seismic Hazards. Therefore, as a multi-site licensee, Exelon has taken a broad approach to this recommendation. This approach consists of the following five components. First, Exelon has actively participated in development of industry guidance associated with the recommendation. Secondly, Exelon's consultants prepared a report summarizing existing relevant seismic information for all Exelon's NPPs. Thirdly, Exelon conducted a focused review meeting with its PRA engineers, structural engineers and industry consultants to review the industry guidance documents and internal seismic summary report to collectively determine the status of each Exelon NPP's seismic risk analysis, screening and scope potential relative to the recommendation. Fourthly, Exelon organized an industry peer team that provides a forum for seismic and risk engineers to identify and address implementation issues associated with the recommendation that was developed by a separate industry task force comprised of NRC and industry representatives. Lastly, Exelon is currently developing a comprehensive action plan with a phased approach to comply with the recommendation. This paper also provides a summary for each Exelon NPP, of the current seismic risk analysis method utilized and a preliminary assessment compared to the new requirements. In addition, Exelon's approach and strategy to implement the requirements contained in NTTF Recommendation 2.1 for Seismic Hazards and the related NRC-endorsed supplemental guidance are presented.