NPP SUBSEQUENT LICENSE RENEWAL: LESSONS LEARNED FROM AMP EFFECTIVENESS AUDITS

摘要

NRC staff recendy completed the analysis of first-of-a-kind effectiveness audits of Aging Management Programs (AMPs) at Ginna Nuclear Power Plant (Ginna), Nine Mile Point Nuclear Station, Unit 1 (NMP-1) and H. B. Robinson Steam Electric Plant, Unit 2 (RNP). The staff reviewed the licensee's implementation of the AMPs during the early years of the period of extended operation (PEO), from 40-60 years. This included 29 mechanical system AMPs at Ginna, 30 mechanical system AMPs at NMP-1 and 25 mechanical system AMPs at RNP. Eight structural system AMPs and seven electrical system AMPs each were reviewed at Ginna and NMP-1. At RNP, staff reviewed seven structural system AMPs and six electrical system AMPs. In addition, three AMPs associated with time-limited aging analyses (TLAAs) were reviewed at Ginna and two each at NMP-1 and RNP. The process involved NRC staff conducting onsite interviews with licensee plant personnel, with additional technical experts participating remotely. Among the areas considered by the staff during its audit activities were (1) Inspection accessibility issues, adequacy of inspection methods, and frequency of inspections; (2) Unanticipated structure and component degradation, related equipment failures, or premature repair/replacement; and (3) Trending information that can yield insights regarding the actual effectiveness of the current AMPs and aging management reviews (AMRs). The knowledge obtained from these audits was a primary source enabling the staff to develop new subsequent license renewal guidance documents (SLRGDs), to be used following the first PEO. The existing license renewal guidance documents (LRGDs, such as NUREGs-1800 and-1801) are being significantly revised for subsequent license renewal (SLR).