BWR Pilot Plant life extension study at the Monticello Plant, Phase 2

The Monticello BWR Pilot Plant Life Extension Program was initiated in 1985 to examine in some detail the technical and economic viability of life extension for an operating nuclear power plant. The scope of the Phase I study was the identification, importance ranking and life assessment of the critical plant components. The Phase 1 conclusions, based on the initial 27 critical component assessments, contained a number of qualifiers and assumptions with respect to the remaining plant components. To verify the earlier assumptions and to expand the technical bases for a planned future license renewal process, the scope of the Phase 2 program was chosen to include evaluation of many of the remaining plant components and structures and to supplement the technical assessments with in-plant inspections and component condition assessments. Phase 2 also sought to address major issues identified in Phase 1, such as the impact of life extension on the plant's preventive maintenance program. The results of the Phase 2 study are are presented in EPRI Report NP-5836M and in this report. Additionally, Phase 2 targeted higher priority follow-on activities from Phase 1 for implementation. These included a fatigue assessment of the drywell penetration bellows, development of a transient monitoringmore » program for the reactor coolant piping, and implementation of the workbook methodology. The major conclusion of Phase 2 is that the results confirm the feasibility and the prudency of life extension. 15 refs., 11 figs., 12 tabs.« less