AN AGING MANAGEMENT APPROACH FOR PRESSURIZED WATER-REACTOR PRESSURE-VESSELS

This paper presents a generic approach, based on known and established results of aging damage assessments, for evaluating structural integrity and managing aging damage of pressurized water reactor (PWR) pressure vessels during extended operation. The approach addresses specific technical and regulatory issues that will arise in the assessment of aging damage during extended operation. Three major issues related to vessel integrity are addressed: pressurized thermal shock events, low upper-shelf energy, and revised pressure-temperature limits. Finally, the approach identifies several options available to manage aging. These options include use of advanced inspection methods to reliably detect and size flaws, flux reduction and thermal annealing to mitigate radiation embrittlement, and supplemental surveillance and material sampling to enhance the database for irradiated reactor pressure vessel materials.