Shippingport Station aging evaluation

Abstract

The Shippingport Atomic Power Station, the first US large-scale, central-station nuclear plant, now in the final stages of decommissioning, has been a major source of naturally aged equipment for the Nuclear Plant Aging Research (NPAR) and other US Nuclear Regulatory Commission (NRC) programs. Because naturally aged components and materials experience the actual service-related external stressors, corrosion and wear, testing procedures, and maintenance practices, their evaluation is valuable in verifying degradation models, validating aging projections based on the extrapolation of accelerated test data, and detecting unexpected aging mechanisms (surprises) that could significantly impact component or system safety performance. As part of the Shippingport Station aging evaluation work, more than 200 items, ranging in size from small instruments and materials samples to one of the main coolant pumps, have been removed and shipped to designated NRC contractors. Although detailed evaluations of the components and material from the Shippingport Station are just beginning, the preliminary results from the studies conducted to date are indicative of the value of the aging information that ultimately may be obtained. 30 refs., 18 figs., 7 tabs.