Analysis of the reliability of light water reactor power-actuated pressure-relieving valves and safety (relief) valves and their component parts using the nuclear plant reliability data system (NPRDS). Final report

This summary technical report presents the results of a statistical analysis of Nuclear Plant Reliability Data System (NPRDS) data to assess the inservice performance of light water reactor safety, relief, and power-actuated pressure-relieving valves. The NPRDS data base contains valve population (plant engineering data) and service life termination dates and causes (failure event reports). These data were used to generate reliability functions for those valves whose failures have been identified as significant causes of loss of plant availability (outages) or initiating an accident or a sequential event in loss of coolant accident (Three Mile Island Unit 2).