On the assessments and management of LWR risk during shutdown conditions

Incidents that have occurred during shutdown conditions prompted the Electric Power Research Institute (EPRI) to undertake assessments of pressurized water reactor (PWR) and boiling water reactor (BWR) risk during shutdown conditions. These assessments were initiated as a part of EPRI's outage risk and management (ORAM) program, whose primary program objective is to provide an integrated technical assistance package to utilities for evaluating and managing risk during outages. The key elements of the ORAM program are (1) survey of utilities regarding outage risk management practices, (2) safety assessments of PWR and BWR shutdown risk enhancements from previous EPRI studies, (3) development of PWR and BWR risk management guidelines, (4) development of software that integrates shutdown safety information into an easy-to-use package, and (5) technology transfer to utilities. This paper presents the objectives and insights resulting from the PWR and BWR shutdown safety assessments and an approach for outage risk management guidelines for utility use.