Component fragility research program: prioritization and demonstration testing

Current probabilistic risk assessment (PRA) methods for nuclear power plants utilize seismic fragilities - probabilities of failure conditioned on the severity of seismic input motion - which are based largely on limited test data and on engineering judgement. As part of the NRC Component Fragility Research Program (CFRP), the Lawrence Livermore National Laboratory (LLNL) developed procedures for fragilities testing. These procedures were applied to evaluate actual seismic capacities of motor control center (MCC) electrical devices, to develop seismic fragility curves suitable for PRA application, and to suggest various methods of improving MCC seismic performance. In other CFRP activities, LLNL used high-level qualification data to develop fragility descriptions for selected equipment, and identified candidate components for future comprehensive fragilities testing using similar procedures