Variability Associated with Seismic Testing Methods

Safety related nuclear power plant systems and components are qualified for seismic adequacy by analysis, tests, or a combination of both. These seismic qualification methods are biased towards the conservative side due to the variability associated with the inherent randomness in the phenomenon being simulated and those related to the incomplete knowledge about the simulation. Major sources of variability in the test method of qualification are addressed and their approximate variations are enumerated. These variations are useful in assessing the overall conservatism and in estimating the probabilistic strength capacity of equipment.