Estimates of Rupture Probabilities for Nuclear Power Plant Components: Expert Judgment Elicitation

Abstract

This paper reports that as part of the nondestructive evaluation reliability program sponsored by the U.S. Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory (PNL) developed a risk-based method for establishing inspection priorities for systems and components at nuclear power plants. In this method, the results of probabilistic risk assessment (PRA) are used to estimate the safety consequences of component failures. The method also requires estimates of the probabilities of structural failures. Since sufficient operating experience data and detailed fracture mechanics analyses are not available, an expert judgment elicitation is conducted to estimate component rupture probabilities. (An expert judgment process is generally adapted from the NRC severe accident risk program).