Using probabilistic risk assessment to rank importance of aging on nuclear power plant components

A method is developed and applied for determining the potential risk significance of aging effects on nuclear power plant components. The applications use average component unavailability equations currently employed in PRAs to calculate the risk aging sensitivity. The risk aging sensitivity measure addresses the risk change as of function of the rate of change of the components' failure rates with respect to time. The results identify the component types that exhibit the most potential for risk changes due to aging. This study provides guidance in selection of components for further study and prioritization of resources.