Application of risk-based methods to inservice inspection of piping systems
- Westinghouse Electric Corp., Pittsburgh, PA (United States)
- Northeast Utilities, Hartford, CT (United States)
Research efforts have been underway in the American Society of Mechanical Engineers (ASME) and industry to define appropriate methods for the application of risk-based technology in the development of inservice inspection (ISI) programs for piping systems in nuclear power plants. This paper discusses a pilot application of these methods to the inservice inspection of piping systems of Northeast Utilities Millstone Unit 3 nuclear power station. This demonstration study, which has been sponsored by the Westinghouse Owners Group (WOG), applies probabilistic safety assessment (PSA) models that have already been developed to meet regulatory requirements for an individual plant examination (IPE). The approach calculates the relative importance for each component within the systems of interest. This risk-importance is based on the frequency of core damage resulting from the structural failure of the component. The process inductively determines the effects that such failures have on the desired operational characteristics of the system being analyzed. Structural reliability/risk assessment (SRRA) models based on probabilistic structural mechanics methods are used to estimate failure probabilities for important components. Locations within a system with varying failure probabilities can be defined to focus ISI resources. This paper will discuss the above process and results to show that application of risk-based methods in the development of ISI programs can potentially result in significant savings while maintaining a high level of safety.
- OSTI ID:
- 404247
- Report Number(s):
- CONF-960706--; ISBN 0-7918-1786-5
- Country of Publication:
- United States
- Language:
- English
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