Development of Generic In-Service Inspection Priorities for Pressure Boundary Systems

This paper reports on, to provide a technical basis for improved in-service inspection (ISI) plans, Pacific Northwest Laboratory (PNL) developed and applied a method that uses results of probabilistic risk assessment to establish piping system ISI priorities. In the PNL program, the feasibility of generic ISI guidances is being conducted in two phases. Phase I identifies and prioritizes the systems most relevant to plant safety. These evaluations lead to the development of comprehensive ISI guidances for pressure boundary systems and components that take place in Phase II.