A practical implementation procedure for risk-based inservice inspection

Recently, the ASME Section XI Working Group on Implementation of Risk-Based Examination produced a code case to define risk-based selection rules that could be used for inservice inspection of Class 1, 2, and 3 piping. To provide guidelines for practical implementation of the code case by utilities, EPRI sponsored work to develop evaluation procedures and criteria for defining risk-based inservice inspection programs for nuclear power plant piping. These procedures and criteria include efficient means to identify risk significant piping segments and inspection locations, and are based on evaluations of the potential for and the consequences of piping failure. These procedures have been applied in a pilot study to assess the feasibility of successfully implementing risk-based inservice inspection programs at nuclear plants. The results from the pilot study indicate that implementation of risk-based inservice inspection programs can reduce the cost and radiation exposure associated with inservice inspection, while maintaining a high level of safety