Design of a round robin UT program for piping

A multi-year program in progress at Battelle under sponsorship of the U.S. Nuclear Regulatory Commission has as one of its primary objectives measuring the effectiveness of inservice inspection (ISI) performed on all required nuclear components in U.S. light water reactors. This program has been split into two tasks. The first task addresses ISI for the primary piping system. The second task addresses the effectiveness of ISI for the pressure vessel. The initial years of the program have focused on the first task pertaining to the primary piping. Although engineers and technicians performed many laboratory measurements, it was decided that the only way to establish the performance of ISI teams was through the utilization of a round robin test program. It was impractical to try to include all inspection conditions in the round robin, so a subset of the most important conditions were selected for intensive measurement. Furthermore, the round robin design allows several standard statistical models to be fit to the inspection data. These models will be used to extend the results to pipe diameters, wall thickness, and defect types that were not included in the round robin