Eddy Current Reliability Results from the Steam Generator Mock-up Analysis Round-Robin

摘要

This report presents the results of a nondestructive evaluation roundrobin designed to independently assess the reliability of steam generator (SG) tube inspection. A steam generator mockup at Argonne National Laboratory (ANL) was used for this study. The goal of the roundrobin was to assess the current state of inservice eddycurrent inspection reliability for SG tubing, determine the probability of detection (POD) as a function of flaw size or severity, and assess the capability for sizing of flaws. Eleven teams participated in analyzing bobbin and rotating coil mockup data collected by qualified industry personnel. The mockup contains hundreds of cracks and simulations of artifacts such as corrosion deposits and tube support plates. This configuration mimics more closely than most laboratory situations the difficulty of detection and characterization of cracks experienced in an operating steam generator. An expert task group from industry, ANL, and the Nuclear Regulatory Commission (NRC) has reviewed the signals from the laboratory-grown cracks used in the mockup to ensure that they provide reasonable simulations of those obtained in the field.