Experience with inspection qualifications for austentitic piping

The performance demonstration initiative (PDI) was formed in 1991 to address implementation of appendix VIII to Section XI of the ASME Boiler and Pressure Vessel Code. All US utilities and three foreign utilities are participating. Appendix VIII differs from previous Code approaches in that it does not specify a particular approach. It does require that the capabilities of the personnel, procedures, and equipment be demonstrated. Appendix VIII describes, in detail, the demonstration requirements and acceptance criteria for ultrasonic examinations. Piping demonstrations have been performed for 390 examiners since April 1994. The database of demonstration results includes 10 000 detection and length sizing data points and 5000 depth sizing data points, which are available for analysis. The performance of these candidates provides insight into the difficulties of the inspection process for austenitic piping. The length and depth sizing accuracy along with the detection rate as a function of false call rate will be presented. The results of recent investigations will also be described.