Recently, there has been an increasing trend toward extending the use of Nondestructive Testing (NDT) Performance Demonstration (PD) systems to various fields to improve the reliability of NDT results on a global scale, particularly for nuclear power plants. In Korea, a Phased-Array Ultrasonic Testing (PAUT)–based PD system was developed for pipe butt welds, which are major components of thermal power plants and gas facilities. A pilot test was conducted for the developed PD system, and qualified inspectors participated in the test following the same procedure as a Round Robin Test (RRT). The inspectors measured the size, location, and type of defects and prepared inspection reports. The PD specimens were fabricated using the same materials, specifications, and welding procedures as those applied in actual power and gas facilities, and contained defects such as incomplete penetration (IP), lack of fusion (LF), cracks, porosity, and slag that may occur during fabrication and operation. Reliability analysis was performed using the evaluation metrics of the PD system, including the Probability of Detection (POD) and sizing accuracy. The analysis results showed that inspector skill was identified as the main factor affecting reliability. These findings reaffirmed the necessity and importance of introducing a PD system. In the future, beyond energy facilities such as nuclear, thermal, and gas plants, it is expected that the wider application of PAUT and the introduction of PD systems to major industrial facilities will significantly improve the reliability and consistency of field inspection results.

The Japanese Performance demonstration standards, NDIS0603 "Qualification and certification of personnel for performance demonstration of ultrasonic test systems" was issued in 2005. The Performance Demonstration Center of the Central Research Institute of Electric Power Industry (CRIEPI PD Center) initiated Japanese performance demonstration
examinations (PD examination) for flaw depth sizing of intergranular stress corrosion cracking (IGSCC) in austenitic stainless steel pipes in March 2006. As of the end of FY 2024, a total of 62 examination sessions had been completed and 84 candidates had passed the examination. Including re-examinations and re-certifications, 140 individuals participated in the PD examinations. NDIS 0603 was revised to add the Weld Overlay PD (WOL-PD) and the Dissimilar Metal Weld flaw depth sizing PD (DMW-PD). The CRIEPI PD center has completed preparations for the WOL-PD and DMW-PD examinations with cooperation from the EPRI NDE center.
Candidates who pass this examination demonstrate a high level of accuracy sizing of IGSCC flaw depths. Analysis indicates that both the mean error and standard deviation of the measurements among unsuccessful candidates tend to increase with greater wall thicknesses of the PD specimens. The primary reason for failure is the incorrect identification of SCC crack tip echoes; unsuccessful candidates often struggle to distinguish between weld-to-base metal interface echoes, SCC crack branches, and actual SCC crack tip echoes.
This paper presents the current status and future of Japanese PD systems including the following:
- Trends regarding successful and unsuccessful candidates of IGSCC flaw depth sizing PD examinations
- Preparation status of WOL-PD and DMW-PD

Performance Demonstration, ASME Section XI, KEPIC, CSA N285, ENIQ, Nondestructive Examination, Qualification, Nuclear Power Plant