Papers by Author: Hee Jong Lee

Abstract: The ASME B&PV code section XI adopted the performance demonstration requirements (Appendix VIII) for the ultrasonic examination of nuclear power plant piping weld in the 1989 winter addenda for the first time. Korea Electric Power Research Institute(KEPRI) and Korea Hydro and Nuclear Power Company(KHNP) finished developing Korean Performance Demonstration(KPD) system for the ultrasonic examination to apply pressurized light-water and pressurized heavy-water reactor power plants piping weld in accordance with ASME code section XI, appendix VIII on January 2004. KEPRI has been accomplishing the performance demonstration for nuclear power plant piping weld ultrasonic examination in Korea from April 2004. This paper describes the implementation status of the performance demonstration for nuclear power plant piping weld ultrasonic examination in Korea.

Abstract:
The results of ultrasonic testing performed during in-service inspection period for main components of nuclear power plant are affected by the performance of each inspector. To enhance the inspection reliability, the more restrictive qualification is required. KEPRI established Korean performance demonstration (KPD) system for the ultrasonic testing personnel, equipment and procedure which applied to the piping examination of nuclear power plant. A round robin test was conducted to evaluate the reliability of examination result by comparing conventional (DAC) UT and performance demonstration (PD) UT method. Participants took detection/length sizing test and depth sizing test using DAC method and PD method. The results showed that the PD method was preciser and more accurate than the conventional DAC method in length and depth sizing regardless of field experience and PD qualification status.

Abstract: The Korea Electric Power Research Institute (KEPRI) has developed performance demonstration programs for non-destructive testing personnel who analyze ECT (eddy current testing) data for steam generator tubing since 2001. The purpose of these performance demonstration programs is to ensure a uniform knowledge and skill level of data analysts and contribute to safe operation of nuclear power plants. Many changes have occurred in non-destructive testing of steam generator tubing such as inspection scope, plugging criteria and qualification requirements in Korea. According to the Notice 2004-13 revised by the Ministry of Science and Technology (MOST), the analyst for steam generator tubing shall be qualified as the qualified data analyst (QDA), and the site specific performance demonstration (SSPD) program shall be implemented. KEPRI developed these performance demonstration programs and they are being successfully implemented. The analyst's performance is expected to be improved by the implementation of these programs.

Abstract: Ultrasonic C-scan inspections have been used in various industrial fields. Usually, conventional ultrasonic C-scan systems have several mechanical manipulating axis controlled by a computer or an electronic device. These systems are suitable for the high resolution and inspection quality. But they are too heavy and bulky to carry in general, and many industrial fields do not require higher resolution than a hundred micron order. To take care of such a need, in this study we developed an ultrasonic C-scan system that does not have any mechanical manipulator to transport ultrasonic transducers. This system, named "M-Scanner", adopts an electro-magnetic position tracking sensor instead of mechanical manipulating axes in order to trace the transducer position. Furthermore, this new system is portable and has a reasonable construction cost along with practical inspection resolution required in many industrial field inspections.