Wall Thinning Analyses for Secondary Side Piping of Korean NPPS Using CHECWORKS Code

Abstract

Since the mid-1990s, nuclear power plants in Korea have experienced wall thinning, leaks, and ruptures of secondary side piping caused by flow-accelerated corrosion (FAC). The pipe failures have increased as operating time progresses. In order to prevent FAC-induced pipe failures and to develop an effective FAC management strategy, KEPRI and KOPEC, along with KHNP’s support, have conducted a study for developing a systematic FAC management technology for all domestic nuclear power plants. As part of the study, FAC analyses were performed using CHECWORKS code. The analysis results were used to select components for inspection on each nuclear power plant. The site application feasibility of the analysis results was proven by comparisons of predicted and measured wear rates. This paper focuses on the introduction of the FAC analysis results for secondary side piping associated with three types of domestic nuclear power plants and the comparisons of predicted and measured wear rates. This paper also represents the comparisons of analysis results according to reactor types, power rates, and systems to facilitate the development of FAC management technology.