Evaluation about Detection of Defects in the Nuclear Piping Loop System Using Lock-in Infrared Thermography

Abstract

Using lock-in IR thermography, detection conditions of defect in pipeline for nuclear power plant has been studied according to incidence angle. Defects are manufactured by changing length of wall thinning, angle in circumferential direction, and amount of wall thinning. Corresponding pipe with defect is used to build loop pipeline system for nuclear power plant, and lock-in IR thermography for cold defect condition is applied to detect heating defect. IR thermography camera and cooling unit is used, and distance between cooling device and target loop system is set to 2 m away. For the analysis on experimental results, cooling temperature distribution and phase data are gathered to measure the length of defect.