DEVELOPMENT OF CERAMIC HUMIDITY SENSOR FOR THE APPLICATION OF LEAK-BEFORE-BREAK CONCEPT

摘要

Leak-before-break(LBB) approach has been shown to be both cost effective and risk reductive when applied to high energy piping in nuclear power plants. For the Korean Next Generation Reactor (KNGR) development, LBB application is considered for the Main Steam Line(MSL) piping inside containment. Unlike the primary system leakage, the MSL leak detection systems must be based on principles other than radioactivity measurements. Among humidity, heat and acoustic noise currently being considered as indicators of leakage, we explored humidity as an effective one and developed ceramic-based humidity sensor which can be qualified for LBB applications. The ceramic material, sintered and annealed MgCr_2O_4-TiO_2, is shown to increase its electrical conductivity drastically upon water vapor adsorption over the entire temperature range of interest. In this paper, we describe the progress in the development and characterization of ceramic humidity sensors for LBB application to the MSL of KNGR.