Development of High Temperature Chemistry Measurement System for Establishment of On-Line Water Chemistry Surveillance Network in Nuclear Power Plant

An integrated high-temperature water chemistry sensor (pH, Eredox) was developed for the establishment of the on-line water chemistry surveillance system in nuclear power plants. The basic performance of the integrated sensor was confirmed in high-temperature (280 .deg. C, 150kg/m2) lithium borate solutions by using the relationship between the concentration of lithium ion and pH-Eredox values. Especially, the effects of various environmental factors such as temperature, pressure, and flow rate on YSZ-based pH electrode were evaluated for ensuring the accuracy of high-temperature pH measurement. And the relationships between each water chemistry factor (pH, redox potential, electrical conductivity) were induced for enhancing the credibility of water chemistry measurement. In addition, on the basis of the evaluation of a nuclear plant design company, we suggested potential installation positions of the measurement system in a nuclear power plant