On-line Corrosion Monitoring Of Key Materials Used In PWRs Nuclear Power Plants

high-temperature and high-pressure water. Environmental damage of components in pressurized water reactor(PWR) in high-temperature water is an important factor that impacts nuclear safety. Electrochemical noise detecting sensor is developed to monitor the corrosion behavior of material exposed in HTHP water.Based on the achieved research results of laboratory, the production process of antimony reference electrode has been improved. Meanwhile, the counter electrode has been made by heat spraying Al2O3 or ZrO2+8%Y2O3 on 304NG stainless steel (Φ3cm*5cm)surface. By this way, the area ratio of counter electrode and working electrode is reduced to meet ZRA mode electrochemical noise tests. Ceramic powders was used as a sealant to seal the EN sensor for HTHP water environment.EN sensor was used to detect the corrosion behavior of 304NG stainless steel in HTHP water environment. Test results show that the sensor can be used in up to293℃, 19Mpa high pressure high temperature work environment. Test results agree with the actually corrosion state of 304NG ss. Applied EN sensor to on-site environmental water vapor corrosion detection of carbon steel pipe in high temperature and pressure environment, results show that the EN sensor can correctly reflect the corrosion characteristics of carbon pipe in different working state.316L microcor probe was used to test the corrosion rate of 316L stainless steel in simulated primary water circuit and secondary water circuit. Test results show that the corrosion rate of 316L ss in simulated primary water circuit is higher than that in secondary water circuit. It has also been demonstrated that the corrosion rate of 316L ss increase with the environmental pressure in a given temperature. Under a given pressure, the corrosion rate also increase with the increasing temperature.