Electrochemical Measurement of Radio-Activated Metal Under High Temperature Condition

Fundamental knowledge of electrochemical characteristics of metals under high temperature and radiation conditions is important in development of reactor core materials for light water reactors including a supercritical water-cooled reactor (SCWR). In the past studies, however, the majority of electrochemical measurements of the metals have been conducted at temperatures less than 290 °C and under a non-radiation condition. On the other hand, the radiation induced surface activation (RISA) which enhances of wettability and anticorrosive effect on metal surfaces was first revealed by authors in 1999. This study is aimed to confirm the RISA effect experimentally under high temperature conditions. The electrochemical characteristics measurement of a specimen immersed in pure water in an autoclave were performed at temperatures up to 300 °C. A normal 304 stainless-steel and a radioactivated 304 stainless-steel were used as the specimen. The radioactivated specimen was made by 140 MeV irradiation of C4+ ion beam at a cyclotron accelerator of Tohoku University in Japan. The experimental results showed that the corrosion potential of specimen was lowered due to radioactivation.