[2I01-04] Mitigation of corrosive environment/Dose rate reduction

[2I04] Rotating corrosion tests of steel material in diluted seawater (2)

Effects of oxygen concentration in nitrogen gas and rotating speed

*Takashi Tsukada¹, Hiroshi Terakado¹, Koei Ebata¹, Fumiyoshi Ueno¹ (1. JAEA,Nuclear Science and Engineering Center, Development Group for LWR Advanced Technology )

Keywords:Rotating corrosion test, Carbon steel, Primary containment vessel, Diluted seawater

Corrosion behavior of carbon steel in a diluted seawater has been examined by the specimen-rotating corrosion test method. At the Fukushima Daiichi Nuclear Power Plant, nitrogen gas has been injected into the primary containment vessel, PCV, to prevent the hydrogen explosion and corrosion of steel materials. It is considered that the oxygen concentration in the nitrogen environment varies in PCV and the inner surface of PCV is exposed to water and gas environment alternately near the water surface position. In this study, therefore, corrosion tests by rotating flat-type specimens in diluted seawater/nitrogen environment with oxygen concentrations of 0%, 1% and 5% were performed to study corrosion behavior of the steel material. Results of the tests at 30ºC for 500 hours will be presented and discussed the effects of oxygen concentration and rotating speed in this presentation.