Research for the improvement of SCC evaluation method including the effect of radiation on water, 2; Oxide film structures and environmental parameters on type 316L stainless steel under -ray irradiation in high temperature water

Kato, Chiaki   ; Nakahara, Yukio ; Yamamoto, Masahiro ; Tsukada, Takashi 

It is well known that the decomposition of water by irradiation results in the formation of oxidants, such as hydrogen peroxide and radical species. Inside crevices, the effect of diffusion restriction and surface reactions may become more significant, so that the environments are expected to be different from those in the outsides. Therefore the structural effects using crevice-like specimen have been discussed and corrosion acceleration effects were introduced. In this work, the effects of -ray irradiation and structure on the corrosion of Type 316L SS in high-temperature water of 288 C were examined. We also consider structures of the oxide film on the stainless steel using transmission electron microscope and Raman spectroscope in order to show the differences made by the irradiation and structure. In addition, the environment inside irradiated crevices was estimated from results of the modeling of the oxide film and stable oxide states based on the E-pH diagram.