Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Uchida, Shunsuke*; Morishima, Yusuke*; Hirose, Tatsuya*; Miyazawa, Takahiro*; Sato, Tomonori; Sato, Yoshiyuki*; Wada, Yoichi*
Journal of Nuclear Science and Technology, 44(5), p.758 - 766, 2007/05
Times Cited Count：5 Percentile：37.19(Nuclear Science & Technology)no abstracts in English
Sato, Tomonori; Uchida, Shunsuke; Tsukada, Takashi; Morishima, Yusuke*; Miyazawa, Takahiro*; Sato, Yoshiyuki*
Proceedings of International Conference on Water Chemistry of Nuclear Reactor Systems 2006 (CD-ROM), 6 Pages, 2006/10
To evaluate ECP response of stainless steel in H
O condition, the polarization of stainless steel in highly purified water at elevated temperature was measured. In this study a temporary Pt reference electrode, which was fixed at a natural potential vs. the Ag/AgCl reference electrode, was applied for polarization measurements. Stepwise voltage was supplied to a working electrode vs. the temporary reference electrode. As a result, the followings were concluded. (1) It was confirmed that both anodic and cathodic current densities increased as [HO] increased from 10 ppb to 100 ppb. It might be caused by the contribution of anodic reaction of HO as well as cathodic reaction of HO. (2) Neither anodic nor cathodic polarization curves change as [O] increase from 200 ppb to 2400 ppb. It might be caused by the mitigation of iron dissolution and cathodic reaction of O by the formation of protective oxide layer and lower oxide dissolution.
Uchida, Shunsuke*; Sato, Tomonori; Morishima, Yusuke*; Hirose, Tatsuya*; Miyazawa, Takahiro*; Kakinuma, Nagao*; Sato, Yoshiyuki*; Usui, Naoshi*; Wada, Yoichi*
Proceedings of 12th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors (CD-ROM), p.19 - 29, 2005/00
Static and dynamic responses of stainless steel specimens exposed to HO and O in high temperature water were evaluated by analyzing ECP and FDCI (frequency dependent complex impedance). The oxide films on the specimens were characterized by multilateral surface analyses, e.g., LRS, SIMS, XPS and direct electric resistance measurement. As a result of evaluation, it was confirmed that (1) corrosive condition of BWR normal water chemistry (NWC) was simulated by 100 ppb HO without co-existing O, while that of hydrogen water chemistry (HWC) was simulated by 10 ppb HO, (2) ECP under HWC was as high as that under NWC, while dissolution rate of oxide film under HWC was much lower than that under NWC, (3) combination effects of electric resistance and dissolution rate of oxide caused same level ECP for both NWC and HWC, and (4) distinct weight loss of the specimen exposed to 100 ppb HO was observed.
