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Li, N.*; Sun, Y.*; Nakajima, Kunihisa; Kurosaki, Ken*
Journal of Nuclear Science and Technology, 11 Pages, 2023/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)During the Fukushima Daiichi nuclear power plant (1F) accident, an overwhelming amount of the cesium remaining in the pressure vessel could have been deposited onto 304 stainless steel (SS304) steam separators and dryers, both with large surface areas. During 1F's decommissioning, the deposited cesium is a safety hazard as it can generate radioactive dust. However, the cohesive and adhesive strengths of CsOH-chemisorbed oxide scales are yet to be defined. In this study, we investigated how CsOH-chemisorption affects the cohesive and adhesive strengths between oxide scales and SS304 substrates with a scratch tester. The scratch test results revealed that the cohesive strengths of the oxide scales decreased after CsOH-chemisorption, while adhesive failure could not be reached.
Kato, Chiaki; Sato, Tomonori; Ueno, Fumiyoshi; Yamagishi, Isao
Proceedings of 17th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, Vol.2, p.1357 - 1374, 2016/05
With respect to the long-term storage of the zeolite-containing spent Cs adsorption vessels used at the Fukushima Daiichi Nuclear Power Station, the corrosion of the vessel material is one of the most important issues. In this study, we performed electrochemical tests on stainless steel specimens in zeolite-containing artificial seawater under gamma-ray irradiation. The spontaneous potential ESP and critical pitting potential VC of the type 316L steel in systems in contact with various zeolites were measured in order to evaluate the corrosion resistance of the steel. In addition, the water sample was analyzed after being irradiated, in order to determine the concentrations of various dissolved oxidants such as oxygen and hydrogen peroxide, which can accelerate the corrosion process. The steady-state rest potential increased with an increase in the dose rate; however, the increase was suppressed in contact with the zeolites. The VC value of the steel when in contact with the zeolites was slightly smaller than the VC value in bulk water; however, the choice of the zeolite used as herschelite, IE96 and IE911 hardly affect the VC value. The concentration of H
O in the bulk water under irradiation also increased with the increase in the dose rate. This increase was suppressed in the systems in contact with the zeolites, owing to the decomposition of the HO by the zeolites. A clear relationship was observed between ESP and the HO concentration. As contact with the zeolites caused the increase in ESP under irradiation to be suppressed, it can be concluded that the presence of zeolites in the spent Cs adsorption vessels can reduce the probability of the localized corrosion of the stainless steel in the vessels.
Yamada, Hirohisa*; Yokoyama, Shingo*; Watanabe, Yujiro*; Suzuki, Masaya*; Suzuki, Shinichi; Hatta, Tamao*
Nihon Ion Kokan Gakkai-Shi, 25(4), p.207 - 211, 2014/11
Yamagishi, Isao; Yamaguchi, Isoo; Kubota, Masumitsu*
JAERI-Research 2000-038, 40 Pages, 2000/09
JAERI-Research-2000-038.pdf:1.33MB
no abstracts in English
Sato, Tadashi
Radiochimica Acta, 46, p.101 - 108, 1989/00
no abstracts in English
