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Hata, Kuniki; Hanawa, Satoshi; Chimi, Yasuhiro; Uchida, Shunsuke; Lister, D. H.*
Journal of Nuclear Science and Technology, 60(8), p.867 - 880, 2023/08
Times Cited Count：2 Percentile：53.91(Nuclear Science & Technology)One of the major subjects for evaluating the corrosive conditions in the PWR primary coolant was to determine the optimal hydrogen concentration for mitigating PWSCC without any adverse effects on major structural materials. As suitable procedures for evaluating the corrosive conditions in PWR primary coolant, a couple of procedures, i.e., water radiolysis and ECP analyses, were proposed. The previous article showed the radiolysis calculation in the PWR primary coolant, which was followed by an ECP study here. The ECP analysis, a couple of a mixed potential model and an oxide layer growth model, was developed originally for BWR conditions, which was extended to PWR conditions with adding Li
(Na) and H effects on the anodic polarization curves. As a result of comparison of the calculated results with INCA in-pile-loop experiment data as well as other experimental data, it was confirmed that the ECPs calculated with the coupled analyses agreed with the measured within 
100mV discrepancies.
Hata, Kuniki; Uchida, Shunsuke; Hanawa, Satoshi; Chimi, Yasuhiro
Proceedings of International Symposium on Contribution of Materials Investigations and Operating Experience to LWRs' Safety, Performance and Reliability (Fontevraud 10) (Internet), 11 Pages, 2022/00
Hanawa, Satoshi; Hata, Kuniki; Chimi, Yasuhiro; Kasahara, Shigeki
Proceedings of 21st International Conference on Water Chemistry in Nuclear Reactor Systems (Internet), 12 Pages, 2019/09
Uchida, Shunsuke*; Hanawa, Satoshi; Naito, Masanori*; Okada, Hidetoshi*; Lister, D. H.*
Corrosion Engineering, Science and Technology, 52(8), p.587 - 595, 2017/10
Times Cited Count：4 Percentile：21.41(Materials Science, Multidisciplinary)Based on the relationship among ECP, metal surface conditions, exposure time and other environmental conditions, a model to evaluate the ECP and corrosion rate of steel was developed by coupling a static electrochemical analysis and a dynamic oxide layer growth analysis. Major conclusion obtained on the model are as follows. The effect of H
O and O concentrations on ECP were successfully explained as the effects of oxide layer growth. Hysteresis of ECP under changes in water chemistry conditions were successfully explained with the model. Decreases in ECP due to neutron exposure were explained well by radiation-induced diffusion in the oxide layers.
Uchida, Shunsuke; Hanawa, Satoshi; Kysela, J.*; Lister, D. H.*
Power Plant Chemistry, 18(1), p.6 - 17, 2016/01
In order to establish reliable NPP operation, each plant requires its own unique optimal water chemistry control based on careful consideration of its system, materials and operational history. Electrochemistry is one of key issues that determine corrosion related problems, e.g., FAC. Based on the relationships among ECP, metal surface conditions and exposure time, a model to evaluate ECP and corrosion rate of steel was developed by coupling an electrochemical model and an oxide layer growth model. Major conclusions are as follows. (1) The effects of water chemistry improvement and mass transfer coefficients due to local flow velocity on FAC wall thinning rate and ECP could be evaluated with the proposed model. (2) The effects of HO and O concentrations on ECP were evaluated with the model. Exposure time dependent ECPs were also explained as the effects of oxide film growth on the specimens. (3) Decreases in ECP due to neutron exposure were explained by radiation-induced diffusion in the oxide layers.
; Suzuki, Kazuya
Spectrochimica Acta, Part A, 50(6), p.1057 - 1063, 1994/00
no abstracts in English
Journal of Physical Chemistry, 97(9), p.1832 - 1834, 1993/00
Times Cited Count：10 Percentile：41.34(Chemistry, Physical)no abstracts in English
Spectrochimica Acta, Part A, 49(1), p.81 - 94, 1993/00
no abstracts in English
Journal of Physical Chemistry, 96(14), p.5825 - 5829, 1992/00
Times Cited Count：2 Percentile：11.73(Chemistry, Physical)no abstracts in English
Hidaka, Akihide; Soda, Kunihisa; Sugimoto, Jun; Yamano, N.; Maruyama, Yu
KfK-5108; NEA/CSNI/R(92)10, p.211 - 225, 1992/00
no abstracts in English
Journal of Chemical Physics, 80(4), p.1556 - 1561, 1984/00
Times Cited Count：6 Percentile：29.02(Chemistry, Physical)no abstracts in English
Amamiya, Hiroki; Mizuno, Takashi; Iwatsuki, Teruki; Yuguchi, Takashi; Murakami, Hiroaki; Kokubu, Yoko
no journal, ,
The long-term evolution of geochemical environment in deep underground is indispensable research subject for geological disposal of high-level radioactive waste. Many researchers have made efforts previously to elucidate the geochemical environment within the groundwater residence time based on the analysis of the actual groundwater. However, it is impossible to estimate the geochemical environment for the longer time scale than the groundwater residence time in this method. In this case, analysis of the chemical properties of secondary minerals are one of useful method to estimate the past hydrochemical characteristics (temperature, salinity, pH and redox potential). We reviewed the previous studies on carbonate minerals and geochemical conditions in deep underground and estimated the hydrochemical characteristics of past groundwater by using carbonate minerals in crystalline rock at Tono area, Japan. As a result, it is found that temperature and salinity of the groundwater during crystallization of carbonate minerals were evaluated quantitatively. On the other hand, pH and redox potential can only be understood qualitatively. However, it is suggested that the content of heavy metal elements such as manganese, iron and uranium, and rare earth elements in the carbonate minerals are useful indicators for estimating redox potential.
