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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：28.39(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; Sato, Tomonori
Proceedings of 21st International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors (Internet), 14 Pages, 2023/08
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
Adhi, P. M.*; Okubo, Nariaki; Komatsu, Atsushi; Kondo, Masatoshi*; Takahashi, Minoru*
Energy Procedia, 131, p.420 - 427, 2017/12
Times Cited Count：3 Percentile：83.31(Energy & Fuels)The ionic conductivity of solid electrolyte may insufficient, and the sensor output signal will deviate from the theoretical one in low temperature. The performance of oxygen sensor with Ag/air reference electrode (RE) and liquid Bi/Bi
O
RE was tested in low-temperature LBE at 300
450
C and the charge transfer reactions impedance at the electrode-electrolyte interface was analyzed by electrochemical impedance analysis (EIS). After steady state condition, both of the sensors performed well and can be used at 300450C. Bi/Bi/BiO RE has lower impedance than Ag/air RE. Therefore, the response time of the oxygen sensor with Bi/Bi/BiO RE is faster than the oxygen sensor with Ag/air RE in the low-temperature region.
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：18.63(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 HO 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.*
PowerPlant 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.
Sugikawa, Susumu; Umeda, Miki; Kobayashi, Fuyumi; Nagata, Masanobu*; Dojiri, Shigeru; Amano, Masae*
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 4 Pages, 2005/10
The mineralization of radioactive contaminated organic wastes by mediated electrochemical oxidation process has some attractive features as alternative to incineration process: The process operates safely at low temperatures and ambient pressures. JAERI has been investigated the process since 1996 and confirmed complete mineralization of this organic solvent. In order to greatly improve current efficiency for the oxidation reaction, further experiments were performed under condition of strong mixing of organic solvent and anolyte with an aide of ultrasonic wave. The current efficiencies for the oxidation reaction by ultrasonic agitation between organic solvent and anolyte were twice to that by mechanical agitation. On the basis of these results, two processes, one for destruction of a small amount of TBP/dodecane and the other for destruction of intermediate compounds following alkaline hydrolysis of a large amount of TBP/dodecane, were proposed.
Arai, Yasuo; Minato, Kazuo
Journal of Nuclear Materials, 344(1-3), p.180 - 185, 2005/09
Times Cited Count：24 Percentile：81.23(Materials Science, Multidisciplinary)no abstracts in English
Minato, Kazuo; Hayashi, Hirokazu; Mizuguchi, Koji*; Sato, Takeyuki*; Amano, Osamu*; Miyamoto, Satoshi*
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.778 - 781, 2003/11
The simulation technology for the pyrochemical reprocessing of oxide fuels was developed to analyze experimental data, to predict experimental results, and to propose adequate conditions and processes. The simulation method was based on calculations of chemical equilibrium and electrochemical reactions. Some model calculations to simulate the experimental results were made on the process of electro-codeposition of UO and PuO. Although it was difficult to trace the experiments and compare the calculated results with the experimental results quantitatively due to the limitation of available data on the experimental conditions, the calculated results were consistent with the experimental results. The phenomena of the repeated oxidation-reduction reactions between Pu
and Pu
ions and those between Fe and Fe
ions were theoretically analyzed,which caused the low current efficiency in the electro-codeposition process.
Kondo, Toshihiro*; Tamura, Kazuhisa*; Takahashi, Masamitsu; Mizuki, Junichiro; Uosaki, Kohei*
Electrochimica Acta, 47(19), p.3075 - 3080, 2002/07
Times Cited Count：32 Percentile：58.31(Electrochemistry)A nwely designed spectroelectrochemical cell was constructed for surface X-ray scattering (SXS) to study single crystal electrodes. Electrochemical characteristics of a specific face of a single crystal electrode can be investigated in the meniscus mode, adn SXS measurement can be easily carried out using the spectroelectrochemical cell. The usefulness of the present cell was demonstrated by studying the electrochemical deposition of Pd thin layers on Au(111) and Au(001) that require precise amounts of Pd deposits.
Sakamura, Yoshiharu*; Shirai, Osamu; Iwai, Takashi; Suzuki, Yasufumi
Journal of Alloys and Compounds, 321(1), p.76 - 83, 2001/05
Times Cited Count：59 Percentile：89.31(Chemistry, Physical)no abstracts in English
C and its electrochemical evaluationNishiyama, Yutaka; Fukaya, Kiyoshi; Suzuki, Masahide; Eto, Motokuni
Journal of Nuclear Materials, 258-263, p.1187 - 1192, 1998/00
Times Cited Count：4 Percentile：38.34(Materials Science, Multidisciplinary)no abstracts in English
Uchiyama, Gunzo; Fujine, Sachio
Journal of Radioanalytical and Nuclear Chemistry, 230(1-2), p.105 - 109, 1998/00
Times Cited Count：3 Percentile：31.35(Chemistry, Analytical)no abstracts in English
Nishiyama, Yutaka; Fukaya, Kiyoshi; Suzuki, Masahide; Eto, Motokuni;
Small Specimen Test Techniques; ASTM STP 1204, p.16 - 26, 1993/00
no abstracts in English
Uchiyama, Gunzo; Hotoku, Shinobu; Kihara, Takehiro; Fujine, Sachio; Maeda, Mitsuru
Solvent Extraction in the Process Industries, Vol. 3, p.1797 - 1804, 1993/00
no abstracts in English
;
Proc. of the Int. Symp. on Material Chemistry in Nuclear Environment, p.497 - 506, 1992/00
no abstracts in English
Kawamura, Hiroshi; ; ; ;
Journal of the Ceramic Society of Japan, International Edition, 97, p.1403 - 1408, 1989/00
no abstracts in English
;
JAERI-M 82-055, 51 Pages, 1982/06
no abstracts in English
