| Project/Area Number |
16360467
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nuclear engineering
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| Research Institution | Japan Atomic Energy Agency (2005-2006)
Tohoku University (2004) |
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Principal Investigator |
UCHIDA Shunsuke Japan Atomic Energy Agency, 原子力基礎工学研究部門, 客員研究員 (60321973)
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| Co-Investigator(Kenkyū-buntansha) |
TSUKADA Takashi Japan Atomic Energy Agency, 原子力基礎工学研究部門, グループリーダー (20354798)
SATOH Tomonori Japan Atomic Energy Agency, 原子力基礎工学研究部門, 研究員 (60414554)
SATOH Yoshiyuki Tohoku University, 大学院工学研究科, 助手 (00005480)
IINUMA Koichi Tohoku University, 大学院工学研究科, 助教授 (40005484)
YAMADA Rie Tohoku Electric Industries, Inc., 光技術研究センター長
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥13,600,000 (Direct Cost: ¥13,600,000)
Fiscal Year 2006: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2005: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2004: ¥8,700,000 (Direct Cost: ¥8,700,000)
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| Keywords | boiling water reactor / stress corrosion cracking / hydrogen peroxide / crack growth rate / oxide film / water radiolysis / electrochemical corrosion potential / き烈伸展測度 / 冷却系 |
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| Research Abstract |
1) Improvement of control techniques for H_2O_2 concentration
The previously developed high temperature, high pressure hydrogen water loop [b] with a polytetrafluoroethylene (PTFE) inner liner for the autoclave and H_2O_2 injection and sampling lines has been improved to increase flow velocity in the autoclave and minimize and optimize the autoclave inner volume to get more than 90 % of the H_2O_2 to remain in the autoclave. A supersensitive and simple flow injection type H_2O_2 detection system has been developed to determine [H_2O_2] with a sub-ppb detection limit in a short time.
2) In-situ measurements of corrosion behaviors
In-situ measurement techniques, e. g., ECP, frequency dependent complex impedance (FDCI) and contact resistance measurements, in high temperature water have been established for characterization of oxide film on stainless steel and determination of oxidation reactions. An on line [H_2O_2] monitor has been developed on the basis of a combination of ECP and FD CI se
… More
nsors.
3) Multilateral surface characterization of oxide film
Multilateral surface characterizations based on SEM, STEM-EDX, LRS have been successfully applied to show that the oxide film is divided into two layers, inner and outer. The dense inner oxide layer with higher electric resistance, which was formed by OH radials, a decomposition product of H_2O_2, resulted in higher ECP but less corrosion.
4) Effects of H_2O_2 on corrosion
Anodic current due to oxidation of H_2O_2 and cathodic current due to reduction of H_2O_2 were balanced and a constant ECP was seen in a wide [H_2O_2] range. But corrosion current decreased with [H_2O_2] and then the crack growth rate of IGSCC also decreased. It was concluded that differences in corrosion behaviors between laboratory and operating power plant environments were mainly due to the presence of H_2O_2, and for material research for aged power plants, accumulation of corrosion data obtained in the plant H_2O_2 environment would be essential.
The Award for Distinguished Technology of Atomic Energy Society of Japan was given for the research results together with the previous results of two JAPS projects (Grant-in-Aid for Scientific Research : Subject No. 13480140 (2001-2003) and Subject No. 16360467 (2001-2003)) in March 2007. Less
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