Elucidation of corrosion acceleration mechanism by surface excitation effect under gamma rays

Research Project

Project/Area Number	18K05003
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 31010:Nuclear engineering-related
Research Institution	Japan Atomic Energy Agency
Principal Investigator	IOKA Ikuo 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門原子力科学研究所原子力基礎工学研究センター, 研究職 (10354804)
Co-Investigator(Kenkyū-buntansha)	小河浩晃国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門原子力科学研究所原子力基礎工学研究センター, 研究職 (10414559)
Project Period (FY)	2018-04-01 – 2023-03-31
Project Status	Completed (Fiscal Year 2022)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2018: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Keywords	放射線励起 / 表面励起 / 腐食促進 / 放射線作用
Outline of Final Research Achievements	For the elucidation of the corrosion mechanism of the materials inside the reactor, we propose a unique "new corrosion promotion model" focusing on the "surface excitation effect". The purpose of this study is to quantitatively elucidate the corrosion acceleration mechanism in nuclear reactors from the "increased amount of ion species caused by surface excitation effect". The "surface excitation effect" is verified by measuring hydrogen gas and oxygen gas generated from "water-Zr system" and "water-Pt system" under Co-60 irradiation. As a result, about 8000ppm hydrogen generation was observed in Zr and Pt. Although the surface excitation effect could be confirmed, the surface excitation effect due to the difference in materials could not be clearly confirmed.
Academic Significance and Societal Importance of the Research Achievements	我々は、原子炉内の炉内材料の腐食機構解明を行うために、表面励起効果に注目した「新しい腐食促進モデル」を提案してきている。「表面励起効果」の検証は、「水-Zr系」及び「水-Pt系」から発生する水素ガスの発生が確認できた。しかしながら、材質の違いによる表面励起効果は、明瞭には確認できていない。提案している「新しい腐食促進モデル」を発展させることは、原子炉内の炉内材料の複雑な腐食機構解明に貢献できるものである。