| Project/Area Number |
17K14901
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Nuclear fusion studies
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| Research Institution | National Institute for Fusion Science |
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Principal Investigator |
Kobayashi Makoto 核融合科学研究所, ヘリカル研究部, 助教 (50791258)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2017: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
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| Keywords | トリチウム / ステンレス / タングステン / 超透過現象 / プラズマ・核融合 |
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| Outline of Final Research Achievements |
This study aimed to develop the decontamination method of tritium retained in metal components with using super-permeation of hydrogen isotopes. The simulation code which can estimate the hydrogen diffusion, solution, recombination in solids was combined with the dynamics of hydrogen injection during plasma exposure and hydrogen isotope exchange reaction in solids. According to this code, the decontamination of tritium in stainless steel was expected under sufficient high hydrogen diffusion and high tritium detrapping rate condition.
To evaluate the tritium detrapping in the trapping sites such as irradiation defects in solid, radiation irradiation into metals was carried out, then hydrogen isotope introduction into metal materials was performed. Thermal desorption of hydrogen isotopes showed tritium detrapping is a rate-determining step in some metals such as tungsten.
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| Academic Significance and Societal Importance of the Research Achievements |
核融合炉では燃料に放射性核種であるトリチウムを使用します。トリチウムは材料内に溶解するため、メンテナンス時等に炉機器から作業環境及びプラント外へのトリチウム移行が懸念されます。本研究では材料中のトリチウム移行現象を数値的にモデル化し、その除染の予測が可能となりました。除染においては材料中の水素同位体の拡散速度と照射欠陥などの水素同位体捕捉サイトからの脱捕捉速度が律速過程となることを示しました。
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