Elucidation of mechanism for tritium accumulation to soil and proof of principle for new decontamination method

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H01877
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 14020:Nuclear fusion-related
• Research Institution: Kyushu University
• Principal Investigator: Katayama Kazunari 九州大学, 総合理工学研究院, 准教授 (90380708)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: トリチウム / トリチウム水 / 土壌 / 粘土鉱物 / 同位体交換 / マイクロ波加熱 / 環境保全 / 有機結合型トリチウム

Outline of Final Research Achievements

The positions of the tritium release peak due to heating from the natural soil sample immersed in tritiated water and the water release peak were the same. This suggests that tritium is taken up by the water or hydrogen existing in the soil through an adsorption reaction or an isotope exchange reaction, respectively. It was revealed that the amount of tritium released by dissolving the soil by the microwave-assisted acid dissolution method is larger than the amount of tritium released by heating to 1000 ℃. This indicates that it is difficult to recover all tritium from tritium-contaminated soil only by heating, and complete dissolution is required. Arabidopsis thaliana was grown in tritium-containing soil, and a part of the tritium supplied to the soil was accumulated as organic bound tritium.

Free Research Field

核融合炉工学　トリチウム理工学　物質移動工学

Academic Significance and Societal Importance of the Research Achievements

高度な社会文明を維持するために必要なエネルギーを継続的に安定して供給可能なエネルギー源として、核融合炉の実現が期待されている。しかしながら、核融合炉が社会に受け入れられるためには、万が一の事故により燃料トリチウムが施設外へ漏洩した際の環境・公衆への影響を科学的根拠に基づいて説明することが求められる。本研究は、トリチウム水が土壌に漏洩した際のトリチウム挙動を解明するものであり、核融合炉の受容性向上の観点から社会的意義は大きい。また、土壌中でのトリチウム移動現象は解明されておらず、本研究で得られるトリチウム実験による成果は学術的意義が大きい。