2023 Fiscal Year Final Research Report
Evaluation method on water transfer characteristics of bentonites considering ground water quality in radioactive waste disposal
| Project/Area Number |
21K04260
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 22030:Geotechnical engineering-related
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| Research Institution | Waseda University |
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Principal Investigator |
Ito Daichi 早稲田大学, 理工学術院, 講師(任期付) (40875225)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Keywords | 放射性廃棄物処分 / ベントナイト / 水分移動特性 / 地下水質 |
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| Outline of Final Research Achievements |
The purpose of this study is to develop a database for water migration characteristics of bentonite materials considering the effects of various groundwater quality, groundwater pressure, and exhaust conditions, which are essential for the safety assessment of radioactive waste disposal. The effects of ionic species present in seawater and groundwater on the infiltration properties of Na, Ca, and Ca-Mg bentonite with different exchangeable cation compositions were evaluated. In addition, water movement characteristics at unsaturated conditions were evaluated under increased water pressure up to 4 MPa, and it was confirmed that the water diffusion behavior was consistent and that no significant differences in water diffusion coefficients occurred. Finally, the effects of exhaust conditions on moisture migration behavior were evaluated, suggesting that the effects of pore air volume and air pressure should be considered.
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| Free Research Field |
地盤工学
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| Academic Significance and Societal Importance of the Research Achievements |
本研究で得られた成果は，各種放射性廃棄物処分のバリアシステムにおけるキーコンポーネントであるベントナイト系材料による遮水材の材料仕様決定に直接的に応用可能である．幅広い水質，水圧環境における水分移動特性を実験的に明らかにしており，処分施設の様々な立地条件や地層環境に応用可能な基礎的知見である．ゆえに，現在選定が進んでいて今後建設が想定される，地層処分施設をはじめとした各種放射性廃棄物処分施設のバリア材の仕様設計に貢献できる．
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