Challenging research in self-contained buffer-barrier stabilized in long term by expression of improvement functions at different time scale

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K18345
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nuclear engineering
• Research Institution: Tohoku University
• Principal Investigator: Chida Taiji 東北大学, 工学研究科, 講師 (30415880)
• Research Collaborator: NIIBORI YUICHI 東北大学, 大学院工学研究科, 教授 (90180562)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: ケイ酸 / ベントナイト / 析出 / 時間スケール / 核種閉じ込め / 地層処分 / 放射性廃棄物 / 原子力

Outline of Final Research Achievements

For the new concept of the buffer-barrier which exhibits the higher performance of nuclide confinement at different time scale, this study examined the deposition behavior of supersaturated silicic acid on clay minerals (bentonite) used for the geological disposal system, and estimated the clogging effect of flow-paths with the deposition of silicic acid. The results of deposition experiments showed that the deposition of supersaturated slicic acid on Na-type bentonite, Ca-type bentonite and amorphous silica significantly progressed under some conditions (pH, temperature, salt concentration) of the underground environment. In the estimation of the clogging effect considering the apparent deposition rate constants, the calculation results suggested that flow-paths and porous media for the migration of radionuclides around the repository will be sufficiently clogged by the deposition of silicic acid within 1,000 years assuming as the period guaranteed the performance of waste container.

Free Research Field

工学