Development of performance assessment method for barrier materials in geological disposal of radioactive waste using multifunctionalized gold nanoparticles

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04990
• 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: Hokkaido University
• Principal Investigator: KOZAKI Tamotsu 北海道大学, 工学研究院, 教授 (60234746)
• Co-Investigator(Kenkyū-buntansha): 渡辺 直子 北海道大学, 工学研究院, 准教授 (20624711)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 高レベル放射性廃棄物 / 地層処分 / 多機能化金ナノ粒子 / 移行遅延 / 天然バリア / 人工バリア / コロイド

Outline of Final Research Achievements

As a fundamental study on the migration behavior of colloidal radionuclides in a geological disposal environment, batch and column experiments were conducted using gold nanoparticles (AuNP) of different sizes coated with polyethylene glycol to study the interactions of AuNPs with silica sand and Na-type montmorillonite. The transport of AuNP was observed to be increased for the smaller nanoparticles, which exhibit increased stability against aggregation. These results suggest interactions other than electrostatic and vdW, including steric effects provided by the PEG coating can control the transport behavior in porous media such as silica sand.

Free Research Field

原子力工学

Academic Significance and Societal Importance of the Research Achievements

高レベル放射性廃棄物の地層処分の安全評価において、地下処分環境下にて多様な形態およびサイズを有するコロイド状放射性核種の移行挙動を把握することは重要な研究課題である。本研究では、異なるサイズの金ナノ粒子を用いた試験結果から、固相であるケイ砂やNa型モンモリロナイトとコロイドとの相互作用が、コロイド周りの配位子層の厚みや固相表面の不均一性などの影響を受け、コロイドの凝集につながる可能性を示すなど、コロイド状放射性核種の移行挙動の理解に資する結果を得た。