Hierarchical structure and its dynamics: self-assembly of extracted coordination species in a spent fuel reprocessing process

2017 Fiscal Year Final Research Report

• Project/Area Number: 26289368
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Nuclear engineering
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Motokawa Ryuhei 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 物質科学研究センター, 研究主幹 (50414579)
• Co-Investigator(Kenkyū-buntansha): 遠藤 仁 大学共同利用機関法人高エネルギー加速器研究機構, 物質構造科学研究所, 准教授 (40447313)
• Research Collaborator: HELLER T. William
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 抽出錯体 / PUREX / 中性子小角散乱 / Ｘ線小角散乱 / 階層構造 / EXAFS / 相分離 / 再処理

Outline of Final Research Achievements

We investigated a microscopic structure of the organic phase containing the extracted coordination species of zirconium/tri-n-butyl phosphate (TBP) through extended X-ray absorption fine structure, small-angle neutron scattering, and molecular dynamics simulations. As a result, it is found that the coordination species aggregate due to a hydrogen-bonding network formed by interaction between the hydrophilic part of the coordination species with extracted water and nitric acid molecules. This reduces the hydrophilic surface area, resulting in subsequent formation of small primal clusters of 2 -3 nm in diameter. The primal clusters further aggregate due to van der Waals interaction to form large aggregates.

Free Research Field

ナノ構造科学