【作者】 郭琪琪； 陈怡志； 蒋德祥； 张鹏； 林子健； 何辉； 林铭章；

【Author】 GUO Qi-qi;CHEN Yi-zhi;JIANG De-xiang;ZHANG Peng;LIN Zi-jian;HE Hui;LIN Ming-zhang;School of Nuclear Science and Technology,University of Science and Technology of China;China Institute of Atomic Euergy,China Institute of Atomic Energy;

【机构】 中国科学技术大学核科学技术学院； 中国原子能科学研究院；

【摘要】 TBP、TiAP、DMHMP等有机磷萃取剂在从乏燃料中回收锕系元素方面表现出了良好的萃取性能。本文利用标量相对论密度泛函理论,研究了TBP、TiAP和DMHMP与锕系元素[Np （Ⅵ）、Pu （Ⅳ）、Am （Ⅲ）]之间的络合性质及热力学行为,旨在阐明萃取剂对锕系元素的萃取机理。结果表明,3种萃取剂对锕系元素的络合能力依次为DMHMP>TiAP>TBP,同时,静电势及分子轨道分析显示DMHMP比其他两种萃取剂具有更强的亲核能力。Wiberg键指数（WBI）表明,DMHMP配合物中的M—O键具有更多的共价,与金属离子形成更稳定的配合物,这与键距结果一致。从能量角度看,DMHMP与金属离子的络合反应更容易发生。本工作阐明了锕系金属离子(NpO₂²⁺、Pu⁴⁺和Am³⁺)与3种萃取剂的配位结构和络合性质,有望为乏燃料后处理中关键锕系元素的高效回收提供理论依据,同时也为相关分离工艺的设计和开发提供了新的思路。更多还原

【Abstract】 TBP,TiAP,DMHMP and other organophosphorus extractants showed good performance in the recovering actinides from spent fuel.In this work,the complexing nature and thermodynamic behaviors of TBP,TiAP and DMHMP with actinides [Np（Ⅵ）,Pu（Ⅳ）,Am（Ⅲ）] have been studied using scalar relativistic density functional theory.The extraction mechanism of actinides by extractants has been further clarified.The results showed that the complexation ability of the three extractants was DMHMP>TiAP>TBP.The electrostatic potential（ESP） and molecular orbitals showed that DMHMP had stronger nucleophilic ability than the other two extractants.Wiberg bond indices（WBI） suggested that the M-O bonds in DMHMP complexes had more covalency and formed more stable complexes with metal ions, which was consistent with the bond distance results.From the viewpoint of energy,the complex reaction between DMHMP and metal ions was more likely to occur.This study elucidated the coordination structures and complexation properties of actinide metal ions(NpO₂²⁺, Pu⁴⁺ and Am³⁺) and three extractants.It is expected to provide a theoretical basis for the efficient recovery of key actinide elements in spent fuel reprocessing,and also provide new ideas for the design and development of related separation processes.更多还原