高放废物处置罐铜材料吸附Cl^(-)、SO_(4)^(2-)第一性原理计算  

First Principle Calculation of Cl^(-) and SO_(4)^(2-) Adsorption of Copper Materials in High-level Radioactive Waste Disposal Canisters

作　　者：陈沫汝 杨波 张梦[1] 魏强林 刘义保 CHEN Moru;YANG Bo;ZHANG Meng;WEI Qianglin;LIU Yibao(College of Nuclear Science and Engineering,East China University of Technology,Nanchang 330013,China;National Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China)

机构地区：[1]东华理工大学核科学与工程学院,南昌330013 [2]东华理工大学核资源与环境国家重点实验室,南昌330013

出　　处：《能源研究与管理》2023年第4期114-119,180,共7页Energy Research and Management

基　　金：国家自然科学基金(11965001);江西省自然科学基金面上项目(20212BAB201004)。

摘　　要：为推进甘肃北山高放废物深地质处置罐材料的选择,参考瑞典KBS-3处置罐,基于第一性原理对铜材料进行Cl^(-)与SO_(4)^(2-)的表面吸附模拟计算,从吸附能、Bader电荷转移、差分电荷密度3个方面揭示阴离子的在铜晶胞模型中的吸附情况,通过分析微观尺度下的电子状态,解决铜材料受辐照损伤及Cl^(-)、SO_(4)^(2-)影响的腐蚀加速机制问题。结果表明:相较于完整Cu(111)表面的吸附,Cl^(-)及SO_(4)^(2-)在缺陷Cu(111)表面吸附更稳定。Cl^(-)在缺陷Cu(111)表面的最佳吸附位点为hcp位,吸附能为-3.799 eV。SO_(4)^(2-)在缺陷Cu(111)表面的最佳吸附位点为hcp位,吸附能为-5.281 eV。在缺陷Cu(111)表面的吸附模型中,Cl表现为得电子;所关心的Cu(Cu9、Cu27、Cu33)则表现为失电子;O表现为得电子,而Cu、S均表现为失电子。在实际高放废物深地质长时间贮存环境中,存在辐照对材料产生原子移位的辐照损伤,诸如Cl^(-)、SO_(4)^(2-)氧化性较强的阴离子,会稳定吸附于材料表面,对处置罐产生腐蚀加速效应。地下水阴离子的吸附机制模拟研究,可在工程应用领域对处置罐材料的选择提供理论参考。In order to promote the selection of Gansu beishan high-level radioactive waste deep geological disposal canisters materials,reference to Sweden KBS-3 disposal canisters,based on the first principle of the copper material Cl^(-)and SO_(4)^(2-)surface adsorption simulation,the adsorption of anions in the copper crystal cell model is revealed from three aspects of adsorption energy,Bader charge transfer and differential charge density.By analyzing the electronic state at the microscopic scale,the corrosion acceleration mechanism of copper material affected by irradiation damage and Cl^(-)and SO_(4)^(2-)is solved.The results show that Cl^(-)and SO_(4)^(2-)are more stable on the defective Cu(111)surface adsorption than on the intact Cu(111)surface.For the Cl^(-),the optimal adsorption site on the surface of the defective Cu(111)is the hcp site,and the adsorption energy is-3.799 eV.For SO_(4)^(2-),the optimal adsorption site on the surface of the defective Cu(111)is the hcp site with an adsorption energy of-5.281 eV.In the defective Cu(111)surface adsorption model,Cl gets electrons,the concerned Cu(Cu9,Cu27,Cu33)loss electrons,and O gets electrons while Cu and S loss electrons.In the deep geological long-term storage environment of high-level waste,radiation damage caused by atomic displacement of materials,such as Cl^(-),SO_(4)^(2-)strong oxidizing anions,will be stably adsorbed on the surface of materials,resulting in accelerated corrosion effect on the disposal canisters.The simulation study of the adsorption mechanism of groundwater anion can provide a theoretical reference for the selection of disposal canisters materials in the engineering application field.

关 键 词：高水平放射性废物 深地质处置罐 吸附机制 第一性原理 

分 类 号：TL942[核科学技术—辐射防护及环境保护]