δ相Pu及Pu-Ga合金老化机理研究

项目名称： δ相Pu及Pu-Ga合金老化机理研究

项目编号： No.51271198

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 何彬

作者单位： 中国人民解放军第二炮兵工程大学

项目金额： 80万元

中文摘要： 钚是一种人工放射性核素，其金属形态具有重要的国防和民用价值。自辐射效应、相稳定性和表面腐蚀是其老化的重要因素，长期以来都是研究的热点之一。本项目在前期研究成果基础上，开展基于原子水平的δ相Pu和Pu-Ga合金的老化机理研究。对纯δ相Pu中α衰变产生的U反冲核所致碰撞位移级联过程、点缺陷团簇的微观演变过程以及破裂与点缺陷团簇之间的相互作用进行计算，耦合从头算法，分子动力学方法和介观蒙特卡罗方法进行多尺度计算，预测点缺陷的长期演变行为，从微观尺度捕获Pu自辐射所致老化特征；研究Pu 5f电子、Ga原子、He泡和U原子对δ-Pu相稳定性的效应，分析δ相Pu-Ga合金的Ga稳定机制；研究Pu 5f, 6d与H 1s, C 2p, N 2p, O 2p 、S 3p 态之间杂化和混合效应以及化学成键行为，揭示Pu表面腐蚀机理。项目研究成果将有助于提高Pu材料部件的贮存安全性、可靠性和表面抗腐蚀性。

中文关键词： 密度泛函理论；嵌入原子方法；点缺陷；相稳定性；化学吸附

英文摘要： Plutonium is a kind of artifical radionuclide, whose metal form has a significant value in defense and civilian. Self-irradiation, Phase stability and surface corrosion in Pu-based materials are the important factors of aging, which are also the focus of research. On the basis of the results of preliminary studies, the microscopic mechanisms of aging of delta phase Pu and Pu-Ga alloy will be studied in this project. The displacement cascade evolution of U recoil nucleus produced by Pu α decay, the microscopic evolution of point defect clusters, and the interactions of extend defect-fracture with point defect clusters will be performed molecular dynamics (MD) calculations. To track the long-term evolution behaviors of point defects in delta-Pu, ab initio, molecular dynamics and mesoscopic Monte Carlo will be coupled to perform the multi-scale calculations.The effects of Pu 5f eletrons, Ga atom, He bubble and U atom on the phase stability in delta-Pu will be evaluated with MD method and Ga-stabilizing mechanisms of delta phase Pu-Ga alloy will be systematically researched.The hybrid and mixture effects of Pu 5f, 6d states with H 1s, C 2p, N 2p, O 2p and S 3p states, and the chemical bonding behaviors of Pu atom with the valence atom will also be described.The mechanism of surface corrosion will be investigated. Th

英文关键词： Density functional theory；Embedded atom method；Point defect；Phase stability；Chemisorption