铀、镅在矿物-水界面吸附现象的分子动力学模拟研究

我国核工业已走过60年的发展历程，一些核施设面临退役和治理的迫切要求，同时，核电快速发展产生的放射性废物也需要处理和处置。放射性核素在环境介质中的吸附、扩散和迁移规律是评估核施设退役治理效果以及评价放射性废物尤其是高水平放射性废物（高放废物）处置库安全性的最重要基础。实验室静态和动态实验研究能够提供一些核素在特定介质中的吸附和扩散参数，但这些参数不足以使我们全面认识这些核素与环境介质的微观作用过程。分子动力学模拟充分考量分子间的相互作用，通过建立相互作用分子间的力场，使其在连续的力场作用下发生位置上的变化，通过观察其终态位置和数量推断其运动规律。该技术可帮助我们了解不同物质间的微观作用过程。本项目拟利用分子动力学模拟技术研究铀和镅在特定场点矿物/水界面上的吸附与扩散，获得这2个核素在相应体系中的微观扩散和分布参数，为我国核施设退役治理及高放废物地质处置安全评价提供基础数据。

The nuclear industry in China has celebrated she’s 60-year anniversary, some nuclear facilities badly need decommissioning and management, in the mean time, the radioactive wastes produced from the fast development of nuclear power need treatment and disposal too. The sorption, diffusion and migration of radionuclides in the environmental medium are important bases for the safety assessment of decommissioning of nuclear facilities and radioactive wastes, especially high level radioactive wastes disposal facilities. Laboratory batch experiments and column experiments can provide with sorption and diffusion parameters for some radionuclides, while these information is far from understanding the micro-processes of radionuclides with the environmental medium. Molecular dynamics simulation concerns the reactions among molecules, based on the settled force fields of molecules, the molecules move continuously, and we can predict the movement rules of molecules by observing the final position and amounts of the simulated molecules. This project will use molecular dynamics simulation techniques to study the sorption and diffusion of uranium and americium in site specific mineral/water interface, thus to obtain the micro-diffusion and distribution parameters in the system interested, and to provide basic data to the safety assessments for the decommissioning of nuclear facilities and waste disposal facilities.