结构材料辐照损伤问题是制约核聚变堆发展的重要因素之一。目前主要采用第一性原理、分子动力学等方法研究小尺寸纳米晶材料的辐照损伤机理。然而，辐照损伤是多尺度问题，急需发展具有宏观时间、空间尺度的数值模拟技术开展较大体系的模拟研究。实体动力学蒙特卡洛方法OKMC是具有这种宏观时空尺度特性的模拟技术。本项目拟以铁素体/马氏体钢的基体结构α-Fe为主要研究对象，基于前期运用第一性原理、分子动力学、分子静力学和温度加速分子动力学等方法在小尺寸体系Fe中辐照缺陷与晶界相互作用的研究结果，进一步运用实体动力学蒙特卡洛方法OKMC研究宏观时空尺度下Fe纳米晶中辐照缺陷与晶界相互作用的关键原子演化过程及其机制，从而补充、完备Fe纳米晶辐照损伤基本规律数据库，力争获得Fe纳米晶宏观辐照损伤修复条件（温度、辐照剂量和晶粒尺寸等），为实验制备抗辐照材料提供理论参考和指导。

Radiation damage in structural materials is one of crucial factors impeding the development of nuclear fusion reactors. Nowadays, main focus is put on density functional theory method and molecule dynamics method for the study of radiation damage mechanism. The methods can only be used to investigate radiation damage mechanism of nano-crystallines in small size system, however, radiation damage is a problem of multiscale. Thus it starves for the simulation technology which can be used to deal with the problems in macroscopic size and time scales. Object Kinetic Monte Carlo is the kind of method meeting the requirement for the simulations in macroscopic size and time scales. The α-Fe is selected as the main model system. Based on the results of the interactions between radiation-induced defect and grain boundary in small size Fe from density functional theory, molecule dynamics, molecular statics, and temperature-accelerated dynamics, Object Kinetic Monte Carlo is used to study the interplay picture and mechanism of radiation-induced defect with grain boundary in nano-crystalline Fe in macroscopic size and time scales. Thus data base of radiation damage in nano-crystallines Fe will be supplemented and consummated. The dependence of radiation damage healing on temperature, radiation dose and the grain size will be clarified. The work will serve as guidance for the design and development of radiation resistant materials.