耐高温、抗辐照的SiC材料是高温气冷堆中放射性裂变产物的主要屏蔽层，Ag、Cs是其辐射屏蔽的重点。由于辐照缺陷能增强裂变产物在SiC中迁移扩散，且高温下裂变产物Ag和Cs在高损伤SiC中迁移扩散机理尚不完全清楚，亟待开展高温环境下高损伤SiC中阻挡裂变产物扩散的方法研究。本项目利用SiC中重惰性空位团簇具有高温下难迁移扩散的特点，结合惰性空位团簇对金属粒子的捕获效应及裂变元素在SiC中的扩散规律，通过离子注入、辐照和惰性气体下高温退火实验，模拟高温环境下Kr-空位团簇和Ag或Cs在高损伤SiC中的迁移扩散过程，通过透射电镜和二次离子质谱得到元素的空间、浓度分布，进而获得高温环境下难迁移惰性元素Kr-空位团簇和裂变产物Ag和Cs之间的相互作用规律，探索利用SiC中分散的纳米重惰性空位团簇来捕获核裂变产物的新方法。本项目对燃料的安全运行具有重要意义，对新型反应堆屏蔽材料的研发也具有借鉴意义。

Due to its excellent high-temperature stability, and good irradiation resistance, silicon carbide (SiC) has been considered as the main shielding layer of fission products in high temperature gas cooled reactor. Fission products Ag and Cs are the main shielding elements, due to high radiation energy and toxicity. The diffusion of fission products in SiC is enhanced due to radiation defects, until now, the mechanism of migration and diffusion of fission products Ag and Cs in highly damaged SiC is not clear at elevated temperatures, therefore, it is urgent to study the methods of blocking fission products. Due to its high-temperature stability and the capture effect on metal ions, Kr-vacancy clusters could be used in the design of trapping fission products，which is a new method for capturing radioactive fission elements. In this project, the experiments of ion implantation, irradiation and high temperature annealing under inert gas are used. The diffusion of fission products in high damage SiC containing Kr-Vacancy clusters at elevated temperatures were studied, and the results of the concentration distribution of each element are obtained by transmission electron microscopy and secondary ion mass spectrometry. The interaction between inert element Kr-vacancy clusters and fission products Ag and Cs in high temperature and high damage environment was studied by the above methods, and a new method of capturing nuclear fission products by using the Nano-Kr-vacancy clusters in SiC was explored. This project has important research value for the safe operation of fuel, meanwhile, it also has reference significance for the development of new reactor shielding materials.