乏燃料运输容器抗脆性断裂评价

Protection against Brittle Fracture in Spent Fuel Transportation Cask

目的研究乏燃料运输容器的材料抗脆性断裂的论证方法,验证乏燃料运输容器的选材是否满足GB 11806《放射性物质安全运输规定》和IAEA SSG-26所要求的-40℃下仍能正常运行的抗脆性断裂要求。方法以某型号乏燃料运输容器为例,采用LS-DYNA进行有限元仿真模拟跌落过程,开展乏燃料运输容器9 m自由跌落冲击分析,依据计算结果分别采用传统的抗脆性断裂论证方法和线弹性断裂力学的分析方法验证材料的抗脆性断裂能力。结果采用传统的抗脆性断裂分析方法时,选材不满足要求;采用线弹性断裂力学进行抗脆性断裂分析时,选材满足要求。结论对比传统的选材方法,采用线弹性断裂力学分析方法能够有效降低抗脆性断裂设计的裕度,为扩大乏燃料运输容器的选材范围提供了有效途径。

The work aims to study the demonstration method for protection against brittle fracture in spent fuel transportation cask and verify whether the materials of spent fuel transportation cask can still work normally at-40 ℃without brittle fracture according to GB 11806 Regulations for the Safe Transport of Radioactive Material and IAEA SSG-26. With some spent fuel transportation cask as an example, the finite element simulation of the drop process was conducted with LS-DYNA to analyze the 9 m free drop impact. The traditional method and the linear elastic fracture mechanics were used to verify the ability of protection against brittle fracture in the transportation cask separately. With respect to the traditional method for the analysis of protection against brittle fracture, the materials selected did not meet the requirements, while the materials analyzed by the linear elastic fracture mechanics met the requirements. Compared to the traditional method for material selection, the analysis conducted by linear elastic fracture mechanics can effectively reduce the margin of anti-brittle fracture design and provide an effective way to expand the material selection range of spent fuel transportation cask.