乏燃料干法贮存系统贮罐模块力学特性数值研究

Numerical Study on Mechanical Characteristics of Storage Canister Module for Spent Fuel Dry Storage System

乏燃料干法贮存是处理乏燃料的重要方法,而贮存过程中燃料产生的高温会引起极大的热应力,可能导致材料的永久变形和破坏,研究乏燃料贮存系统中贮罐模块的力学特性具有重要的意义。以乏燃料干法贮存系统中的贮罐模块为研究对象,建立1/2缩比模型,基于计算的贮罐模块温度分布开展了正常贮存工况下贮罐模块的力学特性数值研究,为乏燃料干法贮存系统的缩比试验提供数据支撑。结果表明:(1)格架应力的总体趋势呈现为中心高、四周低,顶部和底部部分区域存在较大的剪切应力,铝制支撑块总体应力较小,贮存容器在容器壳体和顶部盖板的交界处存在较大应力;(2)在最低环境温度工况下燃料格架、铝制支撑块和贮存容器最大应力分别为253.71、89.99、55.35 MPa,各部件应力均未超过法规限值。

Spent fuel dry storage is an important method for handling spent fuel,however,the high temperature generated by spent fuel may cause great thermal stress,thereby leading to permanent deformation and damage.Therefore,it is of great significance to study the mechanical properties of storage canister module in spent fuel storage system.In this paper,the storage canister module in the spent fuel dry storage system is taken as the research object,and a 1/2 scaled model of the storage canister module is established.Based on the calculated temperature distribution of the storage canister module,the numerical study of the mechanical characteristics of the storage canister module under normal storage conditions is carried out,which provides data support for the scale test of the spent fuel dry storage system.The results show that:①The stress in grid is high in center and low around,and there is a large shear stress in the top and bottom parts,while the overall stress of the aluminum support block is small, and there is a large stress at the junction of the canister shell and the top cover plate;②Under the lowest ambient temperature condition, the maximum stress of the grid, the aluminum support block and the storage canister is 253.71 MPa, 89.99 MPa and 55.35 MPa, respectively. The stress of each component does not exceed the limits.