Numerical Study on Mechanical Characteristics of Storage Canister Module for Spent Fuel Dry Storage System
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摘要: 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。Abstract: 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.
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表 1 热膨胀计算结果
Table 1. Calculation Results of Thermal Expansion
编号 计算对象1 计算对象2 方向 初始间隙/mm 膨胀后间隙/mm 1 燃料模拟体 燃料格架 径向 1.00 1.08 2 燃料模拟体 贮存容器 轴向 36.00 35.42 3 铝支撑块 贮存容器 径向 2.00 1.32 4 燃料格架 贮存容器 轴向 36.00 34.28 表 2 网格敏感性计算结果
Table 2. Calculation Results of Mesh Sensitivity
编号 计算模型 网格数量 最大应力/MPa 1 贮存容器 32474 53.10 2 贮存容器 63355 55.35 3 贮存容器 99015 54.21 4 燃料格架 41202 255.26 5 燃料格架 81750 253.71 6 燃料格架 120990 255.58 7 铝支撑块 138852 77.30 8 铝支撑块 275500 89.99 9 铝支撑块 418760 83.21 表 3 网格信息
Table 3. Mesh Information
编号 计算模型 网格数 节点数 最大偏斜率 1 贮存容器 63355 292945 0.547 2 燃料格架 81750 570370 0.496 3 铝支撑块 275500 1424288 0.744 -
[1] 蔡创广. 乏燃料卧式干法贮存热工安全数值模拟与分析[D]. 广州: 中山大学,2019. [2] KO Y Y, HSU S Y, CHEN C H. Analysis for seismic response of dry storage facility for spent fuel[J]. Nuclear Engineering and Design, 2009, 239(1): 158-168. doi: 10.1016/j.nucengdes.2008.09.006 [3] CHANG C H, CHOU H W, CHUNG C L, et al. Seismic dynamic analysis and structural integrity assessment of the PWR spent fuel pool under beyond design basis earthquake[J]. International Journal of Pressure Vessels and Piping, 2022, 196: 104625. doi: 10.1016/j.ijpvp.2022.104625 [4] LEE J H, SEO K S, CHO C H. Seismic response analysis of a freestanding model of spent fuel storage cask[C]. Proceedings of 18th International Conference on Structural Mechanics in Reactor Technology, Beijing, 2005: 3317-3323. [5] KAMPOY T T. Structural analysis of spent nuclear fuel dry storage casks[D]. Cape Peninsula University of Technology, 2020. [6] YANG Y H, DAI W Y, HUANG T, et al. Numerical simulations of nuclear fuel reprocessing plant subjected to the free drop impact of spent fuel cask and fuel assembly[J]. Nuclear Engineering and Design, 2021, 385: 111524. doi: 10.1016/j.nucengdes.2021.111524 [7] WU T Y, LEE H Y, KANG L C. Dynamic response analysis of a spent-fuel dry storage cask under vertical drop accident[J]. Annals of Nuclear Energy, 2012, 42: 18-29. doi: 10.1016/j.anucene.2011.12.016 [8] ALMOMANI B, LEE S, KANG H G. Structural analysis of a metal spent-fuel storage cask in an aircraft crash for risk assessment[J]. Nuclear Engineering and Design, 2016, 308: 60-72. doi: 10.1016/j.nucengdes.2016.07.014 [9] 祝玲琳,唐琼辉,陈柳彤. 气隙和接触热阻对乏燃料干法转运容器热工安全影响研究[J]. 核动力工程,2021, 42(6): 230-236. [10] 张宇,吕丹,赵善桂,等. 乏燃料干法贮存系统辐射防护问题分析[C]. 中国核科学技术进展报告(第六卷)——中国核学会2019年学术年会论文集第10册(核安全分卷、核安保分卷). 包头: 中国原子能出版社,2019: 112-116. [11] 董海斌. 乏燃料干法贮存辐射防护最优化研究[J]. 电工技术,2022(17): 177-179,183.