热管堆铀钼合金燃料高温辐照肿胀研究  

Irradiation-induced swelling of U-Mo fuel for heat-pipe reactor under high temperature

作　　者：姚钦文 关玺彤 程全 代季高 邹远方 何晓军[1] 张爱民[1] YAO Qinwen;GUAN Xitong;CHENG Quan;DAI Jigao;ZOU Yuanfang;HE Xiaojun;ZHANG Aimin(Department of Reactor Engineering Technology,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院反应堆工程技术研究所,北京102413

出　　处：《核技术》2024年第11期110-118,共9页Nuclear Techniques

摘　　要：热管冷却反应堆(简称热管堆)选用铀钼合金作为堆芯燃料,这种燃料具有显著的热膨胀和辐照肿胀,因此燃料设计需要关注材料高温下的肿胀。基于部分高温下铀钼合金的辐照数据,考虑温度对铀钼合金辐照肿胀影响,使用COMSOL Multiphysics(简称COMSOL)对1 kWe Kilopower热管堆方案构建了三维分析模型,完成了热力耦合分析。计算结果表明:使用COMSOL可以有效模拟燃料热膨胀和辐照肿胀行为;与仅考虑热膨胀计算结果对比,寿期末燃料变形和应力均有所增加;燃耗深度达到0.4%时,燃料最大应力为85.1 MPa。在进行更大功率、更深燃耗热管堆方案设计时,需要考虑燃料的辐照肿胀。[Background]Uranium-molybdenum(U-Mo)alloy,which is applied in the heat-pipe cooled reactor(referred as heat-pipe reactor),has the advantages of high thermal conductivity,high density of uranium and excellent irradiation performance.At the same time,U-Mo alloy has significantly thermal expansion and irradiation swelling whilst the high temperature will aggravate the irradiation swelling of U-Mo alloy and reduce the performance of the material.Hence research on swelling under high temperature of U-Mo alloy is essential in the design of this fuel.[Purpose]The study aims to comprehensively evaluate the effect of fuel swelling under high temperature of U-Mo alloy on reactor core structure.[Methods]Firstly,based on the irradiation data of U-Mo alloy under high temperature,a new type of swelling model considering the effect of high temperature was established.Secondly,a three-dimensional(3D)thermal-mechanical coupling analysis model of U-Mo alloy fuel was set up using finite element analysis(FEA)software COMSOL Multiphysics(referred to as COMSOL).Thirdly,a thermal-mechanical coupling analysis was carried out with concern of the thermal expansion effect to verify the validity of the 3D FEA model.Finally,this swelling model was used to study the fuel swelling effect of reactor core by considering the irradiation swelling of U-Mo alloy at high temperature,and the stress and deformation analysis under different burnup were carried out to evaluate the effect of fuel swelling on the core structural stability.[Results]Under steadystate operating conditions,the core fuel of 1 kWe Kilopower heat-pipe reactor has a large deformation at the end of life(EOL)due to thermal expansion and irradiation swelling,and the maximum deformation reaching 5.28 mm.The maximum stress caused by deformation is 57.4 MPa,which is concentrated on the wall where the heat pipe is connected to the core fuel.Thermal expansion is the main factor that causes stress and deformation of fuel.As the burnup continues to deepen,the irradiation swelling of U-Mo al

关 键 词：热管冷却反应堆 Kilopower 铀钼合金 辐照肿胀 COMSOL 

分 类 号：TL429[核科学技术—核技术及应用]