基于氧化腐蚀行为的铅铋堆燃料组件多物理耦合特性研究  

Multi-physics Coupling Characteristics of Lead-bismuth Reactor Fuel Assembly Based on Oxidative Corrosion Behaviors

作　　者：季旭 柴翔[1] 张乐福[1] 刘晓晶[1] JI Xu;CHAI Xiang;ZHANG Lefu;LIU Xiaojing(School of Nuclear Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学核科学与工程学院,上海200240

出　　处：《原子能科学技术》2024年第10期2139-2152,共14页Atomic Energy Science and Technology

基　　金：上海市2020年度“科技创新行动计划”技术带头人项目(20XD1434100)。

摘　　要：氧是铅铋堆中最具应用潜力的非金属缓蚀剂,在冷却剂中添加一定浓度的氧,可在结构材料表面生成保护性氧化膜,可以极大程度上缓解液态铅铋对结构材料的腐蚀。在铅铋堆中,氧化层的生长-去除行为受温度、氧浓度、冷却剂流速、时间等多种因素影响,同时氧化层的生长也改变了堆芯的热工水力特性和中子物理参数,因此,研究铅铋堆的氧化腐蚀场、热工水力场和中子物理场的耦合作用对铅铋堆应用有重要意义。本文基于MOOSE(面向对象的多物理场仿真环境)平台搭建了核-热-材多物理场耦合框架,开展了铅铋堆在基准工况下的核-热-材耦合分析,并研究了氧浓度和冷却剂入口温度对关键耦合参数时序变化规律和氧化层分布的影响。结果表明,基准工况下氧化腐蚀10 000 h后,燃料组件包壳表面的氧化层平均厚度约为9.86μm,燃料最大温升为13.36 K,k_(eff)下降7 pcm;氧浓度升高可以极有效地抑制磁铁矿溶解,但达到一定浓度后氧浓度的升高对Fe-Cr尖晶石的生长促进作用较小;冷却剂入口温度的升高会导致组件中心处包壳壁面的磁铁矿去除速率增大,并且可以大幅促进Fe-Cr尖晶石的生长。Oxygen is the most promising non-metallic inhibitor in lead-bismuth cooled fast reactors(LFRs).The addition of oxygen to the coolant can format a protective oxide layer on the surface of structural materials,which will effectively alleviate the corrosion of structural materials by the liquid lead-bismuth eutectic (LBE).LFR is a complex environment characterized by the interaction of multiple physical fields.For instance,the growth and removal behaviors of the oxide layer are influenced by various factors such as temperature,oxygen concentration,coolant velocity,and time.Moreover,the formation of the oxide layer changes the thermal-hydraulic characteristics and neutronics parameters of the reactor core.Therefore,studying the coupled effects of oxidation corrosion,thermal-hydraulics,and neutronics is of paramount importance for the development,design,and safety assessment of LFRs.A multi-physics framework that couples neutron physics,thermal-hydraulics,and material corrosion was proposed to investigate the multi-physics coupling characteristics of the fuel assembly in LFRs.Within the coupling framework,neutronics calculations were performed using the open-source neutron diffusion equation solver Moltres,thermal-hydraulic calculations were conducted using the NavierStokes module included in the multi-physics object-oriented simulation environment (MOOSE)platform,and corrosion calculations were carried out using the Seal module developed based on the MOOSE.The coupling framework involves two types of coupling parameter transfer relationships1) The oxidation corrosion field obtains coolant temperature and flow velocity from the thermalhydraulic field to compute the oxide layer thickness and transfers the oxide layer thickness to the thermal-hydraulic field to calculate the convective heat transfer coefficient;2) The neutron physics field receives temperature distribution from the thermal-hydraulic field to compute k_(eff),neutron flux distribution and power distribution,and transfers the power distribution to the ther

关 键 词：核-热-材耦合 氧化腐蚀 铅铋堆 燃料组件 面向对象的多物理场仿真环境 

分 类 号：TL99[核科学技术—核技术及应用]