FCM燃料堆内行为模拟及结构设计研究  

In-pile Performance Simulation and Structure Design of Fully Ceramics Microencapsulated Fuel

作　　者：周毅[1] 刘仕超 陈平[1] 李垣明[1] 辛勇[1] 刘振海[1] 张林[1] 谷明非[1] 赵艳丽 乐韵琳 Zhou Yi;Liu Shichao;Chen Ping;Li Yuanming;Xin Yong;Liu Zhenhai;Zhang Lin;Gu Mingfei;Zhao Yanli;Le Yunlin(Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu,610213,China;School of Nuclear Science and Technology,University of South China,Hengyang,Hunan,421001,China)

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术重点实验室,成都610213 [2]南华大学核科学技术学院,湖南衡阳421001

出　　处：《核动力工程》2020年第5期197-200,共4页Nuclear Power Engineering

摘　　要：本文采用二维特征模型模拟不同无燃料区厚度全陶瓷微封装弥散(FCM)燃料的热力学行为,在保证堆芯装载要求的条件下,研究不同结构FCM燃料SiC基体和包覆燃料颗粒SiC层的应力状态。通过优化无燃料区厚度,调整TRISO颗粒间的间距,保证无燃料区和SiC层同时具有较低的应力水平。分析了无燃料区厚度为100~500μm时基体SiC、无燃料区以及SiC层的应力分布,结果表明,基体SiC和SiC层最大应力随无燃料区厚度增大而增大,而无燃料区的最大应力则随其厚度增大而降低。当无燃料区厚度为400μm时,无燃料区和SiC层均处于较低的应力状态,无燃料区SiC基体应力约为400 MPa,而SiC层的最大环向应力约为200 MPa,其失效概率约为2.5×10^-4。因此,当无燃料区厚度为400μm时,FCM燃料既能维持芯块结构完整,又能保证SiC层具有较低的失效概率。结构优化为FCM燃料的应用提供了基础。The thermal mechanical performance of the fully ceramics microencapsulated fuel(FCM)with different non-fuel part size was simulated using two-dimensional characteristic unit.When the fissile loading meet the requirements of the reactor core,the stress condition of SiC matrix and SiC layers were investigated for FCM pellets with different structures.Non-fuel parts and SiC layers suffered relative lower stress by optimizing FCM pellet structure and adjusting distance between different TRISO particles.The stress distribution of matrix,non-fuel part and SiC layer was discussed for the FCM pellets with non-fuel part size from 100μm to 500μm.The results indicate that,the maximum hoop stress of the matrix and SiC layer increased with the increasing of non-fuel part size,while the non-fuel parts exhibited crosscurrent.Non-fuel parts and SiC layer possessed lower stress when the non-fuel part was 400μm.The stress of non-fuel part was about 400 MPa,and the maximum hoop stress of the SiC layers were about 200 MPa.The failure probability was 2.5×10^-4.The structure integrity was maintained for the pellets with 400μm non-fuel part,at the same time the failure probability SiC layer was low.Structural optimization is the basis for the application of FCM pellet.

关 键 词：FCM燃料 热力学行为 结构优化 失效概率 

分 类 号：TL352[核科学技术—核技术及应用]