摘要
为了明确SiC层中可能出现残余气孔对三向同性燃料(TRISO)颗粒堆内性能影响,确定残余气孔的临界尺寸,本文采用多物理场耦合COMSOL软件对含有残余气孔的TRISO颗粒的堆内行为进行数值模拟,以分析TRISO颗粒裂变气体、CO释放量及内压和残余气孔尺寸对TRISO颗粒包覆层应力分布的影响。分析结果表明,在辐照后期,TRISO颗粒的CO释放比例远高于裂变气体原子,颗粒内压可达49.5 MPa。残余气孔的存在使得碳化硅(SiC)层、内致密热解碳(IPyC)层和外致密热解碳(OPyC)层应力迅速增大,尤其是SiC层,当残余气孔尺寸达到9μm时,SiC层最大应力达600 MPa,远高于其本征强度;当残余气孔尺寸为5μm时,SiC层的最大应力约为450 MPa,与其本征强度相当。因此,在制备过程中为保证SiC层的结构完整性,SiC层的残余气孔尺寸应小于5μm。
In order to investigate the influence of residual pores that may appear in SiC layer on the in-pile performance of TRistructural ISOtropic(TRISO)particle,and find the critical size of residual pores,in this paper,the in-pile performance of TRISO particle with residual pores was numerically simulated by using the multi-physical field coupling COMSOL software,and the effects of fission gas,CO release,internal pressure and residual pore size on the stress distribution of TRISO particle coating were analyzed.The results show that in the later stage of irradiation,the ratio of CO release is much higher than that of fission gas atoms,and the internal pressure of the particle can reach 49.5 MPa in the later stage.The existence of residual pores makes the stress of silicon carbide(SiC),inner dense pyrolytic carbon layer(IPyC)and outer dense pyrolytic carbon layer(OPyC)increase rapidly,especially in the SiC layer.When the size of residual pore reaches 9μm,the maximum stress of SiC layer reaches 600 MPa,which is much higher than its intrinsic strength.When the residual pore size is 5μm,the maximum stress of SiC layer is about 450 MPa,which is equivalent to its intrinsic strength.Therefore,in order to ensure the structural integrity of SiC layer in the preparation process,the residual pore size of SiC layer should be less than 5μm.
作者
赵艳丽
刘仕超
李垣明
唐昌兵
路怀玉
Zhao Yanli;Liu Shichao;Li Yuanming;Tang Changbing;Lu Huaiyu(Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu,610213,China)
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2023年第6期155-161,共7页
Nuclear Power Engineering
基金
国家自然科学基金(12005213)
四川省自然科学基金(2022NSFSC1199)。
