金属基弥散微封装燃料中TRISO燃料颗粒的尺寸优化设计

弥散微封装燃料是将包覆燃料颗粒弥散在基体中形成燃料芯块或者燃料棒，是目前耐事故燃料（ATF）中最具发展潜力的燃料之一。包覆燃料颗粒为三结构同向型（TRISO）或者两结构同向型（BISO）包覆燃料颗粒，基体可以是金属也可以是陶瓷。本文用有限元分析软件ABAQUS对金属基弥散微封装燃料进行了分析计算。通过分析TRISO燃料颗粒各包覆层厚度对燃料性能的影响，提出优化改进的建议。研究结果表明，疏松热解碳层（Buffer）厚度越大，燃料颗粒发生破损失效的燃耗越高，因此设计时应考虑增加其厚度；内部致密热解碳层（IPyC）厚度越大，其自身的最大环向拉应力越大，因此设计时应降低其厚度；碳化硅（SiC）层厚度越大，其自身环向压应力越小，因此设计时应降低其厚度。本文的研究结果可为金属基弥散微封装燃料的优化设计提供指导。 

Dimension Optimization Design of TRISO Fuel Particle in Metal Matrix Microencapsulated Fuels

Microencapsulated fuel is the fuel pellet or fuel rod which formed by coated fuel particles?dispersed in the matrix, and it is one of the most potential accident tolerant fuel(ATF)?fuel. Coated fuel particles?can be tristructural isotropic(TRISO)?or bistructura isotropic(BISO), and the matrix is metal or ceramics. Based on the ABAQUS software, the metal matrix microencapsulated fuel is calculated. By analyzing the effect?of the coating thickness on the fuel performance, suggestions for the optimization are given. The results showed that the thicker the?Buffer?is, the higher the burnup for the?failure?is, and thus, the increasing of the Buffer thickness should be considered in the design. The thicker the IPyC layer is, the larger the maximum hoop stress is, and thus, its thickness?should be reduced in the design. The thicker the SiC layer is, the smaller the hoop stress is, and thus, its thickness should be reduced in the design. The results of this study could provide a guidance for the optimization design of the metal matrix microencapsulated fuels.