气冷堆用棱柱型弥散微封装燃料性能分析及优化研究

Research on Analysis for Performance and Optimization of Prismatic Dispersed Microencapsulated Fuel in Gas-Cooled Reactor

棱柱型弥散微封装燃料是将三重各向同性包覆(TRISO)燃料颗粒弥散于金属或陶瓷基体形成的颗粒增强复合燃料,具有良好的结构稳定性、裂变产物包容能力和辐照稳定性,是高温气冷堆中较具发展前景的燃料形式之一。本文提出将TRISO燃料颗粒弥散于SiC基体的棱柱型弥散微封装燃料设计方案,并基于有限元分析软件COMSOL建立了该燃料元件三维热流固耦合分析模型,初步实现了该燃料元件性能分析和优化设计。结果表明,棱柱型弥散微封装燃料元件的温度最大值位于燃料元件外侧,应力峰值位于冷却剂通道壁面,边距比为0.76~0.84、孔距比为0.68~0.75时燃料元件热应力最小。本文建立的棱柱型弥散微封装燃料性能分析方法和研究结论,可为后续该型气冷堆燃料元件设计提供指导和参考。

Prismatic dispersed microencapsulated fuel is a particle-reinforced composite fuel which is formed by TRISO fuel particles dispersed in metal or ceramic matrix.It has good structural stability,fission product inclusion capacity and irradiation stability,and it is one of the promising fuels in high temperature gas-cooled reactor.A prismatic dispersed microencapsulated fuel with TRISO particles dispersed in SiC matric was proposed in this paper.Based on the finite element analysis software COMSOL,the 3D thermal-fluid-solid coupling analysis model of the fuel element is established,and the performance analysis and optimization design of the fuel element are preliminarily realized.The results show that the maximum temperature of the prismatic dispersed microencapsulated fuel element is located on the outside of the fuel element,the peak stress is on the wall of the coolant channel,and the thermal stress of the fuel element is the lowest when the edge-distance ratio is 0.76 to 0.84 and the hole-distance ratio is 0.68 to 0.75.The performance analysis method and research conclusions of the prismatic dispersed microencapsulated fuel established in this paper can provide guidance and reference for the subsequent design of this type of gas-cooled reactor fuel element.