碳化硅复合材料包壳燃料棒在LOCA事故中的特性研究

Study on LOCA accident of fuel rod with SiCf/SiC cladding

碳化硅复合材料具有热膨胀系数低、中子吸收截面低、抵抗热冲击、高温下耐腐蚀、强度高等特点,是反应堆耐事故燃料的候选材料之一。为分析碳化硅复合材料包壳燃料棒在失水事故下的综合性能,利用公开文献实验数据,拟合碳化硅复合材料物性公式,用FRAPTRAN对比分析与Zr4包壳燃料棒在同种工况下的性能差异。本文整理的公式和使用的方法可初步用于分析碳化硅复合材料燃料棒的综合性能。计算结果表明:在失水事故中,碳化硅复合材料的燃料棒失效时间长,平均温度低,可有效延缓事故进程。

[Background] With low thermal conductivity, low neutron absorption cross section, good corrosion resistance and maintenance of strength in high temperature, silicon carbide (SiC) continuous fiber-reinforced SiC?matrix composites (SiCf/SiC) is one of the candidate materials of accident tolerant fuel (ATF).[Purpose] This study aims at the comprehensive performance of fuel rod with SiCf/SiC cladding under loss of coolant accident (LOCA) condition.[Methods] The material properties of SiCf/SiC were fitted based on open access experimental data. By using FRATRAN, the performance differences between SiCf/SiC cladding and Zr4 cladding under the same condition was achieved.[Results] These material formulas and methods could be preliminary used in the work of SiCf/SiC fuel rod performance analysis.[Conclusion] The analysis shows that the rupture time of SiCf/SiC cladding fuel rod is longer and the average temperature is lower, which could effectively delay the occurrence of accidents.