【作者】 林大超； 郝祖龙； 朱卉平； 牛风雷；

【Author】 LIN Da-chao;HAO Zu-long;Zhu Hui-ping;NIU Feng-lei;School of Nuclear Science and Engineering,North China Electric Power University;

【机构】 华北电力大学核科学与工程学院；

【摘要】 碳化硅（SiC）复合包壳设计是当前轻水堆事故容错燃料的研究方向之一。以三层和双层SiC包壳的设计方案为研究对象,对稳态工况下包壳应力分布及失效概率计算进行了研究。基于线性弹性力学理论和材料辐照肿胀特性,考虑了内外压力差、径向温度梯度以及辐照三种因素影响,经一定简化给出了适用于多层包壳结构的应力计算模型,通过解析解与数值模拟结果相比较,验证了该模型的有效性,并讨论了SiC复合包壳各层厚度比对应力分布的影响。采用改进后的Weibull分布模型对寿期末高燃耗工况下的SiC包壳失效概率进行了计算,结果表明,双层SiC包壳的失效概率在10^-610^-3,明显低于三层SiC包壳的失效概率（>0.01）,有助于SiC结构优化。更多还原

【Abstract】 The design of multi-layered silicon carbide（SiC） cladding is one of the research fields of the accident tolerant fuels（ATF） in pressurized water reactor（PWR）.This paper mainly studies the stress distribution of the three-layered SiC cladding and duplex SiC cladding under steady-state operations.Based on the theory of Linear elasticity and properties of Material irradiation swelling,The influence of internal and external pressure difference,radial temperature gradient and irradiation were considered,and swelling.The stress calculation model for multi-layer cladding structure is presented in this paper.Compared with the numerical simulation results,the validity of the model is verified and the influence of the thickness ratio on the stress distribution is discussed,the failure probability of the SiC package in the high burnable condition of the lifetime is calculated by using the improved Weibull distribution model.The results showed that the failure probability of the duplex SiC cladding was 10^-610^-3,which was significantly lower than the failure probability（> 0.01） of the three-layer SiC cladding,which could help the SiC structure optimization.更多还原