Abstract The heat pipe cooled reactor is an advanced reactor design which is nearly solid-state with an array of in-core heat pipes for passive heat transfer. The local heat pipe failure probability is certainly high over the reactor lifetime. Therefore, the reactor design must include consideration of heat pipe failure accidents which needs to be explored in-depth. The Monte Carlo neutron transport code RMC was used with the general finite element analysis software ANSYS Mechanical to analyze the thermal/mechanical characteristics of a megawatt heat pipe cooled reactor for both normal and heat pipe failure conditions. The simulations were verified against a previous study with the predicted temperature distributions being consistent with each other with an absolute error of less than 3 K. Further analyses show that a 2-D model simulation can also well represent the 3-D model for heat pipe failure accident analyses. Sterbentz et al. (2017) simplified the heat pipe model with a constant temperature boundary condition along the evaporator wall of 950.15 K regardless of the heat load or heat pipe operating temperature. Therefore, a heat pipe subroutine was added to the codes to predict the heat pipe temperatures during a heat pipe failure accident. The results show that the heat pipe failure will cause larger temperature rises and stress concentrations. The heat pipe wall temperatures in the core differ from each other with the differences between the heat pipe loads during normal heat pipe operation and with failures reflecting the local effect of the heat pipe failures. The operating conditions far from the failure area are little affected (

中文翻译：

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兆瓦级热管冷堆热管失效事故分析

摘要 热管冷却反应堆是一种先进的反应堆设计，它几乎是固态的，具有一系列用于被动传热的堆芯热管。在整个反应堆寿命期间，局部热管故障的概率肯定很高。因此，反应堆设计必须考虑热管失效事故，需要深入探讨。Monte Carlo 中子输运代码 RMC 与通用有限元分析软件 ANSYS Mechanical 一起用于分析兆瓦级热管冷却反应堆在正常和热管故障条件下的热/机械特性。模拟已根据先前的研究进行了验证，预测的温度分布彼此一致，绝对误差小于 3 K。进一步的分析表明，2-D 模型模拟也可以很好地代表热管故障事故分析的 3-D 模型。斯特本茨等人。(2017) 简化了热管模型，沿蒸发器壁采用恒定温度边界条件 950.15 K，而不管热负载或热管工作温度如何。因此，在代码中添加了一个热管子程序，以预测热管故障事故期间的热管温度。结果表明，热管失效会引起较大的温升和应力集中。核心区的热管壁温因热管正常运行时热管载荷的差异而不同，而故障则反映了热管故障的局部影响。