Abstract Stability analyses of nuclear-coupled thermal hydraulics are carried out for SUPERSTAR – a natural circulation heavy metal (lead-cooled) fast reactor. Attributed to its natural circulation characteristic, flow stability as well as nuclear-coupled thermal hydraulics stability are of some concern. Modal expansion method as an extension for point reactor kinetics is used for neutronics and reduced order model for thermal hydraulic part. These two separate models are coupled through feedback effects. Different scenarios initiated by reactivity and thermal hydraulics conditions are simulated using the coupled models in time domain. It is shown that SUPERSTAR design has considerable stability margin at the nominal operating point. Design becomes less stable as transit time between core exit and core inlet is increased.

中文翻译：

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自然循环铅冷快堆核耦合热工水力稳定性分析

摘要 对自然循环重金属（铅冷）快堆 SUPERSTAR 进行了核耦合热工水力稳定性分析。由于其自然循环特性，流动稳定性以及核耦合热工水力稳定性受到一些关注。模态膨胀法作为点反应器动力学的扩展用于中子学和热工液压部分的降阶模型。这两个独立的模型通过反馈效应耦合。使用时域中的耦合模型模拟由反应性和热力水力条件引发的不同场景。结果表明，SUPERSTAR 设计在标称工作点具有相当大的稳定性裕度。随着岩心出口和岩心入口之间的通过时间增加，设计变得不太稳定。