Spent fuel pools are used as temporary storage for spent fuel assemblies in nuclear power plants and are filled with coolant which removes the decaying heat from spent fuel assemblies. Sloshing of the coolant can occur if an earthquake occurs in the area. It may produce additional forces on the pool or inner structure and cause overflow of the coolant. It is therefore critical to investigate the phenomenon of sloshing in a seismic assessment of the spent fuel pool. The size of an actual spent fuel pool is excessive for carrying out an experimental study; thus, a scale model is necessary for experimentation. In this study, a scaling law was defined for test conditions using a scale model to understand sloshing behavior, and the results were validated via computational fluid dynamic analysis. Because sloshing is resonant in a fluid and the first mode natural frequency of a fluid is dominant in sloshing behavior, the test condition could be obtained based on the natural frequency of the fluid. In the model, which is scaled with a factor of “,” the scale factors “,” “,” “,” and “” were used for displacement, acceleration, excitation frequency, and excitation time, respectively. Approximately 5% difference in maximum sloshing height between two models was predicted in the only case that 1/8 and 1/4 models (1/8 and 1/4 scaled down from an actual spent fuel pool) were excited with 10 Hz and 7.071 Hz, respectively, but the same sloshing height and pressure were predicted in other cases. The results of this study support the idea that the Froude scaling law can be used when using a scale model for a seismic assessment of spent fuel pools to investigate sloshing behavior.

中文翻译：

---

关于晃荡行为的乏燃料池地震安全性评估的等效测试条件的研究

乏燃料池用作核电站乏燃料组件的临时存储，并充满冷却剂，以消除乏燃料组件中的衰变热量。如果该区域发生地震，冷却剂可能会晃动。它可能会在水池或内部结构上产生额外的力，并导致冷却液溢出。因此，在乏燃料池的地震评估中研究晃动现象至关重要。实际乏燃料池的规模太大，无法进行实验研究；因此，比例模型对于实验是必要的。在这项研究中，使用比例模型定义了测试条件的比例定律，以了解晃荡行为，并通过计算流体动力学分析验证了结果。因为晃动在流体中共振，并且流体的第一模式固有频率在晃动行为中占主导地位，所以可以基于流体的固有频率来获得测试条件。在模型中，其缩放比例为“， “比例因子” ， “ ” ， “” ， “” ， “”和“ ”分别用于位移，加速度，激励频率和激励时间。仅在以10 Hz和7.071激励1/8和1/4模型（从实际的乏燃料池中按比例缩小的1/8和1/4）的情况下，两个模型之间的最大晃动高度大约有5％的差异被预测Hz，但在其他情况下预测的晃动高度和压力相同。这项研究的结果支持以下想法：在将比例模型用于乏燃料池的地震评估以调查晃荡行为时，可以使用弗洛德比例定律。