The recirculation system of a BWR-5 has 20 jet pumps. They are submerged in water in the cylindrical annular zone of the reactor. Their main function is the development of a forcing flow through the nuclear core. It increases the power of the reactor compared with the one obtained by natural circulation. These components have an important safety function in the operation of the reactor. In accordance with document BWRVIP-41 R4, it was concluded that the vibration induced by cross flow over the jet pump assemblies is one of the degradation mechanisms of such pumps. In this paper, the vibration induced by the cross flow at a jet pump assembly BWR-5 was analyzed. A numerical approach was developed. The natural frequencies were obtained, considering the Fluid-Structure Interaction (FSI). The first natural frequency was 25.7 Hz. A Computational Fluid Dynamics (CFD) analysis was carried, in conjunction with the Power Spectral Density (PSD). A frequency of vortex generation of 0.48 Hz was obtained. A vortex generation analysis was carried out with the Q-criteria. The results showed that resonance conditions are unlikely. Therefore, the structural integrity of the jet pump assemblies is maintained.

中文翻译：

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BWR-5反应堆射流泵的错流分析

BWR-5的再循环系统有20个喷射泵。它们浸没在反应器的圆柱形环形区内的水中。它们的主要功能是强迫流过核芯。与通过自然循环获得的反应器相比，它增加了反应器的功率。这些组件在反应堆的运行中具有重要的安全功能。根据文件BWRVIP-41 R4，得出结论，由喷射泵组件上的横流引起的振动是这种泵的退化机理之一。在本文中，分析了由射流泵组件BWR-5的横流引起的振动。开发了一种数值方法。考虑了流体-结构相互作用（FSI），获得了固有频率。第一个固有频率为25.7 Hz。结合功率谱密度（PSD）进行了计算流体动力学（CFD）分析。获得的涡旋产生频率为0.48Hz。用Q标准进行涡旋产生分析。结果表明共振条件是不可能的。因此，维持了喷射泵组件的结构完整性。