Experimental investigations on flow-induced vibration characteristics of fuel rod with an independent channel for small lead-based reactor

Abstract

ABSTRACT The technology of nuclear reactors is evolving rapidly, driven by the pursuit of more powerful and efficient systems. The Small Lead-based Reactor (SLR) represents an advanced nuclear reactor design that holds great promise for delivering enhanced power and efficiency. In the context of the SLR’s fuel rod, the high-speed coolant flow within the reactor can induce vibration, potentially causing fretting wear and damage to the cladding. This study utilized the Burgreen correlation to establish an equivalence relationship between water and Lead-Bismuth Eutectic (LBE). An experiment was then conducted to simulate axial flow-induced vibration (FIV) of a simply supported fuel rod, employing an equivalent water loop. Flow-induced vibration characteristics in both the time and frequency domains were investigated at different flow speeds. The experimental results revealed a positive correlation between flow velocity and amplitude. The fuel rod exhibited low-frequency vibrations with a random pattern, registering frequencies around 14 Hz. These experimental findings can be leveraged to enhance the accuracy of numerical simulations for axial flow-induced vibration (FIV) of the fuel rod. Subsequently, the revised numerical model was applied to simulate FIV in the LBE environment using computational fluid dynamics (CFD), and the numerical results were found to be in agreement with the experimental data.