Effect of neighboring wall on the fluid added mass of CAP1400 spent fuel storage rack

Under seismic conditions, the motion of spent fuel storage racks will be influenced greatly by fluid-structure interaction (FSI) between water, racks and walls. In the design configurations of CAP1400 (a new reactor type designed by China), known as end tube connection construction, the water between the rack storage cells can flow out of the rack, forming a perforate structure. However, the FSI effect for such structure has not been studied in depth. In engineering, the perforations are ignored, leading to an over-conservative added mass. The FSI effect of racks can be categorized into rack-wall FSI (also known as the FSI effect of neighboring wall) and rack-rack FSI. Free vibration experiments for a rack model were carried out to study the FSI effect of neighboring wall of CAP1400 rack. By dimension analysis, it is determined that KC number, oscillatory Re number, and nondimensional gap size are key factors for added mass. The experiments obtained the fluid added mass with different combinations of key parameters. An added mass expression for CAP1400 rack near a wall was obtained and the error was evaluated. The results can be utilized as a reference for the FSI input of the dynamic analysis of CAP1400 spent fuel rack.