The determination of added mass matrix of CAP1400 spent fuel storage racks by porous media method

Abstract

The fluid-structure interaction (FSI) effect is crucial to the seismic response of spent fuel storage racks in an earthquake. Previous studies show that the tiny gaps between rack’s cells (end-tube construction) strongly influence the rack’s added mass. However, accurate added mass for such racks requires huge computational resources. To simplify the determination of added mass, porous media is used. The porous media coefficients determined by oscillating flow are used as input for rack-wall model with an experimental benchmark. The fluid forces on rack/wall by the porous media model agree with the experiment and detail CFD model. After proving that oscillating frequency has limited influence on added mass, the added mass matrix is obtained by multiple transient simulations on whole-pool racks. The porous media method is successfully used to simplify the determination of CAP1400 racks’ added mass matrix with desirable accuracy.