LAUSR

Abstract The seismic study of the spent fuel storage rack (SFSR) is of great significance for ensuring the safety of spent fuel. But it is a challenging topic for the complex nonlinear behaviors such as fluid–structure interaction (FSI), friction and impact. At present, owing to the lack of the understanding of these nonlinear behaviors, in engineering design process, the seismic analysis of SFSRs is usually conducted with a conservative method. To reduce the excessive margin in the seismic design of CAP1400 (a new reactor type developed by China) rack, we have performed a 1/10 scale shaking table experimental study in the previous work. As an extension of the previous study, a series of 3/10 reduced-scale seismic experiments considering the effect of FSI were carried out to study the scale effects in this paper. The experiments obtained friction coefficient between the rack and the tank (spent fuel pool model), the maximum sliding displacement of the rack and the fluid pressure distribution of the tank wall. Furthermore, the seismic responses of the rack under different experimental variables such as the number of racks, experimental scales and vertical excitation were derived. The results showed that the relative uncertainty of the sliding displacement response is very large. Moreover, the large sliding displacement differences between single-rack case and double-rack case indicated that fluid–structure interaction has a strong influence on sliding of rack. We adopted a generally used similarity criterion for seismic experiment of rack, and the experimental results showed the scaling analysis of fluid pressure satisfies the similarity relationship, however, the displacement results were influenced greatly by scale effect. These results can be the benchmarks for the seismic analysis of CAP1400 spent fuel storage rack under dynamic seismic loading.