Experimental investigation on fluid–structure-coupled dynamic characteristics of the double fuel assemblies in a fast reactor

An experiment was performed to investigate the fluid–structure-coupled dynamic characteristics of the under-water hexagonal fuel assemblies used in a fast reactor. As the dynamic characteristics, the added mass and damping caused by fluid–structure interaction (FSI) were usually treated as the constants in the previous researches. By the present experiment, it was proven that the added mass and damping were the variables strongly dependent on the fluid-filled gap between the double hexagonal fuel assemblies. These experimental data can be used as the modeling parameters for the seismic analysis of the core in a fast reactor.