Experimental study of fluid structure interaction on fuel assemblies on the ICARE experimental facility

International audienceAccurate knowledge of the mechanical behaviour of the reactor core is needed to estimate the e↵ects of a seismic excitation on a nuclear power plant. Experimental works are needed in order to validate models and to have a better understanding of involved phenomena. The fuel assemblies, in the reactor core, are subjected to an axial water flow which modifies their dynamical behaviour. In this framework a new experimental facility, ICARE, is designed in order to investigate fluid structure interaction phenomena on half scale fuel assemblies. The design of the ICARE experimental facility allows to emphasise the e↵ects of the coupling between di↵erent fuel assemblies due to the presence of the water flow. In this paper a brief review of previous experimental facilities is presented and the new ICARE experimental facility is illustrated. ICARE facility consists in 4 half scale fuel assemblies (2 ⇥ 2 lattice) in a vertical channel submitted to axial flow; one of the assemblies is excited by an hydraulic jack. The aim of this paper is to discuss the experimental results obtained during four experimental campaigns on the ICARE setup. First, the mechanical behaviour of a single fuel assembly is analysed, and the e↵ect of di↵erent experimental parameters is assessed. Added mass, added damping and added sti↵ness e↵ects due to the water flow are estimated. Later, the coupling between di↵erent assemblies is investigated. The presence of the flow induces hydrodynamic e↵ects on non excited fuel assemblies, both on excitation direction and transversal one. Furthermore the increase of the water flow causes the increase of the coupling forces and gives rise to a static coupling between the assemblies