Hydraulic coupling of fuel assemblies under axial flow, confinement effect

Nuclear industry needs tools to design reactor cores in case of earthquake. Simulation using a fluid-structure model of the core subjected to a seismic excitation is used to make a parametric study in order to observe the effect of confinement on the coupling between fuel assemblies. The modelling used to make the parametric study showed good agreement with experimental results. Simulations showed that the added stiffness should be negligible in a real core configuration, and that damping identified on one fuel assembly gives underestimated values.