Evaluation of Fluid Effects on the Seismic Response of a Fast Reactor Core

The results of dynamic experiments on shaking tables, carried out in water (simulating sodium) on both single and coupled core element prototypes and core simplified mock-up configurations of the Italian PEC fast reactor test facility, with excitation gradually increasing up to above Safe Shutdown Earthquake, have been analysed by use of the one-dimensional computer program CORALIE and the two-dimensional program CLASH. The study confirmed the conservative nature of the PEC core design calculations, provided the natural frequency and damping values to be used in the calculations for the Final Safety Report, and allowed the fluid-structure interaction model to be assessed for the PEC core seismic analysis. It also contributed to the validation of the above-mentioned computer codes for their general use for the fast reactor core analysis as well as to a better understanding of fluid-structure interaction problems concerning the fast reactor core.