Preliminary evaluation of seismic isolation effects in a Generation IV reactor

This paper deals with the treatment of methods for a preliminary safety assessment of next generation nuclear power plant (of Liquid Metal cooled Fast Reactor types) structures. As an example, it was considered the European Lead-cooled System (ELSY) international project response under a reference design basis earthquake (Safe Shutdown Earthquake-SSE) excitation, taking into account also the main isolating device effects in order to increase the reactor safety.This study is intended to analyze the structural effects of a reference SSE by means of an appropriate dynamic FEM code, for possible geometries of both not isolated and isolated ELSY containment building foundation cases.A great attention should be focused too on the arisen hydrodynamic forces and coupling effects between fluid and structures (sloshing phenomenon) that may impair the structures resistance and/or operating capabilities.The obtained numerical results were critically analysed with the intent also to contribute to a step of the safety optimization of the mentioned systems.