Preliminary thermomechanical analysis of the ALFRED fuel element

As a prosecution of the activities on the advancement and refinement of the ALFRED (Advanced Lead-cooled Fast Reactor European Demonstrator) core design, a new line of activities was launched to tackle the thermomechanical aspects of the design. Being a long-term plan, for the first year the activities are focused on the vibrational analysis of the ALFRED fuel pin, with the final aim of developing a sound approach for driving the design and positioning of spacer grids along the bundle of fuel pins so as to prevent detrimental effects possibly due to flow-induced vibrations. The present report describes the dynamic characterization of a single fuel pin and its behavior when immersed in a fluid. A group of seven pins immersed in lead is also studied to highlight the mutual influence when they are submitted to a dynamic load.