Revision of the DEMO core configuration and of its dynamic behaviour

The preliminary core design of DEMO, the Italian proposal for an industriai demonstrator of Lead Fast Reactor, is here discusses and reviewed. The idea of conceiving DEMO so as to be included in the LFR technology chain allows to focus on demonstration goals, abandoning therefore the goal of maximization of the neutron flux which drove the previous design. The simplification of the design objectives allows the possibility of targeting a system responding to the so called "walk-away reactor" concept: a system able to respond autonomously and effectively to every possible accidental condition, guaranteeing the integrity of the containment without any human intervention from the outside. The palatability of such a possibility is even more evident after the well-known Fukushima events.