Detailed thermal modelling of the ALLEGRO ceramic assembly

Gas-Cooled Fast reactor (GFR) is one of the favourable Generation IV type concepts under development. ALLEGRO reactor will be a demonstrator reactor of this gas-cooled fast reactor technology. Compared to conventional gas-cooled reactors in the case of a GFR reactor the power density is one order of magnitude higher, and the high temperature fuel assemblies are cooled by a low-density coolant (He), therefore special attention is paid to the heat transfer and heat removal performance of the reactor.