Materials and design of the European DEMO blankets

The Helium Cooled Lithium Lead (HCLL) and the Helium Cooled Pebble Bed (HCPB) Blanket are the reference concepts in the European Breeding Blanket Programme for the DEMO design and for the related long term R&D. Recently, a similar design for both concepts has been developed, in particular both concepts use helium coolant and RAFM steel EUROFER as structural material. In this paper the interactions between the selected materials and the proposed DEMO designs are discussed. In particular the design features related to the tritium production, power extraction, material compatibility and fabrication processes are addressed. All these features contribute to the definition of DEMO concepts which are attractive for a future fusion power plant in terms of safety, availability and economics.