Flow Channel Inserts Based on Syntactic Closed-Cell SiC Foam for Dual-Coolant ITER Test Blanket Modules

The International Thermonuclear Experimental Reactor (ITER) design requires the development of advanced materials for flow channel inserts, in order to permit the high tritium breeder exit temperature of ~700°C needed to increase overall plant efficiency. The primary requirements for the flow channel insert are low thermal and electrical conductivity, resistance to thermally induced stress, and impermeability to and non-reactivity with the Pb-Li alloy. This project will develop a low-density, high-strength, closed-cell silicon carbide (SiC) foam that meets the requirements for flow channel inserts. The new material will be far more manufacturable in both simple and complex geometries, exhibit higher thermal stress resistance, and cost less than SiC/SiC composites. In Phase I, thermomechanical durability and heat transfer characteristics will be evaluated through design and modeling, and preliminary characterization of behavior under high thermal gradient conditions will be performed via exposure to hot gases. Commercial Applications and other Benefits as described by the awardee: The practical application of fusion for efficient electric energy generation requires the development of materials and structures that can withstand the demanding fusion reactor environment. The proposed flow channel insert would be a key component within reactors that ultimately will be used for large-scale commercial energy generation.