Flow Channel Inserts for Dual-Coolant ITER Test Blanket Modules

79175S The International Thermonuclear Experimental Reactor (ITER) is an international effort to build the first power-producing, magnetically-confined fusion reactor within the next decade. The reactor design requires the development of advanced materials for flow channel inserts that will allow a high Pb-17Li alloy tritium breeder exit temperature of ~700¿C, which will increase overall plant efficiency. The flow channel insert must have low thermal and electrical conductivity, resistance to thermally induce stress, and impermeability and non-reactivity with the Pb-Li alloy. This project will develop a structure for these inserts, using a previously developed, low-density (90% porous), high specific stiffness open-cell silicon carbide (SiC) foam. The foam, which is inherently porous and structural, not only will allow the flow channel inserts to satisfiy the above requirements but also will be far more manufacturable in simple and complex geometries, exhibit higher thermal stress resistance, and be lower in cost than SiC/SiC composites. Phase I will fabricate a flow channel insert composed of an open-cell SiC-foam primary structure with thin, integrally bonded and impermeable SiC facesheets. Thermomechanical durability and heat transfer characteristics will be evaluated, and behavior under high thermal gradient conditions will be characterized through hot gas exposure testing. 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 requirements. The proposed flow channel insert would be a key component within reactors that will ultimately be used for large-scale commercial energy generation.