HELIUM-COOLED DIVERTORS WITH LOW ACTIVATION MATERIALS AND SIMPLE FABRICATION TECHNIQUES

HELIUM COOLING IS ATTRACTIVE FOR HIGH HEAT FLUX COMPONENTS IN TOKAMAK FUSION REACTORS BECAUSE THERE ARE LARGE SAFETY ADVANTAGES COMPARED TO WATER COOLANT. HOWEVER, CURRENT TECHNOLOGY FOR HELIUM COOLING IS HAMPERED BY THE COMPLEXITY OF THE HOUSING REQUIRED TO PROVIDE HELIUM TO THE NORMAL FLOW HEAT EXCHANGER AND BY THE USE OF MATERIALS WHICH BECOME HIGHLY RADIOACTIVE WHEN OPERATED IN THE ENVIRONMENT OF A TOKAMAK DIVERTOR. THIS PROJECT WILL DEVELOP TECHNOLOGY TO OVERCOME THESE DIFFICULTIES. INNOVATIVE AND SIMPLIFIED FABRICATION METHODS WILL BE DEVELOPED FOR THE NORMAL FLOW HEAT EXCHANGER WHICH CAN EASILY BE SCALED UP TO A FULL SIZE DIVERTOR PANEL. THESE SIMPLIFIED FABRICATION TECHNIQUES ARE MADE POSSIBLE BECAUSE THE HEAT EXCHANGER HOUSING WILL BE MADE FROM HIGH PERFORMANCE MATERIALS SUCH AS AN ORDERED INTERMETALLIC ALLOY OF TITANIUM ALUMINIDE. THE HEAT EXCHANGER WILL BE FABRICATED ENTIRELY FROM LOW ACTIVATION MATERIALS LIKE TITANIUM AND ALUMINUM, SO THAT THE STRUCTURE WILL NOT BECOME HIGHLY RADIOACTIVE IN A TOKAMAK'S NEUTRON FLUX. PHASE I IS DESIGNED TO PROVE THE FEASIBILITY OF THIS CONCEPT BY DEMONSTRATING THE KEY FABRICATION METHODS, AND ANALYZING THE BELIUM FLOW AND HEAT TARNSFER IN THE NORMAL FLOWHEAT EXCHANGER TO SHOW THAT EFFECTIVE COOLING IS POSSIBLE IN THE NEW CONFIGURATION. IN PHASE II LARGE-SCALE TEST MODELS FOR PERFORMANCE TESTING IN ELECTRON BEAM TEST FACILITIES WILL BE DESIGNED AND FABRICATED.