Helium-cooled refractory alloys first wall and blanket evaluation

Under the APEX program the He-cooled system design task is to evaluate and recommend high power density refractory alloy first wall and blanket design s and to recommend and initiate tests to address critical issues. We comple ted the preliminary design of a helium-cooled, W-5Re alloy, lithium breeder design and the results are reported in this paper. Many areas of the desig n were assessed, including material selection, helium impurity control, and mechanical, nuclear and thermal hydraulics design, and waste disposal, tri tium and safety design. Systems study results show that at a closed cycle g as turbine (CCGT) gross thermal efficiency of 57.5%, a superconducting coil tokamak reactor, with an aspect ratio of 4, and an output power of 2 GWe, can be projected to have a cost of electricity at 54.6 mill/kW h. Critical issues were identified and we plan to continue the design on some of the cr itical issues during the next phase of the APEX design study. (C) 2000 Else vier Science B.V. All rights reserved.