A D-T tokamak fusion reactor with advanced blanket using compact fusion advanced Rankine (CFAR) cycle

Abstract

Recent progress of a D-T tokamak fusion reactor with advanced blanket concept using CFAR (Compact Fusion Advanced Rankine) cycle is presented. High enthalpy extraction in excess of 50% was found achievable by a nonequilibrium disk-type MHD generator for gas stagnation temperatures of 3000 K superheated by synchrotron radiation, leading to a 40% overall plant efficiency with recuperative heat cycle and advanced thermoelectric converters. The stored magnetic energy of a 10 T MHD three-pairs Helmholtz-type magnet was estimated to be about 600 MJ per MHD generator. A mixture of mercury and lithium liquid flow was examined and found applicable to reduce the mercury inventory. The tritium permeation loss inherent in the relatively high temperature CFAR cycle, neutronics relating to tritium breeding and streaming through the waveguide and the MHD generator duct are discussed. Results of a 2000 h high temperature (600–700°C) mercury corrosion test of Type 304 stainless steel, a TZM alloy and four kinds of ceramic rods in refluxing mercury with 0.004 mol fraction of potassium admixture have shown no noticeable corrosion except for Type 304 stainless steel.