Conceptual design of a 5000 MW(th) D-T Tokamak reactor

The results of self-consistent design effort on a large Tokamak fusion reactor are presented. The reactor, fuelled with a deuterium-tritium mixture, operates at 5000 MW(th) and uses 3l6 stainless steel as a structural material. A compatibility problem between the liquid lithium coolant and the steel limits the operating temperature to 500degC and the electrical output to 1500 MW(e). The ion temperature of the 5-m radius plasma is 11.1 keV and the mean confinement time and fractional burn-up are 14.2 seconds and 7.2% respectively. A double-null poloidal divertor is used to protect the plasma from impurities. Cryogenically stabilized niobium-titanium superconducting magnets are used to provide a 3.82 tesla field on the plasma axis. Neutron and photon transport calculations indicate that the breeding ratio in UWMAK-I is 1.49 and doubling times may be as low as 2-3 months. The tritium leakage is 10.1 Ci/d. The total energy per fusion neutron, including the 3.52-MeV α particle, is calculated to be 20.08 MeV. Radiation embrittlement of the stainless steel limits the first-wall lifetime to two years while swelling and/or surface erosion limits the wall life to about five years. Radioactivity and afterheat calculations reveal that after ten years of operation there will be 1.6 x 109 Ci of activity and 31 MW(th) of afterheat. (author)