A KrF Laser Driven Inertial Fusion Reactor “SOMBRERO”

The SOMBRERO inertial fusion reactor conceptual design study is of a 1000 MWe KrF laser driven near symmetric illumination system which utilizes a Li₂O solid breeder moving bed in a blanket made entirely of low activation carbon/carbon composite material. The Li₂O particles flow through the various parts of the blanket under gravity, then are transported through an intermediate heat exchanger and around the loop in a fluidized state by helium gas at 0.2 MPa. Liquid lead is used in the intermediate loop, going to a steam generator and a double reheat steam power cycle. There are 60 beams in the near symmetric illumination configuration. The laser energy is 3.4 MJ, the target gain 118 and the rep-rate 6.7 Hz. At the mid-plane, the blanket thickness is 1 m giving a tritium breeding ratio of 1.25 and an overall energy multiplication of 1.08. The first wall is at 6.5 m radius and is protected from x-rays and ions by 0.5 torr of Xe gas. Grazing incidence metallic mirrors are located at a distance of 30 m and dielectric final focusing mirrors at 50 m from the target Source neutrons are directed into neutron traps located in line with the grazing incidence mirrors. The final focusing mirrors which are out of line of sight of source neutron are subjected to low energy scattered neutrons only and can survive the 30 full power year reactor lifetime. The Li₂O particles enter the chamber at 550°C and exit at an average temperature of 740°C, giving a power cycle efficiency of 47%. The gross power output is 1360 MW and for a 7% laser efficiency, the driver power is 325 MWe, with the remaining 35 MWe used for auxiliary equipment. The chamber and shield qualify for near surface burial as Class A waste while the Li₂O breeder, as Class C waste.