Outlook for binary power plants using liquid-metal MHD

Preliminary testing and extrapolations thereof indicate that liquid-metal MHD can be used as a topping cycle to increase the efficiency of large central-station power plants. Because maximum temperatures as low as 870° C are effective, such binary plants are possible with existing material technology. The best present choices appear to be a potassium working fluid and either a (helium-or sodium-cooled) nuclear reactor or a fossil-fueled furnace. Cost estimates for a possible plant with 1-GW output-based on the use of a coal-fired furnace operating at 870°C with a condensing type of MHD cycle-suggest that, for a capital-cost outlay approximately equal to that for a conventional coal-fired plant, 13 percent more efficiency is achieved by the plant with the topping cycle.