Binary cycles for a high temperature gas cooled reactor with helium turbine

The heat rejection of power plants to the environment can be reduced by using a binary (bottoming) power cycle which receives its energy input from the primary cycle cooler. High temperature gas cooled reactors with helium turbines are particularly favourable for binary cycle application due to their relatively high heat rejection temperatures and wide temperature range. The feasibility of such cycles was investigated for several working fluids. Their thermodynamic characteristics and estimated efficiency were compared. The results indicate that overall plant efficiencies of 49 per cent are attainable with hydrocarbons and 47 per cent with fluorocarbons (Freons) as working media. The incremental specific costs of the binary system would be substantially less than the cost of current nuclear plants.