Steam Turbine vs. Gas Turbine Efficiency

A new nuclear reactor being built in China will be the first commercial nuclear plant in the world to operate at high enough temperatures to use the Brayton gas turbine cycle--a more efficient cycle as noted in the graphic above. It is more efficient because it runs at a higher temperature (basic thermodynamics). High Temperature Reactors (HTRs) can utilise gas turbines that are driven by inert helium gas that has been heated in a nuclear reactor to extreme temperatures. The Chinese reactor will initially use steam turbines, then later switch over to gas turbines.

A steam cycle could then be "tacked on" to the end of the gas turbine cycle to improve overall efficiencies even more.

The HTR being built in China is a type of modular helium reactor (MHR), and as different aspects of the design are proven and standardised, it should be much faster to build in the future.

More information at NextBigFuture