People don't talk about it, but what killed the Light Water Reactor is the same thing that killed coal burning power plants -- the size and cost of the steam turbine.
Gas turbines revolutionized power generation in the 1970s and since because the power density is so much higher than steam turbines, greatly lowering the capital costs of a power plant. For a while coal still competed based on cheap fuel, but after fracking came along the fuel is cheap and the power plant is cheap so natural gas overtook coal quickly.
A reactor that runs at a higher temperature than an LWR can operate a Brayton cycle gas turbine using Helium, Carbon Dioxide or Nitrogen Tetroxide as a working fluid. Some possibilities are liquid metal reactors (metal coolant), liquid salt reactors (liquid fuel!), HTGR (carbide fuel) or GCFR (nitride fuel).
It is a lot of technology to perfect, but as long as a nuclear heat source is coupled to a huge expensive steam turbine, the economics are going to bad even if we learn how to build reactors right the first time.
This is also a problem for any future fusion power plants. Using the fusion power as a dumb heat source to create steam is not going to be economically competitive.
Gas turbines revolutionized power generation in the 1970s and since because the power density is so much higher than steam turbines, greatly lowering the capital costs of a power plant. For a while coal still competed based on cheap fuel, but after fracking came along the fuel is cheap and the power plant is cheap so natural gas overtook coal quickly.
A reactor that runs at a higher temperature than an LWR can operate a Brayton cycle gas turbine using Helium, Carbon Dioxide or Nitrogen Tetroxide as a working fluid. Some possibilities are liquid metal reactors (metal coolant), liquid salt reactors (liquid fuel!), HTGR (carbide fuel) or GCFR (nitride fuel).
It is a lot of technology to perfect, but as long as a nuclear heat source is coupled to a huge expensive steam turbine, the economics are going to bad even if we learn how to build reactors right the first time.