The traditional role of nuclear power has been the production of base-load electricity. However, the needs of the electricity grid are changing because of (a) the introduction of significant electricity generation by nondispatchable wind and solar and (b) increasing restrictions on using fossil fuels because of concerns about climate change. To meet these changing requirements, a fluoride-salt–cooled high-temperature reactor (FHR) with a nuclear air-Brayton combined-cycle power system is proposed. This technology (a) can be the enabling technology for a low-carbon nuclear-renewables electrical grid and (b) can substantially improve nuclear power plant economics by increasing plant revenue by 50% or more relative to a base-load nuclear power plant. This is because the plant can be operated at full power to produce base-load electricity, stabilize the grid, produce process heat to reduce sales of low-priced electricity, and produce peak electricity with auxiliary natural gas or hydrogen. The market basis for this reactor is described with implications on the design requirements for an FHR.