The US Energy Information Administration has compiled a detailed inventory of small modular reactor and microreactor designs under development in the United States as of February 2026, mapping a pipeline of new nuclear technology against the roughly 98 gigawatts of conventional nuclear capacity utilities operate today.

Where a large-scale nuclear unit typically ranges between 550 and 1,500 megawatts, SMR designs come in at about 300 megawatts per unit or less, with factory-assembled modular components intended to shorten construction timelines. Microreactors, a subset of SMRs, generally have a capacity of 20 megawatts or less and can run connected to the grid, independently, or as part of a microgrid, making them candidates for data centers, industrial sites, and remote communities with high transmission costs.

The EIA review groups the designs into four technology families: light water-cooled reactors, which are smaller versions of today's pressurized water reactors; high-temperature gas reactors that use helium coolant and can supply industrial process heat; molten salt reactors, in which salts serve as fuel, coolant, or both; and sodium-cooled fast reactors that operate at higher temperatures and lower pressures.

Many of the designs rely on high-assay low-enriched uranium, fuel enriched between 5 and 20 percent uranium-235. That is above the sub-5-percent enrichment used in today's reactors, and the higher burnup can improve efficiency, shrink reactor footprints, and reduce spent fuel volumes.

Source: U.S. Energy Information Administration -- https://www.eia.gov/todayinenergy/detail.php?id=67584