US utilities operate about 98 gigawatts of nuclear capacity today, but very little has been built in recent decades because of high capital costs and long licensing timelines, according to the Energy Information Administration. A new generation of smaller designs aims to change that. Conventional large reactors range from roughly 550 to 1,500 megawatts per unit, while small modular reactors are about 300 megawatts or less, and microreactors generally produce 20 megawatts or less.

Many of the new designs rely on high-assay low-enriched uranium, enriched between 5 percent and under 20 percent, compared with the below 5 percent fuel used in today operating reactors. The higher enrichment can allow smaller footprints and improved efficiency.

Federal support has expanded across multiple agencies. The Department of Energy reissued a $900 million funding tender for small modular reactors in March 2025 and launched an Energy Reactor Pilot Program in June 2025, selecting nine vendors including Oklo, Aalo Atomics, Terrestrial Energy, and Radiant Industries. The Army Janus Program, announced in October 2025, named nine candidate installations for microreactors, among them Fort Benning, Fort Bragg, Fort Campbell, and Redstone Arsenal. The Air Force is planning its first microreactor at Eielson Air Force Base in Alaska with Oklo, targeting 1 to 5 megawatts by 2027.

The data shows a sector shifting from large, costly single units toward a broader portfolio of smaller, factory-built designs backed by federal and military demand.

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