Nuclear power startup Antares announced Monday that it has raised $470 million in a Series C funding round to develop small modular reactors (SMRs) for deployment at U.S. military bases.
Led by Paradigm and Caffeinated Capital, with participation from Industrious Ventures, Point72 Ventures, and Shine Capital, the round comprises $370 million in equity and $100 million in debt. The investment reflects surging investor interest in advanced nuclear startups, a trend driven by the rapid expansion of AI data centers and growing demand for new, reliable power sources.
Antares is developing a small modular reactor capable of generating between 100 kilowatts and 1 megawatt of electricity—enough to power up to 750 homes. Like many next-generation nuclear startups, Antares uses TRISO fuel, which encases uranium in carbon and ceramic shells. TRISO has long been promoted as a safer alternative to conventional nuclear fuel. The billiard ball-sized spheres can be cooled by gases such as helium or molten salts, and their coating is designed to prevent melting even in high-temperature reactors.
Antares’s demonstration reactor, the Mark-0, achieved criticality on June 4 at the Idaho National Laboratory, marking a key milestone. The company is one of three finalists in the Pentagon’s Advanced Nuclear Power for Installations program, which plans to test SMRs on Air Force bases in Colorado and Montana. Antares aims to bring its first electricity-producing reactor online next year, with deployments at U.S. military installations scheduled for 2028.
Investors are flocking to nuclear power, particularly fission, as electricity demand soars amid data center construction and broader economic electrification. In April 2026, X-energy raised $1 billion through an IPO. Since December 2025, Radiant Energy, Standard Nuclear, and Last Energy each announced nine-figure funding rounds. Antares closed its $96 million Series B in December 2025 as well. According to a TechCrunch analysis of PitchBook data, the company has raised $604 million to date.
Despite the enthusiasm, advanced nuclear startups face significant hurdles to commercialization. The U.S. supply chain for nuclear components remains immature, and scaling production poses major challenges. Many SMR companies tout the benefits of mass manufacturing, claiming it will drive down costs substantially. However, industry analysts note that such advantages typically take at least a decade to materialize, and no startup has yet reached that stage. The first SMRs are expected to enter service in the early 2030s but are unlikely to be cost-competitive with most new power plants. Lazard, which analyzes the levelized cost of energy, projects new SMRs will cost around $214 per megawatt-hour—more expensive than all but the most costly gas turbines.
via TechCrunch