Antares secures $470M for small nuclear reactors bound for US military bases
Nuclear startup Antares has raised $470 million to develop small modular reactors for US military installations, driven by surging electricity demand from data centers and AI.
Antares Nuclear announced on Monday that it has raised $470 million to build small reactors for US military bases. The Series C round was led by Paradigm and Caffeinated Capital, with participation from Industrious Ventures, Point72 Ventures, and Shine Capital. It comprises $370 million in equity and $100 million in debt. The investment reflects growing interest in advanced nuclear startups, fueled by the AI data center boom and the need for new power sources.
The company is developing a small modular reactor (SMR) capable of producing between 100 kilowatts and 1 megawatt of electricity, enough to power up to 750 homes. Like many other advanced nuclear firms, Antares uses TRISO fuel, which encapsulates uranium in carbon and ceramic shells. This fuel is considered safer than traditional nuclear fuel, as the coating prevents melting in high-temperature reactors. The billiard ball-sized TRISO spheres can be cooled by gases like helium or molten salts.
Antares' demonstration reactor, the Mark-0, reached criticality on June 4 at the Idaho National Laboratory. The company is one of three finalists in the Pentagon's Advanced Nuclear Power for Installations program, which will test SMRs at Air Force bases in Colorado and Montana. Antares aims to bring its first electricity-producing reactor online next year, with deployments at US military installations planned for 2028.
Investor enthusiasm for nuclear power has been high, as electricity demand surges from data center construction and electrification. In April, X-energy raised $1 billion via an IPO, while other startups like Radiant Energy, Standard Nuclear, and Last Energy each secured nine-figure rounds since December. Antares had previously raised a $96 million Series B in December, bringing total funding to $604 million.
Despite the excitement, advanced nuclear startups face hurdles including an immature US supply chain and scaling challenges. Many SMR startups tout mass manufacturing benefits, but these typically take at least a decade to realize. The first SMRs, expected in the early 2030s, are unlikely to be cost-competitive. Lazard estimates new SMRs will cost about $214 per megawatt-hour, more than all but the most expensive gas turbines. Antares has not disclosed its pricing, but targeting the US military—a famously price-insensitive customer—makes strategic sense.
