Antares fetches $470M to move on military base reactor push

Antares, a nuclear power startup that designs small modular reactors, has completed a $470 million Series C capital raise to move ahead on efforts to build those systems for U.S. military bases.

For Antares, this new financing round announced Tuesday comes a mere seven months after the three-year-old company closed a $96 million Series B raise ahead of a key demonstration for the Idaho National Laboratory.

Paradigm and Caffeinated Capital led the Series C round with participation from Industrias Ventures, Point72 Ventures and Shine Capital.

Nuclear power is of keen interest to government agencies and commercial enterprises, as well as investors, amid rising electricity demand from data center operators and others that run artificial intelligence workloads.

Antares’ Mark-0 reactor achieved criticality on June 4 at INL in what the company touts as the first time in four decades that a privately-developed, non-light-water reactor achieved such a designation.

Antares is also one of three finalists in a Defense Department initiative for testing small modular reactors at Air Force bases in Colorado and Montana.

Radiant Industries and Westinghouse are competing with Antares for selection under the Advanced Nuclear Power for Installation program. The winner will work with the Air Force to have advanced nuclear reactor operating on at least one of the service branch’s installation by 2030 or sooner.

"On June 4th, we won the race to criticality, and now we’ve shifted to the race to commercialization," Jordan Bramble, CEO and co-founder of Antares, said in a release. "The military has been a partner to us every step of the way. We’ve secured firm contracts to build reactors.”

Antares describes its government customer network as including the Air Force, Space Force, Defense Innovation Unit and NASA.

“Our deep customer relationships and committed orderbook allow us to focus our engineering roadmap on one simple thing from here on out - reactors that operate reliably and safely for 6+ years deployed to military installations as soon as 2028,” Bramble added.

The $470 million Series C figure breaks out to $370 million in equity and $100 million in debt, which Antares will use to accelerate its path from demonstrating its reactor to fielding by 2028.

Sept. 30, 2028 also represents a deadline set forth by President Trump’s Executive Order 14299 for DOD to begin operating a reactor at a domestic military installation.

Antares is eyeing 2027 as the year for the Mark-1 reactor to begin producing electricity.