Just three years after its founding, Antares Nuclear has raised a hefty $470 million to develop microreactors that could replace diesel generators in powering US military bases. These miniature nuclear plants aim to deliver a reliable energy source in remote, hard-to-reach locations where fuel supply lines are often vulnerable.
Swift progress from startup to reactor criticality
Started in 2023 by Jordan Bramble and Julia DeWahl, Antares made headlines when its R1 microreactor achieved criticality on June 4, 2026. This milestone took place at Idaho National Laboratory as part of the Department of Energy’s Reactor Pilot Program. Antares became the first private company to hit this benchmark under the DOE initiative, a significant leap forward for advanced nuclear tech.
Before this recent funding round, the company had already raised over $130 million. A $96 million Series B round in late 2025 brought in $71 million in equity, led by Shine Capital, alongside $25 million in debt financing. Earlier, a Series A round in 2024 gathered $30 million, setting the stage for its rapid development pace.
Meeting Pentagon needs with long-life microreactors
The R1 is designed to produce between 100 kWe and 1 MWe enough to power isolated military outposts without the logistical headaches of diesel fuel. It offers continuous operation for more than six years without refueling, a critical advantage in defense applications.
Antares has already forged ties with the US Department of Defense, Department of Energy, NASA, and key military branches such as the Air Force and Space Force. The Department of Defense awarded the startup $3.75 million in September 2024 to support development efforts. Their vertically integrated California facility aims to roll out ten units annually once production scales.
Racing to deploy microreactors amid growing competition
Antares plans to start power generation by 2027, with initial military deployments slated for 2028. This timeline positions it among the first advanced reactor companies to reach operational status. With the Pentagon shifting focus to resilient, low-footprint energy solutions, Antares could shape the future of military power infrastructure.
The move towards compact nuclear power echoes broader shifts in energy innovation, including Bloom Energy’s recent developments and ongoing efforts to support critical infrastructure with cleaner alternatives.
This material is for informational purposes only and does not constitute financial advice.
