Antares Nuclear raises $470M to build tiny reactors for US military bases

A nuclear startup founded just three years ago has pulled in $470 million to build microreactors small enough to power US military bases, a bet that the Pentagon’s energy future looks less like diesel generators and more like miniature nuclear plants. Antares Nuclear, headquartered in the Torrance area of California, is developing its R1 microreactor for defense and strategic applications. The reactor generates between 100 kWe and 1 MWe, which in practical terms means enough juice to keep a remote military installation running without relying on vulnerable fuel supply chains. From founding to fission in three years Antares was founded in 2023 by Jordan Bramble and Julia DeWahl. By June 4, 2026, their reactor achieved criticality at the Idaho National Laboratory under the Department of Energy’s Reactor Pilot Program, making Antares the first privately developed advanced reactor to get there under the DOE program. The company had previously closed a $96 million Series B funding round in December 2025, which included $71 million in equity led by Shine Capital and $25 million in debt. Before that, Antares raised $30 million in a Series A round in 2024, bringing its total funding past $...