Paradigm and Caffeinated Capital jointly led the Series C, which includes $370 million in equity and $100 million in debt, as Antares targets first power production next year and U.S. military deployments in 2028.
Antares Nuclear has completed a $470 million Series C to advance compact reactors aimed at U.S. military bases and other strategic uses. The round was jointly led by Paradigm and Caffeinated Capital and included $370 million in equity and $100 million in debt. The California startup, founded in 2023, is developing small modular reactors ranging from 100 kilowatts to 1 megawatt and using TRISO fuel. Antares says its R1 reactor achieved criticality on June 4, 2026 at Idaho National Laboratory through the Department of Energy’s Reactor Pilot Program, making it the first privately developed advanced reactor to do so under that program. The company is targeting its first power-producing reactor next year and plans initial deployments to U.S. military bases in 2028. Earlier financing included a $96 million Series B in December 2025, made up of $71 million in equity led by Shine Capital and $25 million in debt, and a $30 million Series A in 2024. Antares says the R1 can run for more than six years without refueling and has built ties with the US Department of Defense, the Department of Energy, NASA, the Air Force and the Space Force.