Antares Nuclear, a startup focused on advanced nuclear technology, recently secured $470 million in funding to develop small modular nuclear reactors (SMRs) for U.S. military use. The Series C financing was led by Paradigm and Caffeinated Capital, with contributions from Industrious Ventures, Point72 Ventures, and Shine Capital. This round included $370 million in equity and $100 million in debt, reflecting growing investor enthusiasm for nuclear energy, fueled partly by expanding data center infrastructure and rising power demands.

The company is engineering SMRs capable of producing between 100 kilowatts and 1 megawatt of electricity, which could power up to 750 homes per unit. Antares utilizes TRISO fuel technology, where uranium is encapsulated within robust carbon and ceramic coatings. Known for its safety advantages, this fuel type prevents melting in high-temperature reactor environments and may be cooled by gases such as helium or molten salts. The startup’s Mark-0 demonstration reactor achieved criticality at Idaho National Laboratory on June 4, 2026, marking a significant technical milestone.

Antares is among three finalists competing in the Pentagon’s Advanced Nuclear Power for Installations program, aiming to deploy reactors on Air Force bases in Colorado and Montana. The company intends to have its first electricity-producing reactor operational by 2027, with broader military base deployments targeted for 2028. Securing military contracts aligns with the startup’s strategic approach, given that early-stage SMRs are expected to be costly compared to conventional power sources, making price-insensitive government customers an attractive market.

Despite strong investor interest and technological progress, the nuclear startup sector faces challenges including an immature U.S. supply chain and the long timelines required to achieve cost savings through mass manufacturing. Industry analysis projects that initial SMRs will have high electricity costs, estimated at about $214 per megawatt-hour, exceeding those of most gas-fired plants. Antares has not disclosed specific pricing, but its focus on military applications highlights the difficulty of achieving commercial competitiveness in the near term.