Antares, a Torrance, California-based developer of compact fission microreactors, has raised $470 million in Series C funding. The round includes $370 million in equity and $100 million in debt, co-led by Paradigm and Caffeinated Capital with participation from Point72 Ventures, Shine Capital, and others. Antares builds TRISO-fueled, sodium heat-pipe cooled reactors that deliver 100 kWe to 1 MWe for six or more years without refueling, targeting remote military bases and austere sites. The capital will accelerate manufacturing at its 322,000-square-foot Antares Prime facility and support customer deployments beginning in 2028.
Defense Deadlines Drive Capital Surge
The timing aligns with federal mandates. Executive Order 14299 requires an operational reactor at a domestic military base by September 2028, and the Army's Project Janus has named nine candidate installations. Antares was selected for the Air Force ANPI initiative at Joint Base San Antonio. Radiant Industries raised $300 million in its Series D in December 2025 after a $100 million Series C in May 2025, while X-energy secured a $700 million Series D in November 2025. Antares' approach emphasizes vertical integration and defense-specific transportability.
Grid Dependence Creates Operational Risk
Military installations rely heavily on commercial grids and diesel generators, creating vulnerabilities in contested environments. The Pentagon has identified the need for resilient, on-site power that eliminates fuel convoys. Current solutions fall short because diesel requires continuous logistics support and grid connections expose bases to disruption. Antares' design uses passive sodium heat pipes and a nitrogen Brayton cycle to eliminate pumps and moving parts, enabling autonomous operation for years.
Hardware-First Design Accelerates Validation
Antares achieved first criticality of its Mark-0 demonstration reactor at Idaho National Laboratory in June 2026 under the DOE Reactor Pilot Program, ahead of the July deadline and with less capital than peers. The Mark-1 electricity-producing unit is targeted for 2027. Unlike larger-scale competitors such as Kairos Power's 50 MW Hermes or X-energy's 80 MWe Xe-100, the R1 microreactor prioritizes mobility and rapid factory production.
"Simply put, this capital is going to build reactors, and we'll have our full commercial product operating and producing electricity at Idaho National Lab next year. For our customers, that means they'll be receiving systems in 2028 with proven operational heritage." — Jordan Bramble, CEO
Mission Capital Validates Procurement Path
Paradigm and Caffeinated Capital led the round, signaling that non-traditional investors now view nuclear microreactors as a de-risked government procurement opportunity. The funding follows Antares' selection for multiple DoD programs and a long-term HALEU supply agreement with Urenco. Total capital raised exceeds $600 million since founding in 2023.
Microreactor Market Expands With Policy Support
The microreactor technology market is projected to grow from $597.9 million in 2024 to $1.41 billion by 2033 at a 10.1% CAGR, per Grand View Research. Broader micro nuclear reactors are expected to reach $13.8 billion by 2034 at 13.8% CAGR, according to Precedence Research. Key drivers include the ADVANCE Act's streamlined licensing, DoD energy resilience programs, and demand for always-on power for AI infrastructure.
Manufacturing Scale and 2028 Deployments Ahead
With the new capital, Antares plans to ramp production capacity at Antares Prime toward 10 units per year. Initial deployments to U.S. military installations are scheduled for 2028, following electricity production from Mark-1 in 2027. The company also maintains ambitions in space and undersea applications.