Antares has raised $470 million to develop and deploy compact nuclear reactors for US military installations. The Series C consists of $370 million in equity and $100 million in debt, bringing the company’s total reported funding to more than $600 million.
Paradigm and Caffeinated Capital co-led the round, with participation from Industrious Ventures, Point72 Ventures and Shine Capital. Antares plans to use the financing to move its reactor technology from testing into electricity production and field deployment.
Microreactor Reaches Criticality
Antares is developing factory-built reactors designed to produce between 100 kilowatts and 1 megawatt of electricity. The systems are intended to supply reliable power for military facilities, remote infrastructure, space missions and other locations where conventional power grids may be unavailable or vulnerable.
Its Mark-0 demonstration reactor reached initial criticality at Idaho National Laboratory on June 4. The test produced a self-sustaining nuclear chain reaction at low power, validating the reactor’s fuel loading, control systems and physics models without generating electricity.
Antares said the milestone was the first criticality achieved under the US Department of Energy’s Reactor Pilot Program. Its first electricity-producing system is scheduled to begin operating in 2027, followed by initial military deployments in 2028.
TRISO Fuel Supports Compact Design
The reactor uses TRISO fuel produced by BWX Technologies. Each fuel particle contains uranium surrounded by carbon and ceramic layers designed to retain radioactive material at high temperatures.
This structure allows the fuel to withstand conditions that could damage conventional reactor fuel. Antares combines it with a high-temperature heat-pipe design that avoids some of the pumps and complex cooling systems used in larger nuclear plants.
The company is participating in federal programmes seeking resilient power sources for military installations. Small reactors could continue supplying electricity during grid failures and support facilities with growing computing and operational demands.
Commercial Costs Remain Uncertain
Investor interest in nuclear startups has increased alongside electricity demand from AI data centres and the wider electrification of the economy. However, advanced reactor companies still face manufacturing, regulatory, fuel-supply and construction challenges before they can produce systems at scale.
Antares has not disclosed the expected cost of electricity from its reactors. Cost estimates for new nuclear technologies vary widely and depend heavily on construction expenses, financing, manufacturing volume and government support.
The company’s initial focus on defence customers could provide stable demand while it develops its manufacturing process. Antares said the latest funding will support deployments for critical missions on Earth, underwater and in space.
Featured image credits: Magnific.com
For more stories like it, click the +Follow button at the top of this page to follow us.