Antares Raises $470 Million for Next Round of Nuclear Reactor Development

By Katherine Hamilton

Antares has raised $470 million in Series C funding to support its path from demonstrated nuclear reactor to fielded power systems ready to be deployed in 2028.

The nuclear-energy startup said Monday that the funding round was co-led by Paradigm and Caffeinated Capital, with participation from Point 72 Ventures, Shine Capital, Industrious Ventures and others.

The capital includes $370 million in equity and $100 million in debt.

Antares aims to execute initial deployments for U.S. military installations starting in 2028, with a goal of serving the defense and space systems with its reactor.

Last month, Antares' Mark-0 reactor achieved criticality at Idaho National Laboratory, meaning it reached a self-sustaining nuclear fission chain reaction. That marked the first privately developed non-light-water reactor to achieve criticality in the U.S. in more than 40 years.

The funding will go toward the next steps, including Antares' Mark-1 reactor, which will produce electricity and is slated to come out in 2027. Initial deployments in 2028 are set to go to the U.S. Air Force.

An executive order signed by President Trump last year set a deadline of Sept. 30, 2028, for the Pentagon to start operating a reactor at a domestic military installation.

A slew of nuclear-energy startups, many of which are designing micro-reactors, have been racing to develop a small, accessible reactor to meet soaring energy demands. Artificial intelligence development is fueling a jump in energy demand, which nuclear companies hope to address by designing clean, affordable reactors.

Write to Katherine Hamilton at katherine.hamilton@wsj.com

(END) Dow Jones Newswires

July 27, 2026 08:28 ET (12:28 GMT)