4 US Advanced Nuclear Reactors Successfully Demonstrated, DOE Says

Aalo Atomics said it had successfully shown "criticality" for a commercial-scale advanced nuclear reactor - the fourth United States design to do so under an ongoing federally supported campaign, according to the Department of Energy (DOE).

"Our Critical Test Reactor (CTR) went from groundbreaking to a sustained chain reaction in less than eight months - one of the fastest reactor builds in 80 years - and our company has gone from founding to fission in less than three years", the Austin, Texas-based company said in a statement. "The CTR includes a full-scale core, demonstrating the nuclear components of our 10 MWe [megawatts electric] reactors, which will be deployed in 50 MWe Aalo Pods to power AI data centers".

"We stood up our own safety programs, built 10 MW worth of fuel assemblies, and manufactured and quality-controlled commercial scale systems in-house", it added.

DOE said separately, "The experiment took place at Idaho National Laboratory and is the fourth DOE-authorized advanced reactor to achieve the criticality milestone, exceeding the July 4th goal outlined by President Trump in his May 2025 executive order".

Aalo added, "We have already begun work on our second nuclear reactor for Project Ascension, a commercial-scale system located on the Aalo-X Campus at INL. The new reactor will produce 10 MWe of electricity and power an on-site data center in 2027. 

"Criticality has validated our supply chain, reactor physics, control systems, and fueling procedures at commercial scale.

"We are now expanding into a one-million square-foot factory to apply assembly-line manufacturing to reactor production, which will open the door to mass-producing the Aalo Pod, our fully modular nuclear plant purpose-built for AI data centers".

The technology is among 11 initial selections announced by DOE under President Donald Trump's Reactor Pilot Program on August 12, 2025. The program implements a presidential order that seeks to reform the national lab process for reactor testing, launch a pilot program for reactor construction and operation outside of national labs and streamline environmental reviews for reactor facilities.

Trump's executive order May 23, 2025 aims to have at least three advanced reactors achieve "criticality" by the U.S.' anniversary on July 4, 2026 to help grow the country's nuclear energy capacity from about 100 gigawatts (GW) to 400 GW by 2050. 

Aalo's achievement means Trump's target has been exceeded. The earlier three projects to achieve criticality are Antares Nuclear’s Mark-0 reactor, Valar Atomics’ Ward 250 and Deployable Energy’s Unity, DOE said.

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