Deployable Energy becomes third reactor to hit milestone

Deployable Energy has become the third advanced reactor in the US Department of Energy Reactor Pilot programme to reach criticality. That means the reactor has achieved a self-sustaining nuclear chain reaction.

In May 2025, President Donald Trump signed an executive order on nuclear energy. It directed federal agencies to facilitate the criticality of at least three new advanced reactors by 4 July 2026.

Criticality is a key step in commercialising advanced nuclear technology. For the DOE pilot effort, it marked the point where the reactor could sustain its own chain reaction.

Will Shackel, founder of Nuclear for Australia, said the US target was meant “to show that microreactor technology is no longer theoretical, but deployable”.

Deployable Energy in 150 days

Shackel also highlighted an Australian link because Deployable Energy chief executive and co-founder Bobby Gallagher is Australian. He said the reactor powered up ahead of the 4 July milestone.

According to Nuclear for Australia, Deployable Energy went from project start-up to powering up its microreactor in just 150 days. That pace stands out in advanced reactor development.

Shackel described microreactors as transportable “batteries” that can provide reliable electricity and heat for remote and off-grid uses.

Possible customers include mining operations, remote critical minerals projects, defence facilities and critical infrastructure. Nuclear for Australia also pointed to future AI and hyperscale data centres because they need round-the-clock power.

After the US milestone, Nuclear for Australia renewed its push to change Australian policy. The group says advanced nuclear technology could strengthen energy security, reduce emissions and improve the competitiveness of remote industries.

Australia still has bans on nuclear technology, according to Shackel. He said, “Australia must capitalise on this nuclear renaissance and open the door to nuclear in Australia.”

Meanwhile, Nuclear for Australia says it has more than 118,000 supporters. The grassroots organisation says it wants to advance public debate on the peaceful use of nuclear science and technology.

More broadly, the reactor milestone forms part of a US effort to restore nuclear leadership. Reaching criticality for three advanced reactors before 4 July 2026 became a clear benchmark for government and industry.