Reactor criticality, states’ new nuclear plans among NECX 2026 highlights

Start-ups on reactor criticality: Matthew McClellan, Aalo’s senior manager for costing, recalled the day the Department of Energy launched its Reactor Pilot Program. It prompted a change of pace in Aalo’s plans, as the company had originally set criticality for 2027.

“We read the thing and it said at least three reactors by July 4, 2026 . . . this changes everything. That night, I think [cofounder and chief technical officer Yasir Arafat] went home and created a plan [for] how can we actually achieve this? Because it felt impossible,” McClellan said. “The next day, he called the fuel supply chain and said, ‘The president says this needs to happen. Can you all do this?’ And the resounding answer was ‘Yes.’ From that point forward, we just adopted a mindset that this was possible.”

Aalo achieved criticality on the full-scale, zero-power version of its 10-MWe Aalo-X on July 4. Deployable Energy, meanwhile, achieved criticality with its 1-MWe high-temperature, gas-cooled Unity microreactor on July 1. Unlike the other three companies that met the July 4 deadline, Deployable was not an RPP participant; rather, it was part of the DOE’s Nuclear Energy Launch Pad program.

Deployable CEO Bobby Gallagher said they “unlocked the American spirit” by having advanced reactors achieve criticality. Deployable took 155 days to hit the milestone, he said, adding that while some said it couldn't be done, their supply chain providers confirmed it was feasible.

“We didn't even apply for the Reactor Pilot Program. We were like, this doesn't make any sense . . . but when we talked to the supply chain, when we talked to our partners, when we talked to [Idaho National Laboratory], we actually were encouraged,” he said.

Jason Andrus, Antares’s head of nuclear operations and regulatory affairs, said what excited him was the fact that Antares set aggressive goals, and everyone was on board.

He admitted that when the July 4, 2026, deadline was announced, he too did not see how it would be possible to achieve criticality by that date. But Antares became the first to reach the milestone—nearly a full month before the deadline. Antares achieved criticality with its Mark-0 reactor, a forerunner to the R1, which is the company’s flagship design.

“Oftentimes in my career, I have thought that more time maybe meant more certainty. What I realized was more time often meant my ability to be distracted by something else rather than really having to prioritize what was urgent,” Andrus said.

American Nuclear Society President Mark Peters, who spoke briefly at the start of the plenary, said the nuclear industry saw something happen that some would have once considered unattainable: multiple advanced reactors achieving criticality on a quick timeline. What was accomplished was more than just a series of technical milestones; it represented a change in how industry and government approached nuclear innovation.

“Criticality, of course, is not the finish line—it's the beginning,” Peters said. “The challenge now is to convert these achievements into deployable technologies, repeatable projects, reliable supply chains, capable workforces, and ultimately operating reactors serving customers.”

States talk new nuclear plans: Kentucky state Sen. Danny Carroll (R., 2nd Dist.), New York State Energy Research and Development Authority Director of Strategy Erich Scherer, and Utah Advanced Nuclear and Energy Initiative Director Jeremy Pearson had plenty to share about their states’ plans for new nuclear initiatives. Kentucky recently opened $75 million in grants to fund new nuclear projects as part of its Nuclear Reactor Site Readiness Pilot Program. New York has plans to add at least 5 gigawatts of new nuclear power. And Utah’s Operation Gigawatt calls for doubling the state’s energy production by 2034.

Utah’s efforts to become a larger player in nuclear energy received a boost in July when the DOE signed a memorandum of understanding with the state that could lead to Utah hosting a Nuclear Lifecycle Innovation Campus.

“We're really in a good position. We have multiple locations and communities that want to be hosts, multiple legislators putting forth legislation to help us out . . . but this is just such a big nut to crack. We’re talking about long-lead-time projects that are going to be around for decades," said Pearson.

Scherer said New York’s nuclear power history dates back decades but, like in many other states, growth has stagnated. New York released an options paper in June that provides an in-depth analysis of the feasibility of new nuclear projects in the state.

Many see hyperscalers as the answer to expanding nuclear power. Scherer said it is not that simple, with reactor costs and financing uncertainties and options among the lingering questions.

“What is the mix of contributions from the private sector but also the possible interventions that are needed from the state?” he asked.

Over in Kentucky, plans are for the state to pick three projects to receive up to $25 million each. Carroll said it should be happening early next year.

“We've come a long way,” he said. “In 2017, the moratorium [on new nuclear power] was lifted in our state. After that, I was all excited and ready to go but then it was crickets until about 2023, when things started happening.”