Three advanced reactor startups describe path to criticality at NECX 2026, as Kentucky, New York, and Utah announce nuclear expansion plans

On the second day of NECX 2026, three advanced reactor companies took the stage to recount something the nuclear industry hadn’t seen in decades: multiple startups achieving reactor criticality on a compressed timeline. Representatives from Aalo Atomics, Antares Nuclear, and Deployable Energy opened Wednesday’s plenary session describing how they each hit the milestone set by Executive Order 14301’s July 4 deadline—in one case, nearly a month early. State officials from Kentucky, New York, and Utah followed with their own announcements on nuclear expansion.

Three startups recount race to meet July 4 criticality deadline

When the DOE launched its Reactor Pilot Program, Aalo Atomics was already working toward criticality—just on a much slower clock. The company had originally targeted 2027. Then Executive Order 14301 landed, calling for at least three reactors to hit criticality by July 4, 2026. That night, Aalo cofounder and CTO Yasir Arafat went home and started drawing up a new plan.

“It felt impossible,” recalled Matthew McClellan, Aalo’s senior manager for costing, speaking at Wednesday’s plenary. But the next morning, Arafat called the fuel supply chain. The answer came back: yes, it could be done. “From that point forward, we just adopted a mindset that this was possible,” McClellan said.

What happened—multiple advanced reactors reaching criticality on a compressed timeline—was something many in the industry would once have considered out of reach.

Aalo achieved criticality on July 4 with a full-scale, zero-power version of its 10-MWe Aalo-X reactor. Deployable Energy hit its milestone three days earlier, on July 1, with its 1-MWe high-temperature, gas-cooled Unity microreactor. Antares crossed the line nearly a full month before the deadline—first of the group to do so—with its Mark-0 reactor, a forerunner to the company’s flagship R1 design.

Executive order and DOE programs drove compressed development schedules

What made these timelines stand out wasn’t just the speed. It was how fast each team pivoted once a hard deadline existed—schedules that had been measured in years got compressed into months.

Deployable Energy completed its milestone in 155 days. CEO Bobby Gallagher said the company didn’t even apply for the Reactor Pilot Program at first. “We were like, this doesn’t make any sense,” he said. Conversations with supply chain partners and Idaho National Laboratory changed the math. Those partners confirmed the timeline was doable, and the team moved forward. Gallagher described the achievement as “unlocking the American spirit.”

Antares Head of Nuclear Operations and Regulatory Affairs Jason Andrus offered a candid take on what urgency actually does to a team. He admitted he didn’t see how the July 4 deadline was achievable when it was announced, but the hard cutoff forced a kind of clarity. “Oftentimes in my career, I have thought that more time maybe meant more certainty,” Andrus said. “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.”

Deployable’s path also looked different structurally. Rather than the Reactor Pilot Program, the company worked through DOE’s Nuclear Energy Launch Pad—a separate pathway that still led to the same July 4 finish line.

ANS president and executives frame criticality as a starting point, not a finish line

American Nuclear Society President Mark Peters opened the plenary with some perspective. What happened—multiple advanced reactors reaching criticality on a compressed timeline—was something many in the industry would once have considered out of reach. Peters was careful not to let the moment become an endpoint, though.

“Criticality, of course, is not the finish line—it’s the beginning,” he said. The real challenge, in his framing, is turning technical milestones into something durable: deployable technologies, repeatable projects, reliable supply chains, capable workforces, and reactors that actually serve customers.

The executives on stage largely agreed. Urgency created by the executive order helped teams focus, but commercialization is a longer and messier process. What the three companies demonstrated was proof of concept under pressure—not a finished product ready for the grid. Peters framed the broader significance as a shift in how both industry and government approach nuclear innovation, not just a set of technical wins.

Kentucky, New York, and Utah present state-level nuclear expansion programs

After the startup presentations, officials from three states laid out their own plans—each at a different stage, all pointing the same direction.

Kentucky recently opened $75 million in grants through its Nuclear Reactor Site Readiness Pilot Program, with plans to select three projects, each receiving up to $25 million. State Sen. Danny Carroll said selections should happen early next year. He noted that Kentucky lifted its moratorium on new nuclear power in 2017, but real momentum didn’t arrive until around 2023.

New York is aiming to add at least 5 gigawatts of new nuclear capacity. A feasibility options paper released in June took an in-depth look at what new nuclear projects would require. Erich Scherer of the New York State Energy Research and Development Authority acknowledged that while hyperscalers are often cited as the demand driver for new nuclear, financing and cost uncertainties remain unresolved. “What is the mix of contributions from the private sector but also the possible interventions that are needed from the state?” he asked.

Utah’s Operation Gigawatt sets an ambitious target: doubling the state’s energy production by 2034. In July, the DOE signed a memorandum of understanding with Utah that could lead to the state hosting a Nuclear Lifecycle Innovation Campus. Jeremy Pearson, director of Utah’s Advanced Nuclear and Energy Initiative, said the state has willing host communities and supportive legislators—but cautioned that the scale of the challenge is real. “We’re talking about long-lead-time projects that are going to be around for decades,” he said.

Key highlights from NECX 2026’s second day

The through-line across Wednesday’s sessions was that the nuclear industry is moving—but speed and permanence are two different things. Three startups showed that compressed timelines are achievable when deadlines are clear and supply chains are engaged early, with the July 4 criticality milestone functioning as a forcing mechanism that reshaped development plans across the sector.

Kentucky, New York, and Utah each signaled that nuclear expansion is now a policy priority, backed by funding and feasibility planning. The remaining obstacles—project financing, long lead times, and questions about public-private cost sharing—are well understood. What’s less clear is how quickly those obstacles will give way. The industry now has proof that the pace of nuclear development can change. Whether that pace holds through commercialization is the next question.

Kelly Lippke

Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.