# Was the U.S. Advanced Reactor Criticality Deadline Actually Met?

Three companies — Aalo Atomics, Antares Nuclear, and Deployable Energy — achieved [nuclear criticality](https://smrintel.com/glossary/criticality) on or before Executive Order 14301's July 4, 2026 target date, and all three sent representatives to the Nuclear Energy Conference & Expo (NECX 2026) in Washington this week to describe how they pulled it off. A fourth company also met the deadline but did not appear on Wednesday's opening plenary panel.

The short answer: aggressive timelines, a responsive fuel supply chain, and a cultural shift away from treating "more time" as synonymous with "more certainty." Aalo Atomics achieved criticality on July 4 with a full-scale, zero-power version of its 10-MWe Aalo-X. Antares Nuclear was the first to cross the milestone — nearly a full month ahead of the deadline — with its Mark-0 reactor, a forerunner to its flagship R1 design. Deployable Energy, the only one of the three that was not a DOE Reactor Pilot Program participant, achieved criticality with its 1-MWe [high-temperature, gas-cooled](https://smrintel.com/glossary/htgr) Unity microreactor on July 1, doing so in 155 days under the DOE's Nuclear Energy Launch Pad program instead.

On the state side, Kentucky opened $75 million in grants for new nuclear projects, New York announced plans to add at least 5 gigawatts of new nuclear capacity, and Utah's Operation Gigawatt aims to double the state's total energy production by 2034.

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## How Three Startups Beat EO 14301's July 4 Deadline

The origin story shared by each company at NECX 2026 is remarkably similar: the executive order arrived, it seemed impossible, and then the supply chain said yes.

Matthew McClellan, Aalo's senior manager for costing, described the night after the DOE's Reactor Pilot Program launched. Aalo had originally targeted criticality for 2027. Cofounder and CTO Yasir Arafat went home that evening and mapped out a revised plan.

"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,'" McClellan said. "From that point forward, we just adopted a mindset that this was possible."

Aalo's Aalo-X is a 10-MWe design, and the criticality achieved was on a full-scale, zero-power version — meaning the unit is not yet generating commercial electricity. That distinction matters for investors and utility procurement teams tracking what "criticality" actually means on the path to commercial operation.

Antares's head of nuclear operations and regulatory affairs, Jason Andrus, offered what may be the most quotable operational philosophy to emerge from this year's conference: "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."

Antares's Mark-0 is explicitly described as a forerunner to the R1, which is the company's commercial flagship. The Mark-0 hitting criticality nearly a month early is a meaningful proof point, but the gap between a prototype forerunner and a commercially licensed, grid-connected unit remains substantial.

Deployable Energy CEO Bobby Gallagher took a different path entirely. His company did not apply for the Reactor Pilot Program — "We were like, this doesn't make any sense" — but pursued the Nuclear Energy Launch Pad program with Idaho National Laboratory as a key partner. The Unity microreactor's 155-day sprint to criticality was encouraged by supply chain partners and INL, Gallagher said, despite external skepticism.

The [First of a Kind (FOAK)](https://smrintel.com/glossary/foak) commercial deployment risk for all three designs remains the central question the industry must now answer. As American Nuclear Society President Mark Peters put it at the plenary's opening: "Criticality, of course, is not the finish line — it's the beginning. The challenge now is to convert these achievements into deployable technologies, repeatable projects, reliable supply chains, capable workforces, and ultimately operating reactors serving customers."

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## State Nuclear Ambitions: Kentucky, New York, and Utah

The second half of Wednesday's plenary shifted from startup engineering culture to state-level policy, and the numbers were substantial.

**Kentucky** has opened $75 million in grants through its Nuclear Reactor Site Readiness Pilot Program. Three projects are expected to be selected, each eligible for up to $25 million. State Sen. Danny Carroll (R., 2nd Dist.) said selections should occur early next year. Carroll noted how far the state has traveled — alluding to a 2017 moratorium that previously constrained nuclear development in Kentucky.

**New York** is targeting at least 5 gigawatts of new nuclear capacity. The New York State Energy Research and Development Authority's Director of Strategy, Erich Scherer, acknowledged the state has a long nuclear history that has stagnated. NYSERDA released an options paper in June providing feasibility analysis for new nuclear projects. Scherer was notably candid about the limits of hyperscaler demand as a financing mechanism, flagging reactor costs, financing uncertainties, and the unresolved question of how much state intervention will be required alongside private capital.

**Utah** is the most ambitious of the three. Operation Gigawatt targets doubling the state's total energy production by 2034. Utah Advanced Nuclear and Energy Initiative Director Jeremy Pearson cited multiple willing host communities and supportive legislative activity, while tempering expectations around timelines: "We're talking about long-lead-time projects that are going to be around for decades." Utah received a meaningful federal endorsement in July when the DOE signed a memorandum of understanding with the state that could lead to Utah hosting a Nuclear Lifecycle Innovation Campus.

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## What This Means for the Industry

The EO 14301 criticality milestone is real and historically significant — multiple advanced reactor designs achieving first criticality within weeks of each other has not happened in the United States in decades. But the industry should be clear-eyed about what it represents and what it does not.

Zero-power criticality is a nuclear physics milestone, not a commercial operations milestone. None of the three reactors described at NECX 2026 are currently generating electricity for customers. The path from first criticality to NRC licensing, construction of commercial units, supply chain replication at scale, and economically competitive [LCOE](https://smrintel.com/glossary/lcoe) involves challenges that a favorable executive order cannot compress away.

The state-level policy acceleration is arguably the more commercially durable signal from this week's conference. $75 million in Kentucky grants, 5 GW targets in New York, and a DOE MOU with Utah for a potential innovation campus represent concrete procurement and siting infrastructure that advanced reactor developers need to convert technical milestones into revenue. Scherer's skepticism about hyperscaler-led financing — publicly aired at a major ANS event — is worth noting: utilities and state energy authorities are not convinced that data center PPAs alone solve the FOAK cost and financing problem.

The pressure is now on the supply chain. Every company at NECX 2026 credited fuel and component suppliers for making the July 4 deadline possible. Whether that same supply chain can scale from demonstration-scale to commercial-scale deployment — and at what cost — is the question that will define the next chapter of this story.

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## Key Takeaways

- **Three companies achieved criticality by EO 14301's July 4, 2026 deadline:** Aalo Atomics (July 4, 10-MWe Aalo-X), Antares Nuclear (nearly a month early, Mark-0 prototype), and Deployable Energy (July 1, 1-MWe Unity HTGR microreactor).
- **Deployable Energy was not a DOE Reactor Pilot Program participant;** it operated under the Nuclear Energy Launch Pad program with Idaho National Laboratory support and completed the milestone in 155 days.
- **Criticality is a physics milestone, not a commercial one.** No commercial electricity generation has occurred; licensing, supply chain scale-up, and cost competitiveness remain unresolved.
- **Kentucky opened $75 million in nuclear site grants,** with up to $25 million per project and selections expected early next year.
- **New York is targeting at least 5 GW of new nuclear capacity** following a June feasibility options paper from NYSERDA.
- **Utah's Operation Gigawatt aims to double state energy production by 2034,** supported by a July DOE MOU toward a potential Nuclear Lifecycle Innovation Campus.
- **Supply chain responsiveness was the decisive factor** cited by all three startups in meeting the EO 14301 deadline — and will be the binding constraint for commercial-scale replication.

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## Frequently Asked Questions

**What is Executive Order 14301 and why does the July 4 criticality deadline matter?**
EO 14301 directed the DOE to establish a Reactor Pilot Program targeting at least three advanced reactors achieving criticality by July 4, 2026. The deadline served as a policy forcing function that compressed development timelines for multiple startup developers, with Aalo Atomics, Antares Nuclear, and Deployable Energy all confirming they met or beat it.

**What does "criticality" actually mean — are these reactors generating power?**
Nuclear criticality means the reactor has achieved a self-sustaining chain reaction. In Aalo's case, the milestone was achieved on a "full-scale, zero-power" version of the Aalo-X — meaning the reactor demonstrated the physics of sustained fission but was not generating commercial electricity. Criticality is a necessary step toward power generation, not power generation itself.

**What is the Aalo-X reactor's power rating?**
The Aalo-X is a 10-MWe design. The criticality achieved at NECX 2026 was reported on a full-scale, zero-power version.

**What is Deployable Energy's Unity reactor and how is it different from the RPP participants?**
The Unity is a 1-MWe high-temperature, gas-cooled microreactor. Unlike Aalo and Antares, Deployable Energy was not part of the DOE's Reactor Pilot Program; it developed Unity under the DOE's Nuclear Energy Launch Pad program, with Idaho National Laboratory as a key partner. It achieved criticality on July 1 in 155 days.

**How much money is Kentucky investing in new nuclear, and when will projects be selected?**
Kentucky opened $75 million in grants through its Nuclear Reactor Site Readiness Pilot Program. Up to three projects can each receive as much as $25 million. State Sen. Danny Carroll said selections are expected to occur early in 2027.

**Why is New York skeptical about hyperscaler-led nuclear financing?**
NYSERDA's Erich Scherer flagged that reactor costs, financing uncertainties, and the unresolved mix of private versus state contributions make data center PPA demand an insufficient standalone solution for funding new nuclear builds in New York. The state's June options paper analyzes feasibility but has not yet committed to a specific procurement model.