Aalo‑X Groundbreaking

Moving fast toward a Second Atomic Age

Three years ago, a small group of engineers and entrepreneurs asked a simple question: what if nuclear power plants could be assembled like data‑center equipment rather than bespoke megaprojects? We started Aalo in 2023 after leaving careers in national labs and software. Today, just two years later, we have broken ground on Aalo‑X, our first nuclear power plant, in the desert beside Idaho National Laboratory (INL).

The speed is unprecedented in an industry where the last sodium‑cooled reactor constructed in the United States – the Fast Flux Test Facility – took shape in the late 1970s and achieved its first criticality in early 1980. That four‑decade gap is why President Trump’s 2025 executive order on Reforming Nuclear Reactor Testing set a goal of achieving criticality in at least three pilot reactors by July 4, 2026.

Our groundbreaking ensures that Aalo‑X will meet that mandate.

Introducing the first XMR

Traditional categories of microreactors (<10 MWe) and small modular reactors (SMRs, up to ~300 MWe) leave a gap between tiny reactors that can be delivered to remote sites and larger units that supply cities. We created the extra‑modular reactor (XMR) to fill that gap. It’s a category of modular reactors that is a crossover between microreactors and SMRs. Our product is an Aalo Pod that contains five 10 MWe Aalo‑1 reactors arranged around a single turbine; the resulting 50 MWe plant is purpose‑built for power‑hungry data centers.

The XMR category blends factory‑manufacturing techniques from microreactors, the higher power levels of SMRs, and the economic targets of large reactors. The Aalo‑1’s liquid‑sodium metal coolant extracts heat far faster than water, allowing the reactor to deliver up to ten times more energy per unit size than conventional designs. The plant’s small footprint and lack of external cooling water make it easy to co‑locate with data centers anywhere, and the entire reactor and all plant modules can be shipped via standard transport.

These characteristics create a unique proposition for our customers. Because each pod is factory‑built and hyper modular, capacity can be increased simply by adding more pods – no design work or new containment buildings required. For data‑center operators facing soaring electricity demand, the ability to contract for several 50 MWe pods that install on-site in months instead of years will be transformative.

Aalo-X comprises the same reactor that goes in each of the Aalo-pods, except it is a single reactor, connected to a 10 MWe turbine. As we prove Aalo-X, we also prove the entire life cycle of the Aalo Pod, from design, safety basis, procurement, manufacturing, installation and interfacing, operation, refueling, to decommissioning.

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Re‑engineering the civil works

Aalo‑X looks like a commercial building because it is. In legacy reactors, the containment and safety systems are huge concrete structures, costing $3,000–6,000 per square foot and taking years to build. Our team miniaturised every safety‑related civil structure (e.g., containment, shielding, etc) into equipment modules (including the containment and shielding) with a small volume that wraps around the reactor itself. The result is significantly less steel and concrete per MWe than most traditional designs. Therefore, the building superstructure is nothing but a frame and metal‑panel building that can be erected by the same crews that build warehouses and data centers. Because over 90 % of the plant is manufactured in factories, the on‑site work is limited to months, not years. This approach slashes capital costs, reduces risk, and allows us to replicate plants rapidly. By turning the “nuclear building” into ordinary infrastructure, we intend to make nuclear power competitive with natural gas.

Why the Aalo‑X project matters

The Reactor Pilot Program, created by President Trump’s “Reforming Nuclear Reactor Testing at the Department of Energy” executive order, tasked the Department of Energy with approving at least three reactors and getting them to criticality by July 4, 2026. DOE selected Aalo‑X as one of those candidate reactors, and we had serendipitously already been spending the past eighteen months preparing for this moment. Our team completed a comprehensive Conceptual Design Review and secured official site allocation from DOE‑Idaho. The environmental approvals for the site have been completed, and we unveiled a 40,000 ft² pilot factory in Austin to build reactor modules. These milestones mean the groundbreaking is not the start of our journey – it is the culmination of careful design, rapid execution, and significant regulatory work.

Aalo‑X will continue the long history of American innovation in sodium‑cooled reactors.

The last U.S. sodium‑cooled research reactor, the Fast Flux Test Facility, achieved its first criticality in 1980 and was shut down in the early 1990s. Before that, the Experimental Breeder Reactor II (EBR‑II) reached criticality in 1965. Our reactor will thus be the first new U.S. sodium‑cooled test reactor to go critical in more than forty years. The lessons we learn from manufacturing, shipping, installing, and licensing Aalo‑X will determine whether advanced reactors like the Aalo Pods can truly be produced at scale.

By building from the ground up, we will gain hands‑on experience with excavation, construction, utilities tie-in, community integration, and power production – knowledge that would be impossible to acquire just by placing a test reactor inside existing DOE facilities.

Looking ahead

Breaking ground on Aalo‑X is a proud moment for our company and the broader nuclear community. It demonstrates that with the right design philosophy – being obsessed with modularity, factory manufacturability, and rapid iterative learning – we can compress timelines from decades to years. Within months, we will have assembled the first XMR at our Idaho site; by July 4, 2026, we will reach criticality, and by July 2027, we will power a collocated datacenter, with next-generation AI chips. Once operational, Aalo‑X will be a tangible proof‑of‑concept that nuclear energy can power the AI revolution rapidly and cost‑effectively.

Our success has been made possible by partnerships with the Department of Energy, Idaho National Laboratory, key suppliers, and investors who share our vision. It is also the result of our team’s relentless focus on fundamentals:

Speed and economics, without compromising safety and quality.

As we look toward a future where datacenters, municipalities, and even off-planet facilities need reliable, zero-carbon power, Aalo-X is the first step in a journey to deliver clean energy everywhere and make unlivable places livable.

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