Nuclear construction commences at Idaho lab for the United States' inaugural modular reactor

In a significant stride for American energy innovation, Aalo Atomics, a U.S. startup based in Austin, Texas, has commenced construction on the nation's first experimental extra modular nuclear reactor (XMR). The reactor, named Aalo-X, is being built next to the Idaho National Laboratory's Materials and Fuels Complex in Idaho Falls.

Selected by the Department of Energy to participate in President Trump's Nuclear Reactor Pilot Program, announced in June 2025, Aalo-X is set to make history as the first sodium-cooled reactor to start up in the United States in over four decades.

Aalo-X is a crucial step towards addressing the rapid energy demand from sectors such as artificial intelligence and data centers. The reactor, once operational, is expected to provide a reliable and sustainable energy source for these power-hungry industries.

John Wagner, director of the Idaho National Laboratory, hailed the project as a milestone, "Aalo-X marks a significant step forward in American energy innovation. The potential of this reactor to revolutionize the energy landscape is immense."

Aalo Atomics' modular approach allows for facilities to expand power supply to a gigawatt scale without the need for major infrastructure overhauls. Each Aalo Pod contains five Aalo-1 reactors, with the Aalo Pod being a 50-megawatt modular power plant designed specifically for data centers.

The Aalo Pod's design is scalable and flexible, with the potential to colocate directly at data center sites. Moreover, the modular approach avoids reliance on external water sources, making it an eco-friendly solution for the energy needs of the future.

The company operating the Aalo-X plant is Aalo Atomics, which has raised over $136 million from investors. The components for Aalo-X are being manufactured at the company's pilot factory in Austin.

Aalo expects to complete construction and reach criticality by July 4, 2026. The leadership at Aalo describes the pace of progress as unprecedented, marking a promising future for nuclear energy in the United States.

Nuclear construction commences at Idaho lab for the United States' inaugural modular reactor