Federal regulators officially cleared construction of the first commercial advanced nuclear project at an American industrial plant. The U.S. Nuclear Regulatory Commission approved a construction permit application from X-energy and Dow to build four small modular reactors at Dow’s Seadrift Operations site in Texas.

The project, called the Long Mott Generating Station, is the first advanced nuclear facility approved for an industrial site in the U.S. Additionally, it’s the first time in nearly 60 years that the NRC has approved a construction permit for a high-temperature gas-cooled reactor, and the first approval ever for a pebble-bed design. These advanced reactors have been around for over 80 years, first being introduced in 1944.

Running Plants on Steam and Physics

A rendering of the Dow Plant; Photo: X-energy

X-energy’s plan is for four Xe-100 reactors to generate electricity and high-temperature steam on-site. Ideally, the output will replace older energy assets at the Texas facility that are nearing the end of their working life.

An extra safety measure is Xe-100, which runs on TRISO-X fuel, which the U.S. Department of Energy has called “the most robust nuclear fuel on earth.” These fuel particles trap radiation naturally. As a result, the plant needs an emergency planning zone of less than a quarter mile rather than the 10 miles required around traditional reactors.

Advertisement

Once built, the setup is expected to supply clean power to the Seadrift site for 60 years.

A First-of-a-Kind Plant

Getting the permit does not mean construction crews will immediately break ground. First-of-a-kind plants like this will come with extensive costs and timing risks. Dow and X-energy are spending the next phase finalizing components, maturing their supply chains, and preparing an operating license application.

Dow expects to make a preliminary investment decision in 2027. Full-scale construction will only begin after a final call on funding, with the first delivery targeted for the early 2030s.

“Getting the construction permit earlier than expected is reflective of the thorough and efficient work of the NRC, the reforms that have been put in place by the Congress over the last six years, and the phenomenal work of the X-energy and Dow teams,” J. Clay Sell, CEO of X-energy said. “This milestone is further validation of the XE regulatory approach that can be replicated across our growing commercial pipeline, giving our customers greater confidence in the regulatory process and a clearer path to deployment.”