Another novel nuclear project gets green light to start construction

The United States just cleared another novel nuclear energy project to begin construction.

On Monday, the U.S. Nuclear Regulatory Commission approved a joint application by X-energy and Dow Chemical to build four Xe-100 advanced nuclear reactors at a Texas industrial site owned by the Michigan-based chemicals giant. The energy plant, known as Long Mott Generating Station, does not yet have an operating license from the NRC and will not be complete until well into next decade.

The reactors will generate electricity and high-temperature steam for Dow’s UCC Seadrift Operations, a facility that makes plastics and petroleum derivatives used in everything from food and beverage packaging to paints and solvents. The Seadrift facility currently relies on aging fossil-fueled equipment.

The NRC took less than 18 months to review the application, a record pace for contested hearings amid a broad-based — and controversial — effort to streamline U.S. nuclear regulation that has been in the works since the Biden administration.

“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,” X-energy CEO J. Clay Sell said in a statement.

The approval comes amid a wave of federal support for new nuclear energy projects. In recent years, the U.S. Department of Energy has funded tens of billions of dollars in grants, awards, and loan guarantees to build new reactors and expand capacity at existing nuclear power plants. Support has been consistent throughout both Trump administrations as well as under the Biden administration, which viewed the carbon-free energy source as a way to decarbonize the grid. Quadrupling commercial nuclear capacity by 2050 is now official U.S. government policy.

The Xe-100 is one of several non-water-cooled reactors, known as ​“Generation IV” reactors, recently granted or seeking NRC permission to begin construction. 

The NRC has also greenlit construction of three molten-salt-cooled reactors by Kairos Power in Tennessee and one liquid-sodium-cooled reactor by Bill Gates–backed TerraPower in Wyoming. TerraPower and X-energy are both set to receive at least $2 billion each in federal funding through the DOE’s Advanced Reactor Demonstration Program. 

The Xe-100’s coolant of choice is helium, a lightweight, inert gas that allows the reactor to operate safely at far higher temperatures than traditional nuclear power plants. Each reactor is designed to generate up to 80 megawatts of electricity and 200 MW of thermal energy, enough to make Seadrift the first U.S. industrial site directly powered and heated by nuclear fission.

It’s the first time in nearly 60 years that the NRC has approved construction of a high-temperature gas reactor, or HTGR. The first, a 40-MW design, produced electricity at the still-operating Peach Bottom power plant in Pennsylvania from 1966 to 1974. Another HTGR ran from 1979 to 1989 at Fort St. Vrain Generating Station in Colorado, which is now a natural-gas-fired power plant owned by Xcel Energy. 

Both 20th-century HTGRs retired early because of ​“funding and technical problems,” according to the International Atomic Energy Agency. X-energy said this week that it expects its Texas reactors to operate for 60 years.

The Peach Bottom and Fort St. Vrain reactors were ​“a technology ahead of their time,” Robert Taylor, X-energy’s vice president of regulatory affairs and licensing, told Canary Media in May. In the 50 years since, HTGRs have operated successfully in ​“multiple countries” around the world, improving to the point that ​“it’s an Edsel-to-a-Ferrari comparison,” Taylor said, referring to Ford’s notorious automotive flop.

But X-energy has a lot of work to do before the United States’ first commercial nuclear cogeneration plant comes online. 

One key challenge is fuel supply. X-energy says it has a federal commitment for the high-assay, low-enriched uranium (HALEU) it needs to get Long Mott running and a binding commercial agreement for enough to support at least some of the 11-plus gigawatts of reactors it hopes to build. But its plans depend on the completion of its Tennessee fabrication facility, where the startup will turn HALEU into stable fuel pellets capable of withstanding temperatures higher than 1,000 degrees Fahrenheit. That facility is on track to open in early 2028, X-energy said in September.

X-energy and Dow will also have to ask the NRC for permission to run Long Mott once it’s built. That could take another 18 months, according to the NRC’s generic licensing schedule, though the companies would likely submit the application during construction.

Dow, for its part, has yet to make a final decision on the multibillion-dollar project and isn’t expected to do so before 2028, though it may ​“consider a preliminary investment decision” next year, X-energy said.

A Monday statement from Edward Stones, Dow’s business vice president for energy and climate, did little to tip the company’s hand.

“As we move forward, we will continue to evaluate the project through the lens of competitiveness, execution readiness, and capital affordability before any decision regarding construction is made,” Stones said.

And why rush? According to the construction permit, the payoff for Long Mott won’t come until this year’s high school freshmen gear up for their senior year of college.

“The earliest date for the completion of the construction of the facility is July 1, 2033,” the permit reads.