NATIONAL NEWS

A look inside a lab making the advanced fuel to power growing US nuclear energy ambitions

Jul 16, 2025, 6:02 AM

A laboratory worker holds a cross section of TRISO fuel Friday, June 27, 2025, in Oak Ridge, Tenn. ...

A laboratory worker holds a cross section of TRISO fuel Friday, June 27, 2025, in Oak Ridge, Tenn. (AP Photo/George Walker IV)
Credit: ASSOCIATED PRESS

(AP Photo/George Walker IV)

OAK RIDGE, Tenn. (AP) — Near signs that warn of radioactive risk at Oak Ridge National Laboratory, a half-dozen workers from the nuclear power company X-energy are making what appear to be gray billiard balls. Inside, they’re packed with thousands of tiny black spheres that each contain a speck of uranium enriched beyond what today’s power plants use.

The United States is chasing a new age of nuclear power that banks on domestic production of reactor fuel like X-energy is making, and though the work at Oak Ridge is unfolding across just 3,000 square feet, X-energy and others are already revving up for big production.

President Donald Trump set a goal of quadrupling domestic production of nuclear power within the next 25 years, signing executive orders in May to speed up development. A new wave of advanced nuclear reactors could be operational around 2030.

But just like cars won’t run without gas, those plants won’t run without fuel. To expand nuclear energy long-term, the nation must maximize its nuclear fuel production, .

In Oak Ridge, X-energy has broken ground on a massive, nearly $2 billion campus for a new fuel fabrication facility, the first in the United States in over half a century. The nuclear fuel company Standard Nuclear, also in Oak Ridge, aims to produce metric tons of fuel for advanced reactors. A supplier named Orano is likewise looking to build a multibillion-dollar uranium enrichment facility nearby.

“This is a unique time,” said Tyler Gerczak, Oak Ridge National Laboratory’s principal investigator for the cooperative with X-energy’s subsidiary TRISO-X. “The momentum is incredible.”

Making the ‘most robust nuclear fuel’

The Associated Press toured the lab where X-energy is making small amounts of fuel for testing. Anyone beyond a magenta-and-yellow chain that warns of radioactivity must wear gowns, two layers of gloves and radiation monitors. When they leave, they’re tested for radioactivity.

X-energy, a Maryland-based company, uses uranium to make so-called TRISO fuel — inside what’s known as “pebbles.” Those are the billiard balls. The Energy Department says it’s the because the particles cannot melt in a reactor.

At the lab, the first step is making a uranium cocktail that resembles dark yellow lemonade.

Uranium powder, in the form of triuranium octoxide, gets added to nitric acid, said Dan Brown, vice president of fuel development for TRISO-X. Then carbon and an organic solution are added. They have two glass containers set up — one wears a heated jacket, looking almost like a little sweater, that helps the uranium dissolve into the acid solution. The second cools the acid solution while the carbon source is added, which turns the mix near-black, he said.

At another station, in a long clear tube, the cocktail solidifies into small black spheres with a jellybean-like consistency. Those black balls, about the size of poppyseeds, then travel through machines under temperatures as high as 1,800 degrees Celsius to get protective carbon coatings — like candy dipping — that make them look like very tiny BBs.

X-energy uses graphite and other cohesive materials to bind 18,000 kernels together into a larger sphere. That gets coated in a final layer of graphite to seal the final pebble. In the end, it’s strong enough to withstand the weight of an SUV.

The pebbles will eventually give up their energy in the high-temperature gas-cooled nuclear reactor X-energy is developing, with about 220,000 pebbles per reactor, like gumballs in a gumball machine. When they exit the bottom, if energy remains, the pebbles will return to the top for another pass. Each one could be used about six times. X-energy also plans to make fuel products for other advanced reactor designs.

The national laboratory lends X-energy its expertise, research and high-tech equipment for analysis and will evaluate samples, as will some universities. Other samples are archived. Idaho National Laboratory received a batch for its advanced test reactor, Brown said.

Critics of building more nuclear reactors say they’re too expensive and riskier than other low-carbon energy sources.

“Without a substantial decrease in construction costs, it’s not worth the avoided greenhouse gas emissions,” said David Kemp, a Cato Institute policy analyst.

Kemp said Trump’s 25-year quadrupling goal is unrealistic because it would mean building nuclear reactors faster than ever. The United States lacks any next-generation reactors operating commercially and only two new large reactors have been built from scratch in nearly 50 years. Those two, at a Georgia nuclear plant, were completed years late and at least $17 billion over budget.

Working to ‘amp up’ domestic nuclear fuel production

Many next-generation reactors will use high-assay low-enriched uranium. It’s fuel that’s enriched to a higher level than traditional large nuclear reactors use, allowing the newer reactors to run longer and more efficiently, sit on smaller footprints and produce less waste, according to the .

There’s little of it made in the United States right now.

Only Russia and China currently have the infrastructure to make large amounts of high-assay low-enriched uranium. In the United States, Centrus Energy produced the nation’s first 20 kilograms of high-assay low-enriched uranium in late 2023, to show it can produce limited quantities for commercial reactors.

A big takeaway from Trump’s executive orders is the need to “amp up” domestic production of nuclear fuel to reduce dependence on foreign sources and enable in the long term expansion of American nuclear energy, according to the Energy Department.

At the Nuclear Energy Institute trade association, Benjamin Holtzman, director of new nuclear, said he thinks the fuel will be ready for a new generation of U.S. nuclear reactors needed to meet the growing demand for electricity — if the right actions are taken now.

X-energy CEO J. Clay Sell said he hopes to help solve the fuel problem so it doesn’t hold back new reactor development. The Energy Department has awarded funding to X-energy. Amazon invested in X-energy too, and they’re collaborating to bring more than 5 gigawatts of new U.S. power projects online by 2039.

X-energy is the only one with an application before the U.S. Nuclear Regulatory Commission to license a new fabrication facility to transform enriched uranium into fuel products for nuclear reactors. Another applicant has asked to amend an existing license to make fuel for advanced reactors, according to the NRC. About five additional companies have told the NRC they are interested in making fuel for advanced reactors.

X-energy’s pilot lab at the National Laboratory started in 2016. The company now has 100 acres in Oak Ridge and growing for its nuclear fuel production complex.

The first factory could be operational by late 2027 or early 2028, capable at full operation of assembling enough fuel orbs to power 11 of its new-age reactors; a second by late 2029, with a capacity four times greater, said TRISO-X President Joel Duling.

“I’ve been through two or three ‘nuclear renaissances,’” Duling said. “This isn’t a renaissance. This is a game-changer.”

___

McDermott reported from Providence, Rhode Island.

___

The Associated Press’ climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP’s for working with philanthropies, a list of supporters and funded coverage areas at .

National News

trump washington dc national guard...

Associated Press

Trump says he’s placing DC police under federal control and deploying National Guard

President Donald Trump said Monday he’s placing the Washington, D.C., police department under federal control and deploying the National Guard to make the nation’s capital safer.

4 hours ago

fort stewart georgia shooting...

Associated Press

5 soldiers shot before arrest made at Army’s Fort Stewart in Georgia

Five soldiers were shot Wednesday at Fort Stewart in Georgia, leading to a lockdown at the Army base before the shooter was arrested, officials said.

5 days ago

Titan...

Associated Press

Titan sub disaster was caused by weak safety and oversight, Coast Guard says

The Coast Guard said the Titan sub disaster was caused by weak safety and oversight.

6 days ago

Texas...

Associated Press

Why dozens of Democrats left Texas and how Republicans want to punish them

Dozens of Democratic state lawmakers in Texas have scattered to points across the country.

7 days ago

The U.S. Capitol, Wednesday, July 16, 2025, in Washington. (AP Photo/Julia Demaree Nikhinson)Credit...

Associated Press

August recess can’t hide tensions ahead for Congress on spending and Trump nominations

WASHINGTON (AP) — Lawmakers have left Washington for the annual August recess, but a few weeks of relative quiet on the U.S. Capitol grounds can’t mask the partisan tensions that are brewing on government funding and President Donald Trump’s nominees. It could make for a momentous September. Here’s a look at what’s ahead when lawmakers […]

7 days ago

FILE - Damage can be seen to a front window as law enforcement officers work the scene of a shootin...

Associated Press

Arkansas man sentenced to life without parole for 2024 mass shooting at grocery store

FORDYCE, Ark. (AP) — An Arkansas man who killed four people and injured 11 others last year in a mass shooting at a grocery store was sentenced Monday to life in prison without parole. A state judge sentenced Travis Eugene Posey to four life sentences for each count of capital murder. Posey was also sentenced […]

7 days ago

A look inside a lab making the advanced fuel to power growing US nuclear energy ambitions