Corrects headline and first paragraph to show that Triso-X is using HALEU to make reactor fuel, not making HALEU, describes TRISO fuel in paragraph 2

By Timothy Gardner

WASHINGTON, Feb 13 (Reuters) - The U.S. nuclear power regulator said on Friday it issued a license to Triso-X to use a more enriched uranium known as HALEU for making a new fuel for planned high-tech commercial reactors.

Triso-X, a subsidiary of X-energy, plans to make the TRISO fuel, which contains uranium coated in hard ceramic and carbon layers, at a plant in Oak Ridge, Tennessee. "Commercial-scale production of this fuel is key to enabling the deployment of advanced reactor designs," said Ho K. Nieh, the chairman of the Nuclear Regulatory Commission.

Joel Duling, president of TRISO-X, said: "Regulatory approval brings us one step closer to a resilient, American fuel supply for next-generation nuclear technology, closing a longstanding gap in the U.S. nuclear fuel cycle."

Several new reactors being planned by X-energy and other companies are designed to run on HALEU, but are not yet licensed by the NRC.

President Donald Trump wants the U.S. to quadruple nuclear energy output by 2050 as U.S. power demand rises for the first time in decades because of large new data centers needed for artificial intelligence, electric transportation and cryptocurrencies. Last May, Trump ordered the regulator to speed up permitting for nuclear reactors and facilities.

HALEU includes up to 20% enriched uranium, as opposed to about 5% enriched fuel used in today's reactors. It has traditionally been made in commercial amounts only by Russia but is now also being developed in the United States by Centrus LEU.N.

Proliferation experts have warned that HALEU above about 12% enriched could be used to create a crude nuclear weapon.

An X-energy spokesperson said its fuel is proliferation-resistant: "The design of our reactors – to be melt-proof and achieve high burnup and fuel utilization – means there are virtually no remaining active materials in our spent fuel once it leaves the reactor."

(Reporting by Timothy Gardner; Editing by Ethan Smith)

((timothy.gardner@tr.com))