NRC issues first high-temperature gas-cooled reactor construction permit in nearly 60 years

ROCKVILLE, Md. — The Nuclear Regulatory Commission (NRC) has issued a construction permit for the Long Mott Generating Station in Calhoun County, Texas, which the NRC said is the first construction permit for a high-temperature gas-cooled reactor in nearly 60 years.

The permit clears the way for Long Mott Energy to build a four-reactor facility. It is the third advanced reactor construction permit the NRC has issued this year, the NRC said.

The facility is designed to include four X-energy Xe-100 reactors. According to the NRC, it will primarily generate high-temperature steam for industrial use at the Dow Seadrift Operations site and export excess electricity to the grid.

The NRC said the permit marks several regulatory firsts:

- its first approval of a multimodule advanced reactor facility - its first approval of a reactor with a pebble-bed core - its first approval of a design featuring online nuclear refueling - its first review of a high-temperature gas-cooled reactor under its risk-informed, technology-inclusive Licensing Modernization Project framework

"We delivered on the 18-month schedule, proving we can do rigorous safety reviews on predictable timelines that move advanced nuclear technology from design to construction," NRC Chairman Ho K. Nieh said.

NRC staff completed the safety evaluation in October, one month ahead of schedule, according to the NRC. The NRC issued its Environmental Assessment and Finding of No Significant Impact in May.

The construction permit authorizes the company to build the facility but does not authorize operation. Before loading fuel or operating the reactors, the company must obtain a separate operating license from the NRC.