NRC approves X-energy’s four-reactor Texas construction permit
The permit clears the way for four X-energy Xe-100 reactors at Dow’s Texas site, but a separate operating licence will still be required.
The U.S. Nuclear Regulatory Commission has approved a construction permit for the Long Mott Generating Station in Calhoun County, Texas — the first permit for a high-temperature gas-cooled reactor that the agency has issued in nearly 60 years.1
The project will contain four X-energy Xe-100 reactors at Dow’s Seadrift Operations site. The facility is designed to provide high-temperature steam for industrial use, with excess electricity sent to the grid.1 The NRC says the decision is also its first approval of a multimodule advanced reactor facility, a pebble-bed core, online nuclear refuelling and a high-temperature gas-cooled reactor reviewed under its risk-informed licensing framework.1
What the permit means
A construction permit is not permission to operate the plant. The project will need a separate operating licence before it can load fuel or begin generating power.1 The NRC’s Long Mott project page describes the proposed plant as a four-module, 800 MWth/320 MWe facility using graphite pebbles with TRISO particle fuel.2
That distinction matters because the permit is a regulatory milestone, not a launch date. It clears the way for construction while leaving further safety and operating approvals ahead. X-energy and Dow are pitching the project as a way to supply both industrial heat and electricity from one site, a combination that could make advanced nuclear more relevant to heavy industry than a power-only plant.
Our opinion
The interesting part is not simply that another reactor design has received permission to be built. It is that the Long Mott project treats nuclear power as industrial infrastructure: a source of process steam as well as electricity. If the next licensing steps and construction schedule hold, this could become a useful test of whether advanced reactors can serve factories directly rather than waiting for the grid to absorb them. The permit is a significant step, but the technology still has to move from a detailed rendering to a working plant.
The NRC says its staff completed the project’s comprehensive safety evaluation in October, one month ahead of schedule.1 The permit therefore marks the start of a new phase for X-energy and Dow, not the end of the regulatory process.