NRC clears construction of four reactors at Dow’s Seadrift

By Daniel Okafor

The NRC has authorized construction of four 80-megawatt X-energy Xe-100 reactors at Dow’s Seadrift Operations petrochemical complex on the rural Texas Gulf Coast, adding 320 MW, or 0.32 gigawatt, of planned dedicated onsite capacity to a project still awaiting Dow’s final investment decision. Construction could begin before 2030. The sequence matters. Federal approval comes first; corporate commitment comes next.

What does the permit change?

The permits cover the Long Mott Generating Station, developed by Dow and X-energy at Seadrift, between Houston and Corpus Christi. Long Mott was one of two flagship projects selected by the Department of Energy in 2020 for the Advanced Reactor Demonstration Program, created to stimulate the US nuclear sector.

The NRC approved Dow’s reactor construction permit after an expedited review under executive orders from President Donald Trump intended to accelerate the national energy sector. NRC Chairman Ho K. Nieh said the agency completed its review on an 18-month schedule and showed that rigorous safety reviews can move advanced reactor technology from design to construction on predictable timelines.

Department of Energy principal deputy assistant secretary for nuclear energy Mike Goff called the approval meaningful progress toward deployment. The permit removes the federal construction barrier. It does not compel Dow to build. Dow still owns the final go-or-no-go decision.

How does the Xe-100 work?

Each proposed unit is a small modular reactor designed for factory production, shipment and assembly onsite, rather than the tower-sized construction required for conventional plants. The format supports dedicated installations ranging from petrochemical plants to data centers.

Advanced designs use alternatives to conventional water cooling, from molten salt to gas. X-energy’s Xe-100 uses helium gas and replaces conventional fuel rods with pelletized TRISO particles in a moving bed of pebbles. TRISO fuel, developed in Energy Department laboratories over decades, cannot melt in a commercial high-temperature reactor, according to the department.

The NRC describes the design’s central feature as functional containment. Fuel resilience and pebble circulation are intended to prevent runaway warming that could lead to meltdown. NRC deputy director for advanced reactors Mehdi Reisi Fard said the design relies less on pumps or human intervention to mitigate anomalies than current control systems.

The approved design does not require the towering concrete containment structures characteristic of existing reactors or a 10-mile emergency planning zone. X-energy CEO J. Clay Sell, a former deputy energy secretary, has described the Xe-100 as “physically impossible to melt down.” The wording belongs to the developer; critics dispute it.

Dow’s North American business director for energy and climate, Kreshka Young, said owning a nuclear facility is a different kind of responsibility and that Dow does not take it lightly. The commercial case rests on modular construction and a new safety architecture.

What remains disputed?

Diane Wilson, a retired fourth-generation shrimper from nearby Seadrift and director of San Antonio Bay Waterkeeper, remains deeply skeptical. She called the approval outrageous. Wilson says spent fuel from the reactors would remain on site indefinitely as nuclear waste because the US still has no permanent national disposal site.

In 2025, Waterkeeper challenged the permit application on safety grounds; the NRC dismissed those challenges. Edwin Lyman, director of nuclear power safety with the Union of Concerned Scientists, also rejects the safety claims. “This fuel has vulnerabilities,” he said.

Lyman said developers have sought lower containment costs by arguing that physical containment is unnecessary, while warning that claims of indestructible or meltdown-proof fuel are myths. Regulatory approval settles the permit process, not the technical dispute over fuel behavior and waste storage.

What could Long Mott prove?

At a September public meeting in Port Lavaca, the NRC took questions and comments on Long Mott. Martin O’Neal, general counsel for the Nuclear Energy Institute, said the nuclear industry was watching the project very closely. If successful, Long Mott could provide a pathway for other industries to install dedicated onsite power generation.

National context is thin. In the last three decades, the US has built only one new nuclear power plant, while federal authorities have pushed for a revival based on new reactor designs. The NRC issued its first construction permit for an advanced test reactor in 2023 and its first for an advanced commercial reactor in March 2026.

At Seadrift, the test is practical: four 80-MW modules, 320 MW in total, on one operating petrochemical site. Dow would decide whether to proceed with the four-module build. Other industrial operators would then judge whether the schedule and operating model work. Long Mott could become a template, but only if Dow turns an approved design into an operating plant.

What is the next milestone?

Dow still must make a final decision to proceed. If it gives approval, construction could begin before 2030. No commercial operation date is stated, so a reactor startup schedule would be premature. A permit is not a power station.

Three items now matter:

• Dow’s final decision to proceed.
• A firm construction start, potentially before 2030.
• A commercial operation date and the unresolved spent-fuel storage question.

O’Neal believes success could give other industries a model for dedicated onsite generation. The permit was the first gate. The watch item is Dow’s final investment decision and whether site construction can start before 2030. Without those dates, 320 MW remains an approved plan, not operating capacity.