Last Energy Seeks Permit for PWR-20 Reactor

The Texas-planned 20-megawatt pressurized-water reactor takes a step toward construction with a limited work authorization request for its foundation.

Updated on Nov. 9, 2026 in Nuclear

Isometric editorial illustration of an excavated foundation pit with exposed steel rebar and a small cylindrical reactor vessel outline on a flat plain. — Last Energy submitted an initial construction permit application to the Nuclear Regulatory Commission on Oct. 20, seeking limited work authorization for its 20-megawatt PWR-20 reactor foundation in Texas. AI Illustration. Upload story photo >

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Last Energy submitted an initial component of a construction permit application to the Nuclear Regulatory Commission on Oct. 20, requesting limited work authorization for the foundation of its PWR-20 reactor. The pressurized-water design is intended to produce about 20 megawatts of electricity.

Why it matters

The filing advances a project that uses technology found in most U.S. commercial reactors and fuel nearly identical to commercial low-enriched uranium pellets, a combination that bears on how advanced reactors reach Texas. The company's separate challenge to a 1956 classification rule also shapes the regulatory path for small reactors.

The filing is an official NRC submission requesting limited work authorization for the PWR-20 foundation, with the design rated at about 20 megawatts. The source does not say whether the NRC will approve the request or what the review timeline will be.

The players

Last Energy

Last Energy is a nuclear reactor developer pursuing small pressurized-water designs for deployment in Texas.

Nuclear Regulatory Commission

The Nuclear Regulatory Commission is the independent U.S. federal agency that licenses and regulates civilian nuclear reactors.

The details

Last Energy submitted the initial construction permit component to the Nuclear Regulatory Commission, seeking limited work authorization for the PWR-20 foundation. The company's separate PWR-5 pilot, scaled to 5 megawatts, is part of the Department of Energy's Reactor Pilot Program at Texas A&M's RELLIS campus.

December 2024: Last Energy joined Texas and Utah in a federal lawsuit challenging the 1956 reactor rule.
July 4: Deadline by which program participants had reached criticality; Last Energy was not among them.
Oct. 20: Last Energy submitted the PWR-20 construction permit application component.

Big Picture

Last Energy's federal lawsuit, joined by Texas and Utah, challenges the 1956 rule that treats all reactors as utilization facilities requiring an NRC license. The plaintiffs argue the Atomic Energy Act applies only to reactors relevant to common defense or public health and safety.

If approved, the PWR-20 would add roughly 20 megawatts of electricity generation in Texas using fuel nearly identical to standard commercial uranium pellets. The outcome of the NRC's review will determine whether small reactors like this can be built under the existing licensing framework.

The takeaway

Small reactors built on commercial-style technology may face a licensing path shaped by the outcome of the 1956 rule challenge. Readers tracking Texas energy policy should watch how the NRC responds to the limited work authorization request.