Last Energy's Texas micro-modular reactor clears safety analysis

Thursday, 8 October 2026

The Department of Energy's approval of the Documented Safety Analysis clears Last Energy's planned pilot reactor at Texas A&M-RELLIS to move into the readiness review, the final step before authorisation for criticality and reactor operations.

Last Energy's Texas micro-modular reactor clears safety analysis — The pilot facility at RELLIS has already been built (Image: Last Energy)

The Documented Safety Analysis - also known as a DSA - is the final and most comprehensive safety analysis in the Department of Energy (DOE) authorisation process, documenting in detail how the reactor and facility will be operated safely. It builds on the Preliminary Documented Safety Analysis, approved in May 2026.

Last Energy was selected in August 2025 to take part in the DOE Reactor Pilot Program, launched earlier that year to accelerate reactor demonstration by authorising test reactors through the DOE's licensing process. The initiative is part of the Reforming Nuclear Reactor Testing at the Department of Energy executive order signed by President Donald Trump earlier in 2025. Licensing for commercial - rather than demonstration - nuclear plants remains the responsibility of the US Nuclear Regulatory Commission.

A little under a year ago - on 15 October 2025 - Last Energy and the Texas A&M University System announced plans for a microreactor pilot project at Texas A&M-RELLIS, an applied research and advanced technology campus in Bryan, Texas.

Last Energy's PWR-20 is a 20 MWe micro-modular nuclear plant designed for factory fabrication, standard road transport, rapid on-site assembly, and 24/7 baseload power delivery to industrial customers, data centres, and other high-energy users. It is based on existing pressurised water reactor technology, using existing "off-the-shelf" low-enriched uranium fuel and existing supply chains - which the company says reduces technical risk and accelerates project delivery - in a 1,000-tonne, hermetically sealed steel structure designed for factory fabrication and no-access operation.

The PWR-5 pilot plant which will be built at RELLIS will use the same full-scale reactor core as the commercial PWR-20 design. This provides a direct bridge to Last Energy's commercial deployment model, the company says.

Last Energy is also in the licensing process for a proposed plant featuring four PWR-20 modules at Prosiect Egni Glan Llynfi (Llynfi Clean Energy Project) in South Wales in the UK.