The Construction Permit Application process was initiated with the limited work authorisation request and Environmental Report submitted in December of 2025. A limited work authorisation allows certain construction activities to commence before a construction permit or combined construction and operating licence has been issued. The Nuclear Regulatory Commission (NRC) accepted it for review and docketed it in February. Holtec said the NRC’s draft Safety Evaluation Report for the limited work authorisation application, the first phase of the Construction Permit Application, is anticipated in December 2026.
The Preliminary Safety Analysis Report provides the NRC with detailed technical and safety information supporting Holtec’s application to construct Pioneer 1 and 2, two planned SMR-300 small modular reactors at the Palisades site. The SMR-300 is a pressurised water reactor (PWR) producing about 300 MW of electrical power or 1,050 MW of thermal power for process applications. The Palisades site is also home to a single-unit 805 MWe PWR, which closed in 2022 and Holtec is now in the process of bringing it back into service.
“This submittal, the most significant step to date toward establishing the regulatory framework for the Pioneer plant, was preceded by numerous pre-submittal engagement meetings with the NRC and sustained rigorous technical interactions with the Commission’s staff,” Holtec said.
Holtec said it will now work completing a Class 2 construction estimate, a 4D simulation of the entire plant showing the step-by-step evolution of construction, and completion of the confirmatory safety analyses supporting the plant’s Final Safety Analysis Report.
A safety evaluation report and environmental assessment are required before the NRC can approve reactor projects. Holtec will need to file a separate licence application to operate the units after they are built.
An exemption granted by the NRC on 28 August authorised installation of permanent support-of-excavation and cutoff-wall systems for Pioneer units 1 and 2. These systems include diaphragm walls, soldier-pile soil-mix walls, and perimeter cutoff walls, with tiebacks or struts as needed, Holtec said. These early works will establish the stable excavation and foundation conditions needed to support and accelerate subsequent plant construction following limited work authorisation approval. The support-of-excavation walls will eventually be “retired in place”, with the space between the walls and permanent structures backfilled to grade, it added.
“We are grateful for the US Department of Energy’s generous and timely support of the Pioneer deployment programme, which is helping accelerate the project,” the company said. “We also appreciate the NRC’s risk-informed regulatory posture, critically constructive engagement, and responsiveness of their staff, which have helped enable the strong pace of progress reported herein. And we remain in debt to our global SMR-300 team for their hard work, dedication, and commitment to our shared goal to provide clean baseload electrical energy to people in the US and around the world.”
The Pioneer reactors are planned to be brought online in the early 2030s.
