NRC grants Holtec exemption to begin early ground construction for Pioneer nuclear units at Palisades site in Michigan
The U.S. Nuclear Regulatory Commission granted Holtec an exemption on August 28, 2026, letting the company kick off early ground construction at the Palisades Energy Center in Covert, Michigan — before a formal Limited Work Authorization has even been issued. The approval covers installation of support-of-excavation and cutoff-wall systems for Pioneer Units 1 and 2, two planned small modular reactors at the site.
That’s not how this usually goes. Construction-related work at a nuclear facility typically follows regulatory authorization milestones, not the other way around.
NRC issues exemption ahead of formal construction permit
The NRC granted the exemption under 10 CFR 50.12 — the federal regulation that lets the commission authorize specific activities that would otherwise require a full permit. It came roughly eight months after Holtec submitted its exemption request on December 31, 2025, as part of Phase 1 of a phased Construction Permit Application. That package also included a Limited Work Authorization application and an Environmental Report.
On August 25, 2026 — three days before the exemption was formally granted — the agency published an Environmental Assessment and a Finding of No Significant Impact.
Here’s the key distinction: this exemption is not the LWA itself. The NRC was explicit — granting it doesn’t commit the agency to issuing a Limited Work Authorization or a full construction permit down the road. It clears a narrow set of early ground activities, and nothing more.
What the exemption authorizes and why Holtec requested it
Holtec’s goal was straightforward: get ground prep moving without waiting for the full LWA process to wrap up. The company can now proceed with excavation, dewatering, and ground-improvement work at Palisades while the broader regulatory review runs in parallel.
The authorized systems are quite specific — diaphragm walls, soldier-pile soil-mix walls, and perimeter cutoff walls, with tiebacks or struts as needed. Together, these stabilize excavations, protect nearby structures and utilities, and manage groundwater pressure during construction. One detail worth flagging: the support-of-excavation walls won’t actually be removed when construction advances. They’ll be retired in place, with backfill applied between the walls and the permanent structures, which simplifies the construction sequence considerably.
NRC environmental and safety review findings
Before issuing the exemption, the NRC ran its own environmental and safety review. On August 25, 2026 — three days before the exemption was formally granted — the agency published an Environmental Assessment and a Finding of No Significant Impact. The authorized activities wouldn’t significantly affect the human environment or historic properties, and a separate environmental impact statement wasn’t required.
On the safety side, the NRC determined the exemption presents no undue risk to public health and safety and is consistent with common defense and security requirements. The agency also found reasonable assurance that installing and later retiring the SOE walls wouldn’t adversely affect the safe design or siting of Pioneer Units 1 and 2.
Holtec carries ongoing obligations under the exemption. Geologic mapping and data collection must be performed during excavation, the NRC must be notified when excavations are open for inspection, and the retired SOE walls must be factored into soil-structure interaction analyses. These conditions keep the agency informed as work progresses.
Scope of early construction work enabled at Palisades
The exemption covers early works across three major areas of the planned plant: the Nuclear Island, the Turbine Island, and the Balance of Plant structures. Each zone needs stable excavation and foundation conditions before more advanced construction can begin.
Authorized activities include SOE and cutoff-wall installation, excavation, dewatering, and ground improvement. The intent is to get the site’s foundation conditions ready so that once the LWA is formally approved, construction can accelerate rather than restart ground prep from zero. The scale of what’s planned is significant — Pioneer Units 1 and 2 are designed to generate a combined 680 megawatts of capacity, enough to power hundreds of thousands of homes once operational.
Background: Holtec’s broader nuclear development program at Palisades
The Pioneer units aren’t the only major nuclear project Holtec is managing at Palisades. The company is simultaneously working to recommission the existing Palisades nuclear power plant — a project that, if completed, would make it the first commercial reactor in the U.S. to come back online after a permanent shutdown. Holtec holds NRC-authorized operator status for that plant.
Pioneer Units 1 and 2 are based on Holtec’s SMR-300 small modular reactor design, which uses passive safety systems. Rather than active mechanical systems, the reactor relies on natural forces like gravity and convection to maintain safe conditions. The Palisades site in Covert, Michigan, is company-owned, and Holtec International currently expects it to host the first SMR-300 deployment. As of mid-2026, Holtec holds more than 200 granted patents, operates across five continents, and has provided products and services to more than 150 nuclear reactors worldwide.
An unusual sequence in nuclear development
The August 28 exemption is a concrete step forward for Pioneer Units 1 and 2 — but a narrow one. Holtec now has regulatory clearance to begin support-of-excavation and cutoff-wall installation at Palisades before a Limited Work Authorization is in hand, which is an unusual sequence in nuclear development.
The NRC’s environmental and safety reviews found no significant concerns with the authorized activities. Holtec must still meet ongoing inspection and mapping obligations as excavation moves forward. The LWA itself — and eventually a full construction permit — remain separate regulatory milestones. The exemption gets the ground ready. Everything else still has to follow the standard process.
Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.
