Palisades Nuclear Power Plant Restart: After Removing a Tilted Fuel Assembly, How Far Remains to Grid Connection?

At the Palisades Nuclear Power Plant on the eastern shore of Lake Michigan, Holtec manufactured a specialized lifting rig and transfer cask for a tilted fuel assembly. On October 21, the company confirmed that the assembly had been removed from the reactor pressure vessel and transferred to the spent fuel pool. On October 29, U.S. Secretary of Energy Chris·Wright visited the plant, and Holtec's project update on the same day still listed fuel loading completion, testing, inspections, and operational readiness as return-to-service work. Palisades was shut down in 2022 and had entered the decommissioning pathway. This removal allowed the fuel loading project to continue, and also exposed a period in the restart plan that is easily underestimated—after equipment is brought back to condition, its performance must still be demonstrated item by item under the current license.

Why Conventional Handling Equipment Must Stop When a Fuel Assembly Is Misaligned

A pressurized water reactor fuel assembly consists of a bundle of slender fuel rods and their supporting structure. During normal fuel loading, the lifting rig grasps the assembly from the top at the designed position, the handling machine moves underwater along a prescribed path, and the assembly is then placed into the core support structure. The geometric position during operation is related to coolant flow channels and core configuration, so grasping and seating during the loading phase also have strict positioning requirements. Once an assembly deviates from its intended orientation, the previously known grasping angle, lifting point loads, and surrounding clearances may all change. Continuing to apply force with conventional handling machines could bring the assembly or reactor internals into a position that is more difficult to remediate.

In this recovery operation, Holtec used a specially designed Fuel Movement Device and transfer cask. The assembly was controllably lifted from its original position, placed into the cask, and subsequently transferred to the pool. The company disclosed that the U.S. Nuclear Regulatory Commission approved a license amendment application for this special removal method. The approval here has a very specific object, namely completing the disposition of an abnormal fuel assembly using a specific method. After disposition is complete, fuel loading records, core configuration, and equipment inspections must still each form traceable evidence.

Long-Term Shutdown Has Changed the Entire Plant's Demonstration Task

Startup following a periodic refueling outage typically continues a maintenance, training, and equipment management system that has been maintained under an operating license throughout. Palisades' engineering scope is larger. After the unit was shut down in May 2022, the project was initially carried out along the decommissioning pathway before subsequently pivoting to power restoration. The U.S. Nuclear Regulatory Commission established a dedicated restart review mechanism for this purpose, incorporating restoration of the licensing basis, confirmation of equipment condition, and required modifications into separate reviews. In July 2025, the regulator approved a series of licensing items to advance return-to-service, while making clear that conditions remained to be satisfied.

For the plant, the most direct task is to restore systems to a mutually compatible state. An emergency pump starting on its own only demonstrates that it has completed partial functional verification. Whether it can automatically engage under an accident signal, how power supplies and valves switch over, where cooling water comes from, and how the control room confirms status must still be demonstrated through corresponding integrated tests. Disconnections, replacements, long-term layup, or configuration changes that occurred during the shutdown period must also be aligned with current drawings, test procedures, and operating procedures. Operating experience preserved from the older unit is valuable, but the final review must answer questions based on the current equipment condition.

What the Loan, Power Purchase Agreement, and Startup Testing Each Address

In September 2024, the U.S. Department of Energy completed a $1.52 billion loan to provide financing support for the restoration project of this approximately 800-megawatt nuclear power plant. This figure is the loan amount for the U.S. project; total project investment, actual amount drawn, and final levelized cost of electricity are different measures. Holtec also disclosed that the project has a long-term Power Purchase Agreement (PPA) with a regional electric cooperative. The loan addresses part of the funding source for the modification and preparation phase, while the PPA provides contractual demand for future electricity. Both can only manifest as capacity actually delivered to the grid after the unit meets operating conditions.

Initial Criticality in this project should be understood as the first controlled criticality after return-to-service, i.e., the in-core chain reaction reaching a self-sustaining state. This is followed by low-power testing, phased power ascension, and turbine-generator grid connection and load verification. Each stage observes different parameters. The low-power stage focuses on verifying core physics characteristics and instrumentation response, while the high-power stage also tests the integrated performance of the steam-water system and electrical equipment under load. First delivery of electricity to the grid is one visible milestone; sustained delivery must be judged by subsequent operating records.

The Experience from This Restart Will Be Reflected in the Engineering Record

What is most worth verifying in the Palisades follow-up is how fuel loading and system inspections are completed, how the regulator records satisfaction of return-to-service conditions, and whether equipment issues requiring rework arise during power ascension. If stable power generation can be achieved, the actual shutdown duration, equipment restoration investment, startup testing period, and electricity sales realization can be placed on the same timeline. Whether other shut-down plants can learn from this depends on whether each has retained comparable equipment condition, technical records, and personnel capabilities.

(This article is based on Holtec's fuel disposition and site updates, U.S. Nuclear Regulatory Commission licensing materials, and U.S. Department of Energy loan records, and was independently written after AI-assisted organization, for the purpose of explaining the engineering and regulatory processes of restoring operation after a nuclear power plant shutdown. The October events serve as known background; return-to-service and grid connection milestones are subject to subsequently officially disclosed records.)