A tilted fuel assembly pauses loading at the Palisades restart
Serguey Asael Shinder2 min readFuel loading at the Palisades nuclear plant in Covert, Michigan, has been paused after an incident with a fuel assembly, operator Holtec has acknowledged, according to the American Nuclear Society's Nuclear Newswire. Palisades, which last operated in 2022, is attempting to become the first US reactor to return to service after being shut down for decommissioning.
Loading began on 30 August, when the plant entered Mode 6, the refuelling stage. The core holds 204 fuel assemblies, a mix of new fuel and partially used fuel from the plant's last operating cycles. During loading, one previously used assembly tilted from its upright position after it had been placed in the vessel; Holtec says the fuel-handling machine's grapple had already disengaged. Staff notified the Nuclear Regulatory Commission but determined that the event did not trigger reporting requirements under NRC regulations.
Holtec has started a root cause evaluation, and engineers are developing equipment to retrieve the assembly and return it to the spent fuel pool. The plant will submit a licence amendment request to the NRC for the retrieval. Work that does not depend on fuel loading continues, Holtec says, but progress to cold shutdown (Mode 5) and beyond depends on resolving the incident, completing testing and modifications, and receiving NRC approvals. The company did not give a revised timeline; earlier reports said it is contracted to start supplying power by March 2027. Separately, the plant was reconnected to its 345 kV switchyard on 11 September, in coordination with transmission operator ITC.
What it means
A tilted assembly is not a safety event in the sense that matters to the public - the reactor is shut down and the fuel is under water - and Holtec's position is that it was not reportable. But it is a schedule event. Retrieving a leaning assembly from a reactor vessel requires tooling that does not exist yet and an NRC approval that has to be applied for, and until it is out, the core cannot be completed.
Restarts are being watched as a test of whether retired reactors can be brought back quickly. The switchyard reconnection shows the grid side moving; the fuel incident shows how a single mechanical problem inside the vessel can set the pace for everything else.