The nuclear plant near Annan stopped generating in 2004
The Chapelcross nuclear plant has been given formal permission to start the three-and-a-half-year defuelling of its four reactors.
It is the latest step in the lengthy process to decommission the Dumfries and Galloway power station.
Chapelcross ceased generation in 2004 and preparation for defuelling has now been completed.
The radioactive fuel rods will be taken to the nearby Sellafield plant in Cumbria for reprocessing.
Site director Dave Wilson said it was a "major step forward" in the decommissioning programme.
"The main focus for the next three-and-a-half years will be the safe defuelling of the site's four Magnox reactors and the transportation of the fuel to Sellafield for reprocessing," he said.
"This is also a very significant part of the national programme for the closure, defuelling and decommissioning of the UK's Magnox reactor sites."
Chapelcross nuclear plant, near Annan, was built in 1959. Its landmark cooling towers were demolished in May last year.