First nuclear waste moved from Dounreay to Sellafield
17 December 2012 Last updated at 15:40 GMT
The first of dozens of rail shipments of nuclear waste from Dounreay to Sellafield was made overnight.
A total of 44 tonnes of material is being moved.
The shipment will be turned into plutonium and uranium to create more fuel for nuclear power plants.
Environmental group Friends of the Earth have said moving the material is a risk to communities along the route.