Nuclear fuel called 'exotics' to leave Dounreay
The remainder of nuclear fuel at Dounreay in Caithness is to be transferred to Sellafield in Cumbria.
Known as "exotics", it includes material containing highly enriched uranium.
The Nuclear Decommissioning Authority (NDA) said arrangements were being made on how to transport the fuel safely and securely.
The first shipments are expected to start in 2014 or 2015 and continue for six years. Dounreay is in the process of being demolished.
In December, work started on moving material called breeder from Dounreay for reprocessing at Sellafield.
The breeder has to be taken by road to a railway station at Georgemas for the rest of the journey from Scotland to England.
Removing all nuclear fuel from Dounreay will mean facilities for handling it there will not have to be built.
The NDA said it would also mean that security at the site could be significantly downgraded once decommissioning was finished at Dounreay by 2025.