Dounreay’s clean-up teams are stripping out the equipment that reprocessed the nuclear fuel, to get the plant ready for demolition in 2020.
During the plant’s operational days, irradiated fuel rods from the reactors were received and cropped to remove the fuel, which would be dissolved in hot acid and then separated from the waste fission products in mixer settler vessels in the chemical separation cells.
Decommissioning experts are now emptying the chemical separation cells so that they can be prepared for disposal as bulk low level waste blocks.
They worked in airline suits to remove the pulse generator units which cycled the active liquor in the chemical process cells earlier this year. This forms part of the early facility decommissioning work.
The next phase of work will see all ancillary equipment including the redundant gloveboxes and services external to the cells removed to enable more detailed assay and characterisation of the shielded facilities to be carried out. This will take place over the next year.
Gordon Tait, Dounreay’s senior project manager responsible for the project, said: “The nature of the ground-breaking experimental chemical research work undertaken in the facility over the years has left it heavily contaminated internally.
“We are using lessons learned from the decommissioning of other chemical facilities on site, and drawing on experience gained across the entire nuclear industry to safely tackle this fresh challenge.”
Once the data from the characterisation process has been assessed, the team will begin to remove the remaining intermediate level waste in the cells, before size-reducing the cells themselves. These will be sentenced as bulk low level waste packages in the new waste facility currently being built next to the site.
The work is expected to take 5-6 years to complete, following which the facility will be prepared for demolition.