A project to drain around a million gallons of water and remove over 10 tonnes of redundant equipment from the largest used fuel storage pond in the Magnox fleet has been completed.
Finishing the complex work to empty and decontaminate the former used nuclear fuel storage pond at Magnox’s Hunterston A Site, which is owned by the Nuclear Decommissioning Authority, has seen one of the site’s highest hazards removed.
The project has overcome several unique decommissioning challenges including the removal of radioactive sludge and fixed equipment on the pond floor under around nine meters of water.
The team at Hunterston A pioneered several innovative decommissioning approaches such as decontamination of the pond walls using ultra-high pressure water jetting and ‘concrete shaving’ on some of the surfaces.
Richard Murray, Magnox Ponds Programme Manager, said: “The team at Hunterston A has worked together to complete the work safely, often in difficult conditions. The complex nature of the work meant we needed to come up with new ways of completing challenging tasks in a safe and efficient manner, a challenge the team has continually risen to.”
As well as installing a new water treatment system, to safely process radioactively contaminated water, the project also pioneered the use of a floating ‘pontoon’ on the pond water surface – allowing workers to ‘walk on water’ and manually decontaminate the pond walls, removing the hazards of working at height and over water.
Another major benefit of this approach was the ability to access all areas of the pond safely and simultaneously allowing different work to progress in parallel – significantly reducing the time, cost and delivering value to the taxpayer.
The NDA’s Lead Programme Manager, David Rushton, said: “Completing this work in the ponds is a great stride forward in decommissioning and hazard reduction at Hunterston A, but the team also deserve recognition for developing innovative approaches to overcome the challenges they’ve faced.
“Many of these problems are being tackled for the first time anywhere in the world and the tools, and techniques the Magnox team has developed will be invaluable for the decommissioning work at other sites across the NDA estate.”
Work has already begun on the next stage of decommissioning the ponds building, removing redundant plant and equipment around the outside of the ponds building.