A project to has been completed drain around a million gallons of water and remove over 10 tonnes of redundant equipment from the former used nuclear fuel storage pond at UK Magnox Ltd’s Hunterston A Site, which is owned by the Nuclear Decommissioning Authority.
The project, to finishing the work to empty and decontaminate the largest used fuel storage pond in the Magnox fleet, has overcome several unique decommissioning challenges. Magnox Ltd said. These included the removal of radioactive sludge and fixed equipment on the pond floor under around nine metres of water.
The Hunterston A team pioneered several innovative decommissioning approaches including decontamination of the pond walls using ultra-high pressure water jetting and ‘concrete shaving’. 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, which allowed workers to ‘walk on water’ and manually decontaminate the pond walls, removing the hazards of working at height and over water. Magnox said another significant 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.
“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,” said NDA’s Lead Programme Manager, David Rushton, said: 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.