Hunterston A storage pond clearance completed

02 October 2018

Work to empty and decontaminate the former used fuel storage pond at the Hunterston A Magnox nuclear power plant in Scotland was recently completed, removing one of the site's highest hazards.

The emptied storage pond at Hunterston A (Image: Magnox Ltd)

The project involved draining some one million gallons of water and removing more than 10 tonnes of redundant equipment from the largest used fuel storage pond in the Magnox fleet, Magnox Limited said.

The company said the project had to overcome "several unique decommissioning challenges". These included the removal of radioactive sludge and fixed equipment on the pond floor under around 9 metres of water.

The project team 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. In addition to 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. This, Magnox Ltd said, "enabled workers to 'work on water' and manually decontaminate the pond walls, removing the hazards of working at height and over water."

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."

David Rushton, the NDA's lead programme manager, 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." He added, "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."

Magnox Ltd said work has already begun on the next stage of decommissioning the ponds building, removing redundant plant and equipment around the outside of the building.

Hunterston A - a twin Magnox reactor site - is 30 miles south west of Glasgow and was Scotland's first civil nuclear generating station. The plant, opened in 1969, ceased operations in 1989 after generating a total of 73 TWh of electricity.

Magnox Ltd, owned by Cavendish Fluor Partnership, is the management and operations contractor responsible for safely managing 12 nuclear sites and one hydroelectric plant in the UK working for the sites' owner, the Nuclear Decommissioning Authority (NDA). The company is to become an NDA subsidiary from 1 September 2019.

Researched and written by World Nuclear News