Magnox, a wholly-owned subsidiary of the Nuclear Decommissioning Authority, is the management and operations contractor responsible for 12 nuclear sites and one hydroelectric plant in the UK. Under contract to the site owner, the Nuclear Decommissioning Authority, the company is responsible for electricity generation at Maentwrog, defuelling at Wylfa and the decommissioning of Berkeley, Bradwell, Chapelcross, Dungeness A, Harwell, Hinkley Point A, Hunterston A, Oldbury, Sizewell A, Trawsfynydd and Winfrith.