The world’s oldest operating nuclear reactors will be taken out of action on Sunday when British Nuclear Group closes Dungeness A and Sizewell A. The reactors, which have been producing electricity for 40 years, are being decommissioned partly because increased safety inspection demands will render them no longer cost effective. Their lives have also been shortened because a reprocessing plant at Sellafield, which is necessary to make their spent fuel safe, is itself due to close in a few years.  The closure of the reactors will further dent the finances of the Nuclear Decommissioning Authority, which is suffering after the Government decided not to make up a shortfall caused by a loss of revenue from commercial operations.The authority receives about half its £2 billion income from work carried out by BNG, whose assets it owns. The income comes from generation and from reprocessing clean-up work. Last year the Magnox fleet generated £514 million for the authority. BNG said that the two stations that are to close are capable of producing enough electricity for all of the UK’s domestic customers. The closure of Sizewell A in Suffolk and Dungeness A in Kent will leave just two Magnox reactors in the country Oldbury, in Gloucestershire, and Wylfa, on Anglesey, North Wales. In recent years, Britain’s Magnox stations, which produce electricity using heated magnesium alloy, have been overtaken by newer technology, first in advanced gas reactors and then in Britain’s only pressurised water reactor at Sizewell B. The world’s first nuclear reactor was a Magnox reactor Calder Hall, which opened on the Sellafield site in 1956. That plant closed three years ago. The other Magnox reactors that have closed are: Berkeley, in Gloucestershire; Hunterston A, in Ayrshire; Hinkley Point, in Somerset; Trawsfynydd, in Gwynedd, North Wales; Bradwell, in Essex; and Chapelcross, in Dumfriesshire.

Last week, Berkeley achieved partial delicensing as it continues its decommissioning. This means that a large section of land is considered safe enough to make it available for reuse. The Magnox fleet was put into British Nuclear Fuels Ltd when the newer part of the nuclear industry was privatised in the form of British Energy. The bulk of BNFL has now been renamed as BNG and soon will be privatised in a four-way split. However, private contractors will be able to bid only for management contracts rather than assets in the break-up of the operation. Last week it began the process of selling its reactor sites management business. The management of the sites will deal with both generation at the two remaining sites and decommissioning at the others. The electricity trading division has also been put up for sale.