1947: Old munitions factory site at Windscale chosen for producing plutonium after the Prime Minister, Clement Attlee, takes the decision to mount a crash programme to build British atomic bomb.

1950: First plutonium production reactor starts up. Site remains a secret. Anyone disclosing information about the plant liable to five years in jail. But newspapers arrive every day at the railway station marked for delivery to "The Atom Bomb Plant".

1956: Queen opens Britain's first commercial nuclear power station at Calder Hall next to the plant, predicting a solution to the energy crisis as this new power "which has proved itself to be such a terrifying weapon of destruction, is harnessed for the first time for the common good".

1957: Fire rages out of control for four days in the world's worst nuclear accident before Chernobyl. Full-scale disaster averted because of the installation of safety filters which trap the radio- activity. But 260 people are thought to have contracted cancer.

1977: Windscale Inquiry into building the Thorp plant to reprocess modern reactor fuel after an accident contaminates 35 workers. Plant gets go-ahead, but not built for over a decade.

1981: After more accidents name changed to Sellafield. Mishaps continue, giving Sellafield an even worse name.

1983: Discharge of radio- active waste contaminates coast. BNFL plays down incident, but TV documentary discovers high levels of leukaemia in local children.

1993: John Gummer, then environment secretary, gives permission for Thorp to start on the basis of a report by Touche Ross that it would be profitable. Last year IoS revealed this report had never existed. Thorp begins operations, but fails to reach targets.

1994: Main raison-d'etre for reprocessing nuclear fuel destroyed when the Conservative government scraps programme of fast-breeder reactors, designed to be fuelled by plutonium.

1997: Another disaster for Sellafield. On the day the election is called, Mr Gummer halts investigations into building a nuclear dump near the complex after studies show that it is likely to leak.

1998: Britain agrees to cut discharges from Sellafield to "close to zero" by 2020. Opponents say this would make reprocessing impossible. Ministers are asked to rule on application to start up a new plant at Sellafield to make fuel from plutonium. Opponents say this would put enough plutonium for 550 bombs on to the roads and railways each year.

1999: New German government says it will stop sending spent fuel to Sellafield for reprocessing.