Watch BBC Documentaries online: Episode 37 Windscale: Britain's Biggest Nuclear Disaster

Fifty years ago, Britain suffered its worst nuclear accident. On the night of 10 October 1957, a fire began to spread throughout the core of the Windscale nuclear reactor, sending radioactive dust across Britain. Using the taped recordings of the inquiry into the fire - which have been kept secret ever since the disaster and are heard for the first time - and featuring interviews with the men who risked their lives to prevent a tragedy, this film reveals how political ambition fuelled the fire and then dictated that the heroes of Windscale be made the scapegoats. The Windscale nuclear reactor was a project on an unprecedented scale. Designed to produce materials first for Britain's A-bomb, and then for the H-bomb, it was a triumphant statement of British scientific and technological prowess. But, beneath its image, Windscale had been built in a hurry - with dire consequences. Radioactive leaks were found and the core of the reactor began dangerously overheating. Some scientists warned that radioactive materials inside could catch fire. But the leaks were hushed up and the warnings ignored. Instead, Windscale was ordered to achieve even greater increases in output to meet a political deadline to explode Britain's first H-bomb. The result was potential disaster - the core of the reactor caught fire and radioactive dust began spreading over the country. Windscale workers faced a terrible dilemma - if they tried to put the fire out with water they risked turning the reactor into a gigantic nuclear bomb, and if they let the fire burn, it could contaminate people across a huge area. Risking death from explosion and radioactive poisoning, the Windscale men averted a major tragedy. The inquiry revealed that the warnings about the risks had been hushed up or ignored. But the government kept its findings secret, and instead blamed the fire on an "error of judgement" by the very workers who had first warned of the potential problems and then battled so heroically to prevent tragedy. Now, for the first time, they are able to tell the full story of what happened 50 years ago.

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