Fifty years ago, on the night of 10 October 1957, Britain was on the brink of an unprecedented nuclear tragedy. A fire ripped through the radioactive materials in the core of Windscale, Britain's first nuclear reactor. Tom Tuohy, the deputy general manager at the site, led the team faced with dealing with a nightmare no-one had thought possible.
"Mankind had never faced a situation like this; there's no-one to give you any advice," he said. Tuohy and his men were confronted by a terrifying dilemma.
If they let the fire burn out, it could spread radioactivity over a large area of Britain. But if they put water on the reactor, they risked turning it into a nuclear bomb that could kill them all.
Now tapes of the inquiry into the accident, heard for the first time in a BBC film, reveal the reasons why the politicians covered up the causes of the accident. Scientists had been warning about the dangers of an accident for some time. The safety margins of the radioactive materials inside the reactor were being further and further eroded.
"They were running much too close to the precipice," says Dr Dunworth, a senior manager in the Nuclear Research Laboratory in Harwell, Oxfordshire, who was one of those highlighting the potential dangers.
But the politicians and the military ignored the warnings; instead they increased demands on Windscale to produce material for an H-bomb.
For 50 years, the official record on the accident has been that the very men who had averted a potentially devastating accident were to blame for causing it.
"I resented it at the time," says Peter Jenkinson, who was an assistant physicist at the reactor, "and I hoped the record would be put straight." After the inquiry, he and his colleagues finally got their wish.