Generating electricity by means of nuclear energy was a young industry in 1957. The Windscale plant on the Irish Sea was not about providing electricity for the people, but weapons-grade plutonium for the military. The on-site Calder Hall nuclear power station did generate power, but the two air-cooled reactors at Windscale commissioned back in 1950 (Piles 1 and 2) had only one purpose – producing plutonium-239 for Britain’s H-bombs.
In October, the graphite core of Pile 1 caught fire, initially without its operators realizing there was a problem. But when radiation gauges on the cooling-tower filters redlined, two men suited up and went to inspect the reactor. They removed an inspection plug and to their horror saw fuel within the core was red-hot. It was more than possible that the fire would reach temperatures at which the reactor’s reinforced concrete containment would collapse, releasing a disastrous cloud of radioactive contaminants.
Initial firefighting attempts failed miserably. The ejection of undamaged fuel cartridges merely stopped the raging inferno from becoming even more intense. An attempt to blow out the fire by using the reactor’s powerful fans merely exacerbated the situation, and the injection of carbon dioxide to starve the fire also proved unsuccessful. As the soaring temperature became critical, there was only one highly risky option left – water.
This was incredibly dangerous. The molten metal core would oxidize in water, creating hydrogen that could mix with air and cause a massive explosion, which would undoubtedly demolish the reactor and scatter lethal radioactivity far and wide. Mercifully, the forced gamble paid off and 24 hours later the fire was out and Pile 1 was cold, with a relatively minor radiation spill in comparison with what might have been. A mass tragedy had been averted. But it was the nearest of misses.
When: October 10 1957
Where: Near Seascale, Cumbria, UK
Death toll: There were no casualties at the time. Whether or not the later cancer cluster in the area is attributable to Windscale is a matter of controversy. It is estimated that some 240 cancer deaths probably resulted from the radiation released into the atmosphere.
You should know: Late in the construction of Windscale Piles 1 and 2, Sir John Cockcroft – director of Britain’s Atomic Energy Research Establishment and an eminent nuclear physicist – asked that bulky and expensive high-performance filters should be fitted to the cooling towers. He was roundly criticized for this demand, but insisted, in the event his foresight would prevent a serious industrial accident becoming a major nuclear catastrophe.