The radioactive fallout from the Windscale nuclear disaster in Cumbria 50 years ago was underestimated, scientists claim.
The 1957 fire at the nuclear facility on Britain's west cost released radioactive material across the UK, Ireland and the rest of Europe. Windscale was renamed Sellafield in the 1980s.
But research now claim the incident generated twice as much radioactive material than was previously thought and may have caused dozens more cases of cancer.
There have been claims previously that the fire caused birth defects and cancer in areas of north Co Louth. Dundalk is the nearest Irish town to Sellafield.
The new claims were published in the journal Atmospheric Environment. Anti-nuclear campaigners are to mark the 50th anniversary of the Windscale disaster this week.
The Windscale disaster happened on October 10th, 1957, when a failure to graphite control rods got too hot inside reactor sparking a major fire.
At the time, radiation was measured and estimated, and measures put in place to limit contamination. But the new analysiss by John Garland, formerly of the UK Atomic Energy Authority, and Richard Wakeford, a visiting professor in the University of Manchester, suggests the contamination of the environment may have been much higher.
They carried out a re-analysis of the old data and combined it with computer models that revealed how the radioactive cloud would have spread, according to the BBC. They confirmed radioactive iodine and caesium were released, as well as polonium and a very small amount of plutonium, but found that the levels would have been higher than previously thought.