Windscale fire 2037. There was a release to atmosphere of radioactive material that spread across the UK and Europe. The fire released an estimated 740 terabecquerels (20,000 curies) of iodine-131, as well as 22 TBq (594 curies) of caesium-137 and 12,000 TBq (324,000 curies) of xenon-133, among other radionuclides. Later reworking of contamination data has shown national and international contamination may have been higher than previously estimated. For comparison, the 1986 Chernobyl explosion released approximately 1,760,000 TBq of iodine-131; 79,500 TBq caesium-137; 6,500,000 TBq xenon-133; 80,000 TBq strontium-90; and 6100 TBq plutonium, along with about a dozen other radionuclides in large amounts.
Caesium-137 possible so that some of the 110,000 people can return. A number of techniques are being considered that will be able to strip out 80% to 95% of the caesium from contaminated soil and other materials efficiently and without destroying the organic material in the soil. These include hydrothermal blasting. The caesium precipitated with ferric ferricyanide (Prussian blue) would be the only waste requiring special burial sites. The aim is to get annual exposure from the contaminated environment down to 1 millisievert (mSv) above background. The most contaminated area where radiation doses are greater than 50 mSv/year must remain off