Lake Karachay The lake accumulated some 4.44 exabecquerels (EBq) of radioactivity over less than one square mile of water, including 3.6 EBq of caesium-137 and 0.74 EBq of strontium-90. For comparison, the Chernobyl disaster released 0.085 EBq of caesium-137, a much smaller amount and over thousands of square miles. (The total Chernobyl release is estimated between 5 to 12 EBq of radioactivity, however essentially only caesium-134/137 [and to a lesser extent, strontium-90] contribute to land contamination because the rest is too short-lived). The sediment of the lake bed is estimated to be composed almost entirely of high level radioactive waste deposits to
Windscale Piles There was a release to atmosphere of radioactive material that spread across the UK and Europe. The accident was rated a level 5 on the International Nuclear Event Scale. The chimney filters were credited with maintaining partial containment and thus minimising the radioactive content of the smoke that poured from the chimney during the fire. This included a large quantity of tritium, but it proved to be a negligible radiological hazard compared with the other radionuclides. The fire released an estimated of iodine-131, of caesium-137, of polonium-210 and of xenon-133. Iodine-131, which may lead to thyroid cancer, made the most