Fukushima Daiichi nuclear disaster for caesium-137, which is about 11% of Chernobyl emissions. Earlier estimations were 150 PBq and 12 PBq. In 2011, scientists working for the Japan Atomic Energy Agency, Kyoto University and other institutes, recalculated the amount of radioactive material released into the ocean: between late March through April they found a total of 15 PBq for the combined amount of iodine-131 and caesium-137, more than triple the 4.72 PBq estimated by TEPCO. The company had calculated only the direct releases into the sea. The new calculations incorporated the portion of airborne radioactive substances that entered the ocean as rain. In the
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