It is now considered the third most serious nuclear disaster, behind Chernobyl and Fukushima. However, if the amount of Caesium (Cs-137) and Strontium (Sr-90) isotope emissions from both disasters is analyzed, it turns out that the Kyshtym disaster ranks second.
The Mayak tank explosion released 1,080,000 Ci of Cs-137 and Sr-90 into the atmosphere, while the Fukushima explosion released "only" 350,000 Ci of these isotopes, of which 280,000 Ci into the ocean and 70,000 Ci into the atmosphere.
A report by the UN Scientific Committee on the Effects of Atomic Radiation showed that the Mayak plant's activities released almost three times as many Cs-137 and Sr-90 isotopes as all the nuclear tests conducted in the atmosphere. Most of the radioactive pollution was concentrated in Lake Karachay.
