Kyshtym disaster

On a seven-point scale for assessing the impact of radiation events, the Kyshtym disaster earned a level six - major accident.

An excerpt from the article 42 facts about Kyshtym disaster

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.

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