This Day in History: 1957-09-28

Kyshtym disaster Radiation spreads following a Soviet (Russian) conventional explosion that scatters radioactive debris. The 1957 accident is the world’s third worst (at level 6) after Fukushima in 2011 and Chernobyl in 1986 (both level 7s). The accident was due to the failure of a cooling system for radioactive waste. Solvents such as ammonium nitrate and acetates exploded after temperatures built up in the waste holding tanks, contaminating a 800 to 20,000 square kilometers area. Although there were no immediate casualties, evacuations took weeks. It’s not known how many people died from radiation poisoning, and in fact, the mysterious accident wasn’t even known in the west until 1976. The Soviets covered up the radiation zone by creating what they called the East-Ural Nature Reserve.