25 years ago, on 26 April 1986, a nuclear power plant catastrophe took place in Chernobyl, near Kiev, in the Ukraine. It was the worst nuclear power plant accident in history. The accident was the result of a flawed reactor design. A sudden high power output surge took place, and when an attempt was made for emergency shutdown, a more extreme spike in power output, about 10 times the rated maximum output, occurred leading to reactor core explosion. This threw large quantities of radioactive core materials into the atmosphere and exposed the graphite moderator components of the reactor to air so they started to burn. The resulting fire sent a cloud of radioactive fallout into the atmosphere that drifted over large parts of the western Soviet Union, and Europe. Large areas in Ukraine, Belarus, and Russia had to be evacuated, with over 300,000 people resettled. About five million people lived in areas contaminated.