On April 26th, 1986, at the Chernobyl Nuclear Power Plant in Ukraine, an extreme power surge caused a nuclear reactor to rupture, sending plumes of highly radioactive contamination into the atmosphere.Chernobyl is now regarded as the worst nuclear plant disaster ever. More than 300,000 people were hastilly evacuated and the cleanup and containment of the disaster required the help of more than 500,000 workers.