What Was the Worst Nuclear Accident in History?

The expolsion at Chernobyl was the worst nuclear accident to date. CREDIT: USSR. View full size image

In 1986, a nuclear reactor exploded at Chernobyl in Ukraine, then part of the Soviet Union.

The blast, which blew the 2,000-ton lid off the reactor, sent out 400 times more radioactive fallout than the Hiroshima bomb, contaminating more than 77,000 square miles (200,000 square km) of Europe.

Roughly 600,000 people were exposed to high doses of radiation, and more than 350,000 people had to be evacuated from contaminated areas.

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