Were did the worst nuclear disaster in history occur?

Answer 1

Chernobyl, Russia on April 26th, 1986. A nuclear power plant exploded and the nuclear radiation spread all across Russia and many parts of Europe. There were 31 recorded deaths that were directly related to the accident and an estimated 30,000-60,000 cancer related deaths linked to it over the years.

Answer 2

Which one? There have been dozens of nuclear disasters or near-nuclear disasters. Some more catastrophic than others.

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Answer 3

Possibly the Chelyabinsk-40 nuclear waste dump criticality accident steam explosion in the early 1960s.

Answer 4

Chernobyl, Ukraine.