The 2 Billion Year Old Natural Nuclear Fission Reactor of Gabon Discovered in 1972

It was found in 1972 when a group of French scientists tested uranium ore from a mine in Gabon. Uranium ore is typically composed of three varieties (isotopes) of uranium, each with a different number of neutrons: uranium 238, the most abundant, uranium 234, the rarest, and uranium 235, which nuclear physicists are most interested in due to its ability to sustain nuclear chain reactions.

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