Civil Nuclear
The Oklo uranium deposit in Gabon ran as a natural nuclear reactor roughly 1.7 billion years ago, cycling on and off in three-hour pulses for hundreds of thousands of years before the first cells with a nucleus even existed on Earth.
In a Gabonese uranium deposit 1.7 billion years old, groundwater and rich U-235 combined to run a natural fission reactor in three-hour pulses for hundreds of thousands of years — the only confirmed natural reactor ever found on Earth.
