Nuclear energy, as we know it, was unleashed by nature at Oklo in Gabon, Africa, when uranium formed rings on its mountains billion of years ago. Natural uranium contains at least three per cent uranium. This uranium formed rings around the mountain and acted as fuel rods in a reactor. When rain water was run across the fuel rod, it acted as a reactor. The Oklo phenomenon was discovered only in 1972. The International Atomic Energy Agency (IAEA) saw fit to run an international conference on the subject.