Nuclear physics is relatively a young science. A human being created the first nuclear reactor only about 60 years ago – in 1942. However, nuclear reactors existed on the planet two billion years ago. So far, the science knows about 17 nuclear reactors that are located in Gabon - one of the African countries.
All reactors were found around uranium deposits in Oklo and Bangomba in the south-east of Gabon. Nine of 17 reactors were found on the completely depleted uranium deposits. The ancient reactors were found in 1972.
French chemist Bugzig, who worked at one of nuclear fuel factories, paid attention to an unusual correlation of uranium isotopes in ore, uranium 235 and uranium 238. It basically makes up 0.007202, whereas Bugzig discovered 0.00717. There were several variants to explain the strange correlation of uranium isotope in ore. It was originally believed that the ore was poisoned with spent nuclear fuel. However, when they measured the radiation level, it turned out that the theory was wrong.
Then it became known that the uranic ore with extremely high uranium 235 constituent was mined in Gabon. At first, it was a mystery, why the ore was enriched with the given isotope. It was believed that the uranium deposit was contaminated with spent UFO fuel. Others said that the ore was mined from the place, where an ancient civilization stored its radioactive wastes. Further research showed that the unusual ore appeared in a natural way. The products of deep radioactive decay that were found in the ore proved that nuclear reactions happened on the site of the uranium deposit two billion years ago.
Natural nuclear reactors were possible to appear because of the fact that there used to be more of uranium 235 on the Earth than nowadays.
A nuclear reaction requires not less than three percent of 235 isotope in uranium. In addition to that, there should be a good space and no neutron-absorbing materials. The reactors in Gabon worked for about one million years.
It is impossible for such natural nuclear reactors to appear nowadays. Uranium 235 concentration in the nature is very low now. Natural reactors are of huge interest to scientists. The reactors are unique objects that could not be found anywhere else in the world. They allow to learn a lot about the past of out planet. They also give an opportunity to explore the consequences of nuclear reactors’ super-long operation. Furthermore, the study of ancient reactors will be helpful in terms of development of radioactive waste disposal technologies.
Translated by Dmitry Sudakov