Nuclear Reactors Existed on Earth Two Billion Years Ago

Natural nuclear reactors found in Africa’s Gabon

Nuclear physics is a relatively young science. Humans created the first man-made nuclear reactor only about 60 years ago, in 1942. However, nuclear reactors existed on the planet two billion years ago. So far, science knows of 17 nuclear reactors located in Gabon, an African country.

All of these natural reactors were found around uranium deposits in Oklo and Bangomba, in the southeast of Gabon. Nine of 17 reactors were found on completely depleted uranium deposits. These ancient reactors were found in 1972.

The French chemist Bugzig, who worked at one of nuclear fuel factories, paid attention to an unusual correlation of uranium isotopes in the ore, uranium 235 and uranium 238. This basically makes up 0.007202, whereas Bugzig discovered 0.00717. There were several variants to explain the strange correlation of uranium isotope in the 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 this theory was wrong.

Then it became known that the uranium ore with an extremely high uranium 235 constituent was mined in Gabon. At first, it was a mystery why the ore was enriched with the given isotope. Some 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. However, further research showed that the unusual ore appeared in a natural way. The products of deep radioactive decay 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 because of the fact that there used to be more uranium 235 on Earth there is currently.

A nuclear reaction requires not less than three percent of 235 isotopes in uranium. In addition to that, there should be 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. The uranium 235 concentration in nature is very low now. Natural reactors are of huge interest to scientists. The reactors are unique objects that cannot be found anywhere else in the world. They allow us learn a lot about our planet's history. They also give us an opportunity to explore the consequences of such long operation of nuclear reactors. Furthermore, the study of the ancient reactors will be helpful in terms of developing radioactive waste disposal technologies.

Translated by Dmitry Sudakov