How natural nuclear reactor dating back 2 billion years was found in Gabon

Stephen Nartey October 27, 2022
The Oklo site/Photo credit: Medium

In the 1970s, a contract was given to mine uranium ore at the Oklo Uranium Mines in Gabon. However, after the initial samples were collected and submitted to the Soviet Company, they noticed that the uranium content did not measure to the specified standards; the quality was low and some key ingredients missing.  

Not satisfied with the geological history of the site and the reality on the ground, the investors dispatched a team of experts to investigate the disparity, according to

The scientists found that there was a stark difference in the isotope content in different sections of the uranium content collected. The researchers were at a loss at the conclusion of the findings because isotope content on the ground was expected to be uniform in ore as it is characteristic of uranium. But, this was not the case. 

Due to the difference in the quality of the uranium which is uranium-235 isotope, it dissolved faster compared to what would have been the case for uranium-238 isotope. It came out that the Oklo site’s uranium could perform the role of a natural reactor. This had existed in the ground two billion years ago.

Its uranium content was estimated to be 3.5 percent of the uranium-235 isotope, which has the capacity to enrich a modern nuclear reactor. The scientists also found out that there were 16 natural reactors which were active at the Oklo site for several hundreds of thousands of years.

The explanation was that the fissile uranium-235 which is extremely rich for modern nuclear reactors made it possible for the unexplained natural reactor at the site. The researchers found out that the chemical evolution at the site was a process that underwent changes through fire for 100,000 years. The Oklo site incident is considered a rare phenomenon of nature which has converted residues from the earth’s crust into a natural reactor.  

The researchers said their analysis of the site also revealed that radioactive waste is active in the Oklo area and the uranium ore has a record of negative 235 isotope content. They explained that they studied the movement of the radioactive elements in the soil for a period of time to come to the conclusion they made.

But, they indicated that the movement of the radioactivity at the Oklo site has not been at a terrific speed but one that is slow. They established that the phosphates enabled the retention of the radioactivity content in the ground.

What they found intriguing is how the environment contained the radioactive elements in the uranium ore. It used boiling water which was generated by the natural reactor to cleanse the radioactive content from the ground and pollute the environment.

The researchers said it is difficult to determine such a cleaning of radioactivity event happened at the site. Fossil reactors have been under the earth for over two billion years without causing any havoc.

Last Edited by:Mildred Europa Taylor Updated: October 27, 2022


Must Read

Connect with us

Join our Mailing List to Receive Updates