English 
Spanish 
4 min read
75 comments
In the 1970s, scientists discovered natural fission nuclear reactors that had been operating for more than 150 years, revealing a phenomenon unique to Earth.
In the 1970s, a stunning discovery in the Gabon, West Africa, shook the world of geoscience and nuclear physics,. Fifteen “fossils"Of natural nuclear reactors fission have been identified, dating back to about two billion years ago.
Fourteen of them are located at the uranium mine in Okay, while the smallest is in the small Bangombé deposit, 30 kilometers from distance.
While the Oklo reactors were fully or partially mined and are now flooded, Bangombé was preserved for scientific studies on radioactive waste in hazardous environments. geological.
- US scientists create strongest ever armor material with 100 trillion bonds
- Bracell Uses Cutting-Edge Technology to Fight Wildfires and Protect the Environment
- No Volkswagen, Toyota or BYD: Brazil's most modern automotive factory belongs to the company that is often overlooked by Brazilians
- Iron Dome: The incredible invisible wall that protects Israel from thousands of missiles and revolutionizes global defense
The initial discovery of nuclear reactors
In 1972, French scientists analyzing uranium mined from Oklo discovered something curious. The fraction of uranium-235 in the material was slightly lower than expected. Under normal conditions, terrestrial uranium contains 0,720% uranium-235.
However, the uranium from Oklo was only 0,717%. This difference, although small, raised a number of questions. Since uranium-235 is used in nuclear weapons, it was essential to unravel what had happened.
It was then that scientists remembered a 1956 study by Japanese-American chemist Paul Huroda. He had suggested the possibility of natural nuclear reactors under certain geological conditions.
The answer was there: at Oklo, two billion years ago, the conditions necessary for natural nuclear fission were present, consuming uranium-235 and explaining the reduction in observed isotopic enrichment.
How natural reactors worked
Scientists have discovered that during the Proterozoic Period, about two billion years ago, two critical factors aligned:
- Uranium enrichment: At that time, natural uranium was enriched to about 3,5% uranium-235, the same level used in modern nuclear reactors.
- Increased oxygen in the atmosphere: This increase allowed geochemical reactions that concentrated uranium into high-quality veins.
With these two factors combined and other secondary conditions, natural fission reactors came into operation.
This occurred about 1,95 billion years ago, at a time when uranium enrichment was sufficient to sustain nuclear chain reactions.
Why aren't there newer natural nuclear reactors?
The key lies in the interaction between uranium enrichment and oxygen concentration. In times prior to two billion years ago, despite there being more uranium-235, the lack of oxygen in the atmosphere prevented the formation of highly concentrated uranium ores.
On the other hand, natural uranium enrichment has decreased over time due to radioactive decay. Thus, reactors could not emerge in more recent periods.
Currently, even in sites with high-quality uranium like Bangombé, enrichment is insufficient to sustain natural nuclear reactions. This makes the Oklo phenomenon unique in the geological history of the Earth.
What's left in Oklo?
The former Oklo reactors now contain high-grade uranium ore with high levels of radioactive waste.
These wastes include fission products of uranium-235 and plutonium-239, as well as end elements from their decay processes.
This unique environment offers a valuable opportunity for scientists to study how radioactive waste interacts with geological formations over billions of years.
The lessons from Oklo are useful for planning modern nuclear waste storage sites, which also depend on stable geological environments.
Operation of natural reactors
Studies indicate that these reactors operated for about 150 years, consuming more than five tons of uranium-235. Their average power was approximately 150 kW, comparable to that of modern small research reactors.
Water is believed to have played a key role, acting as a moderator. The moderator slows down the neutrons, allowing them to be absorbed by the uranium-235 nuclei and sustain the chain reaction.
This process also had a self-regulating mechanism. When the temperature rose, the water evaporated, interrupting the thermalization of neutrons and, consequently, the nuclear reaction. When the reactor cooled, the water returned, restarting the reaction.
This generated 30-minute pulses of activity followed by 2,5 hours of inactivity, a pattern recorded in the isotopic signatures of xenon in minerals near the reactor core.
Impact on the study of radioactive waste
One of the biggest challenges of nuclear energy is the fate of radioactive waste, which remains dangerous for thousands of years.
Many countries are considering storing them in underground caves or other geological formations. At Oklo, Nature conducted this experiment on its own, offering important clues about the safety and stability of such environments.
Scientists continue to analyze what's left of natural reactors to better understand how radioactive elements behave over time.
This information could help improve nuclear waste storage systems on a global scale.
Signs of the presence of evolved civilizations on Earth since the beginning of time.
He didn't understand anything about the subject.
This is the level of the average Brazilian. **** functional
Reread the article about 50 times to extract something real…
How convenient that something so strange could be found so close together!
It is more likely that they were built by advanced civilizations or even aliens who used these energy sources for some time!
And that's why Brazil is such a backward civilization. From comments like this one, you can see that they don't know how to understand what they read.
Dear professional reader, know that every reality of today in the relatively recent past would be considered insanity or even witchcraft. Open your mind and consider that other unexplored theories may emerge, as has already happened in several scientific fields over the years.
I do not believe in such a possibility, nature would not be able to create a nuclear power plant on its own, these scientists probably made a mistake in their calculations and overestimated the natural conditions for this to happen, there is nothing spectacular, just men making mistakes in their calculations and creating con stories.
Pios is “da pá veja”: that you skipped Portuguese class my friend lol
John Smith, and you skipped those Portuguese classes with your friend Augusto, didn't you??? Did you do "Swap Swap"??? LOL
Lol..... Homosapiens Sapiens will study.