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Oklo natural reactor7/22/2023 ![]() ![]() That tiny discrepancy was enough to alert French scientists that something strange had happened. But in these samples, which came from the Oklo deposit in Gabon (a former French colony in west equatorial Africa), uranium 235 constituted just 0.717 percent. Elsewhere in the earth’s crust, on the moon and even in meteorites, uranium 235 atoms make up 0.720 percent of the total. As is the case with all natural uranium, the material under study contained three isotopes- that is to say, three forms with differing atomic masses: uranium 238, the most abundant variety uranium 234, the rarest and uranium 235, the isotope that is coveted because it can sustain a nuclear chain reaction. He had been conducting a routine analysis of uranium derived from a seemingly ordinary source of ore. ![]() In May 1972 a worker at a nuclear fuel–processing plant in France noticed something suspicious. Gall et al.Editor's Note: This article originally appeared in the October 2005 issue of Scientific American. Natural Nuclear Reactor Explained (Science, ).Nature's Nuclear Reactors: The 2-Billion-Year-Old Natural Fission Reactors in Gabon, Western Africa (Scientific American, ).Meet Oklo, the Earth’s Two-billion-year-old only Known Natural Nuclear Reactor (International Atomic Energy Agency (IEAA), ).More information about the Oklo natural nuclear reactor: The drawing on the right locates reactors 1 to 9 on a 3D perspective of the Oklo deposit. Informations complémentaires A B. Geological map of the Oklo area of the Franceville basin (left). The event is organised by Benoît Gall and colleagues, and co-funded by USIAS.įor more information, contact Benoît Gall ( email) This symposium is part of the 10 th International Conference on High Level Environmental Radiation Areas ( ICHLERA-2022), which takes place on 27-30 June 2022, also in Strasbourg. (2014) The 2.1 Ga Old Francevillian Biota- Biogenicity, Taphonomy and Biodiversity. El Albani A, Bengtson S, Canfield DE, Riboulleau A, Rollion Bard C, et al. Gabonionta from a mine near the OKLO reactors. It will also address the question of the influence of the Great Oxidation Event 2.1 billion years ago, as discovery of the Gabonionta fossils was made only a few dozen kilometres from these reactors. It will highlight the Oklo phenomenon with presentations from historical actors in this scientific adventure, and will cover this amazing topic from its discovery and very first questions up to the most modern points of view on these reactors. In honour of this occasion, a special symposium will take place on the afternoon of 28 June 2022, at the University of Strasbourg. This year - 2022 - marks the 50 th anniversary of the discovery of the Oklo natural nuclear reactor. In addition, at the Gabon reactors, many of the radioactive products of the nuclear fission have been contained for two billion years, providing a natural site of long-term geologic storage for nuclear waste. ![]() Despite their modest power output, the Gabon natural nuclear reactors are remarkable because they spontaneously began operating around two billion years ago, and continued to do so in a stable manner for several hundreds of thousands of years. Oklo is the only known location for this in the world. On 25 September 1972, the French Alternative Energies and Atomic Energy Commission (CEA) announced its finding that self-sustaining nuclear chain reactions had occurred on Earth about two billion years ago. Further investigations resulted in surprising findings which suggested the presence of processes exactly like those in a nuclear reactor – but natural, not man-made. Given that U-235 can be used to build nuclear bombs, an explanation was urgently needed. The concentration of uranium-235 was significantly lower than would be expected, suggesting a disappearance of U-235. In June 1972, at the Tricastin uranium enrichment site at Pierrelatte in France, a routine mass spectrometry analysis that compared samples from the Oklo mine - located in Gabon on the west coast of Africa - detected a puzzling discrepancy. The last natural nuclear fission reactor. Nature, vol. The most valued specimens from the Moon and Mars.” “This deposit is no less unique, and certainly more irreplaceable, than View of the open pit of Oklo during exploration of the reactors (1973). ![]()
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