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Oklo

The natural nuclear fission reactors of Oklo:
  1. Nuclear reactor zones
  2. Sandstone
  3. Uranium ore layer
  4. Granite

Oklo is a geological region near Franceville in the Haut-Ogooué Province of Gabon. Several natural nuclear fission reactors were discovered in the uranium mines in the region in 1972.

Natural nuclear fission reactor

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Some of the mined uranium was found to have a lower concentration of uranium-235 than expected, as if it had already been in a nuclear reactor. When geologists investigated they also found products typical of a reactor. They concluded that the deposit had been in a reactor: a natural nuclear fission reactor, around 1.8 to 1.7 billion years BPin the Paleoproterozoic Era during Precambrian times, during the Statherian periodand continued for a few hundred thousand years, probably averaging less than 100 kW of thermal power during that time. At that time the natural uranium had a concentration of about 3% 235U and could have reached criticality with natural water as neutron moderator allowed by the special geometry of the deposit.[1][2][3][4][5][6][7]

See also

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References

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  1. Kean, Sam (12 July 2010). The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements. Little, Brown. pp. 324–. ISBN 978-0-316-05164-4.
  2. Lederman, Leon; Hill, Christopher (2004). Symmetry and the Beautiful Universe. Amherst: Prometheus Books. pp. 40-42. ISBN 9781591022428.
  3. Zoellner, Tom (2009). Uranium. Viking Penguin. pp. 291–292. ISBN 9780670020645.
  4. Cowan, George (1976). "A Natural Fission Reactor". Scientific American. Vol. 235, no. 1. pp. 36–47. Bibcode:1976SciAm.235a..36C. doi:10.1038/scientificamerican0776-36. JSTOR 24950391. Archived from the original on 15 August 2023. Retrieved 15 August 2023.
  5. Cowan, George (1976). "Oklo – A Natural Fission Reactor" (PDF). Federation of American Scientists. Los Alamos Scientific Laboratory. Archived (PDF) from the original on 29 March 2024. Retrieved 15 August 2023.
  6. Gauthier-Lafaye, F.; Holliger, P.; Blanc, P.-L. (December 1996). "Natural fission reactors in the Franceville basin, Gabon: A review of the conditions and results of a 'critical event' in a geologic system". Geochimica et Cosmochimica Acta. 60 (23): 4831–4852. doi:10.1016/s0016-7037(96)00245-1. ISSN 0016-7037.
  7. Meshik, Alex P. (2005-11-01). "The Workings of an Ancient Nuclear Reactor". Scientific American. Vol. 293, no. 5. pp. 82–91. doi:10.1038/scientificamerican1105-82. Archived from the original on 2024-03-25. Retrieved 2024-03-25.

Further reading

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1°23′40″S 13°9′39″E / 1.39444°S 13.16083°E / -1.39444; 13.16083