Oklo
- (1) Nuclear reactor zones
- (2) Sandstone
- (3) Uranium ore layer
- (4) Granite
Oklo is a region near the town of Franceville, in the Haut-Ogooué province of the Central African country of Gabon. Several natural nuclear fission reactors were discovered in the uranium mines in the region in 1972.
History[]
Gabon was a French colony when prospectors from the French nuclear energy commissariat (the industrial parts, which later became the COGEMA and later Areva NC) discovered uranium in the remote region in 1956. France immediately opened mines operated by Comuf (Compagnie des Mines d'Uranium de Franceville) near Mounana village to exploit the vast mineral resources, and the State of Gabon was given a minority share in the company.
For 40 years, France mined uranium in Gabon. Once extracted, the uranium was used for electricity production in France and much of Europe. Today the uranium deposits are exhausted, and the mine is no longer worked. Currently, mine reclamation work is ongoing in the region affected by the mine operations.
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 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 BP – in the Paleoproterozoic Era during Precambrian times. 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]
See also[]
- Oklo Mine
- Deep geological repository
- List of uranium mines
- Mounana
References[]
- ^ 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.
- ^ Lederman, Leon; Hill, Christopher (2004). Symmetry and the Beautiful Universe. Amherst: Prometheus Books. pp. 40-42. ISBN 9781591022428.
External links[]
- Yucca Mountain Project (YMP) (Nov 2004). "Oklo: Natural Nuclear Reactors". Office of Civilian Radioactive Waste Management (OCRWM). Fact sheets. DOE. YMP-0010. Archived from the original on 2004.
- Manaugh, Geoff (Dec 8, 2009). "One Million Years of Isolation: An Interview With Abraham Van Lu". World Changing. Archived from the original (pdf) on December 12, 2009. Alt URL
- Uranium mines
- Radioactive waste repositories
- Mines in Gabon
- Energy in Gabon
- Nuclear reactors