THE NATURAL NUCLEAR REACTOR AT OKLO

The "Oklo phenomenon» was discovered in 1972 at Pierrelattes (France) when routine analyses conducted by the Commissariat à l’Energie Atomique (CEA) pointed out an anomalic depletion in U-235, the fissile isotope used in nuclear power plants, in uranium ore from the Oklo mine (Eastern Gabon). After inquiry, the CEA announced the discovery of the first natural nuclear reactor : the anomaly results from fission chain reactions which took place two billion years ago in the Oklo deposit.

The nuclear phenomenon at Oklo is the only known case of fission products (FP) and transuranians (TU) being stored in a geological, natural environment for a long period of time. Therefore, the Oklo uranium deposit is a valuable site for the study of radionuclide mass transfer processes, and the natural analogy with deep underground radioactive waste disposals. Presently, many countries are concerned about the need for a safe method to dispose of high-level nuclear wastes and prevent potential returns of radioactive wastes from underground repositories to the biosphere. The various national regulatory agencies involved generally require quantitative predictions for at least the first 104 years after disposal, and qualitative predictions of repository safety performance for up to 106 years. The prediction of various scenarii and the sequence of events that are expected to affect the repository site over long periods of time can be achieved by verification and validation using laboratory and field experiments. However, by necessity, these experiments are carried out over relatively short periods of time and therefore are only of limited value. Predicting the long-term behaviour of buried radioactive wastes can be facilitated by comparison with the long-term evolution of natural geochemical systems, or natural analogues, such as Cigar Lake (Canada) and Poços de Caldas (Brazil). Oklo, by representing a fossil natural reactor which achieved criticality two billion years ago, provides a unique scientific and public awareness opportunity to show whether or not the FP and TU radionuclides have remained confined in the near-vicinity of the reactors subsequent to nuclear reactions.

Of particular interest is the reactor found in the Bangombé uranium deposit, which is located 30 km far from the main Oklo deposit. Due to its shallow location (depth: 10-12 m) within the saturation zone, the Bangombé reactor has undergone extensive weathering phenomena and continues to be affected by the penetration of meteoric waters. This shallow system allows to evaluate the influence of various rock matrices (shales, sandstones) and mineral phases on the mobilization/retardation of various actinides and fission products.

FOR MORE INFORMATION ON THE WEB

at the Centre de Geochimie de la Surface
CNRS, wants to save a two-billion year old natural nuclear reactor from being mined in the Oklo uranium deposit off ...

Alexander,WR, McKinley,IG, MacKenzie,AB
Brookins, DG, Radionuclide Behaviour at the Oklo Nuclear Reactor, Gabon, Waste Management, Vol.10, pp.285-296. ...

A natural nuclear reactor
Oklo is the name of a uranium mine in the African nation of Gabon, where France obtains much of the uranium for her nuclear program …

Ancient African Nuclear Reactors
Oklo: Ancient African Nuclear Reactors Credit & Copyright: Robert D. Loss, WAISRC …

ANS : Public Information : Newspapers : Oklo's Natural Fission
Oklo's Natural Fission Reactors. More than 1.5 ... power plants. Oklo Mine Site in Oklo, Gabon, Photo courtesy of Andreas Mittler. When …

Oklo: Ancient African Nuclear Reactors
Credit & Copyright: Robert D. Loss, WAISRC. ... Pictured above is Fossil Reactor 15, located in Oklo, Gabon …

BIOLOGICAL EFFECTS OF IONIZING RADIATION
Based on evidence discovered in 1972, scientists believe that about 2.0 billion years ago, a fission chain reaction occurred spontaneously at Oklo, Gabon, in …

BOOK REVIEW
The sandstone-type deposits among which are the Oklo natural fission reactors of Gabon and the roll front deposits of the western United States are ...

CEA : Dossier déchets
Il ya deux milliards d'années, dans un gisement d'uranium naturel, sur le site d'Oklo au Gabon, un "réacteur nucléaire" s'est spontanément déclenché et a …

CHEMICALLY FRACTIONATED FISSION (CFF)
OKELOBONDO (ZONE 13 OF OKLO): IMPLICATIONS FOR THE ORIGIN OF TERRESTRIAL XENON, A. Meshik 1 , C. Hohenberg, K …

Congrès - Cote : B02751: Le Phénomène d'Oklo
The Oklo Phenomenon AGENCE INTERNATIONALE DE L'ENERGIE ATOMIQUE Vienne : Agence Internationale de l'Energie …

CRSQ Abstracts, Volume 19, Number 1
The Oklo Natural Uranium Reactor Examined From A Creationist's Viewpoint. ... At least six reactor zones existed in the pre-Cambrian rock found at Oklo …

Eos
In a masterful example of analytical detective work, the French scientists traced the anomaly to a particular area of a uranium mine located at Oklo in the ...

Evidence about Constants Being the Same in the Distant Past
Another evidence is the natural nuclear reactor at Oklo, in Gabon. ... The Oklo Natural Nuclear Reactor …

Fossil Reactors: Where
All but one of the reactors are located at a place known as the OKLO uranium deposit located in the south eastern corner of the country….

Galena S Isotopes in and Around the Natural Fission Reactors at at Oklo and Bangombé
Gabon Lena Zetterström (lena.zetterstrom@nrm.se) & Torbjörn Sunde …

General Information. Oklo: natural nuclear reactors.
Creating a nuclear reaction is not simple. ... What happened to the nuclear waste left at Oklo? ...

Geochemistry Group Home Page and H. Hidaka (2001)
Alteration of monazite and zircon and lead migration as geochemical traces of fluid paleocirculations around the Oklo-Okelobondo and ...

GEOL568_Lecture_15d
DISPOSAL. Geochemistry of Np. Analogue Studies - The Oklo Natural Reactor …

Hasadási reaktorok a föld felszínén
In the course of his routine measurements he found a strange anomaly.Discovery of the Oklo reactors. ... How did the Oklo reactors evolve? ...

Health Physics News on the Net 10-98
Robert Loss of the Western Australian Isotope Science Research Centre has developed an interesting web site dealing with the Oklo natural reactor www. ...

Helioseismology and nuclear reactions in the sun
G.Fiorentini. 13. The Oklo phenomenon. A natural fission reactor. which released about 20 KW….

INIS Web Services: Oklo Fossil Reactors
In 1972 the very well preserved remains of several ancient natural nuclear reactors were discovered in the middle of the Oklo Uranium ore deposit …

Invited Papers and Presentations
Heterogeneity and Alteration of Uraninite from the Natural Fission Reactor 10 at Oklo, Gabon": invited presentation at the 2nd Joint CEC-CEA OKLO Working ...

Isotope Science
2000 de Laeter Youth Lecture. Photosynthesis, Fission and Fossils: The story of the Oklo Fossil reactors. Dr Bob Loss. ... Port. Gentile. Oklo: Location. 0o. 10o E. 200 km. ...

lamonitor
Lately, the Oklo reactor, one of the world's most remarkable phenomena, continues to inspire new scientific hypotheses and underpin important cosmological ...

L'aval du cycle nucléaire
Le 7 juillet 1972, des chercheurs du CEA Cadarache découvrent une anomalie dans le minerai d'uranium provenant d'Oklo au Gabon….

Lena Zetterström Evins
Geochronology of the Oklo and Bangombé fossil natural fission reactors: tracing the effects of geological events. ...

Nagra Forschung_Publikationen
MB. The Oklo phenomenon, 42 sec, 1,2 MB. The natural reactors at Oklo (Gabon), 42 sec, 1,0 MB. Uranium ... The natural reactors at Oklo (Gabon ...

Graph showing the Neodynium isotope differences
between Oklo samples and normal natural abundance. Atomic weight is shown on the ...

Natural analogue studies
The basic aims of natural analogue radioactive materials. A good example is the natural fission reactor in the Oklo ore deposit in Gabon, Africa (IAEA, 1975, 1978). This ...

NATURAL NUCLEAR REACTORS (OKLO)
From ... accident. At Oklo, there is a mine that supplies uranium mainly for the French nuclear industry. ...

Natural Radioactivity
Chang et al, 1974 " Hamilton, 1970. Oklo Natural Reactor. Adapted from August 1976 Scientific American article on Oklo by Cowan.

News
at the core. The theory is based on studies at one of the world's richest uranium mine in Oklo, Central Africa. French scientists …

Nuclear reactor at the core of the Earth! ­ A solution to the
A careful check on the source materials traced the uranium ore back to a very high concen- tration uranium deposit present in a mine- site at Oklo in Gabon …

NUCLEAR DATA IN OKLO AND TIME VARIABILITY OF FUNDAMENTAL COUPLING
Y. Fujii(Nihon Fukushi U.), A. Iwamoto(JAERI), T. Fukahori(JAERI), T. Ohnuki(JAERI)

Oklo
Modelling heat and mass transfer around a natural fission reactor at Oklo. The 3D modelling has been used in quantification of thermal …

Oklo
Coupled heat and mass transfers in the Oklo basin (without reactor) are investigated on the following geometry to study global fluid circulations and their ...

Oklo Fossil Reactors
Where are the Oklo reactors located? When did the nuclear reactions occur? What caused the nuclear reactions to start? ... Other Oklo/Nuclear Links….

Oklo: Nature's Fission Reactor
answers to these and other ques- tions, visit http://www.ans.org/pi/np/oklo/ n Volume 17 * September 2001 Radioactive Waste from Nature Oklo: Nature's Fission …

Oklo: natural nuclear reactors
General Information Creating a nuclear reaction is not simple. In power …

Oklo
Un exemple "d'analogue" naturel pour l'étude de la dispersion hydrothermale des produits de fission et le stockage des déchets nucléaires - Géochimie ...

Oklo
The natural reactors at Oklo were active about 1.9 billion years ago and the individual reactors are thought to have remained active for anything from ...

Oklo
des réacteurs nucléaires fossiles. Titre: Oklo : des réacteurs nucléaires fossiles. Auteur: Naudet. Rubriques: Relié

Oklo
Phenomenon - At the site of the Oklo uranium mine, Republic of Gabon, nature sustained a fission reaction about 2 billion years ago. Goto: chain reaction. ...

Oklo
A prehistoric natural "nuclear reactor", which was in operation about 2 bn years ago, was discovered in the uranium deposit Oklo/Gabon in 1972. ...

okloreferences.page
The Oklo Phenomenon : Proceedings of Symposium, June 23 - 27, 1975, organised by - Inter Atomic Energy Agency. ... Title Oklo-natural fission reactor program.

PureInsight Net- Prehistoric Nuclear Reactor In Gabon Republic
Oklo is the site of a uranium mine in the Gabon Republic. ... The uranium indeed had been used. One may wonder what exactly happened at Oklo? ...

Reactor Zone 15: Oklo

Study on the Isolation of Radionuclides in Natural Geological
To accomplish thsi, rock samples obtained from the Koongarra uranium deposit in Australia and the Oklo uranium deposit in Gabon were investigated.

The Fine Structure Variable?
The Oklo Phenomenom Controlled Fission. Enrico Fermi did it in 1942 in Chicago. ... Page 12. Cosmological Variation of a Oklo gets us back 1.8 bn yr.

The Implications of the Oklo Phenomenon on the THE CONSTANCY OF RADIOMETRIC DECAY RATES.
... 1975. Some United States studies of the Oklo Phenomenon.

The Misappliance Of Science
I bet real estate is a steal at Oklo. True: There was a natural nuclear reaction in Africa long ago. In Gabon, at a place called Oklo.

THE NATURAL NUCLEAR REACTOR AT OKLO: A COMPARISON WITH MODERN REACTORS.
By Andrew Karam karam.1@osu.edu.

The Oklo data method up
The Oklo phenomenon denotes a natural fission reactor (moderated by water) that operated about two billion ...

THE OKLO NATURAL NUCLEAR REACTORS (GABON)
The disposal of radioactive wastes - What do we learn from the Oklo natural nuclear reactors (Gabon). Régis BROS and Toshihiko OHNUKI. ...

THE OKLO NATURAL NUCLEAR REACTORS (GABON)
NATURAL ANALOGUES FOR RADIOACTIVE WASTE REPOSITORIES Régis BROS, Toshihiko OHNUKI, Hiroshi ...

Uranium Use and Mining: Early Histroy
2.8 Billion Years Ago: A deposit of uranium ore in Gabon, Africa, located at a place known as the Oklo uranium deposit spontaneously goes into atomic chain ...

UxC: Regional Links - Other Countries
Natural Fossil Fission Reactors (Oklo uranium deposit) - Presented by the Western Australian Isotope Science Research Centre, this site gives detailed ...

WHAT WE LEARN FROM THE NUCLEAR DATA IN OKLO NATURAL REACTOR
Akira Iwamoto Dep. Materials Science, Japan Atomic Energy Research ...