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Topic: Oklo

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  Oklo - Wikipedia, the free encyclopedia
Oklo is a place in the West African state of Gabon.
The natural reactor of Oklo can also be used to check if the fine-structure constant α might have changed over time, since there is no physical reason why it should be exactly constant.
Alex Shlyakhter proposed in 1976 to measure the abundance of Sm-149 to estimate the cross section for neutron capture of this isotope at that time and check it against the present value.
en.wikipedia.org /wiki/Oklo   (425 words)

 astronomy news
The Oklo reactor started up nearly two billion years ago when groundwater filtered through crevices in the rocks and mixed with uranium ore to trigger a fission reaction that was sustained for hundreds of thousands of years.
Several studies that have analysed the relative concentrations of radioactive isotopes left behind at Oklo have concluded that nuclear reactions then were much the same as they are today, which implies alpha was the same too.
It seems that the Oklo reactors didn't plunge straight into a runaway chain reaction, or meltdown of the veins because of the presence of water in the rocks.
www.geocities.com /goarana669/speedlight.html   (1994 words)

The natural reactors are important as natural analogs to nuclear waste repositories mainly as Oklo is the only known occurrence in the world where actinides and fission products have been in a near-surface geological environment for an extremely long period of time.
Implications from Oklo include the concept of planetary-scale nuclear fission reactors as energy sources for the giant planets and for the terrestrial planets and the idea that reversals and changes in the geomagnetic field have their origins in variable or intermittent nuclear reactor output.
Implications from Oklo also include the concept that thermonuclear reactions in protostars are ignited mainly by nuclear fission energy and the idea of the dark matter possibility of stellar non-ignition.
www.nuclearplanet.com /eos_paper.htm   (2140 words)

 Ancient nuclear reactors
Oklo became the likely crash point of an UFO and the uranium that was found there was the fuel of the reactor that powered the UFO.
In the Oklo area, a series of about 17 natural reactor sites were developed and it appears that they remained active for a few million years, operating in energy levels on the order of 1 Kw.
Finally it was observed that the areas with the larger uranium deposits were also the ones with the smaller percentages of the fissionable isotope, precisely as one would have expected in the case of a nuclear reactor.
www.e-telescope.gr /en/cat04/art04_021201.htm   (1279 words)

 Webster, C. L. --- The Implications of the Oklo Phenomenon on the Constancy of Radiometric Decay Rates
Application to the Oklo data of the isotopic systematics developed from current reactor theory reveals a remarkable fit of theory with field data.
In order to compare the Oklo reactor neodymium with that of fission neodymium, the Oklo signature must be corrected for the presence of the natural neodymium.
Oklo reactor neodymium isotopic signature corrected for the presence of naturally occurring neodymium.
www.grisda.org /origins/17086.htm   (1502 words)

 Brainstorms: Solar eclipses and CSI?
In particular, Dembski's reservations about the variables involved in the Oklo reactors notwithstanding, it should be substantially easier to estimate the probabilities of occurrence and joint coincidence of those variables and their values and thus to more precisely estimate the probability associated with the design inference engine.
Further, the physical arrangement of the components is critical: They had to be in a particular configuration, with a relatively compact mass of uranium within a dome-shaped containment structure with a surrounding geological formation that held a sufficient quantity of water to serve as a moderator of the reaction.
That is the case for the Oklo reactor, and it therefore forms an ideal kind of test case for escaping the anthropomorphism of the human design analogy and for doing the necessary work of developing and validating design detection methodologies on non-biological structures and processes.
www.iscid.org /boards/ubb-get_topic-f-6-t-000182.html   (3404 words)

 Primordial Nukes (Prehistoric Nukes Found)   (Site not responding. Last check: 2007-10-09)
It was unearthed in the early 1970s at the Oklo uranium mine in the west African Republic of Gabon.
Shortly after the Oklo fossil reactor was discovered, researchers recognized that it might provide data that could help them learn about the number called alpha, also known as the fine-structure constant, that's associated with the strength of the electromagnetic force.
Oklo, Gabon has been recognized for decades as an example of placer uranium nuggets, which incidently can only exist as the native element in an anoxic environment going critical.
www.freerepublic.com /focus/f-news/1362835/posts   (2789 words)

 OKLO reactor natural nuclear   (Site not responding. Last check: 2007-10-09)
Two billion years ago, in a sedimentary layer of earth rich in uranium, a nuclear fission chain reaction occurred and kept running during 150 million years.
By measuring the proportion of nine isotopes of xenon in a minuscule sample of rock taken from Oklo, this scientist has demonstrated the existence of a periodic cycle of three hours in the chain reaction.
Perhaps Oklo could teach us lessons and bring useful indications regarding the safe storage of nuclear waste during two billion years.
www.ecolo.org /documents/documents_in_english/oklo_nuclear_natural.htm   (332 words)

 Natural Nuclear Reactors (Oklo)
At Oklo, there is a mine that supplies uranium mainly for the French nuclear industry.
During the 1970s, a shipment of uranium from Oklo was founded to be depleted in the fissionable isotope Uranium-235.
In the place that is now Oklo such a stream flowed into an algal mat that included microorganisms with a strange capacity to collect and concentrate uranium specifically.
www.alamut.com /proj/98/nuclearGarden/bookTexts/Lovelock_Oklo.html   (922 words)

 physics central physics in action - Chaos rules - page 2   (Site not responding. Last check: 2007-10-09)
At Oklo, these byproducts were captured surprisingly well by surrounding mineral grains, and careful analysis showed a match to known fission byproducts with great accuracy, establishing the existence of the natural reactor.
Incidentally, the fact that plutonium was produced at Oklo, even two billion years ago, complicates the classification of plutonium as an “artificial element,” i.e., one not found in nature.
The Oklo reactor operated at a power of about 100 kilowatts, typical of a small research reactor, and in its 150,000 years of operation consumed more than five tons of U-235.
www.physicscentral.com /action/action-05-02b.html   (642 words)

 Oklo: Natural Nuclear Reactors - Fact Sheet
They found that the percentages of many isotopes at Oklo strongly resembled those in the spent fuel generated by nuclear power plants, and, therefore, reasoned that a similar natural process had occurred.
The Oklo phenomenon gives scientists an opportunity to examine the results of a nearly natural two billion-year experiment, one that cannot be duplicated in the lab.
When the Oklo reactors were discovered in 1972, the conditions found there were very similar to his predictions.
www.ocrwm.doe.gov /factsheets/doeymp0010.shtml   (1227 words)

 APOD: 2002 October 16 - Oklo: Ancient African Nuclear Reactors   (Site not responding. Last check: 2007-10-09)
Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Uranium oxide remains are visible as the yellowish rock.
Oklo by-products are being used today to probe the stability of the
antwrp.gsfc.nasa.gov /apod/ap021016.html   (120 words)

 Some Thoughts about the Discovery of a Two Billion Year Old Nuclear Reactor | Clearharmony - Falundafa in Europe
Oklo by-products are being used today to study the stability of the fundamental constants over cosmological time-scales and to develop more effective means for disposing of human-manufactured nuclear waste.
Surprisingly the uranium concentration in the ore was as low as spent uranium fuel from a nuclear reactor.
According to geological dating, the Oklo uranium mine was formed about 2 billion years ago.
www.clearharmony.net /articles/200402/17684.html   (587 words)

 About James Lovelock and Nuclear Power
During the 1970s, a shipment of uranium from Oklo was found to be depleted in the fissionable isotope 235U.
The Oklo reactors ran gently at the kilowatt- power level for millions of years and used up a fair amount of the natural 235U in doing so.
The presence of the Oklo reactors confirms an oxidizing envi- ronment.
www.ecolo.org /lovelock/lovelock-oklo.htm   (1259 words)

 Natural Radioactivity
In 1972, natural nuclear reactor was found in a Western Africa in the Republic of Gabon, at Oklo.
The concentration of Uranium 235 is artificially enriched for most modern reactors, but at the time of the Oklo reactor it was naturally enriched with an abundance of approximately 3%.
The abundance of the neodymium at Oklo sites was compared to other areas and to the neodymium found in modern reactors.
www.physics.isu.edu /radinf/natural.htm   (2866 words)

 Physics & Theoretical Colloquia Abstract
OKLO vs. QSO: On time-variability of the fine structure constant
OKLO is a uranium mine located in the Republic of Gabon, midwest Africa, where a natural U(235)-based chain reaction occurred two billion years ago.
In contrast, during the last two years, a group of scientists are claiming that they find a definite difference between the fine-structure constant of the QSO era and its present value, based on QSO spectroscopy.
www.lanl.gov /orgs/p/colloquium/abstracts_03_04/abstract_iwamoto.shtml   (233 words)

 Natural Nuclear Reaction Powered Ancient Geyser
Evidence for this natural reactor was found in 1972 at the Oklo mine in the West African country of Gabon.
Although scientists had long suspected that water was important for the Oklo reactor, the idea was not confirmed until Meshik’s team looked at levels of xenon gas in the uranium deposits.
The Oklo mine is located in the West African country of Gabon.
www.livescience.com /forcesofnature/041109_gabon_reactor.html   (651 words)

 Oklo natural reactors - 4Forums.com
Using a number of radioactive clocks the Oklo fossil reactors have been radioactively dated to be about 2000 million years old.
The uranium in these reactors is thought to have come from the tiny amounts of uranium orginally scattered throughout the earth's crustal rocks during its formation.
The best thing about Oklo (and supernovas like SN1987A) is that it shows radioactive decay rates are not "assumed to have been the same in the past": they *were* the same.
www.4forums.com /political/showthread.php?t=782   (777 words)

 New Scientist Breaking News - Speed of light may have changed recently
Now, Lamoreaux, along with LANL colleague Justin Torgerson, has re-analysed the Oklo data using what he says are more realistic figures for the energy spectrum of the neutrons present in the reactor.
That translates into a very small increase in the speed of light (assuming no change in the other constants that alpha depends on), but Lamoreaux's new analysis is so precise that he can rule out the possibility of zero change in the speed of light.
While Lamoreaux has not addressed any possible change in alpha(s) in his Oklo study, he argues that it is important to focus on possible changes in alpha because the Oklo data has become such a benchmark in the debate over whether alpha can vary.
www.newscientist.com /article.ns?id=dn6092   (1421 words)

Ultimately, the mystery was unraveled, when it was discovered that in the pockets of depleted uranium ore a characteristic spectrum of byproducts of nuclear fission were also present and in the distinctive ratio that might be anticipated if a natural fission reactor had produced them.
For Cowan, the lesson of Oklo did not point to a geological solution to waste storage, but rather to the chemical and mineralogical processes by which nature aggregates and keeps intact whole storehouses of its treasures over billions of years.
Oklo, because of its 2.5 billion year history, because of the unique properties of its nuclear materials, because of its very implausibility, apparently still has a number of stories to tell.
www.nuclearplanet.com /lamonitor.htm   (2312 words)

 The University of Michigan Health Physics Web Site: Radioactivity in Nature
At Oklo, the area was naturally loaded with uranium by water transport and deposition.
Oklo site was saturated with groundwater, which served as a moderator, reflector and cooling for the fission reaction.
Once the samples were compared, the abundance of neodymium was found to be almost exactly that found in present day reactors.
www.umich.edu /~radinfo/introduction/natural.htm   (2517 words)

 Monkey Kingdom News and Rants: Oklo: Natural Nuclear Reactors   (Site not responding. Last check: 2007-10-09)
I think nuclear reactors are the way to go (I mean, how long can we rely on fossilized material?), and finding a secure way to store nuclear waste would do much to quell public fears.
Oklo: Natural Nuclear Reactors - Fact Sheet: "It came as a great surprise to most, therefore, when, in 1972, French physicist Francis Perrin declared that nature had beaten humans to the punch by creating the world’s first nuclear reactors.
Indeed, he argued, nature had a two-billion-year head start.1 Fifteen natural fission reactors have been found in three different ore deposits at the Oklo mine in Gabon, West Africa.
www.stanford.edu /~aylin/blog/2005/09/oklo-natural-nuclear-reactors.html   (201 words)

 Oklo: An Unappreciated Cosmic Phenomenon
This implies that natural breeder reactors are also possible, raising the possibility of hitherto unappreciated, long-lived heat sources deep in the earth, in the other planets, and inside some of the stars.
Don't worry that the Oklo phenomenon might occur today on the earth's surface.
In the deep earth, where pressures and densities are high, natural nuclear reactors may generate intermittent bursts of heat -- just as they did at Oklo -- and thereby cause the earth's dynamo to falter and reverse.
www.science-frontiers.com /sf121/sf121p02.htm   (365 words)

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