Read Phillip Morrison's commentary, "Where Fiction Became Ancient Fact," from Scientific American, June 1998. The pages provide information about the "where, when, what, why, who, and how" of the Oklo reactors. Visit, Australian web sites about the Natural Fossil Fission Reactors at Oklo, Gabon. This is probably the best-known article about Oklo it contains readable scientific information for non-specialists. It contains photos, diagrams, and a description of the research into the Oklo reactors. Visit your local library and ask the reference librarian or periodicals desk for the article: Seeking to explain the discrepancy, scientists began some detective work. What led to the discovery of the Oklo natural fission reactors?Ī scientist making a routine test noted a tiny "discrepancy" in the amount of uranium-235 present in some uranium which was undergoing enrichment. Studying what happened to the fission products in the reactor has provided valuable insight into the requirements for a long-term waste repository. The Oklo reactor provided an interesting natural analog for waste management. In fact, it was studies of the fission products found in the uranium mine which showed that a natural reactor had operated there. When evidence of the Oklo reactor was discovered in 1972, the fission products had been lying in Mother Nature's repository for about a billion years (that's 1,000 million years). While it was active, the natural reactor generated fission products (wastes) very similar to those produced when fission occurs in modern nuclear reactors at power plants. The fission reaction continued - off and on - for hundreds of thousands of years. As the Oklo-reactor demonstrates, the ruthenium-compounds remain stable even if exposed to radioactivity and corrosion by water over vast geological periods.More than 1.5 billion years ago (that's more than 1,500 million years) a nuclear fission reaction took place in an underground uranium deposit in Oklo, Gabon, Africa. If so, containers made of ruthenium alloys could be used to safely store radioactive waste for a very long time. The scientists believe that the radioactive plutonium and cesium were encapsulated and safely isolated from the environment by a shell of ruthenium-compounds. Native ruthenium is a rare and inert metal often associated with ore of other elements. In rocks recovered from the Oklo mine, barium (the 'trace' left by the former radioactive elements) is not found evenly distributed, but rather found in nests surrounded by a thin layer of ruthenium-compounds. and published in the journal PNAS has investigated how the Oklo-reactor was able to work so long and yet not pollute the environment.
Research by a team of scientists of the US Naval Research Laboratory in Washington D. By studying the Oklo-reactor, scientists hope to find a way to safely dispose of nuclear waste as produced by modern reactors. Steel will rust, concrete can leak and even glass is damaged by the emitted radiation.
The problem is that we don't know what materials to use for the containers to store the waste. A permanent repository for nuclear waste must contain toxic elements and radioactivity for at least 100,000 years. Many experts believe that nuclear energy could be a temporary solution until renewable energy sources are ready to meet the demand. Unfortunately, nuclear energy comes with radioactive waste.
During this process, however, no harmful radioactivity has leaked into the environment.Īs t he planet warms due to our carbon emissions, burning oil and coal is no longer a sustainable way to meet humanity’s hunger for energy. Over time the Oklo-reactor has produced large quantities of toxic plutonium and cesium-isotopes, which have since decayed into stable and harmless barium. As the uranium decays, it forms other radioactive elements fueling the reactor. Then water that infiltrated the formation along faults slowed down the emitted neutrons enough to sustain slow and stable nuclear fission. Weathering of magmatic rocks and bacterial activity concentrated the uranium enough to start a nuclear chain reaction. In the Oklo-reactor, two factors came together to sustain a slow nuclear fission for hundreds of thousands of years.
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