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Oklo
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 Alternative Energies and Atomic Energy Commission (the industrial parts, which later became Orano Cycle) discovered uranium in the remote region in 1956. France immediately opened mines operated by Comuf () 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Nuclear Fission Reactor
A natural nuclear fission reactor is a uranium deposit where self-sustaining nuclear chain reactions occur. The conditions under which a natural nuclear reactor could exist had been predicted in 1956 by Japanese American chemist Paul Kuroda. The remnants of an extinct or fossil nuclear fission reactor, where self-sustaining nuclear reactions have occurred in the past, can be verified by analysis of isotope ratios of uranium and of the fission products (and the stable daughter nuclides of those fission products). An example of this phenomenon was discovered in 1972 in Oklo, Gabon by French physicist Francis Perrin under conditions very similar to Kuroda's predictions. Oklo is the only location where this phenomenon is known to have occurred, and consists of 16 sites with patches of centimeter-sized ore layers. Here self-sustaining nuclear fission reactions are thought to have taken place approximately 1.7 billion years ago, during the Statherian period of the Paleoproterozoic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oklo Mine
Oklo Mine (sometimes Oklo Reactor or Oklo Mines), located in Oklo, Gabon on the west coast of Central Africa, is believed to be the only natural nuclear fission reactor. Oklo consists of 16 sites at which self-sustaining nuclear fission reactions are thought to have taken place approximately 1.7 billion years ago, and ran for hundreds of thousands of years. It is estimated to have averaged under 100 kW of thermal power during that time. History In May 1972 at the Tricastin uranium enrichment site at Pierrelatte in France, routine mass spectrometry comparing UF6 samples from Oklo showed a discrepancy in the amount of the isotope. Normally the concentration is 0.72% while these samples had only 0.60%, a significant difference (some 17% less U-235 was contained in the samples than expected). This discrepancy required explanation, as all civilian uranium handling facilities must meticulously account for all fissionable isotopes to ensure that none are diverted to the construct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium Mines
Uranium production is carried out in about 13 countries around the world, in 2017 producing a cumulative total of 59,462 tonnes of uranium (tU). The international producers were Kazakhstan (39%), Canada (22%), Australia (10%), Namibia (7.1%), Niger (5.8%), Russian Federation (4.9%), Uzbekistan (4.0%), China (3.2%), United States (1.6%), Ukraine (0.9%), India (0.7%), South Africa (0.5%) and Pakistan (0.1%). Since 2009 the in-situ leach (ISL) operations of Kazakhstan have been producing the largest share of world uranium. The largest conventional uranium mines are Cigar Lake and McArthur River (Canada); Ranger and Olympic Dam (Australia); Krasnokamensk (Russia) and Rossing (Namibia). The largest uranium producers are Cameco, Rio Tinto, Areva, KazAtomProm and ARMZ-TVEL. The production methods employed are conventional underground and open cast (50%) and in-situ leaching (50%). About 50 uranium production centers are operational. Viable projects Potentially viable projects N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Uranium Mines
Uranium production is carried out in about 13 countries around the world, in 2017 producing a cumulative total of 59,462 tonnes of uranium (tU). The international producers were Kazakhstan (39%), Canada (22%), Australia (10%), Namibia (7.1%), Niger (5.8%), Russian Federation (4.9%), Uzbekistan (4.0%), China (3.2%), United States (1.6%), Ukraine (0.9%), India (0.7%), South Africa (0.5%) and Pakistan (0.1%). Since 2009 the in-situ leach (ISL) operations of Kazakhstan have been producing the largest share of world uranium. The largest conventional uranium mines are Cigar Lake and McArthur River (Canada); Ranger and Olympic Dam (Australia); Krasnokamensk (Russia) and Rossing (Namibia). The largest uranium producers are Cameco, Rio Tinto, Areva, KazAtomProm and ARMZ-TVEL. The production methods employed are conventional underground and open cast (50%) and in-situ leaching (50%). About 50 uranium production centers are operational. Viable projects Potentially viable projects N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly radioactive because all isotopes of uranium are unstable; the half-lives of its naturally occurring isotopes range between 159,200 years and 4.5 billion years. The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordially occurring elements. Its density is about 70% higher than that of lead, and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite. In nature, uranium is found as uranium-238 (99. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franceville
Franceville is one of the four largest cities in Gabon, with a population of 110,568 at the 2013 census. It lies on the Mpassa River and at the end of the Trans-Gabon Railway and the N3 road. It grew from a village named Masuku when Pierre Savorgnan de Brazza chose it to resettle former slaves and renamed it Francheville (meaning "city of the freed") in 1880. The city later came to be called Franceville (meaning "French city"). Overview Brazza founded Franceville on June 13, 1880. The former name was Masuku. As time went on, it became known as Franceville. Features of the town include St Hilaire's Church (built in 1899), a large statue of President Omar Bongo (who was born in Franceville), a primate medical research institute, and a golf course. Its airport is west, in Mvengué. Bongo was buried in Franceville on June 18, 2009. There is a market where numerous items can be purchased, including clothing, fruit and vegetables, electronics, meats, and the market also sells bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Geological Repository
A deep geological repository is a way of storing hazardous or radioactive waste within a stable geologic environment (typically 200–1000 m deep). It entails a combination of waste form, waste package, engineered seals and geology that is suited to provide a high level of long-term isolation and containment without future maintenance. This will prevent any radioactive dangers. A number of mercury, cyanide and arsenic waste repositories are operating worldwide including Canada (Giant Mine) and Germany (potash mines in Herfa-Neurode and Zielitz) and a number of radioactive waste storages are under construction with the Onkalo in Finland being the most advanced. Principles and background Highly toxic waste that cannot be further recycled must be stored in isolation to avoid contamination of air, ground and underground water. Deep geological repository is a type of long-term storage that isolates waste in geological structures that are expected to be stable for millions of years, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gabon Geology Oklo
Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north, the Republic of the Congo on the east and south, and the Gulf of Guinea to the west. It has an area of nearly and its population is estimated at million people. There are coastal plains, mountains (the Cristal Mountains and the Chaillu Massif in the centre), and a savanna in the east. Since its independence from France in 1960, the sovereign state of Gabon has had three presidents. In the 1990s, it introduced a multi-party system and a democratic constitution that aimed for a more transparent electoral process and reformed some governmental institutions. With petroleum and foreign private investment, it has the fourth highest HDI in the region (after Mauritius, Seychelles and South Africa) and the fifth highest GDP per capita (PPP) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive Waste Repositories
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha decay ( ), beta decay ( ), and gamma decay ( ), all of which involve emitting one or more particles. The weak force is the mechanism that is responsible for beta decay, while the other two are governed by the electromagnetism and nuclear force. A fourth type of common decay is electron capture, in which an unstable nucleus captures an inner electron from one of the electron shells. The loss of that electron from the shell results in a cascade of electrons dropping down to that lower shell resulting in emission of discrete X-rays from the transitions. A common example is iodine-125 commonly used in medical settings. Radioactive decay is a stochastic (i.e. random) process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gabon
Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north, the Republic of the Congo on the east and south, and the Gulf of Guinea to the west. It has an area of nearly and its population is estimated at million people. There are coastal plains, mountains (the Cristal Mountains and the Chaillu Massif in the centre), and a savanna in the east. Since its independence from France in 1960, the sovereign state of Gabon has had three presidents. In the 1990s, it introduced a multi-party system and a democratic constitution that aimed for a more transparent electoral process and reformed some governmental institutions. With petroleum and foreign private investment, it has the fourth highest HDI in the region (after Mauritius, Seychelles and South Africa) and the fifth highest GDP per capita (PPP) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons ( Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian fossil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mines In Gabon
Mine, mines, miners or mining may refer to: Extraction or digging *Miner, a person engaged in mining or digging *Mining, extraction of mineral resources from the ground through a mine Grammar *Mine, a first-person English possessive pronoun Military * Anti-tank mine, a land mine made for use against armored vehicles * Antipersonnel mine, a land mine targeting people walking around, either with explosives or poison gas * Bangalore mine, colloquial name for the Bangalore torpedo, a man-portable explosive device for clearing a path through wire obstacles and land mines * Cluster bomb, an aerial bomb which releases many small submunitions, which often act as mines * Land mine, explosive mines placed under or on the ground * Mining (military), digging under a fortified military position to penetrate its defenses * Naval mine, or sea mine, a mine at sea, either floating or on the sea bed, often dropped via parachute from aircraft, or otherwise lain by surface ships or submarines * Par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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