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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] |
Cigar Lake Mine
The Cigar Lake Mine is a large high-grade underground uranium mine, located in the uranium-rich Athabasca Basin of northern Saskatchewan, Canada, at the south-west corner of Waterbury Lake. The deposit, discovered in 1981, is second in size of high-grade deposits only to the nearby McArthur River mine. Other deposits, such as Olympic Dam in Australia, contain more uranium but at lower grades. History Full-scale construction began in 2005 with production originally planned for 2007, but the mine experienced a catastrophic water inflow in October 2006, which flooded the mine. A second inflow occurred in 2008 during the first attempt at dewatering the mine after sealing the initial inflow. Remediation efforts continued, and re-entry was successfully accomplished in 2010. Production was delayed several times with the startup dates being announced for 2011, 2013, and 2014. On March 13, 2014, ore production began at the mine, with the mining system and underground processing circuit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underground Research Laboratory
The Underground Research Laboratory was a test site for deep geological repository of nuclear waste operated by Atomic Energy of Canada Limited's (AECL's) Whiteshell Laboratories near Lac du Bonnet in Manitoba, Canada. The site was built inside a large granite batholith, typical of the Canadian Shield. The site was selected in 1980, construction began in 1982 and it opened in 1985. No radioactive material was stored at the site, it was used purely for measurements of water exchange, rock movement, and other issues that would affect the safety of such materials. The site was also used by a variety of international users. As part of the wider wind-down of AECL activities, the decision was made to close the URL in 2003. Cleanup work began in 2006 and completed in 2010. The site continues to host a single international experiment measuring water leakage through a massive clay plug. History Nuclear Fuel Waste Management Program Through the 1970s the issue of storing nuclear waste became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay particles, but become hard, brittle and non–plastic upon drying or firing. Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as a reddish or brownish colour from small amounts of iron oxide. Clay is the oldest known ceramic material. Prehistoric humans discovered the useful properties of clay and used it for making pottery. Some of the earliest pottery shards have been dated to around 14,000 BC, and clay tablets were the first known writing medium. Clay is used in many modern industrial processes, such as paper making, cement production, and chemical filtering. Between one-half and two-thirds of the world's population live or work in buildings made with clay, often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borehole
A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petroleum), or gases (such as natural gas). It may also be part of a geotechnical investigation, environmental site assessment, mineral exploration, temperature measurement, as a pilot hole for installing piers or underground utilities, for geothermal installations, or for underground storage of unwanted substances, e.g. in carbon capture and storage. Importance Engineers and environmental consultants use the term ''borehole'' to collectively describe all of the various types of holes drilled as part of a geotechnical investigation or environmental site assessment (a so-called Phase II ESA). This includes holes advanced to collect soil samples, water samples or rock cores, to advance ''in situ'' sampling equipment, or to install monitoring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onkalo 2
"Onkalo" is a maxi single released by the J-pop singer Eiko Shimamiya (ETB-0161). Released 21 June 2012, it is her first single after her retirement from I've Sound in April 2011. The single features two new songs; Onkalo and Unison. Track listing #"Onkalo" #"Unison" #"Onkalo"（Instrumental version） References {{Reflist 2012 singles Eiko Shimamiya songs 2012 songs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Water
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from the surface; it may discharge from the surface naturally at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology. Typically, groundwater is thought of as water flowing through shallow aquifers, but, in the technical sense, it can also contain soil moisture, permafro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transuranic Elements
The transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, which is the atomic number of uranium. All of these elements are unstable and decay radioactively into other elements. With the exception of neptunium and plutonium (which have been found in trace amounts in nature), all do not occur naturally on Earth and are synthetic. Overview Of the elements with atomic numbers 1 to 92, most can be found in nature, having stable isotopes (such as hydrogen) or very long-lived radioisotopes (such as uranium), or existing as common decay products of the decay of uranium and thorium (such as radon). The exceptions are elements 43, 61, 85, and 87; all four occur in nature, but only in very minor branches of the uranium and thorium decay chains, and thus all save element 87 were first discovered by synthesis in the laboratory rather than in nature (and even element 87 was discovered from purified samples of its paren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plutonium
Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen. When exposed to moist air, it forms oxides and hydrides that can expand the sample up to 70% in volume, which in turn flake off as a powder that is pyrophoric. It is radioactive and can accumulate in bones, which makes the handling of plutonium dangerous. Plutonium was first synthetically produced and isolated in late 1940 and early 1941, by a deuteron bombardment of uranium-238 in the cyclotron at the University of California, Berkeley. First, neptunium-238 ( half-life 2.1 days) was synthesized, which subsequently beta-decayed to form the new element with atomic number 94 and atomic weight 238 (half-life 88 years). Since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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