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Repository For High-level Radioactive Waste
High-level radioactive waste management addresses the handling of radioactive materials generated from nuclear power production and nuclear weapons manufacture. Radioactive waste contains both short-lived and long-lived radionuclides, as well as non-radioactive nuclides. In 2002, the United States stored approximately 47,000 tonnes of high-level radioactive waste. Among the constituents of spent nuclear fuel, neptunium-237 and plutonium-239 are particularly problematic due to their long half-lives of two million years and 24,000 years, respectively. Handling high-level radioactive waste requires sophisticated treatment processes and long-term strategies such as permanent storage, disposal, or conversion into non-toxic forms to isolate it from the biosphere. Radioactive decay follows the half-life rule, which means that the intensity of radiation decreases over time as the rate of decay is inversely proportional to the duration of decay. In other words, the radiation from a long-l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Spent Nuclear Fuel Hanford
Spent may refer to: * Spent (band), a former indie rock band * Spent (game), ''Spent'' (game), an online game about surviving poverty and homelessness * ''Spent'', a collection of ''Peepshow (comics), Peepshow'' comics by Joe Matt * ''Spent: Sex, Evolution, and Consumer Behavior'', a 2009 book by Geoffrey Miller * ''Spent'', a 2025 comic novel by Alison Bechdel See also * Spend * Spent enactment * Spent nuclear fuel, a fuel no longer useful for sustaining a nuclear reaction {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hannes Alfvén
Hannes Olof Gösta Alfvén (; 30 May 1908 – 2 April 1995) was a Swedish electrical engineer, plasma physicist and winner of the 1970 Nobel Prize in Physics for his work on magnetohydrodynamics (MHD). He described the class of MHD waves now known as Alfvén waves. He was originally trained as an electrical power engineer and later moved to research and teaching in the fields of plasma physics and electrical engineering. Alfvén made many contributions to plasma physics, including theories describing the behavior of aurorae, the Van Allen radiation belts, the effect of magnetic storms on the Earth's magnetic field, the terrestrial magnetosphere, and the dynamics of plasmas in the Milky Way galaxy. Education Alfvén received his PhD from the University of Uppsala in 1934. His thesis was titled "Investigations of High-frequency Electromagnetic Waves." Early years In 1934, Alfvén taught physics at both the University of Uppsala and the Nobel Institute for Physics (lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Oklo Mine
A natural nuclear fission reactor is a uranium deposit where self-sustaining nuclear chain reactions occur. The idea of a nuclear reactor existing ''in situ'' within an ore body moderated by groundwater was briefly explored by Paul Kuroda in 1956. The existence of an extinct or fossil nuclear fission reactor, where self-sustaining nuclear reactions have occurred in the past, are established by analysis of isotope ratios of uranium and of the fission products (and the stable daughter nuclides of those fission products). The first discovery of such a reactor happened in 1972 in Oklo, Gabon, by researchers from the French Alternative Energies and Atomic Energy Commission (CEA) when chemists performing quality control for the French nuclear industry noticed sharp depletions of fissile in gaseous uranium made from Gabonese ore. 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. There, self ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Nuclear Fission
Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactive decay. Nuclear fission was discovered by chemists Otto Hahn and Fritz Strassmann and physicists Lise Meitner and Otto Robert Frisch. Hahn and Strassmann proved that a fission reaction had taken place on 19 December 1938, and Meitner and her nephew Frisch explained it theoretically in January 1939. Frisch named the process "fission" by analogy with biological fission of living cells. In their second publication on nuclear fission in February 1939, Hahn and Strassmann predicted the existence and liberation of additional neutrons during the fission process, opening up the possibility of a nuclear chain reaction. For heavy nuclides, it is an exothermic reaction which can release large amounts of energy both as electromagnetic radiat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Subduction Zone
Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second plate, the heavier plate dives beneath the other and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with rates of convergence as high as 11 cm/year. Subduction is possible because the cold and rigid oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle. Once initiated, stable subduction is driven mostly by the negative buoyancy of the dense subducting lithosphere. The down-going slab sinks into the mantle largely under its own ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Stewardship Cessation
Stewardship cessation{{Cite book, url=https://books.google.com/books?id=nInjCgAAQBAJ&q=The+technology+underlying+the+product+(for+example,+that+of+a+uniquely+flavoured+tea)+may+be+quite+marginal+but+the+process+of+creating+and+managing+its+life+as+a&pg=PA91, title=Proceedings of IAC-MEM 2015 in Vienna, last=group of authors, publisher=Czech Institute of Academic Education z.s., 2015, year=2015, isbn=9788090579156, pages=91 is a concept useful in system engineering. Certain systems remain hazardous for a considerable period after their useful life, and will usually be managed to ensure that the public and the environment is not exposed to the hazard. It is incumbent on the systems designer to consider the outcome should this stewardship be discontinued for any reason, and to design a system which is as robust as possible in the event of stewardship cessation. Examples Nuclear industry The most obvious example is the nuclear industry, and the radioactive waste it generates which will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Tunnel Boring Machine
A tunnel boring machine (TBM), also known as a "mole" or a "worm", is a machine used to excavate tunnels. TBMs are an alternative to drilling and blasting methods and "hand mining", allowing more rapid excavation through hard rock, wet or dry soil, or sand (although each requires specialized TBM technologies). TBM-bored tunnel cross-sections extend up to (through June 2023). TBM tunnels are typically circular in cross-section, but may also be square or rectangular, or U- or horseshoe-shaped. Much narrower tunnels are typically bored using trenchless construction methods or horizontal directional drilling rather than by TBMs. TBMs limit disturbance to the surrounding ground and produce a smooth tunnel wall, which reduces the cost of lining the tunnel; it also allows for tunneling in urban areas. Large TBMs are expensive and challenging to construct and transport, fixed costs which become less significant for longer tunnels. Tunneling speeds generally decline as tunnel size in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Nuclear Spent Fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor and, depending on its point along the nuclear fuel cycle, it will have different isotopic constituents than when it started. Nuclear fuel rods become progressively more radioactive (and less thermally useful) due to neutron activation as they are fissioned, or "burnt", in the reactor. A fresh rod of low enriched uranium pellets (which can be safely handled with gloved hands) will become a highly lethal gamma emitter after 1–2 years of core irradiation, unsafe to approach unless under many feet of water shielding. This makes their invariable accumulation and safe temporary storage in spent fuel pools a prime source of high level radioactive waste and a major ongoing issue for future permanent disposal. Nature of spent fuel Nanomaterial pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Radioactive Waste
Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nuclear weapons reprocessing. The storage and disposal of radioactive waste is regulated by government agencies in order to protect human health and the environment. Radioactive waste is broadly classified into 3 categories: low-level waste (LLW), such as paper, rags, tools, clothing, which contain small amounts of mostly short-lived radioactivity; intermediate-level waste (ILW), which contains higher amounts of radioactivity and requires some shielding; and high-level waste (HLW), which is highly radioactive and hot due to decay heat, thus requiring cooling and shielding. Spent nuclear fuel can be processed in nuclear reprocessing plants. One third of the total amount have already been reprocessed. With nuclear reprocessing 96% of the spent fue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Onkalo 2
The Onkalo spent nuclear fuel repository is a deep geological repository for the final disposal of spent nuclear fuel. It is near the Olkiluoto Nuclear Power Plant in the municipality of Eurajoki, on the west coast of Finland. It will be the world's first long-term disposal facility for spent nuclear fuel. It is being constructed by Posiva, and is based on the KBS-3 method of nuclear waste burial developed in Sweden by Svensk Kärnbränslehantering AB (SKB). The facility will be operational by 2026, and decommissioned by 2100. History After the Finnish Nuclear Energy Act was amended in 1994 to specify that all Radioactive waste, nuclear waste produced in Finland must be disposed of in Finland, Olkiluoto was selected in 2000 as the site for a Deep geological repository, long-term underground storage facility for Finland's spent nuclear fuel. The facility, named "Onkalo" (meaning "small cave" or "cavity") is being built in the granite bedrock at the Olkiluoto site, about five kil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Kristin Shrader-Frechette
Kristin Shrader-Frechette (born 1944) is O'Neill Family Professor, Department of Biological Sciences and Department of Philosophy, at the University of Notre Dame. She has previously held senior professorships at the University of California and the University of Florida. Most of Shrader-Frechette's research work analyzes the ethical problems in risk assessment, public health, or environmental justice - especially those related to radiological, ecological, and energy-related risks. Shrader-Frechette coined the phrase “ecological justice” more than 40 years ago, with the term changing to “environmental justice” over time. Among other things, "environmental injustice" references situations in which certain groups bear disproportionate environmental risks, have unequal access to goods like clean air or water, or have unequal voices in determining the imposition of environmental risks. Shrader-Frechette, who is considered one of the founders of the environmental justice move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
