query: what is a typical value of k for an operating fission power plant

pos: Nuclear chain reaction another fission. The remaining neutrons either are absorbed in non-fission reactions or leave the system without being absorbed. The value of "k" determines how a nuclear chain reaction proceeds: When describing kinetics and dynamics of nuclear reactors, and also in the practice of reactor operation, the concept of reactivity is used, which characterizes the deflection of reactor from the critical state. ρ=(k-1)/k. InHour is a unit of reactivity of a nuclear reactor. In a nuclear reactor, "k" will actually oscillate from slightly less than 1 to slightly more than 1, due primarily to thermal effects (as more power is produced,

pos: Dollar (reactivity) cause exactly one additional fission, and the delayed neutrons will then increase power. Any reactivity above $0 is supercritical and power will increase exponentially, but between $0 and $1 the power rise will be slow enough to be easily and safely controlled with mechanical control rods because the chain reaction partly depends on the delayed neutrons. A power reactor operating at steady state (constant power) will therefore have an average reactivity of $0, with small fluctuations above and below this value. Reactivity can also be expressed in relative terms, such as "5 cents above prompt critical". While power reactors are

pos: Nuclear chain reaction the fuel rods warm and thus expand, lowering their capture ratio, and thus driving "k" lower). This leaves the average value of "k" at exactly 1. Delayed neutrons play an important role in the timing of these oscillations. In an infinite medium, the multiplication factor may be described by the four factor formula; in a non-infinite medium, the multiplication factor may be described by the six factor formula. Not all neutrons are emitted as a direct product of fission; some are instead due to the radioactive decay of some of the fission fragments. The neutrons that occur directly from fission

pos: Prompt criticality and if "k-effective" is greater than 1 the assembly is called supercritical. In a supercritical assembly the number of fissions per unit time, "N", along with the power production, increases exponentially with time. How fast it grows depends on the average time it takes, "T", for the neutrons released in a fission event to cause another fission. The growth rate of the reaction is given by: Most of the neutrons released by a fission event are the ones released in the fission itself. These are called prompt neutrons, and strike other nuclei and cause additional fissions within nanoseconds (an average

pos: Critical mass neutron activity. The constant of proportionality increases as increases. A "supercritical" mass is one in which, once fission has started, it will proceed at an increasing rate. The material may settle into equilibrium ("i.e." become critical again) at an elevated temperature/power level or destroy itself. In the case of supercriticality, "k" > 1. Due to spontaneous fission a supercritical mass will undergo a chain reaction. For example, a spherical critical mass of pure uranium-235 will have a mass of 52 kg and will experience around 15 spontaneous fission events per second. The probability that one such event will cause a

pos: Fukushima Daiichi nuclear disaster fuel which has typical values of 270 Sv/h, after 10 years of cold shutdown, with no shielding. The Fukushima Daiichi Nuclear Power Plant comprised six separate boiling water reactors originally designed by General Electric (GE) and maintained by the Tokyo Electric Power Company (TEPCO). At the time of the Tōhoku earthquake on 11 March 2011, Reactors 4, 5, and 6 were shut down in preparation for re-fueling. However, their spent fuel pools still required cooling. Immediately after the earthquake, the electricity-producing Reactors 1, 2, and 3 automatically shut down their sustained fission reactions by inserting control rods in a legally-mandated

pos: Portland cement (including greenhouse gas emissions, dioxin, NO, SO, and particulates), accidents, and worker exposure to dust. The CO associated with Portland cement manufacture comes from three sources: Source 1 is fairly constant: minimum around CO per kg of cement, maximum 0.54, typical value around 0.50 worldwide. Source 2 varies with plant efficiency: efficient precalciner plant CO per kg cement, low-efficiency wet process as high as 0.65, typical modern practices (e.g. UK) averaging around 0.30. Source 3 is almost insignificant at 0.002–0.005. So typical total CO is around CO per kg finished cement. This omits the CO associated with electric power consumption,

pos: Prompt criticality one and seven neutrons (with an average of 2.4). In this situation, an assembly is critical if every released neutron has a 1/2.4 = 0.42 = 42% probability of causing another fission event as opposed to either being absorbed by a non-fission capture event or escaping from the fissile core. The average number of neutrons that cause new fission events is called the effective neutron multiplication factor, usually denoted by the symbols "k-effective", "k-eff" or "k". When "k-effective" is equal to 1, the assembly is called critical, if "k-effective" is less than 1 the assembly is said to be subcritical,

pos: Prompt criticality have no difference except the energy or speed which have been imparted to them. A nuclear weapon relies heavily on prompt-supercriticality (to produce a high peak power in a fraction of a second), whereas nuclear power reactors use delayed-criticality to produce controllable power levels for months or years. In order to start up a controllable fission reaction, the assembly must be delayed-critical. In other words, "k" must be greater than 1 (supercritical) without crossing the prompt-critical threshold. In nuclear reactors this is possible due to delayed neutrons. Because it takes some time before these neutrons are emitted following a fission

pos: Nuclear technology with the help of the United Kingdom and Canada, developed multiple fission weapons which were used against Japan in 1945 at Hiroshima and Nagasaki. During the project, the first fission reactors were developed as well, though they were primarily for weapons manufacture and did not generate electricity. In 1951, the first nuclear fission power plant was the first to produce electricity at the Experimental Breeder Reactor No. 1 (EBR-1), in Arco, Idaho, ushering in the "Atomic Age" of more intensive human energy use. However, if the mass is critical only when the delayed neutrons are included, then the reaction can

pos: Sequoyah Nuclear Plant containment building. Sequoyah's two units have a winter net dependable capacity of 2,333 megawatts, making Sequoyah the most productive of TVA's three nuclear plants. Sequoyah is the second-most powerful power plant in Tennessee, second only to the Cumberland Fossil Plant northwest of Nashville, but actually generates more power. Following the restart of Brown's Ferry Unit 1, that plant again became most productive at 3,440 MW. The operating license of Sequoyah's Unit 1 was originally set to expire in 2020, and Unit 2's operating license in 2021. In 2015, the NRC renewed the operating license for both units for an additional

pos: Nuclear reactor physics = "fast-fission factor", "L" = "fast non-leakage factor", ρ = "resonance escape probability", "L" = "thermal non-leakage factor", "f" = "thermal fuel utilization factor", and η = "reproduction factor". This equation's factors are roughly in order of potential occurrence for a fission born neutron during critical operation. As already mentioned before, k = (Neutrons produced in one generation)/(Neutrons produced in the previous generation). In other words, when the reactor is critical, k = 1; when the reactor is subcritical, k < 1; and when the reactor is supercritical, k > 1. "Reactivity" is an expression of the departure from criticality.

pos: Gyeongju of GS Group, provides gas to the Gyeongju residents, while, electrical power is supplied by the public enterprises, Korea Hydro & Nuclear Power via the Wolseong Nuclear Power Plant. The plant is known for the only nuclear power plant operating PHWRs (Pressurized Heavy Water Reactor) in South Korea and supplies about 5% of South Korea's electricity. The owner, Korea Hydro & Nuclear Power began to build the Wolseong 1 in the districts of Yangnam-myeon, Yangbuk-myeon and Gampo-eup in 1976. Since 1983, the power plant has been providing commercial service and operating with the PHWRs that has a capacity of 678,000

pos: Thermal efficiency between 0% and 100%. Efficiency is typically less than 100% because there are inefficiencies such as friction and heat loss that convert the energy into alternative forms. For example, a typical gasoline automobile engine operates at around 25% efficiency, and a large coal-fuelled electrical generating plant peaks at about 46%, advances in Formula 1 motorsport regulations have pushed teams to develop highly efficient power units which peak around 45–50% thermal efficiency. The largest diesel engine in the world peaks at 51.7%. In a combined cycle plant, thermal efficiencies are approaching 60%. Such a real-world value may be used as a

neg: Nuclear chain reaction orientation. The value of k can also be increased by using a neutron reflector surrounding the fissile material Once the mass of fuel is prompt supercritical, the power increases exponentially. However, the exponential power increase cannot continue for long since k decreases when the amount of fission material that is left decreases (i.e. it is consumed by fissions). Also, the geometry and density are expected to change during detonation since the remaining fission material is torn apart from the explosion. Detonation of a nuclear weapon involves bringing fissile material into its optimal supercritical state very rapidly. During part of this

neg: Criticality (status) Criticality (status) Criticality, is the state of a nuclear chain reacting medium when the chain reaction is just self-sustaining (or critical), that is, when the reactivity is zero. More loosely, the term is used for states in which the reactivity is greater than zero. In the context of a nuclear reactor, particularly in a nuclear power plant, criticality refers to the normal operating condition of a reactor, in which nuclear fuel sustains a fission chain reaction. A reactor achieves criticality, (and is said to be critical) when each fission event releases a sufficient number of neutrons to sustain an ongoing

neg: Parabolic antenna dB) its maximum value. For parabolic antennas, the HPBW "θ" is given by: where "k" is a factor which varies slightly depending on the shape of the reflector and the feed illumination pattern. For an ideal uniformly illuminated parabolic reflector and "θ" in degrees, "k" would be 57.3 (the number of degrees in a radian). For a "typical" parabolic antenna "k" is approximately 70. For a typical 2 meter satellite dish operating on C band (4 GHz), this formula gives a beamwidth of about 2.6°. For the Arecibo antenna at 2.4 GHz the beamwidth is 0.028°. It can be seen

neg: Integrated gasification combined cycle rank lignites. Third, unplanned down time on the gasifier because of refractory liner problems, and those problems were expensive to repair. The gasifier was originally designed in Italy to be half the size of what was built at Polk. Newer ceramic materials may assist in improving gasifier performance and longevity. Understanding the operating problems of the current IGCC plant is necessary to improve the design for the IGCC plant of the future. (Polk IGCC Power Plant, http://www.clean-energy.us/projects/polk_florida.html.) Keim, K., 2009, IGCC A Project on Sustainability Management Systems for Plant Re-Design and Re-Image. This is an unpublished paper from Harvard University)

neg: Micro combined heat and power 60,000 hours. For PEM fuel cell units, which shut down at night, this equates to an estimated lifetime of between ten and fifteen years. United States Department of Energy (DOE) Technical Targets: 1–10 kW residential combined heat and power fuel cells operating on natural gas. Standard utility natural gas delivered at typical residential distribution line pressures. Regulated AC net/lower heating value of fuel. Only heat available at 80 °C or higher is included in CHP energy efficiency calculation. Cost includes materials and labor costs to produce stack, plus any balance of plant necessary for stack operation. Cost defined at 50,000

neg: Isar Nuclear Power Plant a lot of automatically working active safety systems whose reliableness is based on their plural existence and their autonomously working in separate rooms. This is as necessary for the internal electric power supply as for the reactor cooling system, which guarantees the reliable thermal dissipation in every operating status, even when an implausible accident ingresses (for example a break of a primary coolant line). It constantly controls and compares all the important key operating parameters of the plant and activates automatically the necessary protection measures (independent from the plant operating personnel) if a parameter reaches a limit value. For example,

neg: Criticality (status) 31 October 1991. Criticality (status) Criticality, is the state of a nuclear chain reacting medium when the chain reaction is just self-sustaining (or critical), that is, when the reactivity is zero. More loosely, the term is used for states in which the reactivity is greater than zero. In the context of a nuclear reactor, particularly in a nuclear power plant, criticality refers to the normal operating condition of a reactor, in which nuclear fuel sustains a fission chain reaction. A reactor achieves criticality, (and is said to be critical) when each fission event releases a sufficient number of neutrons to

neg: Springfield (The Simpsons) Springfield Stadium; the NBA's Springfield Excitement (formerly the Austin Celtics); and the Springfield Ice-O-Topes hockey team at the Springfield Arena. The Springfield Nuclear Power Plant is a nuclear power plant in Springfield owned by Charles Montgomery Burns. Opened in 1974, the plant is the key supplier of the city of Springfield's energy supply, and the carelessness of Mr. Burns and the plant's employees (like Homer, who is employed at Sector 7G) often endangers the residents and natural environment of Springfield. At the core of the plant are two Fissionator 1952 Slow-Fission Reactors, operating in spite of more than 342 safety

neg: Nuclear chain reaction = 1/(1-β) is known as delayed supercriticality (or delayed criticality). It is in this region that all nuclear power reactors operate. The region of supercriticality for k > 1/(1-β) is known as prompt supercriticality (or prompt criticality), which is the region in which nuclear weapons operate. The change in k needed to go from critical to prompt critical is defined as a dollar. Nuclear fission weapons require a mass of fissile fuel that is prompt supercritical. For a given mass of fissile material the value of k can be increased by increasing the density. Since the probability per distance traveled

neg: Nuclear Fuel Complex also generate fission products. The fission products, which are radioactive, should be contained and not allowed to mix with coolant water. Hence the UO pellets are contained in zirconium alloy tubes with both ends hermetically sealed. Nuclear Fuel Complex supplies zircaloy clad uranium oxide fuel assemblies and zirconium alloy structural components for all 14 operating atomic power reactors in India. The Hyderabad plant has a capacity to produce 250 tons of UO per year and is expected to expanded to a 600 tons per year capacity. NFC products are supplied to the Department of Atomic Energy, the Indian Navy, Hindustan

neg: Perry K. Generating Station and W, respectively, of the Charles C. Perry Plant. In 2000, IPL sold the district heating system and the Perry K plant to Citizens Gas and Coke Utility (later renamed as Citizens Energy Group). Perry K. Generating Station Perry K. Generating Station is a small multi-fired power station producing steam for one of the largest central district steam heating systems in the United States. The plant is located on the south side of downtown Indianapolis, at the intersection of Kentucky Avenue and West Street. Its coal-fired units, currently being converted to natural gas, are among the oldest operating power plants

neg: Jaitapur Nuclear Power Project waste from the site will be dumped. The plant is estimated to generate 300 tonnes of used nuclear fuel each year, the volume of a 2.5 m sided cube. Owing to the Generation III reactors having a higher fuel efficiency than previous Gen II designs, the smaller amount of used nuclear fuel from an EPR will contain "four times" as much fission products by volume, Iodine, Caesium, etc., compared to presently operating Gen II pressurised water reactors. Since the plant will use the sea water for cooling and then release warmed water in the Arabian Sea, fishermen in villages around

neg: Power history different power history. Power history Power History refers to the power of a nuclear reactor over an extended period of time. Power history is important for calculations and operations that involve decay heat and fission product poisons and to avoid the iodine pit during reactor shutdowns. For example, a nuclear reactor that has operated at 100% power for 100 hours and then has dropped down to 20% power for 5 hours will have a different amount of decay heat and fission product poisons than the same nuclear reactor operating at 20% power for 105 hours. This is because the second

neg: Power history Power history Power History refers to the power of a nuclear reactor over an extended period of time. Power history is important for calculations and operations that involve decay heat and fission product poisons and to avoid the iodine pit during reactor shutdowns. For example, a nuclear reactor that has operated at 100% power for 100 hours and then has dropped down to 20% power for 5 hours will have a different amount of decay heat and fission product poisons than the same nuclear reactor operating at 20% power for 105 hours. This is because the second reactor has a

neg: Burnup per fission event. A typical value is 193.7 MeV () of thermal energy per fission (see Nuclear fission). With this value, the maximum burnup of 100%, which includes fissioning not just fissile content but also the other fissionable nuclides, is equivalent to about 909 GWd/t. Nuclear engineers often use this to roughly approximate 10% burnup as just less than 100 GWd/t. The actual fuel may be any actinide that can support a chain reaction, including uranium, plutonium, and more exotic transuranic fuels. This fuel content is often referred to as the "heavy metal" to distinguish it from other metals present

neg: Pacific Gas and Electric Company of the reorganization, PG&E's 5.1 million electricity customers will have to pay above-market prices for several years to cancel the debt. PG&E's utility-owned generation portfolio consists of an extensive hydroelectric system, one operating nuclear power plant, one operating natural gas-fired power plant, and another gas-fired plant under construction. Two other plants owned by the company have been permanently removed from commercial operation: Humboldt Bay Unit 3 (nuclear) and Hunters Point (natural gas). PG&E is the largest private owner of hydroelectric facilities in the United States including 174 dams. According to the company's Form 10-K filing for 2011, "The Utility’s hydroelectric

neg: Centurion Reactor the operating lifetime of commercial power plants is driven by fundamental investment economics, land use considerations, and social justice considerations. From the investment economics perspective, the allure of an 80-year profit stream to the plant owner/operator is a great attraction. Land-use considerations are also a motivating factor. A qualified and licensed nuclear power plant site is an extremely valuable asset due to the limited number of such sites available to energy produces. The value of a site is directly related to the amount of energy that can be produced on that site. Other considerations aside, the value of a specific

neg: Nuclear fission more detailed description of the physics and operating principles of critical fission reactors, see nuclear reactor physics. For a description of their social, political, and environmental aspects, see nuclear power. One class of nuclear weapon, a "fission bomb" (not to be confused with the "fusion bomb"), otherwise known as an "atomic bomb" or "atom bomb", is a fission reactor designed to liberate as much energy as possible as rapidly as possible, before the released energy causes the reactor to explode (and the chain reaction to stop). Development of nuclear weapons was the motivation behind early research into nuclear fission which

neg: Nuclear power plant Nuclear power plant A nuclear power plant or nuclear power station is a thermal power station in which the heat source is a nuclear reactor. As it is typical of thermal power stations, heat is used to generate steam that drives a steam turbine connected to a generator that produces electricity. , the IAEA report there are 450 nuclear power reactors in operation operating in 31 countries. Nuclear plants are usually considered to be base load stations since fuel is a small part of the cost of production and because they cannot be easily or quickly dispatched. Their operations and

neg: Perry K. Generating Station Perry K. Generating Station Perry K. Generating Station is a small multi-fired power station producing steam for one of the largest central district steam heating systems in the United States. The plant is located on the south side of downtown Indianapolis, at the intersection of Kentucky Avenue and West Street. Its coal-fired units, currently being converted to natural gas, are among the oldest operating power plants in the United States. Perry K. is owned by Citizens Thermal, a division of Citizens Energy Group. In 1892–1893, the Indianapolis Light and Power Company, a predecessor of the Indianapolis Power and Light Company

neg: Neutrino in a nuclear reactor is generated by fission (the four main fissile isotopes in nuclear reactors are , , and ), the resultant neutron-rich daughter nuclides rapidly undergo additional beta decays, each converting one neutron to a proton and an electron and releasing an electron antineutrino (). Including these subsequent decays, the average nuclear fission releases about of energy, of which roughly 95.5% is retained in the core as heat, and roughly 4.5% (or about ) is radiated away as antineutrinos. For a typical nuclear reactor with a thermal power of , the total power production from fissioning atoms is

neg: Fission product yield (the few most absorptive) neutron poison fission products, from thermal neutron fission of U-235 (typical of nuclear power reactors), computed from . The yields in the table sum to only 45.5522%, including 34.8401% which have halflife greater than one year: The remainder and the unlisted 54.4478% decay with halflife less than one year into nonradioactive nuclei. This is before accounting for the effects of any subsequent neutron capture, e.g.: Besides fission products, the other types of radioactive products are Cumulative fission yields give the amounts of nuclides produced either directly in the fission or by decay of other nuclides. Fission

neg: Nuclear reactor power plant accidents include the SL-1 accident (1961), the Three Mile Island accident (1979), Chernobyl disaster (1986), and the Fukushima Daiichi nuclear disaster (2011). Nuclear-powered submarine mishaps include the K-19 reactor accident (1961), the K-27 reactor accident (1968), and the K-431 reactor accident (1985). Nuclear reactors have been launched into Earth orbit at least 34 times. A number of incidents connected with the unmanned nuclear-reactor-powered Soviet RORSAT radar satellite program resulted in spent nuclear fuel re-entering the Earth's atmosphere from orbit. Although nuclear fission reactors are often thought of as being solely a product of modern technology, the first nuclear

neg: Ceiling (aeronautics) Ceiling (aeronautics) With respect to aircraft performance, a ceiling is the maximum density altitude an aircraft can reach under a set of conditions, as determined by its flight envelope. Service ceiling is where the rate of climb drops below a prescribed value. The service ceiling is the maximum usable altitude of an aircraft. Specifically, it is the density altitude at which flying in a clean configuration, at the best rate of climb airspeed for that altitude and with all engines operating and producing maximum continuous power, will produce a given rate of climb (a typical value might be 100 feet

neg: Zwentendorf Nuclear Power Plant a joint venture of several Austrian electric power companies. The initial cost of the plant was around 5.2 billion Austrian schilling, approximately 1.4 billion Euro adjusted for inflation. The ventilation stack chimney of the plant is 110 metres tall. Since the plebiscite, the plant has been partially deconstructed. The Dürnrohr Power Station was built nearby as a replacement thermal power station. Following the 1978 referendum, no commercial nuclear power plant (built for the purpose of producing electricity) ever went into operation in Austria. In 1978, a law Austria was enacted prohibiting the construction and operation of fission reactors for electrical

neg: Nuclear power positive energy gain. Construction of the ITER facility began in 2007, but the project has run into many delays and budget overruns. The facility is now not expected to begin operations until the year 2027 – 11 years after initially anticipated. A follow on commercial nuclear fusion power station, DEMO, has been proposed. There are also suggestions for a power plant based upon a different fusion approach, that of an inertial fusion power plant. Fusion powered electricity generation was initially believed to be readily achievable, as fission-electric power had been. However, the extreme requirements for continuous reactions and plasma containment

neg: Lawrence Lidsky an influential article about the difficulties of making a working nuclear fusion power plant. The ensuing reduction in federal funding for fusion research led him to resign from the center, and caused him to be "drummed out" of the nuclear fusion research community. Because of his concerns with the viability of fusion power, he instead became by 1989 an advocate for safer nuclear fission reactor designs. In 1999 he was named a fellow of the American Association for the Advancement of Science "for outstanding contributions to both nuclear fission and fusion in education, research, system design and analysis, technical publications

neg: Laser Inertial Fusion Energy well. This reaction is used in H-bombs to increase the yield of the fusion section by wrapping it in a layer of depleted uranium, which undergoes rapid fission when hit by the neutrons from the fusion bomb inside. The same basic concept can also be used with a fusion reactor like LIFE, using its neutrons to cause fission in a "blanket" of fission fuel. Unlike a fission reactor, which burns out its fuel once the U-235 drops below a certain threshold value, these fission–fusion hybrid reactors can continue producing power from the fission fuel as long as the fusion reactor

neg: Magnetochemistry established between the spin states, involving what have been called "electronic isomers". Tris-dithiocarbamato iron(III), Fe(SCNR), is a well-documented example. The effective moment varies from a typical d low-spin value of 2.25 μ at 80 K to more than 4 μ above 300 K. Crystal field splitting is larger for complexes of the heavier transition metals than for the transition metals discussed above. A consequence of this is that low-spin complexes are much more common. Spin-orbit coupling constants, ζ, are also larger and cannot be ignored, even in elementary treatments. The magnetic behaviour has been summarized, as below, together with an

neg: Nuclear power led to projections being extended by several decades. In 2010, more than 60 years after the first attempts, commercial power production was still believed to be unlikely before 2050. Nuclear power Nuclear power is the use of nuclear reactions that release nuclear energy to generate heat, which most frequently is then used in steam turbines to produce electricity in a nuclear power plant. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium. Nuclear decay processes are used in

neg: Nuclear power Nuclear power Nuclear power is the use of nuclear reactions that release nuclear energy to generate heat, which most frequently is then used in steam turbines to produce electricity in a nuclear power plant. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators. The possibility of generating electricity from nuclear fusion is still at a research phase with no commercial applications. This article mostly deals

neg: India's three-stage nuclear power programme million) per MW, coupled with a designed plant life of 40 years. Time required for construction has improved over time and is now at about 5 years. Tariffs of the operating plants are in the range of Rs. 1.75 to 2.80 per unit, depending on the life of the reactor. In the year 2007–08 the average tariff was Rs.2.28. In the second stage, fast breeder reactors (FBRs) would use a mixed oxide (MOX) fuel made from plutonium-239, recovered by reprocessing spent fuel from the first stage, and natural uranium. In FBRs, plutonium-239 undergoes fission to produce energy, while the uranium-238

neg: Nuclear power a combination of nuclear fusion and fission processes. The concept dates to the 1950s, and was briefly advocated by Hans Bethe during the 1970s, but largely remained unexplored until a revival of interest in 2009, due to delays in the realization of pure fusion. When a sustained nuclear fusion power plant is built, it has the potential to be capable of extracting all the fission energy that remains in spent fission fuel, reducing the volume of nuclear waste by orders of magnitude, and more importantly, eliminating all actinides present in the spent fuel, substances which cause security concerns. Nuclear fusion

neg: United States Navy Nuclear Propulsion C1W cruiser reactor while the other eight ships were equipped with D2G destroyer reactors. All of the Navy's submarines and aircraft carriers are propelled by nuclear power. In order for this to happen, each ship essentially contains a small nuclear power plant. The power generated by this reactor is created through nuclear fission. During the process of nuclear fission, there are two products of significant importance in the reactor: heat and radiation. The heat is generated from the breaking down of the fuel source (uranium). Uranium creates heat through a self-sustaining reaction as it is bombarded by free neutrons created

neg: Power-to-weight ratio value may vary in use and variations will affect performance. The inverse of power-to-weight, weight-to-power ratio (power loading) is a calculation commonly applied to aircraft, cars, and vehicles in general, to enable the comparison of one vehicle's performance to another. Power-to-weight ratio is equal to thrust per unit mass multiplied by the velocity of any vehicle. The power-to-weight ratio (Specific Power) formula for an engine (power plant) is the power generated by the engine divided by the mass. ("Weight" in this context is a colloquial term for "mass". To see this, note that what an engineer means by the "power

neg: Nuclear reactor safety system capable of providing sufficient electrical power to shut down a plant. Containment systems are designed to prevent the release of radioactive material into the environment. The fuel cladding is the first layer of protection around the nuclear fuel and is designed to protect the fuel from corrosion that would spread fuel material throughout the reactor coolant circuit. In most reactors it takes the form of a sealed metallic or ceramic layer. It also serves to trap fission products, especially those that are gaseous at the reactor's operating temperature, such as krypton, xenon and iodine. Cladding does not constitute shielding, and

neg: Hazen–Williams equation fit data from typical engineering situations. A result of adjusting the exponents is that the value of "C" appears more like a constant over a wide range of the other parameters. The conversion factor "k" was chosen so that the values for "C" were the same as in the Chézy formula for the typical hydraulic slope of "S"=0.001. The value of "k" is 0.001. Typical "C" factors used in design, which take into account some increase in roughness as pipe ages are as follows: The general form can be specialized for full pipe flows. Taking the general form and exponentiating

neg: Isotopes of iodine for the so-called iodine pit phenomenon. In addition to commercial production, I (half-life 8 days) is one of the common radioactive fission-products of nuclear fission, and is thus produced inadvertently in very large amounts inside nuclear reactors. Due to its volatility, short half-life, and high abundance in fission products, I, (along with the short-lived iodine isotope I from the longer-lived Te with a half-life of 3 days) is responsible for the largest part of radioactive contamination during the first week after accidental environmental contamination from the radioactive waste from a nuclear power plant. Radioisotopes of iodine are called radioactive iodine

neg: Nuclear power phase-out likely to go up for currently operating and new nuclear power plants, due to increased requirements for on-site spent fuel management and elevated design basis threats. The environmental impact of nuclear power results from the nuclear fuel cycle, operation, and the effects of nuclear accidents. The greenhouse gas emissions from nuclear fission power are small relative to those associated with coal, oil, gas, and biomass. They are about equal to those associated with wind and hydroelectric. The routine health risks from nuclear fission power are very small relative to those associated with coal, oil, gas, solar, biomass, wind and hydroelectric.

neg: Nuclear energy in Austria a ban (BGBI. No. 676) on using nuclear fission for Austria’s energy supply until March 1998. This law also prohibits the storage and transport of nuclear materials in or through Austria. On 9 July 1997, the Austrian Parliament unanimously passed legislation to remain an anti-nuclear country. Nuclear energy in Austria In the 1960s the Austrian government started a nuclear energy program and parliament unanimously ordered a nuclear power plant built. In 1972, the German company KWU began construction of the Zwentendorf Nuclear Power Plant boiling water 700 MWe reactor. In 1976, two years prior to the nuclear power plant opening,

neg: Novovoronezh Nuclear Power Plant Novovoronezh Nuclear Power Plant The Novovoronezh nuclear power station ( []) is a nuclear power station close to Novovoronezh in Voronezh Oblast, central Russia. The site was vital to the development of the VVER design; every unit built was essentially a prototype of its design. On this site is built the Novovoronezh Nuclear Power Plant II. In 2002 Novovoronezh-3 was modernised and life extended, including new safety systems. In 2010 Novovoronezh-5 was shut down for modernization to extend its operating life for an additional 25 years, the first VVER-1000 to undergo such an operating life extension. The works include the

neg: Spindle (vehicle) and the HAUV has been designed for exploration up to one kilometer radius from the cryobot. The cryobot is bi-directional and vertically controllable both in an ice sheet as well as following breakthrough into a subglacial water cavity or ocean. The vehicle is designed for subsequent return to the surface at a much later date or subsequent season. The required power plant must be very powerful, so the engineers are working on preliminary designs of a compact fission power plant that would be used for actual ocean planet missions. Spindle (vehicle) SPINDLE (Sub-glacial Polar Ice Navigation, Descent, and Lake Exploration)

neg: Watt solar irradiance of 1.366 kW/m, the total power of sunlight striking Earth's atmosphere is estimated at 174 PW (see: solar constant). In the electric power industry, "megawatt electrical" (MWe or MW) refers by convention to the electric power produced by a generator, while "megawatt thermal" or "thermal megawatt" (MWt, MW, or MWth, MW) refers to thermal power produced by the plant. For example, the Embalse nuclear power plant in Argentina uses a fission reactor to generate 2109 MW (i.e. heat), which creates steam to drive a turbine, which generates 648 MW (i.e. electricity). Other SI prefixes are sometimes used, for

neg: Nuclear safety and security Experimental Reactor facility began in 2007, but the project has run into many delays and budget overruns. The facility is now not expected to begin operations until the year 2027 – 11 years after initially anticipated. A follow on commercial nuclear fusion power station, DEMO, has been proposed. There is also suggestions for a power plant based upon a different fusion approach, that of a Inertial fusion power plant. Fusion powered electricity generation was initially believed to be readily achievable, as fission power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended

neg: Low-carbon power CO per kWh of electricity by source are nuclear (5), hydroelectric (9), wind (15), natural gas (503), peat (636), coal (781). A 2008 meta analysis, "Valuing the use Gas Emissions from Nuclear Power: A Critical Survey," by Benjamin K. Sovacool, analysed 103 life cycle studies of greenhouse gas-equivalent emissions for nuclear power plants. The studies surveyed included the 1997 Vattenfall comparative emissions study, among others. Sovacool's analysis calculated that the mean value of emissions over the lifetime of a nuclear power plant is 66 g/kWh. Comparative results for wind power, hydroelectricity, solar thermal power, and solar photovoltaic, were 9-10 g/kWh,

neg: Centurion Reactor site is directly related to the operating lifetime of the power plants on that site. Finally, inter-generational justice considerations motivate for maximizing the value "bequeathed" to following generations in exchange for the responsibilities associated with long-term protection and management of legacy nuclear wastes and spent nuclear fuel. The technical challenges associated with achieving Centurion Reactors lie principally in the realm of materials science. Current Gen-III nuclear plant operating lifetimes appear to be limited primarily by long-term radiation-induced ageing phenomena in the reactor pressure vessel, primary coolant system piping, concrete containment structures, and cabling (particularly medium-voltage power cables). In-situ replacement of

neg: Nuclear power the costs of operating and new LWR power stations, due to increased requirements for on-site spent fuel management and elevated design basis threats. Nuclear reactors have three unique characteristics that affect their safety, as compared to other power plants. Firstly, intensely radioactive materials are present in a nuclear reactor. Their release to the environment could be hazardous. Secondly, the fission products, which make up most of the intensely radioactive substances in the reactor, continue to generate a significant amount of decay heat even after the fission chain reaction has stopped. If the heat cannot be removed from the reactor, the

neg: Fission product yield If a graph of the mass or mole yield of fission products against the atomic number of the fragments is drawn then it has two peaks, one in the area zirconium through to palladium and one at xenon through to neodymium. This is because the fission event causes the nucleus to split in an asymmetric manner, as nuclei closer to magic numbers are more stable. Yield vs. Z - This is a typical distribution for the fission of uranium. Note that in the calculations used to make this graph the activation of fission products was ignored and the fission was

neg: Scram moderator enough to facilitate a sustained reaction, which allows the insertion of neutron absorbers to affect the reactor quickly. As a result, once the reactor has been SCRAMed, the reactor power will drop significantly almost instantaneously. However, a small fraction (about 0.65%) of neutrons in a typical power reactor comes from the radioactive decay of a fission product. These "delayed neutrons," which are emitted at lower velocities, will limit the rate at which a nuclear reactor will shut down. For a reactor that is SCRAMed after holding a constant power level for an extended period (greater than 100 hrs), about

neg: Radiative forcing (Δ"T") arising from that forcing via the equation: where λ is commonly denoted the climate sensitivity parameter, usually with units K/(W/m), and Δ"F" is the radiative forcing in W/m. A typical value of λ, 0.8 K/(W/m), gives an increase in global temperature of about 1.6 K above the 1750 reference temperature due to the increase in over that time (278 to 405 ppm, for a forcing of 2.0 W/m), and predicts a further warming of 1.4 K above present temperatures if the mixing ratio in the atmosphere were to become double its pre-industrial value; both of these calculations assume no

neg: Power-law fluid Power-law fluid A power-law fluid, or the Ostwald–de Waele relationship, is a type of generalized Newtonian fluid (time independent Non-Newtonian fluid) for which the shear stress, "τ", is given by where: The quantity represents an "apparent" or "effective viscosity" as a function of the shear rate (SI unit Pa s). The value of K and n can be obtained from graph off log(µ ) and formula_3. The slope line gives the value of n-1 from which n can be calculated. The intercept at formula_4 gives the value of K. Also known as the Ostwald–de Waele power law this mathematical relationship

neg: Armenian Nuclear Power Plant to construct a new nuclear power plant based on the existing infrastructures and new technologies. However, in his words, it is necessary to determine the amount needed and examine what impact it will have on rates. Robert Kocharyan said that in 2012–2013, active work will be carried out to build a new nuclear power plant and modernize the current one. Armen Movsisyan has also announced that a decision to build a new unit at the operating nuclear power plant to replace the one to be decommissioned has been taken. The new unit would support 1,000 MW, which would "not only

neg: Biomass applications of thermal conversion are combined heat and power and co-firing. In a typical dedicated biomass power plant, efficiencies range from 20–27% (higher heating value basis). Biomass cofiring with coal, by contrast, typically occurs at efficiencies near those of the coal combustor (30–40%, higher heating value basis). A range of chemical processes may be used to convert biomass into other forms, such as to produce a fuel that is more conveniently used, transported or stored, or to exploit some property of the process itself. Many of these processes are based in large part on similar coal-based processes, such as Fischer-Tropsch

neg: MVV Energie Dock by Sittingbourne (Kent), MVV Environment Ltd. builds a biomass power plant, which will also be completed in 2015. After the biomethane plant in Klein Wanzleben (2012), since 2014 a second biomethane plant in Kroppenstedt (both Saxony-Anhalt) has fed a sustainably produced biomethane into the natural gas grid. A third plant of the group in Staßfurt (Saxony-Anhalt) is put into operation 2015. MVV Energie MVV Energie () is a publicly listed company based in Mannheim and one of Germany's leading energy suppliers, operating in both Germany and Europe. The value chain of MVV Energie AG covers: generation, trading, distribution via

neg: Superluminescent diode not exhibit a sharp threshold but it gradually increases with current. A soft knee in the power vs. current curve defines a transition between a regime dominated by spontaneous emission (typical for surface emitting LEDs) and one that is dominated by amplified spontaneous emission (i.e. superluminescence). Even if the output power is based on spontaneous emission it has to be noted that the amplification mechanism affects the polarization state of the emitted radiation in a way which is related to the SLED structure and on the operating conditions. The maximum value of the current that allows a safe operation of

neg: Nuclear and radiation accidents and incidents K-431 (1985). A criticality accident (also sometimes referred to as an "excursion" or "power excursion") occurs when a nuclear chain reaction is accidentally allowed to occur in fissile material, such as enriched uranium or plutonium. The Chernobyl accident is not universally regarded an example of a criticality accident, because it occurred in an operating reactor at a power plant. The reactor was supposed to be in a controlled critical state, but control of the chain reaction was lost. The accident destroyed the reactor and left a large geographic area uninhabitable. In a smaller scale accident at Sarov a technician working

neg: Nuclear power plant against theft of nuclear material (for example to make a dirty bomb) and attack by enemy military (which has occurred) planes or missiles, or planes hijacked by terrorists. The nuclear power debate is about the controversy which has surrounded the deployment and use of nuclear fission reactors to generate electricity from nuclear fuel for civilian purposes. The debate about nuclear power peaked during the 1970s and 1980s, when it "reached an intensity unprecedented in the history of technology controversies", in some countries. Proponents argue that nuclear power is a sustainable energy source which reduces carbon emissions and can increase energy

neg: Prompt criticality multiple layers of containment as a precaution against any accidental releases of radioactive fission products. With the exception of research and experimental reactors, only a small number of reactor accidents are thought to have achieved prompt criticality, for example Chernobyl #4, the U.S. Army's SL-1, and Soviet submarine "K-431". In all these examples the uncontrolled surge in power was sufficient to cause an explosion that destroyed each reactor and released radioactive fission products into the atmosphere. At Chernobyl in 1986, an unusual and unsafe test was performed that resulted in an overheated reactor core. This led to the rupturing of

neg: Distributed generation size and number of power lines that must be constructed. Typical DER systems in a feed-in tariff (FIT) scheme have low maintenance, low pollution and high efficiencies. In the past, these traits required dedicated operating engineers and large complex plants to reduce pollution. However, modern embedded systems can provide these traits with automated operation and renewable energy, such as solar, wind and geothermal. This reduces the size of power plant that can show a profit. Grid parity occurs when an alternative energy source can generate electricity at a levelized cost (LCOE) that is less than or equal to the end

neg: Nuclear criticality safety distance that neutrons must travel before they can reach the surface and escape. Hence, increasing the size of the body increases the likelihood of fission and decreases the likelihood of leakage. Hence, for any given shape (and reflection conditions - see below) there will be a size that gives an exact balance between the rate of neutron production and the combined rate of absorption and leakage. This is the critical size. Temperature is another parameter that affects the criticality of the system. This particular parameter is less common for the criticality safety practitioner, as in a typical operating environment, where

neg: K-25 The K-25 plant was renamed the Oak Ridge Gaseous Diffusion Plant in 1955. Today, uranium isotope separation is usually done by the more energy-efficient ultra centrifuge process, developed in the Soviet Union. Centrifuge cascades began operating at Oak Ridge in 1961. A gas centrifuge test facility (K-1210) opened in 1975, followed by a larger centrifuge plant demonstration facility (K-1220) in 1982. In response to an order from President Lyndon B. Johnson to cut production of enriched uranium by 25 percent, K-25 and K-27 ceased production in 1964, but in 1969 K-25 began producing uranium enriched to 3 to 5 percent

neg: Niederamt Nuclear Power Plant Building work can commence on the nuclear power plant on receipt of the construction licence. The "construction" phase will last between four and six years. Before the new nuclear power plant can be put into operation it is necessary to obtain the operating licence in the relevant licensing procedure. The operating licence is also granted by the Federal Department of the Environment, Transport, Energy and Communications. Niederamt Nuclear Power Plant The Niederamt Nuclear Power Plant (in German Kernkraftwerk Niederamt, abbreviated to "KKN" and not to be confused with the similarly abbreviated ) is the name for a planned nuclear power

neg: Nuclear fission and Nagasaki. In the years after World War II, many countries were involved in the further development of nuclear fission for the purposes of nuclear reactors and nuclear weapons. The UK opened the first commercial nuclear power plant in 1956. By 2013, there were 437 reactors in 31 countries. Criticality in nature is uncommon. At three ore deposits at Oklo in Gabon, sixteen sites (the so-called Oklo Fossil Reactors) have been discovered at which self-sustaining nuclear fission took place approximately 2 billion years ago. Unknown until 1972 (but postulated by Paul Kuroda in 1956), when French physicist Francis Perrin discovered

neg: Nuclear chain reaction for a neutron to collide with a nucleus is proportional to the material density, increasing the density of a fissile material can increase k. This concept is utilized in the implosion method for nuclear weapons. In these devices, the nuclear chain reaction begins after increasing the density of the fissile material with a conventional explosive. In the gun-type fission weapon two subcritical pieces of fuel are rapidly brought together. The value of k for a combination of two masses is always greater than that of its components. The magnitude of the difference depends on distance, as well as the physical

neg: Primary energy typical value is three units of source energy for one unit of site energy. However, this can vary considerably depending on factors such as the primary energy source or fuel type, the type of power plant, and the transmission infrastructure. One full set of conversion factors is available as technical reference from Energy STAR. Either site or source energy can be an appropriate metric when comparing or analyzing energy use of different facilities. The U.S Energy Information Administration, for example, uses primary (source) energy for its energy overviews but site energy for its Commercial Building Energy Consumption Survey and Residential

neg: China General Nuclear Power Group believed to be the company's best example of what the company has to offer. This has been developed into the Generation III Hualong One design. In February 2007, CGN signed a contract with Areva to build Taishan nuclear station with Areva's EPR, and the Xianning nuclear station will use Westinghouse Electric Company's AP1000. These two events makes this company among the first to build a nuclear station with generation III+ reactors. Operating stations: Daya Bay Nuclear Power Plant and Ling Ao Nuclear Power Plant phase I. Under construction: Hongyanhe Nuclear Power Plant, Ningde Nuclear Power Plant, Yangjiang Nuclear Power Station,

neg: Monroe Power Plant Monroe Power Plant The Monroe Power Plant is a coal-fired power plant located in Monroe, Michigan, on the western shore of Lake Erie. It is owned by the DTE Energy Electric Company, a subsidiary of DTE Energy. The plant was constructed in the early 1970s and was completed in 1974. The plant has 4 generating units, each with an output of 850 megawatts. With all four generating units operating, the plant's total output is 3,300 megawatts (3,400 MW total, 100 MW required for the plant to run), the eleventh largest electric plant in the United States. The Monroe Power Plant

neg: Rovigo Photovoltaic Power Plant the plant. Rovigo Photovoltaic Power Plant The Rovigo Photovoltaic Power Plant is a 70 MW solar photovoltaic (PV) plant in Northeast Italy, about 17 km west of Rovigo. Construction of the plant was started in March 2010 and was completed in November 2010 at a cost of 276 million euro. When completed, it was the largest single-operating PV plant in Europe. The project, also called the San Bellino PV power plant, was developed by SunEdison and built by Isolux Corsán. In October 2010, SunEdison sold the project to infrastructure investor First Reserve for US$382 million, and remained responsible for operating

neg: Combined Construction and Operating License Combined Construction and Operating License The Combined Construction and Operating License (Regulatory Guide 1.206, COL) replaced the previous Draft Regulatory Guide 1145 as the licensing process for new nuclear power plants in the United States. It is a part of a newer "streamlined" process that encourages standard plant designs, and prevents delays in operation that contributed to the mothballing of many plants since the 1980s. ""A combined license authorizes construction and conditional operation of a nuclear power plant. The application for a combined license must contain essentially the same information required in an application for an operating license issued under

neg: Nuclear power plant 1954, the world's first nuclear power station to generate electricity for a power grid started operations at the Soviet city of Obninsk. The world's first full scale power station, Calder Hall in England, opened on October 17, 1956. The world's first full scale power station solely devoted to electricity production (Calder Hall was also meant to produce plutonium), Shippingport power plant in the United States, connected to the grid on December 18, 1957. The key components common to current nuclear power plants are: The conversion to electrical energy takes place indirectly, as in conventional thermal power stations. The fission in

neg: Nuclear power proposed as renewable energy organization independent from, but created by, the United Nations, published Our Common Future, in which a particular subset of presently operating nuclear fission technologies, and nuclear fusion were both classified as renewable. That is, fission reactors that produce more fissile fuel than they consume - breeder reactors, and when it is developed, fusion power, are both classified within the same category as conventional renewable energy sources, such as solar and falling water. Presently, as of 2014, only 2 breeder reactors are producing industrial quantities of electricity, the BN-600 and BN-800. The retired French Phénix reactor also demonstrated a greater than

neg: Post Irradiation Examination of radiation and the fission products on materials, scientists also need to consider the temperature of materials in a reactor, and in particular, the fuel. Too high fuel temperatures can compromise the fuel, and therefore it is important to control the temperature in order to control the fission chain reaction. The temperature of the fuel varies as a function of the distance from the centre to the rim. At distance x from the centre the temperature (T) is described by the equation where ρ is the power density (W m) and K is the thermal conductivity. To explain this for

neg: Paducah Gaseous Diffusion Plant U-235 from the heavier non-fissile isotope U-238. The Paducah plant produced low-enriched uranium which was further refined at Portsmouth and the K-25 plant at Oak Ridge, Tennessee. From the 1960s the Paducah plant was dedicated to uranium enrichment for nuclear power plants. In 1984, the operating contract was assumed by Martin Marietta Energy Systems. Lockheed Martin operated the plant until USEC leased the facility in the mid 1990s. The Paducah plant had a capacity of 11.3 million separative work units per year (SWU/year) in 1984. 1812 stages were located in five buildings: C-310 with 60 stages, C-331 with 400 stages,

neg: Integral fast reactor fuel in fast reactors. The waste products of IFR reactors either have a short half-life, which means that they decay quickly and become relatively safe, or a long halflife, which means that they are only slightly radioactive. Due to pyroprocessing the total volume of true waste/fission products is 1/20th the volume of spent fuel produced by a light water plant of the same power output, and is often all considered to be waste. 70% of fission products are either stable or have half lives under one year. Technetium-99 and iodine-129, which constitute 6% of fission products, have very long half

neg: Rovigo Photovoltaic Power Plant Rovigo Photovoltaic Power Plant The Rovigo Photovoltaic Power Plant is a 70 MW solar photovoltaic (PV) plant in Northeast Italy, about 17 km west of Rovigo. Construction of the plant was started in March 2010 and was completed in November 2010 at a cost of 276 million euro. When completed, it was the largest single-operating PV plant in Europe. The project, also called the San Bellino PV power plant, was developed by SunEdison and built by Isolux Corsán. In October 2010, SunEdison sold the project to infrastructure investor First Reserve for US$382 million, and remained responsible for operating and maintaining

neg: Residual-current device three-phase + neutral supplies. Specially designed RCDs can also be used with both AC and DC power distribution systems. The following terms are sometimes used to describe the manner in which conductors are connected and disconnected by an RCD: RCD sensitivity is expressed as the rated residual operating current, noted I. Preferred values have been defined by the IEC, thus making it possible to divide RCDs into three groups according to their I value: The 5 mA sensitivity is typical for GFCI outlets. There are two groups of devices. "G" (general use) "instantaneous" RCDs have no intentional time delay. They

neg: Neutron transport allow some flexibility in the way models are set up, these problems are formulated as eigenvalue problems, where one parameter is artificially modified until criticality is reached. The most common formulations are the time-absorption and the multiplication eigenvalues, also known as the alpha and k eigenvalues. The alpha and k are the tunable quanitites. K-eigenvalue problems are the most common in nuclear reactor analysis. The number of neutrons produced per fission is multiplicatively modified by the dominant eigenvalue. The resulting value of this eigenvalue reflects the time dependence of the neutron density in a multiplying medium. In the case of

neg: Rolls-Royce WR-21 fuel consumption across the engine's operating range. It offers a reduction in fuel burn of 30% across the typical ship operating profile. It is a candidate power plant for propulsion of cruise ships and other large commercial vessels, where fuel efficiency and its small size mean improved operational flexibility and significant lifetime cost reductions to operators. In 2009 it was discovered that the Northrop Grumman intercooler as fitted in the WR-21, on Type 45 destroyers, had a major design flaw, failing to operate in water temperatures beyond 30°C. The intercooler of the first Type 45 destroyer, , failed in the

neg: Nuclear reactor absorbs more neutrons than the material it displaces—often the moderator. This action results in fewer neutrons available to cause fission and reduces the reactor's power output. Conversely, extracting the control rod will result in an increase in the rate of fission events and an increase in power. The physics of radioactive decay also affects neutron populations in a reactor. One such process is delayed neutron emission by a number of neutron-rich fission isotopes. These delayed neutrons account for about 0.65% of the total neutrons produced in fission, with the remainder (termed "prompt neutrons") released immediately upon fission. The fission products

neg: Photoconductive atomic force microscopy on the cantilever: the mass of the cantilever itself and the mass of the tip. The relationship between "f" and the spring constant is such that "k" must be very small in order to make the spring soft. Since "k" and "m" are in a ratio, the value of "m" must also decrease to increase the value of the ratio. Manipulating the values in this way provides the necessary high resonance frequency. A typical "m" value has a magnitude of 10 kg and creates an "f" of approximately 2 kHz. Expression for resonant frequency of a spring: formula_2 Several forces

neg: Gaseous fission reactor of about 20%. In addition, the container must be cooled, and one can extract energy from the coolant by passing it through a heat exchanger and turbine system as in an ordinary thermal power plant. However, there are enormous problems with corrosion during this arrangement, as the uranium hexafluoride is chemically very reactive. Gaseous fission reactor A gas nuclear reactor (or gas fueled reactor or vapor core reactor) is a proposed kind of nuclear reactor in which the nuclear fuel would be in a gaseous state rather than liquid or solid. In this type of reactor, the only temperature-limiting materials

neg: 10G-EPON for PON operating at 10 Gbit/s downstream and 10 Gbit/s upstream. Each power budget is further identified with a numeric representation of its class, where value of 10 represents low power budget, value of 20 represents medium power budget, and value of 30 represents high power budget. The 802.3av draft standard defines the following power budgets: The 802.3bk added support for a new 10/10G-EPON and 10/1G-EPON power class for PR or PRX PMDs, respectively, as shown below: The 10G-EPON employs a "stream-based" forward error correction (FEC) mechanism based on Reed-Solomon(255, 223). The FEC is mandatory for all channels operating at

neg: Nuclear fission product much of the Chernobyl Nuclear Power Plant on day one of the accident and the ground zero sites of U.S. atomic bombings in Japan (6 hours after detonation) are now relatively safe because the radioactivity has decayed to a low level. Many of the fission products decay through very short-lived isotopes to form stable isotopes, but a considerable number of the radioisotopes have half-lives longer than a day. The radioactivity in the fission product mixture is initially mostly caused by short lived isotopes such as Iodine-131 and Ba; after about four months Ce, Zr/Nb and Sr take the largest share,

neg: Molten-Salt Reactor Experiment of gas was entrained from the fuel pump into the circulating loop. The circulating gas and the power fluctuations that accompanied it were eliminated by operating the fuel pump at slightly lower speed. Operation at high power for several months permitted accurate measurement of the capture-to-fission ratio, for U in this reactor, completing the objectives of the U operation. In the concluding months of operation, xenon stripping, deposition of fission products, and tritium behavior were investigated. The feasibility of using plutonium in molten-salt reactors was emphasized by adding PuF as makeup fuel during this period. After the final shutdown in

neg: Leaky wave antenna not blind spots are present. Blind spots refer to angles at which the array cannot radiate or receive any power; if a blind spot occurred at some angle, therefore, the value of α would rapidly go to zero at that scan angle. To check for blind spots, we would then look for any sharp dips in the curves of α/k as a function of scan angle. No such dips were ever found. Typical data of this type exhibit fairly flat behavior for α/k until the curves drop quickly to zero as they reach the end of the conical-scan range, where

neg: Boric acid can effectively regulate the rate of fission taking place in the reactor. Boric acid is used only in pressurized water reactors (PWRs) whereas boiling water reactors (BWRs) employ control rod pattern and coolant flow for power control. BWRs use an aqueous solution of boric acid and borax or Sodium Pentaborate for an emergency shut down system. Boric acid may be dissolved in spent fuel pools used to store spent fuel elements. The concentration is high enough to keep neutron multiplication at a minimum. Boric acid was dumped over Reactor 4 of the Chernobyl Nuclear Power Plant after its meltdown to