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S1W Reactor
The S1W reactor was the first prototype naval reactor used by the United States Navy to prove that the technology could be used for electricity generation and propulsion on submarines. The designation of "S1W" stands for * S = Submarine platform * 1 = First generation core designed by the contractor * W = Westinghouse was the contracted designer and is a later Navy designation. During the plant's early years the project name was "Submarine Thermal Reactor" (STR) The land-based nuclear reactor was built at the National Reactor Testing Station, later called Idaho National Engineering Laboratory near Arco, Idaho. The plant was the prototype for the power system of USS ''Nautilus'' (SSN-571), the world's first nuclear-powered submarine, which used the improved S2W reactor. The specific location within the vast Idaho National Laboratory where the S1W prototype was located was the Naval Reactors Facility. Design Under the leadership of Captain (later Admiral) Hyman G. Rickover, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prototype
A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototype is generally used to evaluate a new design to enhance precision by system analysts and users. Prototyping serves to provide specifications for a real, working system rather than a theoretical one. In some design workflow models, creating a prototype (a process sometimes called materialization) is the step between the Formal specification, formalization and the evaluation of an idea. A prototype can also mean a typical example of something such as in the use of the derivation 'prototypical'. This is a useful term in identifying objects, behaviours and concepts which are considered the accepted norm and is analogous with terms such as stereotypes and archetypes. The word ''wikt:prototype, prototype'' derives from the Greek language, Greek ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressurized Water Reactor
A pressurized water reactor (PWR) is a type of light-water reactor, light-water nuclear reactor. PWRs constitute the large majority of the world's nuclear power plants (with notable exceptions being the UK, Japan and Canada). In a PWR, the primary nuclear reactor coolant, coolant (water) is pumped under high pressure to the reactor core where it is heated by the energy released by the Nuclear fission, fission of atoms. The heated, high pressure water then flows to a Water-tube boiler, steam generator, where it transfers its thermal energy to lower pressure water of a secondary system where steam is generated. The steam then drives turbines, which spin an electric generator. In contrast to a boiling water reactor (BWR), pressure in the primary coolant loop prevents the water from boiling within the reactor. All light-water reactors use ordinary water as both coolant and neutron moderator. Most use anywhere from two to four vertically mounted steam generators; VVER reactors use horizo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Brake
A water brake is a type of fluid coupling used to absorb mechanical energy and usually consists of a turbine or propeller mounted in an enclosure filled with water. As the turbine or propeller turns, mechanical energy is transferred to the water due to turbulence and friction. The shock caused by the acceleration of the water as it passes from pockets in the stator to the pockets in the spinning rotor requires energy. That energy heats the water due to the friction as the water moves through the water brake. Almost all of the horsepower of the system turning the rotor (usually an internal combustion engine) is converted into a temperature change of the water. A very small amount of energy is taken by the bearings and seals within the unit. Therefore, water must constantly move through the device at a rate proportional to the horse power that is being absorbed. Water temperature exiting the unit must be kept under 120–160 °F (50–70 °C) to prevent scale formation and cavitat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturated Steam
Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization. Steam that is saturated or superheated is invisible; however, "steam" often refers to wet steam, the visible mist or aerosol of water droplets formed as water vapor condenses. Water increases in volume by 1,700 times at standard temperature and pressure; this change in volume can be converted into mechanical work by steam engines such as reciprocating piston type engines and steam turbines, which are a sub-group of steam engines. Piston type steam engines played a central role in the Industrial Revolution and modern steam turbines are used to generate more than 80% of the world's electricity. If liquid water comes in contact with a very hot surface or depressurizes quickly below its vapor pressure, it can create a steam explosion. Ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-called compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Diesel engines work by compressing only air, or air plus residual combustion gases from the exhaust (known as exhaust gas recirculation (EGR)). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases the air temperature inside the cylinder to such a high degree that atomised diesel fuel injected into the combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of the fuel is une ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battery (electricity)
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Great Britain and Ireland), North Channel, the Irish Sea, and St George's Channel. Ireland is the List of islands of the British Isles, second-largest island of the British Isles, the List of European islands by area, third-largest in Europe, and the List of islands by area, twentieth-largest on Earth. Geopolitically, Ireland is divided between the Republic of Ireland (officially Names of the Irish state, named Ireland), which covers five-sixths of the island, and Northern Ireland, which is part of the United Kingdom. As of 2022, the Irish population analysis, population of the entire island is just over 7 million, with 5.1 million living in the Republic of Ireland and 1.9 million in Northern Ireland, ranking it the List of European islan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Criticality (status)
In the operation of a nuclear reactor, criticality is the state in which a nuclear chain reaction is self-sustaining—that is, when reactivity is zero. In supercritical states, reactivity is greater than zero. Applications Criticality is the normal operating condition of a nuclear reactor, in which nuclear fuel sustains a fission chain reaction. A reactor achieves criticality (and is said to be critical) when each fission releases a sufficient number of neutrons to sustain an ongoing series of nuclear reactions. The International Atomic Energy Agency defines the ''first criticality date'' as the date when the reactor is made critical for the first time. This is an important milestone in the construction and commissioning of a nuclear power plant. See also *Criticality accident *Critical mass *Prompt criticality In nuclear engineering, prompt criticality describes a nuclear fission event in which criticality (the threshold for an exponentially growing nuclear fission chain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fuel
Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing and sustaining nuclear fission. The three most relevant fissile isotopes are uranium-233, uranium-235 and plutonium-239. When the unstable nuclei of these atoms are hit by a slow-moving neutron, they frequently split, creating two daughter nuclei and two or three more neutrons. In that case, the neutrons released go on to split more nuclei. This creates a self-sustaining chain reaction that is controlled in a nuclear reactor, or uncontrolled in a nuclear weapon. Alternatively, if the nucleus absorbs the neutron without splitting, it creates a heavier nucleus with one additional neutron. The processes involved in mining, refining, purifying, using, and disposing of nuclear fuel are collectively known as the nuclear fuel cycle. Not all typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium-235
Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nature as a primordial nuclide. Uranium-235 has a half-life of 703.8 million years. It was discovered in 1935 by Arthur Jeffrey Dempster. Its fission cross section for slow thermal neutrons is about 584.3±1 barns. For fast neutrons it is on the order of 1 barn. Most but not all neutron absorptions result in fission; a minority result in neutron capture forming uranium-236. Natural decay chain :\begin \ce \begin \ce \\ \ce \end \ce \\ \ce \begin \ce \\ \ce \end \ce \end Fission properties The fission of one atom of uranium-235 releases () inside the reactor. That corresponds to 19.54 TJ/ mol, or 83.14 TJ/kg. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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