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Watts Bar Nuclear Generating Station
The Watts Bar Nuclear Plant is a Tennessee Valley Authority (TVA) nuclear reactor pair used for electric power generation. It is located on a 1,770-acre (7.2 km²) site in Rhea County, Tennessee, near Spring City, between Chattanooga and Knoxville. Watts Bar supplies enough electricity for about 1.2 million households in the Tennessee Valley. The plant, construction of which began in 1973, has two Westinghouse pressurized water reactor units: Unit 1, completed in 1996, and Unit 2, completed in 2015. Unit 1 has a winter net dependable generating capacity of 1,167 megawatts. Unit 2 has a capacity of 1,165 megawatts. Unit 2 was the first of three new power reactors to enter service in the 21st century in the United States, followed by Vogtle Electric Generating Plant Units 3 and 4. Unit 1 Construction on Unit 1 began on 23 January 1973 and suffered from many delays. After construction was halted on both units in 1985, construction resumed on Unit 1 in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooling Tower
A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream, to a lower temperature. Cooling towers may either use the evaporation of water to remove heat and cool the working fluid to near the Wet-bulb temperature, wet-bulb air temperature or, in the case of ''dry cooling towers'', rely solely on air to cool the working fluid to near the Dry-bulb temperature, dry-bulb air temperature using Radiator, radiators. Common applications include cooling the circulating water used in oil refineries, petrochemical and other chemical plants, thermal power stations, nuclear power stations and HVAC systems for cooling buildings. The classification is based on the type of air induction into the tower: the main types of cooling towers are Natural convection, natural draft and Forced convection, induced draft cooling towers. Cooling towers vary in size from small roof-top units to very large hyperboloid structures t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Criticality (status)
In the operation of a nuclear reactor, criticality or critical state is the state in which a nuclear chain reaction is self-sustaining but not growing. Subcriticality or subcritical state is the state in which a nuclear chain reaction is not self-sustaining. Supercriticality or supercritical state is the state in which a nuclear chain reaction is self-sustaining and growing. Sometimes, less preferably, criticality takes a wider definition, and refers to the any state in which a nuclear chain reaction is self-sustaining, no matter growing or not (encompassing criticality in strict definition and supercriticality). In terms of reactivity, reactivity is 0 in criticality, less than 0 in subcriticality, greater than 0 in supercriticality. In terms of effective neutron multiplication factor (), is 1 in criticality, less than 1 in subcriticality, greater than 1 in supercriticality. Applications Criticality is the normal operating condition of a nuclear reactor, in which nuclear fue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Weapons Of The United States
The United States was the first country to manufacture nuclear weapons and is the only country to have used them in combat, with the Atomic bombings of Hiroshima and Nagasaki, bombings of Hiroshima and Nagasaki in World War II against Empire of Japan, Japan. Before and during the Cold War, it conducted 1,054 Nuclear weapons testing, nuclear tests, and tested many nuclear triad, long-range nuclear weapons delivery systems. Between 1940 and 1996, the U.S. federal government spent at least US$ in present-day terms on nuclear weapons, including platforms development (aircraft, rockets and facilities), command and control, maintenance, waste management and administrative costs. It is estimated that the United States produced more than 70,000 nuclear warheads since 1945, more than all other nuclear weapon states combined. Until November 1962, the vast majority of U.S. nuclear tests were above ground. After the 1963 Partial Nuclear Test Ban Treaty, all testing was relegated undergroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Nuclear Security Administration
The National Nuclear Security Administration (NNSA) is a United States federal agency responsible for safeguarding national security through the military application of nuclear science. NNSA maintains and enhances the safety, security, and effectiveness of the U.S. nuclear weapons stockpile; works to reduce the global danger from weapons of mass destruction; provides the United States Navy with safe and effective nuclear propulsion; and responds to nuclear and radiological emergencies in the United States and abroad. Established by the United States Congress in 2000, NNSA is a semiautonomous agency within the United States Department of Energy. History The National Nuclear Security Administration was created by congressional action in 1999, in the wake of the Wen Ho Lee spy scandal and other allegations that lax administration by the Department of Energy had resulted in the loss of U.S. nuclear secrets to China. Originally proposed to be an independent agency, it was inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tritium
Tritium () or hydrogen-3 (symbol T or H) is a rare and radioactive isotope of hydrogen with a half-life of ~12.33 years. The tritium nucleus (t, sometimes called a ''triton'') contains one proton and two neutrons, whereas the nucleus of the common isotope hydrogen-1 (''protium'') contains one proton and no neutrons, and that of non-radioactive hydrogen-2 ('' deuterium'') contains one proton and one neutron. Tritium is the heaviest particle-bound isotope of hydrogen. It is one of the few nuclides with a distinct name. The use of the name hydrogen-3, though more systematic, is much less common. Naturally occurring tritium is extremely rare on Earth. The atmosphere has only trace amounts, formed by the interaction of its gases with cosmic rays. It can be produced artificially by irradiation of lithium or lithium-bearing ceramic pebbles in a nuclear reactor and is a low-abundance byproduct in normal operations of nuclear reactors. Tritium is used as the energy source in radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irradiation
Irradiation is the process by which an object is exposed to radiation. An irradiator is a device used to expose an object to radiation, most often gamma radiation, for a variety of purposes. Irradiators may be used for sterilizing medical and pharmaceutical supplies, preserving foodstuffs, alteration of gemstone colors, studying radiation effects, eradicating insects through sterile male release programs, or calibrating thermoluminescent dosimeters (TLDs). The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to normal levels of background radiation. The term irradiation usually excludes the exposure to non-ionizing radiation, such as infrared, visible light, microwaves from cellular phones or electromagnetic waves emitted by radio and television receivers and power supplies. Applications Sterilization If ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilowatt-hour
A kilowatt-hour ( unit symbol: kW⋅h or kW h; commonly written as kWh) is a non-SI unit of energy equal to 3.6 megajoules (MJ) in SI units, which is the energy delivered by one kilowatt of power for one hour. Kilowatt-hours are a common billing unit for electrical energy supplied by electric utilities. Metric prefixes are used for multiples and submultiples of the basic unit, the watt-hour (3.6 kJ). Definition The kilowatt-hour is a composite unit of energy equal to one kilowatt (kW) multiplied by (i.e., sustained for) one hour. The International System of Units (SI) unit of energy meanwhile is the joule (symbol J). Because a watt is by definition one joule per second, and because there are 3,600 seconds in an hour, one kWh equals 3,600 kilojoules or 3.6 MJ."Half-high dots or spaces are used to express a derived unit formed from two or more other units by multiplication.", Barry N. Taylor. (2001 ed.''The International System of Units.'' (Special publicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generation II Reactor
A generation II reactor is a design classification for a nuclear reactor, and refers to the class of commercial reactors built until the end of the 1990s. Prototypical and older versions of PWR, CANDU, BWR, AGR, RBMK and VVER are among them. These are contrasted to reactors, which refer to the early prototype of power reactors, such as Shippingport, Magnox/ UNGG, AMB, Fermi 1, and Dresden 1. The last commercial Gen I power reactor was located at the Wylfa Nuclear Power Station and ceased operation at the end of 2015. The nomenclature for reactor designs, describing four 'generations', was proposed by the US Department of Energy when it introduced the concept of generation IV reactors. The designation ''generation II+ reactor'' is sometimes used for modernized generation II designs built post-2000, such as the Chinese CPR-1000, in competition with more expensive generation III reactor designs. Typically, the modernization includes improved safety systems and a 60-year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Regulatory Commission
The United States Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operations on January 19, 1975, as one of two successor agencies to the United States Atomic Energy Commission. Its functions include overseeing reactor safety and security, administering reactor licensing and renewal, licensing and oversight for fuel cycle facilities, licensing radioactive materials, radionuclide safety, and managing the storage, security, recycling, and disposal of spent fuel. History Prior to 1975 the Atomic Energy Commission was in charge of matters regarding radionuclides. The AEC was dissolved, because it was perceived as unduly favoring the industry it was charged with regulating.John Byrne and Steven M. Hoffman (1996). ''Governing the Atom: The Politics of Risk'', Transaction Publishers, p. 163. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fukushima Daiichi Nuclear Disaster
The Fukushima nuclear accident was a major nuclear accident at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan, which began on 11 March 2011. The cause of the accident was the 2011 Tōhoku earthquake and tsunami, which resulted in electrical grid failure and damaged nearly all of the power plant's Emergency power system, backup energy sources. The subsequent inability to sufficiently cool reactors after shutdown compromised Primary containment, containment and resulted in the release of radioactive contamination, radioactive contaminants into the surrounding environment. The accident was rated seven (the maximum severity) on the International Nuclear Event Scale by Nuclear and Industrial Safety Agency, following a report by the JNES (Japan Nuclear Energy Safety Organization). It is regarded as the worst nuclear incident since the Chernobyl disaster in 1986, which was also rated a seven on the International Nuclear Event Scale. According to the United Nati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2011 Tōhoku Earthquake And Tsunami
On 11 March 2011, at 14:46:24 Japan Standard Time, JST (05:46:24 UTC), a 9.0–9.1 Submarine earthquake, undersea megathrust earthquake occurred in the Pacific Ocean, east of the Oshika Peninsula of the Tōhoku region. It lasted approximately six minutes and caused a tsunami. It is sometimes known in Japan as the , among other names. The disaster is often referred to by its numerical date, 3.11 (read in Japanese). It was the List of earthquakes in Japan, most powerful earthquake ever recorded in Japan, and the Largest earthquakes by magnitude#Strongest earthquakes by magnitude, fourth most powerful earthquake recorded in the world since modern seismography began in 1900. The earthquake triggered powerful tsunami waves that may have reached heights of up to in Miyako, Iwate, Miyako in Tōhoku's Iwate Prefecture,Yomiuri Shimbun evening edition 2-11-04-15 page 15, nearby Aneyoshi fishery port (姉吉漁港)(Google map E39 31 57.8, N 142 3 7.6) 2011-04-15大震災の津� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Atomic Energy Agency
The International Atomic Energy Agency (IAEA) is an intergovernmental organization that seeks to promote the peaceful use of nuclear technology, nuclear energy and to inhibit its use for any military purpose, including nuclear weapons. It was established in 1957 as an autonomous international organization; though governed by its own founding treaty, the IAEA Statute, the organization reports to both the United Nations General Assembly, General Assembly and the United Nations Security Council, Security Council of the United Nations, and is headquartered at the United Nations Office at Vienna, UN Office at Vienna, Austria. The IAEA was created in response to growing international concern toward nuclear weapons, especially Cold War (1953–1962), amid rising tensions between the foremost nuclear powers, the United States and the Soviet Union. U.S. president Dwight D. Eisenhower's "Atoms for Peace, Atoms for Peace" speech, which called for the creation of an international organiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
