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Timeline Of The Fukushima Daini Nuclear Accidents
The is a nuclear power plant located on a site in the town of Naraha and Tomioka in the Futaba District of Fukushima Prefecture, Japan. The Tokyo Electric Power Company (TEPCO) runs the plant. After the 2011 Tōhoku earthquake and tsunami, the four reactors at Fukushima Daini automatically shut down. While the sister plant Fukushima Daiichi Nuclear Power Plant, approximately to the north, suffered extensive damage, the Daini Plant was back under control within two days, reaching cold shutdown. The plant has not been operating since, and in July 2019 a decision to decommission the plant was made. Description All reactors in the Fukushima II Nuclear Power Plant are BWR-5 type with electric power of 1,100 MW each (net output: 1,067 MW each). The reactors for units 1 and 3 were supplied by Toshiba, and for units 2 and 4 by Hitachi. Units 1–3 were built by Kajima while the unit 4 was built by Shimizu and Takenaka. Electrical connections The Fukushima Daini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naraha, Fukushima
is a town located in Fukushima Prefecture, Japan. , the town had an official registered population of 6,784 in 2956 households, and a population density of 65 persons per km2, although the current actual resident population is significantly smaller. The total area of the town is . From 2011 until 2015, the town was evacuated due to fallout from the Fukushima Daiichi nuclear disaster. While the town wasn't severely contaminated by the fallout, restrictions on residency were held until September 2015 when cleanup efforts concluded, allowing people to return. Naraha is the first of several towns and cities near Fukushima Daiichi Nuclear Power Plant to have been reopened to residents. Repair and reconstruction efforts have been underway in Naraha since 2016, and numerous landmarks in the town have been rebuilt and reopened. Geography Naraha is located in southern of Fukushima Prefecture, bordering on the Pacific Ocean to the east. Surrounding municipalities *Fukushima Prefecture ** I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-force
The gravitational force equivalent, or, more commonly, g-force, is a measurement of the type of force per unit mass – typically acceleration – that causes a perception of weight, with a g-force of 1 g (not gram in mass measurement) equal to the conventional value of gravitational acceleration on Earth, ''g'', of about . Since g-forces indirectly produce weight, any g-force can be described as a "weight per unit mass" (see the synonym specific weight). When the g-force is produced by the surface of one object being pushed by the surface of another object, the reaction force to this push produces an equal and opposite weight for every unit of each object's mass. The types of forces involved are transmitted through objects by interior mechanical stresses. Gravitational acceleration (except certain electromagnetic force influences) is the cause of an object's acceleration in relation to free fall. The g-force experienced by an object is due to the vector sum of all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2016 Fukushima Earthquake
The 2016 Fukushima earthquake struck Japan east-southeast of Namie, Fukushima Prefecture at 05:59 JST on November 22 (20:59 Nov 21 UTC) with depth of . Fukushima is a very dense prefecture in Japan north of Tokyo, with a population of nearly 2 million. The shock had a maximum intensity of VII ''(Very strong)'' on the Mercalli scale. The earthquake was initially reported as a 7.3 magnitude by Japan Meteorological Agency, and was later revised to 7.4, while the United States Geological Survey and GFZ Potsdam determined a magnitude of 6.9. There were no deaths as a result of the earthquake, however seventeen people were injured; three of which were in critical condition. Minor damage was caused, with reports of fires. The Fukushima Daini Nuclear Power Plant had one of its spent fuel cooling systems shut down briefly, though no measurable change in radiation levels was detected. A tsunami warning was issued with waves predicted up to , though actual waves were recorded between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan Times
''The Japan Times'' is Japan's largest and oldest English-language daily newspaper. It is published by , a subsidiary of News2u Holdings, Inc.. It is headquartered in the in Kioicho, Chiyoda, Tokyo. History ''The Japan Times'' was launched by Motosada Zumoto on 22 March 1897, with the goal of giving Japanese people an opportunity to read and discuss news and current events in English to help Japan to participate in the international community. The newspaper was independent of government control, but from 1931 onward, the paper's editors experienced mounting pressure from the Japanese government to submit to its policies. In 1933, the Japanese Ministry of Foreign Affairs appointed Hitoshi Ashida, former ministry official, as chief editor. During World War II, the newspaper served as an outlet for Imperial Japanese government communication and editorial opinion. It was successively renamed ''The Japan Times and Mail'' (1918–1940) following its merger with ''The Japan Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyodo News
is a nonprofit cooperative news agency based in Minato, Tokyo. It was established in November 1945 and it distributes news to almost all newspapers, and radio and television networks in Japan. The newspapers using its news have about 50 million subscribers. K. K. Kyodo News is Kyodo News' business arm, established in 1972.Shrivastava, K. M. (2007). ''News agencies from pigeon to internet.'' Sterling Publishers Pvt. Ltd. p. 208. . The subdivision Kyodo News International, founded in 1982, provides over 200 reports to international news media and is located in Rockefeller Center, New York City. Their online news site is in Japanese, Chinese ( Simplified and Traditional), Korean, and English. The agency employs over 1,000 journalists and photographers, and maintains news exchange agreements with over 70 international media outlets. Satoshi Ishikawa is the news agency's president. Kyodo News was formed by Furuno Inosuke, the president of the Domei News Agency, following the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NOTAM
A Notice to Airmen/Notice to Air Missions (NOTAM), is a notice filed with an aviation authority to alert aircraft pilots of potential hazards along a flight route or at a location that could affect the flight. NOTAMs are unclassified notices or advisories distributed by means of telecommunication that contain information concerning the establishment, conditions or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel and systems concerned with flight operations. NOTAMs are created and transmitted by government agencies and airport operators under guidelines specified by Annex 15: Aeronautical Information Services of the Convention on International Civil Aviation (CICA). The acronym ''NOTAM'' came into common use following the ratification of the CICA, which came into effect on 4 April 1947. Notices to airmen were normally published in a regular publication by each country's air authorities (e.g., in ''Flight Inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Nuclear Event Scale
The International Nuclear and Radiological Event Scale (INES) was introduced in 1990 by the International Atomic Energy Agency (IAEA) in order to enable prompt communication of safety significant information in case of nuclear accidents. The scale is intended to be logarithmic, similar to the moment magnitude scale that is used to describe the comparative magnitude of earthquakes. Each increasing level represents an accident approximately ten times as severe as the previous level. Compared to earthquakes, where the event intensity can be quantitatively evaluated, the level of severity of a man-made disaster, such as a nuclear accident, is more subject to interpretation. Because of this subjectivity the INES level of an incident is assigned well after the fact. The scale is therefore intended to assist in disaster-aid deployment. Details A number of criteria and indicators are defined to assure coherent reporting of nuclear events by different official authorities. There ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scram
A scram or SCRAM is an emergency shutdown of a nuclear reactor effected by immediately terminating the fission reaction. It is also the name that is given to the manually operated kill switch that initiates the shutdown. In commercial reactor operations, this type of shutdown is often referred to as a "scram" at boiling water reactors (BWR), a "reactor ''trip''" at pressurized water reactors and at a CANDU reactor. In many cases, a scram is part of the routine shutdown procedure, which serves to test the emergency shutdown system. The etymology of the term is a matter of debate. United States Nuclear Regulatory Commission historian Tom Wellock notes that ''scram'' is English-language slang for leaving quickly and urgently, and cites this as the original and most likely accurate basis for the use of ''scram'' in the technical context. A persistent alternative explanation posits that ''scram'' is an acronym for "safety control rod axe man", which was supposedly coined by Enrico ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Shutdown
Shutdown is the state of a nuclear reactor when the fission reaction is slowed significantly or halted completely. Different nuclear reactor designs have different definitions for what "shutdown" means, but it typically means that the reactor is not producing a measurable amount of electricity or heat, and is in a stable condition with very low reactivity. Shutdown Margins and Scientific Definitions The shutdown margin for nuclear reactors (that is, when the reactor is considered to be safely in a shutdown state) is usually defined either in terms of reactivity or dollars. For reactivity, this is calculated in units of delta-k/k, where k is equal to the criticality of the reactor (essentially, how fast and controlled the nuclear fission reaction is). It is sometimes also measured in dollars, where one dollar is equal to a reactor in prompt criticality, this can then be used to calculate the change in reactivity required to shutdown or start up the reactor. The shutdown margin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Reactor Safety System
:''This article covers the technical aspects of active nuclear safety systems in the United States. For a general approach to nuclear safety, see nuclear safety.'' The three primary objectives of nuclear reactor safety systems as defined by the U.S. Nuclear Regulatory Commission are to shut down the reactor, maintain it in a shutdown condition and prevent the release of radioactive material. Reactor protection system (RPS) A reactor protection system is designed to immediately terminate the nuclear reaction. By breaking the nuclear chain reaction, the source of heat is eliminated. Other systems can then be used to remove decay heat from the core. All nuclear plants have some form of reactor protection system. Control rods Control rods are a series of rods that can be quickly inserted into the reactor core to absorb neutrons and rapidly terminate the nuclear reaction. They are typically composed of actinides, lanthanides, transition metals, and boron, in various alloys with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan Standard Time
, or , is the standard time zone in Japan, 9 hours ahead of UTC ( UTC+09:00). Japan does not observe daylight saving time, though its introduction has been debated on several occasions. During World War II, the time zone was often referred to as Tokyo Standard Time. Japan Standard Time is equivalent to Korean Standard Time, Pyongyang Time (North Korea), Eastern Indonesia Standard Time, East-Timorese Standard Time and Yakutsk Time (Russia). History Before the Meiji era (1868–1912), each local region had its own time zone in which noon was when the sun was exactly at its culmination. As modern transportation methods, such as trains, were adopted, this practice became a source of confusion. For example, there is a difference of about 5 degrees longitude between Tokyo and Osaka and because of this, a train that departed from Tokyo would arrive at Osaka 20 minutes behind the time in Tokyo. In 1886, Ordinance 51 was issued in response to this problem, which stated: Accordi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reactor Core Isolation Cooling System
Boiling water reactor safety systems are nuclear safety systems constructed within boiling water reactors in order to prevent or mitigate environmental and health hazards in the event of accident or natural disaster. Like the pressurized water reactor, the BWR reactor core continues to produce heat from radioactive decay after the fission reactions have stopped, making a core damage incident possible in the event that all safety systems have failed and the core does not receive coolant. Also like the pressurized water reactor, a boiling water reactor has a negative void coefficient, that is, the neutron (and the thermal) output of the reactor decreases as the proportion of steam to liquid water increases inside the reactor. However, unlike a pressurized water reactor which contains no steam in the reactor core, a sudden increase in BWR steam pressure (caused, for example, by the actuation of the main steam isolation valve (MSIV) from the reactor) will result in a sudden dec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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