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Fukushima Daiichi
The is a disabled nuclear power plant located on a site in the towns of Ōkuma and Futaba in Fukushima Prefecture, Japan. The plant suffered major damage from the magnitude 9.0 earthquake and tsunami that hit Japan on March 11, 2011. The chain of events caused radiation leaks and permanently damaged several of its American-designed reactors, making them impossible to restart. By political decision, the remaining reactors were not restarted. First commissioned in 1971, the plant consists of six American-designed boiling water reactors. These light water reactors drove electrical generators with a combined power of 4.7 GWe, making Fukushima Daiichi one of the 15 largest nuclear power stations in the world. Fukushima was the first nuclear plant to be designed, constructed, and run in conjunction with General Electric and Tokyo Electric Power Company (TEPCO). The March 2011 disaster disabled the reactor cooling systems, leading to releases of radioactivity and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fukushima Daiichi Nuclear Disaster
The was a nuclear accident in 2011 at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The proximate cause of the disaster was the 2011 Tōhoku earthquake and tsunami, which occurred on the afternoon of 11 March 2011 and remains the most powerful earthquake ever recorded in Japan. The earthquake triggered a powerful tsunami, with 13–14-meter-high waves damaging the nuclear power plant's emergency diesel generators, leading to a loss of electric power. The result was the most severe nuclear accident since the Chernobyl disaster in 1986, classified as level seven on the International Nuclear Event Scale (INES) after initially being classified as level five, and thus joining Chernobyl as the only other accident to receive such classification. While the 1957 explosion at the Mayak facility was the second worst by radioactivity released, the INES ranks incidents by impact on population, so Chernobyl (335,000 people evacuated) and Fukushima (154,000 evacu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fukushima Daini Nuclear Power Plant
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 D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discharge Of Radioactive Water Of The Fukushima Daiichi Nuclear Power Plant
Radioactive waste water has been discharged into the Pacific Ocean since the Fukushima Daiichi nuclear disaster, triggered by the 2011 Tōhoku earthquake and tsunami on 11 March 2011 in Japan. Most of the radioactive materials came from immediate leaks into the atmosphere, 80% of which eventually deposited over the Pacific (and over some rivers). Leakage to groundwater has persisted since the disaster and was only first admitted by the nuclear plant in 2013. Water treatment began that year as the "Advanced Liquid Processing System" became operable, which is capable of removing most radionuclides except notably tritium. In 2021, the Japanese cabinet approved the dumping of radioactive water into the Pacific over a course of 30 years. Discharge to groundwater by leakage Initially, as of June 2011, the biggest threat was the leakage of caesium from the nuclear reactors into the Pacific. Over time, groundwater became the main source for leaks. While soil naturally absorbs the ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Containment Building
A containment building is a reinforced steel, concrete or lead structure enclosing a nuclear reactor. It is designed, in any emergency, to contain the escape of radioactive steam or gas to a maximum pressure in the range of . The containment is the fourth and final barrier to radioactive release (part of a nuclear reactor's defence in depth strategy), the first being the fuel ceramic itself, the second being the metal fuel cladding tubes, the third being the reactor vessel and coolant system. Each nuclear plant in the US is designed to withstand certain conditions which are spelled out as "Design Basis Accidents" in the Final Safety Analysis Report (FSAR). The FSAR is available for public viewing, usually at a public library near the nuclear plant. The containment building itself is typically an airtight steel structure enclosing the reactor normally sealed off from the outside atmosphere. The steel is either free-standing or attached to the concrete missile shield. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiling Water Reactor Safety Systems
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 de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Enriched Uranium
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238U with 99.2739–99.2752% natural abundance), uranium-235 (235U, 0.7198–0.7202%), and uranium-234 (234U, 0.0050–0.0059%). 235U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons. Enriched uranium is a critical component for both civil nuclear power generation and military nuclear weapons. The International Atomic Energy Agency attempts to monitor and control enriched uranium supplies and processes in its efforts to ensure nuclear power generation safety and curb nuclear weapons proliferation. There are about 2,000 tonnes of highly enriched uranium in the world, produced mostly for nuclear power, nuclear weapons, naval propulsion, and smaller quantities for research reacto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOX Fuel
Mixed oxide fuel, commonly referred to as MOX fuel, is nuclear fuel that contains more than one oxide of fissile material, usually consisting of plutonium blended with natural uranium, reprocessed uranium, or depleted uranium. MOX fuel is an alternative to the low-enriched uranium (LEU) fuel used in the light-water reactors that predominate nuclear power generation. For example, a mixture of 7% plutonium and 93% natural uranium reacts similarly, although not identically, to LEU fuel (3 to 5% uranium-235). MOX usually consists of two phases, UO2 and PuO2, and/or a single phase solid solution (U,Pu)O2. The content of PuO2 may vary from 1.5 wt.% to 25–30 wt.% depending on the type of nuclear reactor. One attraction of MOX fuel is that it is a way of utilizing surplus weapons-grade plutonium, an alternative to storage of surplus plutonium, which would need to be secured against the risk of theft for use in nuclear weapons. On the other hand, some studies warned that normalisin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plutonium
Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen. When exposed to moist air, it forms oxides and hydrides that can expand the sample up to 70% in volume, which in turn flake off as a powder that is pyrophoric. It is radioactive and can accumulate in bones, which makes the handling of plutonium dangerous. Plutonium was first synthetically produced and isolated in late 1940 and early 1941, by a deuteron bombardment of uranium-238 in the cyclotron at the University of California, Berkeley. First, neptunium-238 ( half-life 2.1 days) was synthesized, which subsequently beta-decayed to form the new element with atomic number 94 and atomic weight 238 (half-life 88 years). Since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kajima
is one of the oldest and largest construction companies in Japan. Founded in 1840, the company has its headquarters in Motoakasaka, Minato, Tokyo. The company is known for its DIB-200 proposal. The company stock is traded on four leading Japanese stock exchanges and is a constituent of the Nikkei 225 stock index. Kajima's services include design, engineering, construction, and real estate development. Kajima builds high-rise structures, railways, power plants, dams, and bridges. Its subsidiaries are located throughout Asia, Oceania, Europe, and North America. A downturn in the construction industry during the latter half of the 1990s prompted Kajima to expand its operations to the environmental sector, specifically waste treatment, water treatment, soil rehabilitation, and environmental consulting. History * 1840 - Iwakichi Kajima, the founder of the present-day company begins carpentry business in Edo (present day Tokyo) * 1860 - Kajima pioneers first western-style build ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Bond And Share Company
The Electric Bond and Share Company (Ebasco) was a United States electric utility holding company organized by General Electric. It was forced to divest its holding companies and reorganize due to the passage of the Public Utility Holding Company Act of 1935. Following the passage of the Act, the U.S. Securities and Exchange Commission (SEC) selected the largest of the U.S. holding companies, Ebasco to be the test case of the law before the U.S. Supreme Court. The court case known as Securities and Exchange Commission v. Electric Bond and Share company was settled in favor of the SEC on March 28, 1938. It took twenty-five years of legal action by the SEC to break up Ebasco and the other major U.S. electric holding companies until they conformed with the 1935 act. It was allowed to retain control of its foreign electric power holding company known as the American & Foreign Power Company (A&FP). After its reorganization, it became an investment company, but soon turned into a major ... [...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 Japa ... [...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 English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national .... The agency employs over 1,000 journa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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