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Tokaimura Nuclear Accident
The Tokaimura nuclear accidents refer to two nuclear related incidents near the village of Tōkai, Ibaraki, Tōkai, Ibaraki Prefecture, Japan. The first accident occurred on 11 March 1997, producing an explosion after an experimental batch of solidified nuclear waste caught fire at the Power Reactor and Nuclear Fuel Development Corporation, Power Reactor and Nuclear Fuel Development Corporation (PNC) radioactive waste bituminisation facility. Over twenty people were exposed to radiation. The second was a criticality accident at a separate fuel reprocessing facility belonging to JCO (company), Japan Nuclear Fuel Conversion Co. (JCO) on 30 September 1999 due to improper handling of liquid uranium fuel for an experimental reactor. The incident spanned approximately 20 hours and resulted in radiation exposure for 667 people and the deaths of two workers. Most of the technicians were hospitalised for serious injuries. It was determined that the accidents were due to inadequate regul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tōkai, Ibaraki
is a village located in Ibaraki Prefecture, Japan. , the village had an estimated population of 37,651 in 15,148 households and a population density of 991 persons per km2. The percentage of the population aged over 65 was 25.8%. The total area of the village is . The Japan Atomic Energy Agency along with other organizations currently operate a number of nuclear technology research facilities in the town. In particular, Tōkai Nuclear Power Plant is located in Tōkai. Geography Located in central Ibaraki Prefecture, approximately north of Tokyo, Tōkai is bordered to the east by the Pacific Ocean. The village is about 15 kilometers northeast of the prefectural capital of Mito. with the Kuji River to the north. The area is located at the northern end of the Hitachi Plateau, and consists of lowlands which are alluvium and covered with rice paddy fields, and the plateau is diluvial, with upland fields and flatland forests. Surrounding municipalities Ibaraki Prefecture * Hitachi * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tōkai Nuclear Power Plant
The was Japan's first commercial nuclear power plant. The first unit was built in the early 1960s to the British Magnox design, and generated power from 1966 until it was decommissioned in 1998. A second unit, nominally a separate power station called , was built at the site in the 1970s, the first in Japan to produce over 1000 MW of electricity. The site is located in Tokai in the Naka District in Ibaraki Prefecture, Japan and is operated by the Japan Atomic Power Company. The total site area amounts to 0.76 km2 (188 acres) with 0.33 km2, or 43% of it, being green area that the company is working to preserve. The plant has been not operational since the reactor shut down automatically due to the 2011 Tōhoku earthquake and tsunami. Reactors on site Unit 1 This reactor was built based on the British-developed Magnox technology for dual-use. Unit 1 is the first full-size nuclear reactor to be decommissioned in Japan. The experience in decommissioning this p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Level
Ionizing (ionising) radiation, including nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light, and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum. Gamma rays, X-rays, and the higher energy ultraviolet part of the electromagnetic spectrum are ionizing radiation; whereas the lower energy ultraviolet, visible light, infrared, microwaves, and radio waves are non-ionizing radiation. Nearly all types of laser light are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area cannot be sharply defined, as different molecules and atoms ionize at different energies. The energy of ionizing radiation starts between 10 electronvolts (eV) and 33 eV. Ionizing subatomic particles include alpha part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cover-up
A cover-up is an attempt, whether successful or not, to conceal evidence of wrongdoing, error, incompetence, or other embarrassing information. Research has distinguished personal cover-ups (covering up one's own misdeeds) from relational cover-ups (covering up someone else's misdeeds). The expression is usually applied to people in positions of authority who abuse power to avoid or silence criticism or to deflect guilt of wrongdoing. Perpetrators of a cover-up (initiators or their allies) may be responsible for a misdeed, a breach of trust or duty, or a crime. Definitions and related terms While the terms are often used loosely, ''cover-up'' involves withholding incriminatory evidence, while '' whitewash'' involves releasing misleadingly exculpatory evidence, and a '' frameup'' involves falsely blaming an innocent person. Misprision is the failure of mandated reporters to disclose crimes they are aware of (e.g., a military officer failing to proactively report evid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caesium
Caesium (IUPAC spelling; also spelled cesium in American English) is a chemical element; it has Symbol (chemistry), symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of , which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. It is pyrophoricity, pyrophoric and reacts with water even at . It is the least electronegativity, electronegative stable element, with a value of 0.79 on the Pauling scale. It has only one stable isotope, caesium-133. Caesium is mined mostly from pollucite. Caesium-137, a fission product, is extracted from waste produced by nuclear reactor technology, nuclear reactors. It has the largest atomic radius of all elements whose radii have been measured or calculated, at about 260 picometres. The German chemist Robert Bunsen and physicist Gustav Kirchhoff discovered caesium in 1860 by the new ... [...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 human-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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitumen
Bitumen ( , ) is an immensely viscosity, viscous constituent of petroleum. Depending on its exact composition, it can be a sticky, black liquid or an apparently solid mass that behaves as a liquid over very large time scales. In American English, the material is commonly referred to as asphalt or tar. Whether found in natural deposits or refined from petroleum, the substance is classed as a pitch (resin), pitch. Prior to the 20th century, the term asphaltum was in general use. The word derives from the Ancient Greek word (), which referred to natural bitumen or pitch. The largest natural deposit of bitumen in the world is the Pitch Lake of southwest Trinidad, which is estimated to contain 10 million tons. About 70% of annual bitumen production is destined for road surface, road construction, its primary use. In this application, bitumen is used to bind construction aggregate, aggregate particles like gravel and forms a substance referred to as asphalt concrete, which is collo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-level Waste
Low-level waste (LLW) or low-level radioactive waste (LLRW) is a category of nuclear waste. The definition of low-level waste is set by the nuclear regulators of individual countries, though the International Atomic Energy Agency (IAEA) provides recommendations. LLW includes items that have become contaminated with radioactive material or have become radioactive through exposure to neutron radiation. This waste typically consists of contaminated protective shoe covers and clothing, wiping rags, mops, filters, reactor water treatment residues, equipments and tools, luminous dials, medical tubes, swabs, injection needles, syringes, and laboratory animal carcasses and tissues. LLW in the United Kingdom In the UK, LLW is defined as waste with specific activities below 12 gigabecquerel/ tonne (GBq/t) beta/gamma and below 4 GBq/t alpha emitting nuclides. Waste with specific activities above these thresholds are categorised as either Intermediate-level waste (ILW) or high heat gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Incident
A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility." Examples include lethal effects to individuals, large radioactivity release to the environment, or a reactor core melt. The prime example of a "major nuclear accident" is one in which a reactor core is damaged and significant amounts of radioactive isotopes are released, such as in the Chernobyl disaster in 1986 and Fukushima nuclear disaster in 2011. The impact of nuclear accidents has been a topic of debate since the first nuclear reactors were constructed in 1954 and has been a key factor in public concern about nuclear facilities. M.V. Ramana. Nuclear Power: Economic, Safety, Health, and Environmental Issues of Near-Term Technologies, ''Annual Review of Environment and Resources'', 2009, 34, p. 136. Technical measures to reduce the risk of accidents or to minimize the amount of radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wet Sulfuric Acid Process
The wet sulfuric acid process (WSA process) is a gas desulfurization process introduced by Danish company Haldor Topsoe in 1987. The WSA process can be applied in all industries where sulfur removal presents an issue, and produces commercial quality sulfuric acid (H2SO4) and high-pressure steam during desulfurization The wet catalysis process is used for processing sulfur-containing streams, such as: * H2S gas from e.g. amine gas treating unit * Off-gas from sour water stripper (SWS) gas *Off-gas from Rectisol *Spent acid from an alkylation unit * Claus process tail gas *Heavy residue or petcoke-fired utility boiler off-gas *Boiler flue gases from various processes SNOX flue gas desulfurization *Metallurgical process gas *Production of sulfuric acid The process ;The main reactions in the WSA process *Combustion: 2 H2S + 3 O2 2 H2O + 2 SO2 (-1036 kJ/mol) *Oxidation: 2 SO2 + O2 2 SO3 (-198 kJ/mol) Vanadium(V)_oxide.html" ;"title="n the presence of a Vanadium(V) oxide">va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive Waste
Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nuclear weapons reprocessing. The storage and disposal of radioactive waste is regulated by government agencies in order to protect human health and the environment. Radioactive waste is broadly classified into 3 categories: low-level waste (LLW), such as paper, rags, tools, clothing, which contain small amounts of mostly short-lived radioactivity; intermediate-level waste (ILW), which contains higher amounts of radioactivity and requires some shielding; and high-level waste (HLW), which is highly radioactive and hot due to decay heat, thus requiring cooling and shielding. Spent nuclear fuel can be processed in nuclear reprocessing plants. One third of the total amount have already been reprocessed. With nuclear reprocessing 96% of the spent fue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
