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  • ionizing radiation
  • This was countered by William H. Taft IV, general counsel for the Department of Defense who wrote that Cranston's bill created "the unmistakable impression that exposure to low-level ionizing radiation is a significant health hazard" and would be "damaging to every aspect of the Department of Defense's nuclear weapons and nuclear propulsion programs. (ratical.org)
  • isotopes
  • Fuel and isotopes were fed into the channels in the front of the reactor, the "charge face", and spent fuel was then pushed all the way through the core and out of the back-the "discharge face"-into a water duct for initial cooling prior to retrieval and processing to extract the plutonium. (thefullwiki.org)
  • When the majority of fissile radioactive isotopes of uranium are removed from natural uranium, what remains is called depleted uranium. (bibliotecapleyades.net)
  • The Japanese government and Fukushima plant owner, Tokyo Electric Power Company (TEPCO), began measuring radiation in the ocean-iodine and cesium isotopes-10 days after the accident and have been monitoring the water around the reactors up to 30 km from shore, where radiation levels have been highest. (whoi.edu)
  • Although the elevated levels offshore pose little direct hazard for human exposure, questions remain about the impact of long-lived isotopes that can accumulate in the food chain and remain present in sediment, emitting a persistent low-dose in the marine environment for years to come. (whoi.edu)
  • Meanwhile, like all radioactive isotopes, it decays. (blogspot.com)
  • This means that it is barely radioactive, less so than many other isotopes in rocks and sand. (blogspot.com)
  • Reactors are utilized for production of electricity at nuclear power plants, for propulsion of ships and submarines, and for the creation of radioactive isotopes used in medicine and industry. (faqs.org)
  • The Tokyo Electric Power Co., which operates the plant, said it found three radioactive isotopes of plutonium - plutonium 238, 239 and 240 - in five locations outside the plant in soil tests on March 21-22. (washingtonsblog.com)
  • Plutonium generally poses a health hazard only if it is taken into the body because all isotopes except plutonium-241 decay by emitting an alpha particle, and the beta particle emitted by plutonium-241 is of low energy. (washingtonsblog.com)
  • 1,000
  • This comes amid Kyodo's reports, citing the same Japanese agency, that radiation levels were 1,000 times above normal in the the control room of the 'No. 1' reactor at one of the facilities. (cnn.com)
  • For nuclear power to make a meaningful contribution to reducing CO2 emissions, 1,000 to 2,500 reactors would have to be operating globally by mid-century. (ieer.org)
  • As the radiation moves offshore, it is diluted and mixed through the ocean depths along the way, so that levels of some contaminants just 15 miles offshore are 100 to 1,000 times lower than waters near the reactors. (whoi.edu)
  • disaster
  • Cham Dallas, a professor of disaster management at the University of Georgia, said that it wouldn't be surprising if reactors get 'both thermally hot and radioactively hot' after the reactors were shut down. (cnn.com)
  • The aim of this paper is to describe the greatly increased risk from hazards that disaster response technical workers faced because of the Fukushima Dai-ichi NPP disaster. (bmj.com)
  • The tasks of disaster response technical workers in Fukushima Dai-ichi NPP after the tsunami were to restore the cooling of reactors and the fuel pools, containment and treatment of water contaminated by radioactive materials, and mitigation of radioactive materials emission in the environment eventually achieving the cold shutdown of the NPP. (bmj.com)
  • cores
  • The announcement followed unsettling news that a midmorning surge in radiation had forced emergency workers to halt their efforts to try to avert a meltdown of three other reactors at the plant, work that included the crucial task of keeping water on the reactors' overheated cores. (latimes.com)
  • fissile
  • When fissile uranium absorbs a neutron, it starts fissioning and releases energy, emitting several neutrons. (nirs.org)
  • At the end of one reactor cycle, the content of fissile uranium is about 0.7%-0.8%, approximately equal to the content of fissile plutonium-239 that is created. (nirs.org)
  • Tokyo Electri
  • On 16 December 2011, the Japanese government, the Tokyo Electric Power Company (TEPCO) and technical-support companies achieved cold shutdown of all the reactors stricken by the tsunami. (bmj.com)
  • Tokyo Electric Power Company, which manages the Fukushima Daiichi facility, said a fire at a fourth reactor on Tuesday morning may also have caused radioactive material to escape. (cnn.com)
  • neutrons
  • When the reactors were being built, little was known about the behavior of graphite when exposed to neutrons. (thefullwiki.org)
  • Reduced Efficacy of Control Rods Control rods work by absorbing neutrons in the reactor core, so maintaining stable power conditions. (nirs.org)
  • However, the fraction of delayed-neutrons in Pu-239 is about one- third that of uranium-235, which means that the reactor is more sensitive to variations in power. (nirs.org)
  • When the nucleus of a U-235 atom is split in two by a neutron d , some energy is released in the form of heat, and two or three additional neutrons are thrown off. (blogspot.com)
  • If enough of these expelled neutrons split the nuclei of other U-235 atoms, releasing further neutrons, a chain reaction can be achieved. (blogspot.com)
  • Through fission, neutrons of low energy can trigger a very large energy release. (faqs.org)
  • plume
  • Dr. Vassily Nesterenko, head of the Ukrainian Nuclear establishment at the time of the accident, flew over the burning reactor and took the only measurements of the radioactive plume. (ratical.org)
  • But hours later, public television broadcaster NHK showed live aerial video of a plume of white smoke rising from the reactor. (latimes.com)
  • the resulting graphite fire sent a plume of radioactive fallout into the atmosphere and over an extensive geographical area, to include significant areas of Western Europe. (blogspot.com)
  • severely damaged
  • TEPCO said "visibility in the pool is only about 1 meter, far less than the approximately 7 meters needed to work at removing nuclear fuel from the pool as part of the process of scrapping the four reactors severely damaged by last year's nuclear accident. (infowars.com)
  • plutonium
  • Still, the plant -- along with its spent nuclear fuel, extracted plutonium and nuclear reprocessing waste -- poses significant radiological hazards that a military strike could disperse into the environment. (taipeitimes.com)
  • The reactors themselves were built of a solid graphite core, with horizontal channels through which cans of uranium and isotope cartridges could be passed, to expose the isotope cartridges to neutron radiation from the uranium and produce plutonium and radioisotopes , respectively. (thefullwiki.org)
  • The most common nuclear fuels are 235 U (the isotope of uranium with an atomic mass of 235 and of use in nuclear reactors, 238) and 239 Pu (the isotope of plutonium with an atomic mass of 239). (newworldencyclopedia.org)
  • In the option to burn plutonium in CANDU reactors, the MOX fuel content could be 100% core. (nirs.org)
  • 3) But this has not been tested, nor is there any experience at all of burning plutonium fuel in CANDU reactors. (nirs.org)
  • 4) For boiling water reactors, four to six different plutonium contents designs are used. (nirs.org)
  • I say again: it is AGAINST THE LAWS OF PHYSICS for a commercial-grade nuclear reactor to explode - the nuclear fuel is not refined to weapons-grade level of concentration, like the plutonium found in nuclear weapons. (blogspot.com)
  • Plutonium can be a serious health hazard if inhaled or ingested , but external exposure poses little health risk, according to the U.S. Environmental Protection Agency. (washingtonsblog.com)
  • Plutonium stays radioactive for a long time. (washingtonsblog.com)
  • The ingestion hazard associated with common forms of plutonium is much lower than the inhalation hazard because absorption into the body after ingestion is quite low. (washingtonsblog.com)
  • So plutonium might be heavier than other radioactive materials, but it is not so heavy that it can't travel hundreds of miles in the right circumstances. (washingtonsblog.com)
  • explosion
  • The spent fuel at the Reactor 4 caused a hydrogen explosion and fire on March 15. (eco-business.com)
  • In the early phase of the accident, the first priority was to minimise the risk of reactor explosion and restore the cooling system by ensuring electrical power that was achieved on March 26. (bmj.com)
  • It's not so much the meltdown itself," Classic says, "it's whether or not it breaches the reactor vessel and gets into the soil, or a build up of pressure and heat causes an explosion to propel fuel into small pieces out into the atmosphere. (popularmechanics.com)
  • If the containment vessel is breached as a result of melting, radioactive fuel could leak into the ground, or pressure buildup could potentially cause an explosion that projects radioactive material into the air. (popularmechanics.com)
  • (CNN) -- The crisis at an earthquake-damaged nuclear plant in Japan continued Tuesday, as radiation levels rose to dangerous levels following an explosion at a third overheating reactor. (cnn.com)
  • accident
  • In the first of these, the Boiling Accident,'' it is assumed that a fraction of the radioactive material in a reactor is released to the atmosphere at a steady rate over a period of hours. (unt.edu)
  • In the second, the Puff Accident,'' it is assumed that the release of the radioactive material takes place instantaneously. (unt.edu)
  • It is concluded that the size of the plant should be set by the hazard of irradiation from the low- lying poison cloud produced in the boiling accident. (unt.edu)
  • New details also emerged about an unrelated accident on Friday, when a contract worker slipped into a pool above the unit 2 reactor, now offline for maintenance, while trying to retrieve a flashlight. (ocregister.com)
  • Numerous close calls have occurred among the aging US reactors in addition to our own Three Mile Island accident. (truthout.org)
  • During 26 years of operation, there was not a single accident at Ignalina related to rupture of the fuel or flooding of the graphite matrix in the reactors. (neimagazine.com)
  • radionuclides
  • The "Basic Recommendations for civil protection in the vicinity of nuclear facilities" and the "Radiological basis for decisions on measures to protect the population against Accidental Releases of radionuclides" regulate these measures. (bfs.de)
  • It's critical to gather early observations of the radioactive contaminants, or radionuclides, in the water and marine biota so we can establish a baseline," said chief scientist Ken Buesseler, a WHOI senior scientist and a recognized expert in the study of radioisotope geochemistry. (whoi.edu)
  • conceptual design
  • In the framework of the European Fusion Program, based mainly on magnetic confinement tokamak-type machines, the complete physical and technological basic demonstration of fusion was approached by the ITER 1 (International Thermonuclear Experimental Reactor) engineering and conceptual design. (hindawi.com)
  • fuel
  • At Fukushima, a perfect storm - a massive earthquake and tsunami, multiple vulnerable coastal reactors with spent-fuel ponds in the same buildings, inadequate barriers, loss of power, and back-up generators situated too low - may have seemed a remote possibility. (eco-business.com)
  • Such outcomes are at least as plausible or likely - if not more so - than a massive earthquake and tsunami causing widespread damage to four Japanese nuclear reactors and their adjacent spent-fuel ponds. (eco-business.com)
  • Following the earthquake and tsunami that damaged the Fukushima plant last year, the Japanese government underestimated the amount of radiation released into the environment, including cessium-137 from the fuel pool at reactor 4. (infowars.com)
  • Ignalina was the first nuclear plant with RBMK reactors to transition to erbium fuel, which significantly improved the thermophysical characteristics of the reactor core and the reliability of the fuel and reactors. (neimagazine.com)
  • By contrast, most chemical oxidation reactions (such as burning coal or TNT ) release at most a few eV per event, so nuclear fuel contains at least ten million times more usable energy than does chemical fuel. (newworldencyclopedia.org)
  • While it is possible to design civilian power reactors with un-enriched fuel, only about 10% of reactors ever built utilize that technology, and both nuclear weapons production and naval reactors require the concentrated isotope. (bibliotecapleyades.net)
  • A nuclear meltdown is where the fuel in the core of the reactor starts to melt. (cnn.com)
  • A fuel melt is a serious problem as it releases a lot of the radioactive material that is contained in that fuel. (cnn.com)
  • According to Sjoden, the main radioactive components likely to escape when a reactor's fuel rods are breached are Iodine-131 and Caesium-137. (cnn.com)
  • Fuel rods are long metal tubes containing pellets of fissionable material which provide fuel for nuclear reactors. (cnn.com)
  • The hope is that robots will be doing the heavy lifting when it comes time to dig out the fuel on a decommissioning job now expected to last another 30 to 40 years at a new cost of $189 billion - nearly double estimates released three years ago. (bellona.org)
  • In the days that followed, uranium fuel melted down in three of the six reactors. (bellona.org)
  • Today the only substantial use for uranium is as fuel in nuclear reactors, mostly for electricity generation. (blogspot.com)
  • To make nuclear fuel, the ore must be "enriched," an energy-intensive process that increases the .72 percent of highly fissionable, highly radioactive U-235 up to 3 to 5 percent. (orionmagazine.org)
  • radiation hazard
  • Americium-241 (²4¹Am) is the second most significant radiation hazard after ²³?Pu at some of the Mayak Production Association facilities. (arctichealth.org)
  • The Nuclear Regulatory Commission conducts the quarterly inspections, which cover everything from drill evaluations and surveillance testing to plant modifications and radiation hazard assessments. (theday.com)
  • rods
  • The spent rods are usually submerged in the pool next to the Unit 4 reactor, which was not operating when the quake struck. (latimes.com)
  • shut
  • Three of the Daiichi reactor's six units shut down because of the earthquake, while operations at the other three were out due to 'regular inspection,' the Tokyo Electric Power Co. said in a news release Saturday. (cnn.com)
  • The trouble the Daiichi plant happened after its once operating reactors had been successfully shut down, Edano said. (cnn.com)
  • In the immediate aftermath, Japan shut down its 42 remaining nuclear reactors. (bellona.org)
  • pools
  • The U.S. Appeals Court for the District of Columbia Circuit ruled that NRC must complete an environmental impact statement on the risks of on-site storage of HLRW at reactors, including in pools. (beyondnuclear.org)
  • And the slag heaps and contaminated pools that were left behind will be radioactive for millennia. (orionmagazine.org)
  • accidents
  • We have had nuclear accidents in the United States - most notably Three Mile Island in 1979, but also significant was the less well-known partial meltdown in 1966 at the Enrico Fermi demonstration nuclear breeder reactor (Enrico Fermi-1 fast breeder reactor) caused by a malfunction of the sodium cooling system. (blogspot.com)
  • leak
  • Dricks and Edison spokesman Gil Alexander, however, said that highly sensitive alarms were tripped in an building next to San Onofre's unit 3 reactor after the leak was detected about 5:30 p.m. Tuesday, indicating that at least some radioactive gas was present. (ocregister.com)
  • But a small leak in one of the tubes could have allowed radioactive water circulating from the reactor to mix with the water in the steam generator. (ocregister.com)
  • steam
  • The reactor is provided with three main coolant circuits, and the steam cycle has three stages of regenerative heating. (unt.edu)
  • Normally, water that is heated by the reactor and flows through the tubes is kept separate from another loop of water, from another source, inside the steam generators. (ocregister.com)
  • electricity
  • The myth that seems to be commonly accepted in this country is that it more dangerous to the health of people living in the vicinity of electric power plants to generate electricity by using nuclear reactors than by burning coal. (blogspot.com)
  • graphite
  • The plant utilized a sodium-cooled graphite-moderated reactor with stainless- steel clad. (unt.edu)
  • The reactors were graphite -moderated and air-cooled. (thefullwiki.org)
  • The only viable solution was also extremely simple: an annealing process, in which the graphite core was heated to 250 degrees Celsius to allow the displaced molecules to slip back into place and gradually release their stored energy (as heat) as they did so, causing a uniform release which spread throughout the core. (thefullwiki.org)
  • The Ignalina nuclear plant comprised two water-cooled graphite-moderated channel-type RBMK-1500 reactors. (neimagazine.com)
  • Scientists
  • This worried British scientists, so a means of safely releasing the stored energy was sought. (thefullwiki.org)
  • Their work will build on efforts by Japanese scientists and lay the foundation for expanded international collaboration and long-term research of questions related to releases from the Fukushima plant. (whoi.edu)
  • exposure
  • As from May, heat exposure became an extremely important hazard because of the hot summer weather and workers having to work outdoors wearing double-layer Tyvek® protective coveralls and full-face respirators 6 ( figure 1 ) which inhibit evaporative cooling. (bmj.com)
  • contaminants
  • The dumping of radioactive matter and other contaminants into the Ottawa River from an inactive nuclear reactor northwest of the capital is causing concern among Indigenous communities, environmental groups and others who monitor toxic waste. (cbc.ca)
  • CNL maintains the contaminants it releases into the Ottawa River fall well below allowable limits. (cbc.ca)