|
List Of Military Nuclear Accidents
This article lists notable military accidents involving nuclear material. Civilian accidents are listed at List of civilian nuclear accidents. For a general discussion of both civilian and military accidents, see nuclear and radiation accidents. For other lists, see Lists of nuclear disasters and radioactive incidents. Scope of this article In listing military nuclear accidents, the following criteria have been adopted: # There must be well-attested and substantial health risks associated with nuclear materials. # To qualify as "military", the nuclear operation/material must be principally for military purposes. # To qualify as "accident", the damage should not be intentional, unlike in nuclear warfare. This list may be incomplete due to military secrecy. 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s See also *1983 Soviet nuclear false alarm incident *International Nuclear Event Scale *List of accidents and incidents involving military aircraft *List of civi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Civilian Nuclear Accidents
This article lists notable civilian accidents involving fissile nuclear material or nuclear reactors. Military accidents are listed at List of military nuclear accidents. Civil radiation accidents not involving fissile material are listed at List of civilian radiation accidents. For a general discussion of both civilian and military accidents, see Nuclear and radiation accidents. Scope of this article In listing civilian nuclear accidents, the following criteria have been followed: # Notably severe: there must be well-attested and substantial health damage, property damage or contamination; if an International Nuclear Event Scale (INES) level is available, of at least two. # Nuclear aspect: the damage must be related directly to nuclear operations or materials; the event should involve fissile material or a reactor, not merely (for example) having occurred at the site of a nuclear power plant. # Primarily civilian: the nuclear operation/material must be principally for non-militar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established as a separate branch of the United States Armed Forces in 1947 with the enactment of the National Security Act of 1947. It is the second youngest branch of the United States Armed Forces and the fourth in order of precedence. The United States Air Force articulates its core missions as air supremacy, global integrated intelligence, surveillance and reconnaissance, rapid global mobility, global strike, and command and control. The United States Air Force is a military service branch organized within the Department of the Air Force, one of the three military departments of the Department of Defense. The Air Force through the Department of the Air Force is headed by the civilian Secretary of the Air Force ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitt Island (Canada)
Pitt Island is an island located within the traditional territory of the Gitxaala Nation on the north coast of British Columbia, Canada. Pitt island is located between Banks Island, across Grenville Channel (part of the Inside Passage) from the mainland, and is separated from Banks Island by Principe Channel. The island has an area of , is long, and ranges from wide. Its highest point is at . Pitt Island is the only island in British Columbia known to host a resident population of Moose Features * Anchor Mountain * Captain Cove * Holmes Lake * Hevenor Inlet * Newcombe Harbour * Pa-aat River * Port Stevens * Monckton Inlet * Mount Hulke * Mount Patterson * Mount Frank * Mount Saunders * Mount Shields * Wyndham Lake * Red Bluff Lake Protected Areas * Union Passage Marine Provincial Park Union Passage Marine Provincial Park is a provincial park within the asserted traditional territory of the Tsimshian First Nations. The marine protected area is located at the southwest en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convair B-36 Peacemaker
The Convair B-36 "Peacemaker" is a strategic bomber that was built by Convair and operated by the United States Air Force (USAF) from 1949 to 1959. The B-36 is the largest mass-produced piston-engined aircraft ever built. It had the longest wingspan of any combat aircraft ever built, at . The B-36 was the first bomber capable of delivering any of the nuclear weapons in the U.S. arsenal from inside its four bomb bays without aircraft modifications. With a range of and a maximum payload of , the B-36 was capable of intercontinental flight without refuelling. Entering service in 1948, the B-36 was the primary nuclear weapons delivery vehicle of Strategic Air Command (SAC) until it was replaced by the jet-powered Boeing B-52 Stratofortress beginning in 1955. All but four aircraft have been scrapped. Development The genesis of the B-36 can be traced to early 1941, prior to the entry of the United States into World War II. At the time, the threat existed that Britain might fall t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1950 British Columbia B-36 Crash
Sometime after midnight on 14 February 1950, a Convair B-36B, United States Air Force Serial Number ''44-92075'' assigned to the US 7th Bombardment Wing, Heavy at Carswell Air Force Base in Texas, crashed in northwestern British Columbia on Mount Kologet after jettisoning a Mark 4 nuclear bomb. This was the first such nuclear weapon loss in history. The B-36B had been en route from Eielson Air Force Base near Fairbanks, Alaska to Carswell AFB, more than 3,000 miles southeast, on a mission that included a simulated nuclear attack on San Francisco. Incident Convair B-36B ''44-92075'' was flying on a simulated nuclear strike combat mission against the Soviet Union. The B-36 took off on 13 February 1950 from Eielson AFB with a regular crew of 15 plus a Weaponeer and a Bomb Commander. The plan for the 24-hour flight was to fly over the North Pacific, due west of the Alaska panhandle and British Columbia, then head inland over Washington state and Montana. Here the B-36 would clim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demon Core
The demon core was a spherical subcritical mass of plutonium in diameter, manufactured during World War II by the United States nuclear weapon development effort, the Manhattan Project, as a fissile core for an early atomic bomb. The core was prepared for shipment as part of the third nuclear weapon to be used in Japan, but when Japan surrendered, the core was retained at Los Alamos for testing and potential later use. It was involved in two criticality accidents at the Los Alamos Laboratory on August 21, 1945, and May 21, 1946, each resulting in a fatality. Both experiments were designed to demonstrate how close the core was to criticality with a tamper, but in each case, the core was accidentally placed into a supercritical configuration. Physicists Harry Daghlian and Louis Slotin suffered acute radiation syndrome (ARS) and died soon after, while others present in the lab were also exposed. Manufacturing and early history The demon core (like the second core used in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray (unit)
The gray (symbol: Gy) is the unit of ionizing radiation dose in the International System of Units (SI), defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose that measures the energy deposited by ionizing radiation in a unit mass of matter being irradiated, and is used for measuring the delivered dose in radiotherapy, food irradiation and radiation sterilization. It is important in predicting likely acute health effects, such as acute radiation syndrome and is used to calculate equivalent dose using the sievert, which is a measure of the stochastic health effect on the human body. The gray is also used in radiation metrology as a unit of the radiation quantity kerma; defined as the sum of the initial kinetic energies of all the charged particles liberated by uncharged ionizing radiation in a sample of matter per unit mass. The gray is an important unit in ionising radiation measuremen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rad (unit)
The rad is a unit of absorbed radiation dose, defined as 1 rad = 0.01 Gy = 0.01 J/kg. It was originally defined in CGS units in 1953 as the dose causing 100 ergs of energy to be absorbed by one gram of matter. The material absorbing the radiation can be human tissue or silicon microchips or any other medium (for example, air, water, lead shielding, etc.). It has been replaced by the gray (Gy) in SI derived units, but is still used in the United States, although this is "strongly discouraged" in Chapter 5.2 of the ''Guide to the SI'', which was written and published by the U.S. National Institute of Standards and Technology. However, the numerically equivalent SI unit, the centigray, is widely used to report absorbed doses within radiotherapy. The roentgen, used to quantify the radiation exposure, may be related to the corresponding absorbed dose by use of the F-factor. Health effects A dose of under 100 rad will typically produce no immediate symptoms other than blood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prompt Critical
In nuclear engineering, prompt criticality describes a nuclear fission event in which criticality (the threshold for an exponentially growing nuclear fission chain reaction) is achieved with prompt neutrons alone (neutrons that are released immediately in a fission reaction) and does not rely on delayed neutrons (neutrons released in the subsequent decay of fission fragments). As a result, prompt supercriticality causes a much more rapid growth in the rate of energy release than other forms of criticality. Nuclear weapons are based on prompt criticality, while nuclear reactors rely on delayed neutrons or external neutrons to achieve criticality. Criticality An assembly is critical if each fission event causes, on average, exactly one additional such event in a continual chain. Such a chain is a self-sustaining fission chain reaction. When a uranium-235 (U-235) atom undergoes nuclear fission, it typically releases between one and seven neutrons (with an average of 2.4). In thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Mass (nuclear)
In nuclear engineering, a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, its nuclear fission cross-section), density, shape, enrichment, purity, temperature, and surroundings. The concept is important in nuclear weapon design. Explanation of criticality When a nuclear chain reaction in a mass of fissile material is self-sustaining, the mass is said to be in a ''critical'' state in which there is no increase or decrease in power, temperature, or neutron population. A numerical measure of a critical mass is dependent on the effective neutron multiplication factor , the average number of neutrons released per fission event that go on to cause another fission event rather than being absorbed or leaving the material. When ''k'' = 1, the mass is critical, and the chain reaction is self-sustaining. A ''subcritical'' mass is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Slotin
Louis Alexander Slotin (1 December 1910 – 30 May 1946) was a Canadian physicist and chemist who took part in the Manhattan Project. Born and raised in the North End of Winnipeg, Manitoba, Slotin earned both his Bachelor of Science and Master of Science degrees from the University of Manitoba, before obtaining his doctorate in physical chemistry at King's College London in 1936. Afterwards, he joined the University of Chicago as a research associate to help design a cyclotron. In 1942, Slotin was invited to participate in the Manhattan Project, and subsequently performed experiments with uranium and plutonium cores to determine their critical mass values. After World War II he continued his research at Los Alamos National Laboratory in New Mexico. On 21 May 1946, he accidentally began a fission reaction which released a burst of hard radiation. He was rushed to the hospital and died nine days later on 30 May. Slotin had become the victim of the second criticality accide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
