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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; or, it must involve nuclear weapons (even if lacking an installed fissile core or if nuclear detonation was not possible). # 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 ... [...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-milit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harry Daghlian
Haroutune Krikor Daghlian Jr. (May 4, 1921 – September 15, 1945) was an American physicist with the Manhattan Project, which designed and produced the atomic bombs that were used in World War II. He accidentally irradiated himself on August 21, 1945, during a critical mass experiment at the remote Omega Site of the Los Alamos Laboratory in New Mexico and died 25 days later from the resultant radiation poisoning. Daghlian was irradiated as a result of a criticality accident that occurred when he accidentally dropped a tungsten carbide brick onto a 6.2 kg bomb core made of plutonium–gallium alloy. This core, subsequently nicknamed the " demon core", was later involved in the death of another physicist, Louis Slotin. Early life and education Haroutune Krikor Daghlian Jr., was born in Waterbury, Connecticut, on May 4, 1921, one of three children of Margaret Rose (''née'' Currie) and Haroutune Krikor Daghlian. His father was an ethnic Armenian from Gaziantep in wha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demon Core
The demon core was a sphere of plutonium that was involved in two fatal radiation accidents when scientists tested it as a fissile core of an early atomic bomb. It was manufactured in 1945 by the Manhattan Project, the U.S. nuclear weapon development effort during World War II. It was a subcritical mass that weighed and was in diameter. The core was prepared for shipment to the Pacific Theater as part of the third nuclear weapon to be dropped on Japan, but when Japan surrendered, the core was retained for testing and potential later use in the case of another conflict. The two criticality accidents occurred at the Los Alamos Laboratory in New Mexico on August 21, 1945, and May 21, 1946. In both cases, an experiment was intended to demonstrate how close the core was to criticality, using a neutron-reflective tamper (layer of dense material surrounding the fissile material). In both accidents, the core was accidentally put into a critical configuration. Physicists Harry ... [...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 absorbing material, 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 (physics), kerma; defined as the sum of the initial kinetic energy , kinetic energies of all the charged particles liberated by uncharged ionizing radiation in a sample of matter per unit mass. The unit was named after British phys ... [...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, air, water, or any other substance. It has been replaced by the gray (symbol Gy) in SI derived units. The rad 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 submultiple, the centigray (symbol cGy), 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 changes. A dose o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prompt Critical
In nuclear engineering, prompt criticality is the criticality (the state in which a nuclear chain reaction is self-sustaining) that is achieved with prompt neutrons alone (without the efforts of delayed neutrons). 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 this situation, an assembly is critical if every released neutron has a 1/2.4 = 0.42 = 42 % probability of causing another fission event as opposed to either being a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Mass (nuclear)
In nuclear engineering, critical mass is the minimum mass of the fissile material needed for a sustained nuclear chain reaction in a particular setup. 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. It is an important parameter of a nuclear reactor core or nuclear weapon. The concept is important in nuclear weapon design. Critical size is the minimum size of the fissile material needed for a sustained nuclear chain reaction in a particular setup. If the size of the reactor core is less than a certain minimum, too many fission neutrons escape through its surface and the chain reaction is not sustained. Criticality When a nuclear chain reaction in a mass of fissile material is self-sustaining but not growing, the mass is said to be in a critical state, in which there is no increase or decrease in power, temperature, or neutr ... [...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 triggered 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 second fatal victim of a crit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Physics
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the atom as a whole, including its electrons. Discoveries in nuclear physics have led to applications in many fields such as nuclear power, nuclear weapons, nuclear medicine and magnetic resonance imaging, industrial and agricultural isotopes, ion implantation in materials engineering, and radiocarbon dating in geology and archaeology. Such applications are studied in the field of nuclear engineering. Particle physics evolved out of nuclear physics and the two fields are typically taught in close association. Nuclear astrophysics, the application of nuclear physics to astrophysics, is crucial in explaining the inner workings of stars and the origin of the chemical elements. History The history of nuclear physics as a discipline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slotin Criticality Drawing
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 triggered 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 second fatal victim of a critic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Mexico
New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also borders the state of Texas to the east and southeast, Oklahoma to the northeast, and shares Mexico-United States border, an international border with the Mexican states of Chihuahua (state), Chihuahua and Sonora to the south. New Mexico's largest city is Albuquerque, and its List of capitals in the United States, state capital is Santa Fe, New Mexico, Santa Fe, the oldest state capital in the U.S., founded in 1610 as the government seat of Santa Fe de Nuevo México, Nuevo México in New Spain. It also has the highest elevation of any state capital, at . New Mexico is the List of U.S. states and territories by area, fifth-largest of the fifty states by area, but with just over 2.1 million residents, ranks List of U.S. states and terri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Poisoning
Acute radiation syndrome (ARS), also known as radiation sickness or radiation poisoning, is a collection of health effects that are caused by being exposed to high amounts of ionizing radiation in a short period of time. Symptoms can start within an hour of exposure, and can last for several months. Early symptoms are usually nausea, vomiting and loss of appetite. In the following hours or weeks, initial symptoms may appear to improve, before the development of additional symptoms, after which either recovery or death follows. ARS involves a total dose of greater than 0.7 Gy (70 rad), that generally occurs from a source outside the body, delivered within a few minutes. Sources of such radiation can occur accidentally or intentionally. They may involve nuclear reactors, cyclotrons, certain devices used in cancer therapy, nuclear weapons, or radiological weapons. It is generally divided into three types: bone marrow, gastrointestinal, and neurovascular syndrome, with bone m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
