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Radiological Protection
Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Exposure can be from a source of radiation external to the human body or due to internal irradiation caused by the ingestion of radioactive contamination. Ionizing radiation is widely used in industry and medicine, and can present a significant health hazard by causing microscopic damage to living tissue. There are two main categories of ionizing radiation health effects. At high exposures, it can cause "tissue" effects, also called "deterministic" effects due to the certainty of them happening, conventionally indicated by the unit gray and resulting in acute radiation syndrome. For low level exposures there can be statistically elevated risks of radiation-induced cancer, called "stochastic effects" due to the uncertainty of them happening, co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Atomic Energy Agency
The International Atomic Energy Agency (IAEA) is an intergovernmental organization that seeks to promote the peaceful use of nuclear technology, nuclear energy and to inhibit its use for any military purpose, including nuclear weapons. It was established in 1957 as an autonomous international organization; though governed by its own founding treaty, the IAEA Statute, the organization reports to both the United Nations General Assembly, General Assembly and the United Nations Security Council, Security Council of the United Nations, and is headquartered at the United Nations Office at Vienna, UN Office at Vienna, Austria. The IAEA was created in response to growing international concern toward nuclear weapons, especially Cold War (1953–1962), amid rising tensions between the foremost nuclear powers, the United States and the Soviet Union. U.S. president Dwight D. Eisenhower's "Atoms for Peace, Atoms for Peace" speech, which called for the creation of an international organiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALARA
As low as reasonably practicable (ALARP), or as low as reasonably achievable (ALARA), is a principle in the regulation and management of safety-critical and safety-involved systems. The principle is that the residual risk shall be reduced as far as reasonably practicable. In UK and NZ Health and safety law, it is equivalent to so far as is reasonably practicable (SFAIRP). In the US, ALARA is used in the regulation of radiation risks. For a risk to be ALARP, it must be possible to demonstrate that the cost involved in reducing the risk further would be disproportionate to the benefit gained. Factors Determining that a risk has been reduced to ALARP involves an assessment of the risk and costs involved in taking measures to avoid that risk, and a comparison of the two according to cost–benefit analysis (CBA). In this context, risk is the combination of the frequency (likelihood) and the consequence of a specified hazardous event. Several factors are likely to be considered whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respirators
A respirator is a device designed to protect the wearer from inhaling hazardous atmospheres including lead, lead fumes, vapors, gases and particulate matter such as dusts and airborne pathogens such as viruses. There are two main categories of respirators: the ''air-purifying respirator'', in which respirable air is obtained by filtering a contaminated atmosphere, and the ''air-supplied respirator'', in which an alternate supply of breathable air is delivered. Within each category, different techniques are employed to reduce or eliminate noxious airborne contaminants. Air-purifying respirators range from relatively inexpensive, single-use, disposable face masks, known as filtering facepiece respirators, reusable models with replaceable cartridges called elastomeric respirators, to powered air-purifying respirators (PAPR), which use a pump or fan to constantly move air through a filter and supply purified air into a mask, helmet or hood. History Earliest records to 19th c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glovebox
A glovebox (or glove box) is a sealed container that is designed to allow one to manipulate objects where a separate atmosphere is desired. Built into the sides of the glovebox are gloves arranged in such a way that the user can place their hands into the gloves and perform tasks inside the box without breaking containment. Part or all of the box is usually transparent to allow the user to see what is being manipulated. A smaller antechamber compartment is used to transport items into or out of the main chamber without compromising the internal environment. Antechambers are much smaller than the main chambers so they can be exposed to ambient conditions more often and achieve inert conditions quickly. Two types of gloveboxes exist. The first allows a person to work with hazardous substances, such as radioactive materials or infectious disease agents, and the second allows manipulation of substances that must be contained within a very high purity inert atmosphere, such as argon o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technetium-99m
Technetium-99m (99mTc) is a metastable nuclear isomer of technetium-99 (itself an isotope of technetium), symbolized as 99mTc, that is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used Radiopharmacology, medical radioisotope in the world. Technetium-99m is used as a radioactive tracer and can be detected in the body by medical equipment (gamma cameras). It is well suited to the role, because it emits readily detectable gamma rays with a photon energy of 140 kiloelectronvolt, keV (these 8.8 Picometre, pm photons are about the same wavelength as emitted by conventional X-ray diagnostic equipment) and its half-life for gamma emission is 6.0058 hours (meaning 93.7% of it decays to 99Tc in 24 hours). The relatively "short" physical half-life of the isotope and its biological half-life of 1 day (in terms of human activity and metabolism) allows for scanning procedures which collect data rapidly but keep total patient radiatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tritium
Tritium () or hydrogen-3 (symbol T or H) is a rare and radioactive isotope of hydrogen with a half-life of ~12.33 years. The tritium nucleus (t, sometimes called a ''triton'') contains one proton and two neutrons, whereas the nucleus of the common isotope hydrogen-1 (''protium'') contains one proton and no neutrons, and that of non-radioactive hydrogen-2 ('' deuterium'') contains one proton and one neutron. Tritium is the heaviest particle-bound isotope of hydrogen. It is one of the few nuclides with a distinct name. The use of the name hydrogen-3, though more systematic, is much less common. Naturally occurring tritium is extremely rare on Earth. The atmosphere has only trace amounts, formed by the interaction of its gases with cosmic rays. It can be produced artificially by irradiation of lithium or lithium-bearing ceramic pebbles in a nuclear reactor and is a low-abundance byproduct in normal operations of nuclear reactors. Tritium is used as the energy source in radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radon
Radon is a chemical element; it has symbol Rn and atomic number 86. It is a radioactive noble gas and is colorless and odorless. Of the three naturally occurring radon isotopes, only Rn has a sufficiently long half-life (3.825 days) for it to be released from the soil and rock where it is generated. Radon isotopes are the immediate decay products of radium isotopes. The instability of Rn, its most stable isotope, makes radon one of the rarest elements. Radon will be present on Earth for several billion more years despite its short half-life, because it is constantly being produced as a step in the decay chains of U and Th, both of which are abundant radioactive nuclides with half-lives of at least several billion years. The decay of radon produces many other short-lived nuclides, known as "radon daughters", ending at stable isotopes of lead. Rn occurs in significant quantities as a step in the normal radioactive decay chain of U, also known as the uranium series, which slo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Dose (radiation)
Effective dose is a dose quantity in the International Commission on Radiological Protection (ICRP) system of radiological protection.ICRP publication, 103 para 103 It is the tissue-weighted sum of the equivalent doses in all specified tissues and organs of the human body. It represents the stochastic health risk to the whole body, which is the ''probability'' of cancer induction and genetic effects, of low levels of ionizing radiation. It takes into account the type of radiation and the nature of each organ or tissue being irradiated, and enables summation of organ doses due to varying levels and types of radiation, both internal and external, to produce an overall calculated effective dose. The SI unit for effective dose is the sievert (Sv) which corresponds to a 5.5% chance of developing cancer. The effective dose is not intended as a measure of ''deterministic'' health effects, which is the ''severity'' of acute tissue damage that is certain to happen, that is measured by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Committed Dose
The committed dose in radiological protection is a measure of the stochastic health risk due to an intake of radioactive material into the human body. Stochastic in this context is defined as the ''probability'' of cancer induction and genetic damage, due to low levels of radiation. The SI unit of measure is the sievert. A committed dose from an internal source represents the same effective risk as the same amount of effective dose applied uniformly to the whole body from an external source, or the same amount of equivalent dose applied to part of the body. The committed dose is not intended as a measure for deterministic effects, such as radiation sickness, which are defined as the ''severity'' of a health effect which is certain to happen. The radiation risk proposed by the International Commission on Radiological Protection (ICRP) predicts that an effective dose of one sievert carries a 5.5% chance of developing cancer. Such a risk is the sum of both internal and external ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Dosimetry
Internal dosimetry is the science of internal ionising radiation dose assessment due to radionuclides incorporated inside the human body. Radionuclides deposited within a body will irradiate tissues and organs and give rise to committed dose until they are excreted from the body or the radionuclide is completely decayed. The internal doses for workers or members of the public exposed to the intake of radioactive particulates can be estimated using bioassay data such as lung and body counter measurements, urine or faecal radioisotope concentration, etc. The International Commission on Radiological Protection (ICRP) biokinetic models are applied to establish a relationship between the individual intake and the bioassay measurements, and then to infer the internal dose. Committed dose The internal radiation dose due to injection, ingestion or inhalation radioactive substances is known as committed dose. The ICRP defines Committed effective dose, as the sum of the products of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Regulatory Commission
The United States Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operations on January 19, 1975, as one of two successor agencies to the United States Atomic Energy Commission. Its functions include overseeing reactor safety and security, administering reactor licensing and renewal, licensing and oversight for fuel cycle facilities, licensing radioactive materials, radionuclide safety, and managing the storage, security, recycling, and disposal of spent fuel. History Prior to 1975 the Atomic Energy Commission was in charge of matters regarding radionuclides. The AEC was dissolved, because it was perceived as unduly favoring the industry it was charged with regulating.John Byrne and Steven M. Hoffman (1996). ''Governing the Atom: The Politics of Risk'', Transaction Publishers, p. 163. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
