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U.S. Nuclear Regulatory Commission
Отрасли: Government
Number of terms: 11131
Number of blossaries: 0
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The concentration of a given radionuclide in air which, if breathed by the reference man for a working year of 2,000 hours under conditions of light work (with an inhalation rate of 1. 2 cubic meters of air per hour), results in an intake of one annual limit on intake (ALI). Established DAC values are given in Table 1, Column 3, of Appendix B to Title 10, Part 20, of the Code of Federal Regulations (10 CFR Part 20), "Standards for Protection Against Radiation. ”
Industry:Energy
Uranium with a percentage of uranium-235 lower than the 0. 7 percent (by mass) contained in natural uranium. (The normal residual U-235 content in depleted uranium is 0. 2?. 3 percent, with U-238 comprising the remaining 98. 7?8. 8 percent. ) Depleted uranium is produced during uranium isotope separation and is typically found in spent fuel elements or byproduct tailings or residues. Depleted uranium can be blended with highly-enriched uranium, such as that from weapons, to make reactor fuel. For further detail, see Background Information on Depleted Uranium and Fact Sheet on Depleted Uranium and Other Waste Disposal.
Industry:Energy
The point at which the heat transfer from a fuel rod rapidly decreases due to the insulating effect of a steam blanket that forms on the rod surface when the temperature continues to increase.
Industry:Energy
The ratio of the heat flux needed to cause departure from nucleate boiling to the actual local heat flux of a fuel rod.
Industry:Energy
An approach to designing and operating nuclear facilities that prevents and mitigates accidents that release radiation or hazardous materials. The key is creating multiple independent and redundant layers of defense to compensate for potential human and mechanical failures so that no single layer, no matter how robust, is exclusively relied upon. Defense-in-depth includes the use of access controls, physical barriers, redundant and diverse key safety functions, and emergency response measures. For further information, see Speech No. S-04-009, "The Very Best-Laid Plans (the NRC's Defense-in Depth Philosophy). ”
Industry:Energy
The external whole-body exposure dose equivalent at a tissue depth of 1 cm (1000 mg/cm<sup>2</sup>). For further information, see Measuring Radiation.
Industry:Energy
A process used to reduce, remove, or neutralize radiological, chemical, or biological contamination to reduce the risk of exposure. Decontamination may be accomplished by cleaning or treating surfaces to reduce or remove the contamination; filtering contaminated air or water; subjecting contamination to evaporation and precipitation; or covering the contamination to shield or absorb the radiation. The process can also simply allow adequate time for natural radioactive decay to decrease the radioactivity.
Industry:Energy
A method of decommissioning, in which structures, systems, and components that contain radioactive contamination are removed from a site and safely disposed at a commercially operated low-level waste disposal facility, or decontaminated to a level that permits the site to be released for unrestricted use shortly after it ceases operation. For further information, see the Fact Sheet on Decommissioning Nuclear Power Plants.
Industry:Energy
The process of safely closing a nuclear power plant (or other facility where nuclear materials are handled) to retire it from service after its useful life has ended. This process primarily involves decontaminating the facility to reduce residual radioactivity and then releasing the property for unrestricted or (under certain conditions) restricted use. This often includes dismantling the facility or dedicating it to other purposes. Decommissioning begins after the nuclear fuel, coolant, and radioactive waste are removed. For additional information, see Decommissioning of Nuclear Facilities and Find Sites Undergoing Decommissioning.
Industry:Energy
A woman who is an occupational radiation worker and has voluntarily informed her employer, in writing, of her pregnancy and the estimated date of conception (see 10 CFR 20. 1003 and 20. 1208).
Industry:Energy