A radioactive substance found in nature. The Energy Policy Act of 2005 gives the NRC regulatory authority for the safe use of radium under certain conditions.
A through-wall crack whose shape is nonidealized, meaning that it has different lengths on the inside and outside surfaces of the component.
A planar crack on the inside surface of a component that has a semielliptical shape.
A planar crack that extends from the inside surface of a piping component to the outside surface with equal radial inner and outer lengths.
Any process involving a chemical or nuclear change.
A special category of sensitive unclassified information that must be protected. Safeguards information concerns the physical protection of operating power reactors, spent fuel shipments, strategic special nuclear material, or other radioactive material. For additional detail...
The use of material control and accounting programs to verify that all special nuclear material is properly controlled and accounted for, as well as the physical protection (or physical security) equipment and security forces. As used by the International Atomic Energy Agency...
The change in reactivity per percent change in power. The power coefficient is the summation of the moderator temperature coefficient of reactivity, the fuel temperature coefficient of reactivity, and the void coefficient of reactivity.
Any deliberate act directed against a plant or transport in which an activity licensed pursuant to 10 CFR Part 73 of NRC's regulations is conducted or against a component of such a plant or transport that could directly or indirectly endanger the public health and safety by e...
Reactors that differ from today’s reactors primarily by their use of inert gases, molten salt mixtures, or liquid metals to cool the reactor core. Advanced reactors can also consider fuel materials and designs that differ radically from today’s enriched-uranium-dio...
A general term for a wide range of waste that is contaminated with radioactive material or has become radioactive through exposure to neutron radiation. A variety of industries, hospitals and medical institutions, educational and research institutions, private or government la...
Primarily, the solid residue from a conventional uranium recovery facility in which uranium or thorium ore is crushed and processed mechanically or chemically to recover the uranium, thorium, or other valuable materials. This naturally radioactive ore residue contains the radi...
Devices used to measure, monitor, and control the thickness of sheet metal, textiles, paper napkins, newspaper, plastics, photographic film, and other products as they are manufactured. Gauges mounted in fixed locations are designed for measuring or controlling material dens...
The splitting of an atom, which releases a considerable amount of energy (usually in the form of heat) that can be used to produce electricity. Fission may be spontaneous, but is usually caused by the nucleus of an atom becoming unstable (or "heavy") after capturin...
Information that has been determined pursuant to an Executive order to require protection against unauthorized disclosure and is marked to indicate its classified status when in documentary form. The NRC has two types of classified information. The first type, known as Nationa...
A term that is used by pressurized water reactors for a reactor scram (see Scram).
A breeder reactor in which the fission chain reaction is sustained by thermal neutrons.
The portion of the natural background radiation that is emitted by naturally occurring radioactive materials, such as uranium, thorium, and radon in the earth.
The condition for increasing the level of operation of a reactor. The rate of fission neutron production exceeds all neutron losses, and the overall neutron population increases.
A powerful short-ranged attractive force that holds together the particles inside an atomic nucleus.
Specifies that information applicable to the particular field was not included in the event report.
The international system (SI) unit for dose equivalent equal to 1 Joule/kilogram. 1 sievert = 100 rem. Named for physicist Rolf Sievert.
A term that may be used for referring to the reactor coolant system.
A human resources measurement equal to one staff person working full-time for one year.
An independent agency that regulates the interstate transmission of electricity, natural gas, and oil. FERC also regulates and oversees hydropower projects, and the construction of liquefied natural gas terminals and interstate natural gas pipelines. FERC protects the economi...