Skip to main content

Alert

Due to a lapse in appropriations, the NRC has ceased normal operations. However, excepted and exempted activities necessary to maintain critical health and safety functions—as well as essential progress on designated critical activities, including those specified in Executive Order 14300—will continue, consistent with the OMB-Approved NRC Lapse Plan.

Filter Search Results

Image

Search Results

Displaying 11 - 20 of 740

Condenser

Condenser … A large heat exchanger designed to cool exhaust steam from a turbine below the boiling point so that it can be returned to the heat source as water. In a pressurized-water reactor , the water is returned to the steam generator . In a …

Ionizing radiation

Ionizing radiation … A form of radiation, which includes alpha particles , beta particles , gamma rays , x-rays , neutrons , high-speed electrons , high-speed protons , and other particles capable of producing ions . Compared to non-ionizing radiation, …

Curie (Ci)

Curie (Ci) … One of three units used to measure the intensity of radioactivity in a sample of material. This value refers to the amount of ionizing radiation released when an element (such as uranium ) spontaneously emits energy as a result of the …

Core

Core … The central portion of a nuclear reactor , which contains the fuel assemblies , moderator , neutron poisons , control rods , and support structures. The reactor core is where fission takes place. … …

Gamma radiation

Gamma radiation … High-energy, short-wavelength, electromagnetic radiation emitted from the nucleus of an atom . Gamma radiation frequently accompanies emissions of alpha particles and beta particles , and always accompanies fission . Gamma rays are …

Feedwater

Feedwater … Water supplied to the reactor pressure vessel in a boiling-water reactor (BWR) or the steam generator in a pressurized-water reactor (PWR) that removes heat from the reactor fuel rods by boiling and becoming steam. The steam becomes the …

Excursion

Excursion … A sudden, very rapid rise in the power level of a reactor caused by supercriticality . Excursions are usually quickly suppressed by the moderator temperature coefficient , the fuel temperature coefficient , or the void coefficient of …

Fissile material

Fissile material … A nuclide that is capable of undergoing fission after capturing low-energy thermal (slow) neutrons . Although sometimes used as a synonym for fissionable material , this term has acquired its more-restrictive interpretation with the …

Pellet, fuel

Pellet, fuel … A thimble-sized ceramic cylinder (approximately 3/8-inch in diameter and 5/8-inch in length), consisting of uranium (typically uranium oxide, UO 2 ), which has been enriched to increase the concentration of uranium-235 (U-235) to fuel a …

Rem

Rem … One of the two standard units used to measure the dose equivalent (or effective dose), which combines the amount of energy (from any type of ionizing radiation that is deposited in human tissue), along with the medical effects of the given type of …