#Define nuclear fission reaction code#

Allegation A declaration, statement, or assertion of impropriety or inadequacy associated with NRC-regulated activities, the validity of which has not been established. The result of the reaction is a gel, which can expand and may cause micro-cracks in the concrete. Alkali silica reaction (ASR) ASR is a chemical combining of reactive silica from the concrete aggregate with the alkali from the cement paste in the presence of moisture.

Aleatory A type of uncertainty that is irreducible. For additional detail, see Dose Limits for Radiation Workers.

#Define nuclear fission reaction code#

ALARA As defined in Title 10, Section 20.1003, of the Code of Federal Regulations ( 10 CFR 20.1003), ALARA is an acronym for 'as low as (is) reasonably achievable,' which means making every reasonable effort to maintain exposures to ionizing radiation as far below the dose limits as practical, consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations, and in relation to utilization of nuclear energy and licensed materials in the public interest. For additional detail, see Appendix B to 10 CFR Part 20, 'Standards for Protection Against Radiation,' and Information for Radiation Workers. For related information, see Detecting Radiation and Regulatory Guide 8.25, 'Air Sampling in the Workplace.' Airborne radioactivity area As defined in Title 10, Section 20.1003, of the Code of Federal Regulations ( 10 CFR 20.1003), the airborne radioactivity area is a room, enclosure, or area in which airborne radioactive materials, composed wholly or partially of licensed material, exist in concentrations that (1) exceed the derived air concentration limits (DACs), or (2) would result in an individual present in the area without respiratory protection exceeding, during those hours, 0.6 percent of the annual limit on intake (ALI) or 12 DAC-hours. Air sampling The collection of samples of air to measure the radioactivity or to detect the presence of radioactive material, particulate matter, or chemical pollutants in the air. Nuclear Regulatory Commission (NRC) authorizing the State to regulate certain uses of radioactive materials within the State. State that has signed an agreement with the U.S. Advanced reactors can also consider fuel materials and designs that differ radically from today’s enriched-uranium-dioxide pellets within zirconium cladding. Advanced reactors 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. For related information, see Measuring Radiation. The units of activity (also known as radioactivity) are the curie (Ci) and the becquerel (Bq). Activity The rate of disintegration (transformation) or decay of radioactive material per unit time. Active fuel length The end-to-end dimension of fuel material within a fuel assembly (also known as a 'fuel bundle' or 'fuel element').

Activation The process of making a radioisotope by bombarding a stable element with neutrons or protons. See also NUREG-0544, 'Collection of Abbreviations' Access hatch An airtight door system that preserves the pressure integrity of the containment structure of a nuclear reactor, while allowing access to personnel and equipment.