A
ASLB - Atomic Safety and Licensing Board
ALARA - As Low As Reasonably Achievable, or keeping radiation emissions and exposures to levels set as far below regulatory limits as is reasonably possible in order to protect public health and the environment.
alpha radiation - The most energetic but least penetrating form of radiation. It can be stopped by a sheet of paper and cannot penetrate human skin. However, if an alpha-emitting isotope is inhaled or ingested, it will cause highly concentrated local damage.
asbestos - A strong and incombustible fiber widely used in the past for fireproofing and insulation. The small, buoyant fibers are easily inhaled or swallowed, causing a number of serious diseases including: asbestosis, a chronic disease of the lungs that makes breathing more and more difficult; cancer; and mesothelioma, a cancer (specific to asbestos exposure) of the membranes that line the chest and abdomen.
atom - The smallest particle of an element having the chemical properties of that element; the fundamental building block of matter.
B
background radiation - Natural radioactivity in the environment. Natural background radiation consists of cosmic rays, filtered through the atmosphere from outer space, and radiation from the naturally radioactive elements in the earth (primarily uranium, thorium, radium and potassium). The average American receives about 360 millirem per year from natural and man-made radiation.
beta radiation - High-energy electrons (beta particles) emitted from certain radioactive material. Can pass through 1 to 2 centimeters of water or human flesh and can be shielded by a thin sheet of aluminum. Beta particles are more deeply penetrating than alpha particles but, because of their smaller size, cause less localized damage.
biological effects - The early or delayed results of biological damage caused by nuclear radiation (alpha, beta, gamma).
C
CFR - Code of Federal Regulations
characterization - Facility or site sampling, monitoring and analysis activities to determine the extent and nature of contamination and provide the basis for selecting appropriate cleanup techniques.
cleanup - The general term for environmental restoration, the process designed to ensure that risks to the environment and to human health and safety from sites that need remediation either are eliminated or reduced to prescribed, safe levels. containment structure - a steel-reinforced, thick concrete dome built over the nuclear reactor. Also houses the steam generators, pressurizer and related equipment. Located in the RCA.
contamination - The presence of foreign materials, chemicals or radioactive substances in the environment (soil, sediment, water or air).
D
D&D - Decontamination & Dismantlement
DOE - Department of Energy
DOT - Department of Transportation
DCGL - Derived Concentrate Guideline Level. Residual radioactivity levels on buildings and soil (above background radiation) that corresponds to the allowable radiation dose limits.
decay - All materials are made of atoms. Radioactive atoms are unstable; that is, they have too much energy. When radioactive atoms release their extra energy, they are said to decay. All radioactive atoms decay. After releasing all their excess energy, the atoms become stable and are no longer radioactive. The time required for decay depends upon the type of atom.
decommissioning - Permanently removing a nuclear facility from service and reducing radioactive material on the licensed site to levels that would permit termination of the Nuclear Regulatory Commission license.
decontamination - To rid structures, equipment and the site of residual radioactivity or other contamination through onsite treatment, or removing material for disposal offsite.
disposal - Waste emplacement designed to ensure isolation of waste from the biosphere, with no intention of retrieval for the foreseeable future.
dose - Quantity of radiation or energy absorbed.
dose equivalent - A term used to express the amount of effective radiation received by an individual. A dose equivalent considers the type of radiation, the amount of body exposed, and the risk of exposure. Measured in rems. (See rem).
dosimeter - An instrument that measures exposure to radiation.
dry storage - Refers to storage of spent nuclear fuel in an Independent Spent Fuel Storage Installation (ISFSI). Spent fuel pools are considered "wet" storage.
dual-purpose canister - A canister containing spent fuel assemblies or high-level waste that also is certified for dry storage and transporting off site.
E
EPA - Environmental Protection Agency
effluent - A waste discharged as a liquid or gas.
exposure - A measurement of the amount of ionization produced by x-rays or gamma rays as they travel through air. The unit of radiation exposure is the roentgen, named for Wilhelm Roentgen, the German scientist who discovered x-rays in 1895
F
FFD - Fitness For Duty
FSS (final status survey) - FSS, a radiological survey systematically conducted to demonstrate that an area is below DCGL.
fission - The splitting of a heavy nucleus into two or more radioactive nuclei, accompanied by the emission of gamma rays, neutrons and a significant amount of energy. Fission usually is initiated by the heavy nucleus absorbing a neutron, but it also can occur spontaneously.
friable asbestos - Asbestos insulation that is loose and capable of becoming airborne.
G
GTCC - Greater Than Class C Waste
gamma rays - Penetrating electromagnetic waves or rays emitted from nuclei during radioactive decay, similar to x-rays. Dense materials such as concrete and lead are used to provide shielding against gamma radiation.
groundwater - Water beneath the earth's surface that fills pores between materials such as sand, soil or gravel. Groundwater is a major source of water for agricultural and industrial purposes and is an important source of drinking water for about half of all Americans.
H
HLW - High-Level Waste
HP - Health Physics
half-life - The time required for a radioactive substance to lose 50 percent of its activity by decay. The half-life of the radioisotope plutonium-239, for example, is about 24,000 years. Starting with a pound of plutonium-239, in 24,000 years there will be one-half pound of plutonium-239, in another 24,000 years there will be one-fourth pound, and so on. (A pound of material remains, but it gradually becomes a stable element.)
hazardous waste - waste with properties that make it dangerous or potentially harmful to human health or the environment. The universe of hazardous wastes is large and diverse. Hazardous wastes can be liquids, solids, contained gases, or sludges.
historical site assessment - HSA, a report that documents various radiological and non-radiological events that could have impacted the site over time to assist with developing a cleanup plan.
I
ISFSI - Independent Spent Fuel Storage Installation
ion - Atomic particle, atom or chemical radical bearing an electric charge, either negative or positive.
ionizing radiation - Radiation that has enough energy to remove electrons from substances it pass through, forming ions.
isotopes - Atoms of the same element that have equal numbers of protons, but different numbers of neutrons. Isotopes of an element have the same atomic number by different atomic mass. For example, uranium-238 and uranium-235.
L
LLW - Low-Level Waste
LTP - License Termination Plan - a detailed document that must be submitted to the NRC at least two years prior to license termination explaining site characterization and remediation plans and compliance with radiological criteria for release.
M
mr - Millirem
MARSSIM - Multi-Agency Radiation Survey and Site Investigation Manual. Guidance developed by the Nuclear Regulatory Commission, the U.S. Environmental Protection Agency, the U.S. Department of Energy and the U.S. Department of Defense that provides a statistical methodology for evaluating radiation survey data.
MCL - Maximum concentration limit, the regulatory limit for various constituents, usually organics and inorganics; there are different levels for different media, such as air, soil, and water. The MCL cannot be exceeded.
millirem - A unit of radiation dosage equal to one-thousandth of a rem. the average person receives about 360 millirems per year from natural and man-made radiation.
mixed waste - Contains both radioactive and hazardous components.
monitoring well - A hole drilled into the ground with a pipe inserted to allow for the collection of groundwater samples.
Multi-purpose canister - Also MPC. A canister containing spent fuel assemblies or high level waste that can be placed in both dry storage containers and transportation containers.
N
NEI - Nuclear Energy Institute
NRC - U.S. Nuclear Regulatory Commission
NUREGS - Nuclear Regulations
NWF - Nuclear Waste Fund
NWPA - Nuclear Waste Policy Act
natural radiation - Radiation that is always present in the environment from such sources as cosmic rays and radioactive materials in rocks and soils.
NPDES - National Pollutant Discharge Elimination System.
nuclear radiation - Ionizing radiation originating in the nuclei of atoms; alpha, beta, and gamma radiation.
nucleus - The central part of an atom that contains protons, neutrons and other particles.
O
OSHA - Occupational Safety & Health Administration
P
PAB - Primary Auxiliary Building
PCs - Protective Clothing
PSDAR - Post Shutdown Decommissioning Activities Report
pathways - The means by which contaminants move. Possible pathways include air, surface water, groundwater, plants and animals.
PCB - Polychlorinated biphenyl, a synthetic, organic chemical once widely used in electrical equipment, specialized hydraulic systems, heat transfer systems, and other industrial products. Any hazardous wastes that contain more than 50 parts per million of PCBs are subject to regulation under the Toxic Substances Control Act.
picocuries - Measurement of radioactivity. A picocurie is one million millionth, or a trillionth, of a curie, and represents about 2.2 radioactive particle disintegration's per minute.
Q
QA - Quality Assurance
R
RCA - Radiological Control Area or Primary side: The area of the plant footprint that houses the spent fuel pool, reactor containment structure and associated equipment.
Rem - Roentgen Equivalent Man - a unit used in radiation protection to measure the amount of damage to human tissue from a dose of ionizing radiation. Incorporates the health risks from radiation.
RP - Radiation Protection
RPV - Reactor Pressure Vessel: Thick steel vessel that contained the nuclear fuel during operation and the nuclear fission process to produce electricity. Located inside the containment structure.
RWP -Radiation Work Permit
RESRAD - Residual radiation computer code developed by Argonne National Laboratory that develops annual dose radiation doses from radioactivity in soil and around water based on all methods of receiving the dose (e.g. ingestion, inhalation, etc.).
radiation - Particles and electromagnetic raysor waves emitted from the nucleus of an atom during radioactive disintegration.
radioactive - Giving off, or capable of giving off, radiant energy in the form of particles (alpha or beta radiation) or rays (gamma radiation) by the spontaneous disintegration of the nuclei of atoms. Radioisotopes of elements lose particles and energy through the process of radioactive decay. Elements may decay into different atoms or a different state of the same atom.
radioactive waste - A solid, liquid or gaseous material that contains radionuclides in excess of threshold quantities except for radioactive material form post-weapons-test activities.
radioisotope - An unstable isotope of an element that eventually will undergo radioactive decay (i.e., disintegration). Radioisotopes with special properties are produced routinely for use in medical treatment and diagnosis, industrial tracers, and for general research.
radionuclide - A radioactive species of an atom.
radon - A radioactive gas produced by the decay of one of the daughters of radium. Radon is hazardous in unventilated areas because it can build up to high concentrations and, if inhaled for long periods of time, may cause lung cancer.
S
secondary side - non-radiological area of the plant footprint that houses the turbine building, support buildings and equipment, and offices.
site release criteria - Radiological criteria established by the NRC that must be met before a decommissioned site can be released from the NRC's regulatory control and made available for reuse.
SFP - Spent Fuel Pool
SG - Steam Generator
stable isotope - An isotope of an element that is not radioactive.
T
TEDE - Total Effective Dose Equivalent
TLD - Thermoluminescent Dosimeter - radiation exposure monitoring device.
threshold dose - The minimum dose of radiation that will produce a detectable effect.
turbine building - enclosed metal and grider structure that houses the turbine, generator and cooling systems. Located on the non-radiological (secondary) side of the plant.
U
used fuel - Nuclear fuel that has been irradiated in a nuclear reactor to the point where it is no longer useful in sustaining a nuclear reaction.
