Glossary
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99Tc
Technetium-99
99Tc is a radioisotope with a half-life of 211,000 years releasing beta particles
as it decays.
Technetium-99 is a man-made radioisotope that is a by-product of the fissioning
of nuclear fuel rods and was introduced to the PGDP enrichment process through spent
nuclear fuel rods from the U.S. Department of Energy (DOE) Savannah River nuclear
facility. Processing
of recycled uranium from nuclear reactors was conducted during 1953-1964
and 1969-1976. During these
recycling periods, PGDP received 100,000 tons of recycled
uranium containing an estimated 661,000 grams of 99Tc.
For more information, see http://www.epa.gov/rpdweb00/radionuclides/technetium.html
Air stripping
The process of bubbling air through water to remove volatile organic compounds from the water.
AOC
Administrative Order on Consent
A consent order is governed by federal and state laws and issued by administrative
agencies. An AOC is a voluntary agreement worked out between two or more parties
to a dispute. An AOC carries the same weight as a court order.
Administrative Orders on Consent (AOCs) and other administrative agreements issued
by EPA, which are consensual, negotiated agreements pursuant to sections 104, 106(a),
107, and 122 of CERCLA, that obligate parties to perform response activity (e.g.,
removal, remedial investigation, feasibility study, remedial design) and/or reimburse
EPA for costs incurred under Superfund.
For a list of the EPA's AOCs in Region 4, visit http://www.epa.gov/region04/foiapgs/readingroom/admin_order_on_consent/index.htm
ACL
Alternate Concentration Limits
Default concentration levels are established through conservative scientific assumptions
but Facility owners/operators may apply for ACLs if they can prove that the ACLs
will not pose a substantial present or potential hazard to human health or the environment.
For more information, download the
EPA's Alternate Concentration Limits/Groundwater Cleanup Levels guide.
AEC
Atomic Energy Commission
Established after World War II by Congress to foster and control the peace time
development of atomic science and technology. The agency was abolished by
the Energy Reorganization Act of 1974, which assigned its functions to two new agencies:
the Energy Research and Development Administration and the Nuclear Regulatory Commission.
AIP
Agreement in Principle
An agreement which clarifies the major terms of an agreement, laying out the groundwork
to make a contract.
Alpha particle
A positively charged particle emitted from the nucleus of an atom having the same charge and mass as that of a helium nucleus (two protons and two neutrons).
Aquifer
A geologic formation, group of formations, or part of a formation capable of yielding a significant amount of groundwater to wells or springs.
Aquitard
A geologic unit that inhibits the flow of water.
Assimilate
To take up or absorb.
Atom
Smallest particle of an element capable of entering into a chemical reaction.
Beta particle
A negatively charged particle emitted from the nucleus of an atom. It has a mass and charge equal to those of an electron.
CAB
Paducah Citizens Advisory Board
CHR
Kentucky Cabinet for Human Resources
CHS
Kentucky Cabinet for Health Services
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act,
commonly known as Superfund, was enacted by Congress on December 11, 1980.
This law created a tax on the chemical and petroleum industries and provided broad
Federal authority to respond directly to releases or threatened releases of hazardous
substances that may endanger public health or the environment.
CERCLA was amended by the Superfund Amendments and Reauthorization Act (SARA) on October
17, 1986.
CERCLA-reportable release
A release to the environment that exceeds reportable quantities as defined by the Comprehensive Environmental Response, Compensation, and Liability Act.
Chain-of-custody form
A form that documents sample collection, transport, analysis, and disposal.
Closure
Formal shutdown of a hazardous waste management facility under Resource Conservation and Recovery Act requirements.
Compliance
Fulfillment of applicable requirements of a plan or schedule ordered or approved by government authority.
Concentration
The amount of a substance contained in a unit volume or mass of a sample.
Conductivity
A measure of a material’s capacity to convey an electric current. For water, this property is related to the total concentration of the ionized substances in water and the temperature at which the measurement is made.
Confluence
The point at which two or more streams meet; the point where a tributary joins the main stream.
Contained landfill
A solid waste site or facility that accepts disposal of solid waste. The technical requirements for contained landfills are found in 401 KAR 47:080, 48:050, and 48:070 to 48:090.
Contamination
Deposition of unwanted material on the surfaces of structures, areas, objects, or personnel.
Ci
Curie
A unit of radioactivity, measures the amount of radioactivity of a material and describes the rate at
which a radioactive substance is decaying through alpha, beta, and/or gama radiation. One curie is defined as 3.7 x 1010 (37 billion) disintegrations
per second. Several fractions and multiples of the curie are used commonly:
- • kilocurie (kCi)—103 Ci, one thousand curies; 3.7 x 1013 disintegrations per second.
- • millicurie (mCi)—10-3 Ci, one-thousandth of a curie; 3.7 x 107 disintegrations per second.
- • microcurie (μCi)—10-6 Ci, one-millionth of a curie; 3.7 x 104 disintegrations per second.
- • picocurie (pCi)—10-12 Ci, one-trillionth of a curie; 3.7 x 10-2 disintegrations per second.
Desublimation
The process when a gas transforms into solid. Also know as deposition. The reverse of deposition is sublimation.
D & D
Decontamination and Decommissioning
Disintegration
nuclear disintegration
A spontaneous nuclear transformation (radioactivity) characterized by the emission
of energy and/or mass from the nucleus of an atom.
DMSA
Department of Energy (DOE) Material Storage Areas
Areas established for storage of unused material and equipment at indoor and outdoor
onsite locations.
DOD
U.S. Department of Defense
DOE
U.S. Department of Energy
DUF6
Depleted Uranium Hexafluoride
DWS
Drinking Water Standards
Federal primary drinking water standards, both proposed and final, as set forth
by the EPA in 40 CFR § 141 and 40 CFR § 143.
Effluent
A liquid or gaseous waste discharge to the environment.
Effluent monitoring
The collection and analysis of samples or measurements of liquid and gaseous effluents for purposes of characterizing and quantifying the release of contaminants, assessing radiation exposures to members of the public, and demonstrating compliance with applicable standards.
Enrichment
Uranium Enrichment is the process used to increase in the percentage of the fissile isotope U-235.
EPA
U.S. Environmental Protection Agency
Fauna
The population of animals in a given area, environment, formation, or time span.
FFA
Federal Facilities Agreement
When a site is listed on the NPL and becomes a Superfund site, federal law requires
that responsible state and federal agencies enter into a
Federal Facilities Agreement (FFA). The FFA outlines the roles and responsibilities
of the responsible agencies for the investigation and implementation of corrective
measures at the facility and integrates state and federal cleanup requirements into
an effective and comprehensive process.
FFOU
Federal Facilities Oversight Unit
Flora
The population of plants in a given area, environment, formation, or time span.
Formation
A mappable unit of consolidated or unconsolidated geologic material of a characteristic lithology or assemblage of lithologies.
Gamma ray
High-energy, short-wavelength electromagnetic radiation emitted from the nucleus of an excited atom. Gamma rays are identical to X-rays except for the source of the emission.
Grab sample
A sample collected instantaneously with a glass or plastic bottle placed below the water surface to collect surface-water samples (also called dip samples).
Groundwater
unconfined groundwater
Water that is in direct contact with the atmosphere through open spaces in permeable
material.
Half-life
radiological half-life
The time required for half of a given number of atoms of a specific radionuclide
to decay. Each nuclide has a unique half-life.
HEU
Highly Enriched Uranium
Enriched uranium containing at least 90% U-235; used in bomb manufacture, research
and naval reactors.
High-level waste
High-level radioactive waste or HLW means:
- (1) Irradiated reactor fuel,
- (2) liquid wastes resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated wastes from subsequent extraction cycles, or equivalent, in a facility for reprocessing irradiated reactor fuel
- (3) solids into which such liquid wastes have been converted.
Hydrogeology
Hydraulic aspects of site geology.
Hydrology
The science dealing with the properties, distribution, and circulation of natural water systems.
In situ
In its original place; field measurements taken without removing the sample from its origin; remediation performed while groundwater remains below the surface.
Ion
An atom or compound that carries an electrical charge. irradiation—Exposure to radiation.
Isotopes
Forms of an element having the same number of protons but differing numbers of neutrons in the nuclei.
- • long-lived isotope
A radionuclide that decays at such a slow rate that a quantity of it will exist for an extended period (half-life is greater than three years). - • short-lived isotope
A radionuclide that decays so rapidly that a given quantity is transformed almost completely into decay products within a short period (half-life is two days or less).
KDFWR
Kentucky Department of Fish and Wildlife Resources
KDWM
Kentucky Division of Waste Management
KRCEE
Kentucky Research Consortium for Energy & the Environment
KWRRI
Kentucky Water Resources Research Institute
LATA
LATA Environmental Services of Kentucky, LLC
The PGDP primary cleanup contractor for the DOE.
LEU
Low Enriched Uranium
The proportion of U-235 in reactor fuel is 3 to 5 percent; used as reactor fuel.
MFNDS
Maxey Flats Nuclear Disposal Site
Minimum detectable concentration
The smallest amount or concentration of a radionuclide that can be distinguished in a sample by a given measurement system at a preselected counting time and at a given confidence level.
MOA
Memorandum of Agreement
Monitoring
Process whereby the quantity and quality of factors that can affect the environment or human health are measured periodically to regulate and control potential impacts.
mR
milliroentgen
A measure of X-ray or gamma radiation. The unit is one-thousandth of a roentgen.
mRem
The dose equivalent that is one-thousandth of a rem.
Natural radiation
Radiation from cosmic and other naturally occurring radionuclide (such as radon) sources in the environment.
Nuclide
An atom specified by its atomic weight, atomic number, and energy state. A radionuclide is a radioactive nuclide.
NPL
NPL National Priorities List,
list of the known releases or threatened releases of hazardous substances, pollutants,
or contaminants throughout the United States and its territories. The NPL is intended
primarily to guide the EPA in determining which sites warrant further investigation.
The NPL is part of the Superfund program, a U.S. environmental policy established
by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
and regulated by the Resource Conservation and Recovery Act (RCRA).
See http://www.epa.gov/superfund/sites/npl/index.htm
for current list status.
NREPC
Natural Resources & Environmental Protection Cabinet
Outfall
The point of conveyance (e.g., drain or pipe) of wastewater or other effluents into a ditch, pond, or river.
PCB
Polychlorinated biphenyl
Any chemical substance that is limited to the biphenyl molecule and that has been
chlorinated to varying degrees.
PEIS
Programmatic Environmental Impact Statement
A document that describes the impacts on the environment as a result of a proposed
action. It also describes impacts of alternatives, as well as plans to mitigate
the impacts. And it evaluates the environmental impacts of broad agency actions,
such as the development of programs or the setting of national policies.
PGDP
Paducah Gaseous Diffusion Plant
A uranium enrichment plant located in Western Kentucky which uses the gaseous diffusion
process; uranium hexafluoride is heated to a gas and passed repeatedly through porous
barriers to separate U235 and U238 isotopes.
Quality factor
The factor by which the absorbed dose (Rad) is multiplied to obtain a quantity that expresses, on a common scale for all ionizing radiation, the biological damage to exposed persons. A quality factor is used because some types of radiation, such as alpha particles, are more biologically damaging than others.
Rad
Radiation Absorbed Dose
The rad is a basic unit of absorbed radiation dose. (This is being replaced by the
"gray," which is equivalent to 100 rad.)
Radioactivity
The spontaneous emission of radiation, generally alpha or beta particles or gamma rays, from the nucleus of an unstable isotope.
Radioisotopes
Radioactive isotopes.
Radionuclide
An unstable nuclide capable of spontaneous transformation into other nuclides by changing its nuclear configuration or energy level. This transformation is accompanied by the emission of photons or particles.
RCB
Radiation Control Branch
Cabinet for Health and Family Services Radiation Control Branch, now the Radiation
Health Branch
http://chfs.ky.gov/dph/radiation.htm
RCRA
Resource Conservation Recovery Act
RCRA gives EPA the authority to control hazardous waste from the "cradle-to-grave."
This includes the generation, transportation, treatment, storage, and disposal of
hazardous waste. RCRA also set forth a framework for the management of non-hazardous
solid wastes. The 1986 amendments to RCRA enabled EPA to address environmental
problems that could result from underground tanks storing petroleum and other hazardous
substances.
ROD
Record of Decision
The Record of Decision (ROD) is a public document that explains which cleanup alternatives
will be used to clean up a Superfund site.
Search for RODs in EPA's Record of Decision System
http://cumulis.epa.gov/superrods/index.cfm?fuseaction=main.search
A ROD contains:
- • site history
- • site description
- • site characteristics
- • community participation
- • enforcement activities
- • past and present activities
- • contaminated media
- • the contaminants present
- • scope and role of response action
- • the remedy selected for cleanup
Release
Any discharge to the environment. Environment is broadly defined as any water, land, or ambient air.
Rem
The unit of dose equivalent (absorbed dose in Rads multiplied by the radiation Quality Factor). Dose equivalent is frequently reported in units of milliRem(mRem).
- mRem milliRem
The dose equivalent that is one-thousandth of a Rem.
Remediation
The environmental cleanup and restoration of a contaminated site.
RFI Program
RCRA Facility Investigation Program
EPA-regulated investigation of a solid waste management unit with regard to its
potential impact on the environment.
Roentgen
A unit of exposure from X-rays or gamma rays. One roentgen equals 2.58 x 104 coulombs per kilogram of air.
- mR milliRoentgen
A measure of X-ray or gamma radiation. The unit is one-thousandth of a roentgen.
Sv
sievert
The SI (International System of Units) unit of dose equivalent; 1 Sv = 100 Rem.
Slurry
A suspension of solid particles (sludge) in water.
Source
A point or object from which radiation or contamination emanates.
Specific conductance
The ability of water to conduct electricity; this ability varies in proportion to the amount of ionized minerals in the water.
Stable
Not radioactive or not easily decomposed or otherwise modified chemically.
Strata
Beds, layers, or zones of rocks.
Substrate
The substance, base, surface, or medium in which an organism lives and grows.
Surface water
All water on the surface of the earth, as distinguished from groundwater.
Suspended solids
Mixture of fine, non-settling particles of any solid within a liquid or gas.
TCE
Trichloroethene
A solvent used to remove grease from metal parts, but it is also an ingredient in
adhesives, paint removers, typewriter correction fluids, and spot removers. Drinking
or breathing high levels of trichloroethylene may cause nervous system effects,
liver and lung damage, abnormal heartbeat, coma, and possibly death.
For more information download the Center
for Disease Control, Agency for Toxic Substances and Disease Registry Factsheet
about TCE.
The DOE has banned the use of TCE at the Paducah plant in 1993.
Terrestrial radiation
Ionizing radiation emitted from radioactive materials, primarily 40K, thorium, and uranium, in the earth’s soils. Terrestrial radiation contributes to natural background radiation.
TLD
Thermoluminescent dosimeter
A device used to measure external gamma radiation.
TMDL
Total Maximum Daily Load
Total activity
The total quantity of radioactive decay particles that are emitted from a sample.
Total solids
The sum of total dissolved solids and suspended solids.
Total suspended particulates
Refers to the concentration of particulates in suspension in the air irrespective of the nature, source, or size of the particulates.
TRU
Transuranic element
An element above uranium in the Periodic Table, that is, with an atomic number greater
than 92. All 11 TRUs are produced artificially and are radioactive. They are neptunium,
plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium,
nobelium, and lawrencium.
Troughing system
A collection and containment system designed to collect leaks of oil that have been contaminated with PCBs.
Turbidity
A measure of the concentration of sediment or suspended particles in solution.
UF6
Uranium Hexafluoride
Upgradient
In the direction of increasing hydrostatic head.
USEC
United States Enrichment Corporation, Inc.
Established by Congress through the Energy Policy Act of 1992, USESC was originally
formed as a government corporation to manage PGDP operations. USEC became
a publically traded company and continued as a DOE contractor. The USEC took
over all operations in 1999.
Vadose zone
Soil zone located above the water table.
VOC
Volatile organic compound
Any organic compound that has a low boiling point and readily volatilizes into air
(e.g., trichloroethane, tetrachloroethene, and trichloroethene). VOCs include a
variety of chemicals and concentrations, the adverse health effects vary.
Watershed
The region draining into a river, river system, or body of water.
Wetland
A lowland area, such as a marsh or swamp, inundated or saturated by surface or groundwater sufficiently to support hydrophytic vegetation typically adapted to life in saturated soils.
WKWMA
Western Kentucky Wildlife Management Area
Area surrounding the PGDP leased and managed by the Kentucky Department of Fish
Á Wildlife Resources (KDFWR) for recreational purposes.
For additional information
download a KDFWR map of the area.