GLOSSARY
abnormal transients
A state resulting from an unusual incident in which operating
parameters affecting control of radioactive materials move out
of the normal operating range.
absorbed dose
The energy deposited per unit mass by ionizing radiation. The
unit of absorbed dose is the rad.
air quality
A measure of the quantity of pollutants in the air.
air quality standards
The prescribed quantity of pollutants in the outside air that
cannot be exceeded legally during a specified time in a
specified area.
alpha (a) particle
A positively charged particle consisting of two protons and
two neutrons that is emitted from the nucleus of certain
nuclides during radioactive decay. It is the least penetrating
of the three common types of radiation (alpha, beta, and
gamma).
ambient air
The surrounding atmosphere, usually the outside air, as it
exists around people, plants, and structures. It is not the
air in immediate proximity to emission sources.
aqueous
In liquid form (i.e., dissolved in water).
aquifer
A geologic formation that contains sufficient saturated
permeable material to conduct groundwater and to yield
worthwhile quantities of groundwater to wells and springs.
atmosphere
The layer of air surrounding the earth.
AXAIR89Q
A computer model used to analyze doses from accidental
airborne radionuclide releases. Developed in accordance
with U.S. Nuclear Regulatory Commission Regulatory Guide 1.145,
Atmospheric Dispersion Models for Potential Accidental
Consequence Assessments at Nuclear Power Plants, February
1993.
background exposure
See exposure to radiation.
background radiation
Normal radiation present in the lower atmosphere from cosmic
rays and earth sources. Background radiation varies with
location, depending on altitude and natural radioactivity
present in the surrounding geology.
beta (b) particle
An elementary particle emitted from a nucleus during
radioactive decay. It is negatively charged, is identical to
an electron, and is easily stopped by a thin sheet of metal.
bounded
Producing greater or lesser consequences than other accidents;
or would "bound" the remainder of the accidents.
burial ground
A place for burying unwanted radioactive materials in which
the earth acts to contain or prevent the escape of radiation.
In this eis, materials are incorporated into concrete to
prevent the leaching of materials or movement in the
underground environment.
button
Plutonium metal in a hemispherical shape, weighing about 1.8
kilograms (4 pounds).
yC
Degree Celsius. yC = \|F(5,9) - (yF - 32).
cancer
A malignant tumor of potentially unlimited growth, capable of
invading surrounding tissue or spreading to other parts of the
body by metastasis.
canister
A metal (stainless-steel) container in which nuclear material
is sealed.
canyon
A heavily shielded building used in the chemical processing of
radioactive materials to recover special isotopes for national
defense or other programmatic purposes. Operation and
maintenance are by remote control.
capable (fault)
Determination if a geological fault has moved at or near the
ground surface within the past 35,000 years.
carcinogen
An agent capable of producing or inducing cancer.
carcinogenic
Capable of producing or inducing cancer.
cask
A heavily shielded massive container for holding nuclear
materials during shipment.
cesium
Naturally occurring element with 55 protons in its nucleus.
Some manmade isotopes of cesium are radioactive (e.g.,
cesium-134, cesium-137).
cladding
The material (generally aluminum in SRS reactors) that covers
each tubular fuel and target assembly.
collective dose
The sum of the individual doses to all members of a specific
population.
committed effective dose equivalent
Used in cases when a person has an intake of radioactive
material to denote that the dose is calculated for a period of
50 years following the intake. (See effective dose
equivalent.)
community (environmental justice definition)
A group of people or a site within a spatial scope exposed to
risks that potentially threaten health, ecology, or land
values, or exposed to industry that stimulates unwanted noise,
smell, industrial traffic, particulate matter, or other
nonaesthetic impacts.
concentration
The amount of a substance contained in a unit quantity of a
sample.
condensate
Liquid water obtained by cooling the steam (overheads)
produced in an evapo rator system.
constituents
Parts or components of a chemical system.
converting
The process for changing special isotopes into usable chemical
forms to satisfy current or projected needs for a unique
product.
criticality
A state in which a self-sustaining nuclear chain reaction is
achieved.
cumulative effects
Additive environmental, health, and socioeconomic effects that
result from a number of similar activities in an area.
curie (Ci)
A unit of radioactivity equal to 37,000,000,000 decays per
second.
daughter
A nuclide formed by the radioactive decay of another nuclide,
which is the "parent."
decay, radioactive
The spontaneous transformation of one nuclide into a different
nuclide or into a different energy state of the same nuclide.
The process results in the emission of nuclear radiation
(alpha, beta, or gamma radiation).
decommissioning
The removal from service of facilities such as processing
plants, waste tanks, and burial grounds, and the reduction or
stabilization of radioactive contamination. Decommissioning
concepts include:
- Decontaminate, dismantle, and return area to original
condition without restrictions.
- Partially decontaminate, isolate remaining residues,
and continue surveillance and restrictions.
defense waste
Nuclear waste generated by government defense programs as
distinguished from waste generated by commercial and medical
facilities.
depleted uranium
A mixture of uranium isotopes where uranium-235 represents
less than 0.7 percent of the uranium by mass.
design-basis accident (DBA)
A postulated accident scenario for establishing the need for
certain design features; normally, the accident that causes the
most severe consequence when engineered safety features
function as intended.
disposal/disposition
After designation as "surplus"; movement; placement in an
onsite or offsite facility after a decision that future uses
are unlikely or undesirable; determining whether the disposal
of items must be "retrievable" under public law.
dose rate
The radiation dose delivered per unit time (e.g., rem per
year).
ecology
The science dealing with the relationship of all living things
with each other and with the environment.
ecosystem
A complex of the community of living things and the
environment forming a functioning whole in nature.
effective dose equivalent
A quantity used to estimate the biological effect of ionizing
radiation. It is the sum over all body tissues of the product
of absorbed dose, the quality factor (to account for the
different penetrating abilities of the various types of radiation), and
the tissue weighting factor (to account for the different radiosensitivity
of the various tissues of the body).
effluent
Liquid or airborne material released to the environment. In
common usage, however, the term "effluent" implies liquid releases.
effluent standards
Defined limits of effluent in terms of volume, content of
contaminants, temperature, etc.
eis
Environmental impact statement; a legal document required by
the National Environmental Policy Act (NEPA) of 1969, as
amended, for Federal actions involving potentially significant
environmental impacts.
element
One of the 105 known chemical substances that cannot be
divided into simpler substances by chemical means. All
isotopes of an element have the same atomic number (number of
protons) but have a different number of neutrons.
Emergency Response Planning Guidelines (ERPG)
Values used to determine potential health effects from
chemical accidents.
emission standards
Legally enforceable limits on the quantities and kinds of air
contaminants that can be emitted into the atmosphere.
endangered species
Plants and animals in an area that are threatened with either
extinction or serious depletion.
energy
The capacity to produce heat or do work.
environment
The sum of all external conditions and influences affecting
the life, development, and ultimately the survival of an
organism.
epicenter
The point on the earth's surface directly above the focus of
an earthquake.
EPICODE
A computer model used to estimate the airborne concentration
of toxic chemicals as a result of routine or accidental
releases to the environment.
erosion
The process in which the actions of wind or water carry away
soil and clay.
exceedence
A value over a prescribed limit.
exposure to radiation
The incidence of radiation on living or inanimate material by
accident or intent. Background exposure is the exposure to
natural background ionizing radiation. Occupational exposure
is the exposure to ionizing radiation that occurs during a
person's working hours. Population exposure is the exposure to
a number of persons who inhabit an area.
yF
Degree Fahrenheit. F = yC - \|F(9,5) + 32.
fallout
The descent to earth and deposition on the ground of
particulate matter (that might be radioactive) from the
atmosphere.
fault
A fracture or a zone of fractures within a rock formation
along which vertical, horizontal, or transverse slippage of the
earth's crust has occurred in the past.
fissile
Capable of being split or divided (fissioned) by the
absorption of thermal neutrons. The most common fissile
materials are uranium-233, uranium-235, and plutonium-239.
fission
The splitting of a heavy nucleus into two approximately equal
parts, which are nuclei of lighter elements, accompanied by the
release of energy and generally one or more neutrons. Fission
can occur spontaneously or can be induced by nuclear
bombardment.
fission products
Nuclei from the fission of heavy elements (primary fission
products); also, the nuclei formed by the decay of the primary
fission products, many of which are radioactive.
floodplain
Level land built up by flowing stream deposition and
periodically submerged by floodwater from that stream.
frit
Finely ground glass.
gamma (g) rays
High-energy, short-wavelength electromagnetic radiation
accompanying fission, radioactive decay, or nuclear reactions.
Gamma rays are very penetrating and require relatively thick
shields to absorb the rays effectively.
geology
The science that deals with the earth: the materials,
processes, environments, and history of the planet especially
the lithosphere, including the rocks, their formation and
structure.
glovebox
Large enclosure that separates workers from equipment used to
process hazardous material but enables the workers to be in
physical contact with the equipment; normally constructed of
stainless steel with large acrylic/lead glass windows. Workers
have access to equipment through the use of heavy-duty,
lead-impregnated rubber gloves, the cuffs of which are sealed
in portholes in the glovebox windows.
groundwater
The supply of fresh water under the earth's surface in an
aquifer.
habitat
The place or type of site where a plant or animal naturally or
normally lives and grows.
half-life (radiological)
The time in which half the atoms of a radioactive substance
disintegrate to another nuclear form. Half-lives vary from
millionths of a second to billions of years.
heavy metals
Metallic elements of high molecular weight, such as mercury,
chromium, cadmium, lead, and arsenic, that are toxic to plants
and animals at known concentrations.
HEPA filter
High efficiency particulate air filter designed to remove 99.9
percent of particles as small as 0.3 micrometer in diameter from
a flowing air stream.
high-fired oxide
Oxide chemical form of plutonium produced by heating the
material to approximately 1,000-C. High-fired oxide is
considered more chemically stable than low-fired oxide because
the higher heat removes moisture and other impurities more
effectively.
high-level waste
The highly radioactive wastes that result from processing of
defense materials at SRS.
historic resources
The sites, districts, structures, and objects considered
limited and nonrenewable because of their association with
historic events, persons, or social or historic movements.
immobilization
Conversion of high-level waste into a form that will be
resistant to environmental dispersion.
intensity (earthquake)
A numerical rating used to describe the effects of earthquake
ground motion on people, structures, and the earth's surface.
The numerical rating is based on an earthquake intensity scale
such as the Richter Scale commonly used in the United States.
interim storage
Providing safe and secure capacity in the near term to support
continuing operations in the interim period (10 years).
ion
An atom or molecule that has gained or lost one or more
electrons to become electrically charged.
ion exchange
Process in which a solution containing soluble ions to be
removed is passed over a solid ion-exchange medium, which
removes the soluble ions by exchanging them with labile ions
from the surface of the column. The process is reversible so
that the trapped ions can be collected (eluted) and the column
regenerated.
ion-exchange medium
A substance (e.g., a resin) that preferentially removes
certain ions from a solution.
ionization
The process that creates ions. Nuclear radiation, X-rays,
high temperatures, and electric discharges can cause
ionization.
ionizing radiation
Radiation capable of displacing electrons from atoms or
molecules to produce ions.
irradiation
Exposure to radiation.
ISC2
A computerized dispersion program used to calculate
ground-level concentrations of air pollutants.
isotope
An atom of a chemical element with a specific atomic number
and atomic weight. Isotopes of the same element have the same
number of protons but different numbers of neutrons. Isotopes
are identified by the name of the element and the total number
of protons and neutrons in the nucleus. For example,
plutonium-239 is a plutonium atom with 239 protons and
neutrons.
LADTAP
A computer program used to calculate individual and population
doses from liquid pathways.
latent cancer fatalities
Deaths resulting from cancer that has become active following
a latent period (i.e., a period of inactivity).
low-fired oxide
Oxide chemical form of plutonium produced by heating the
material to approximately 550-C. Low-fired oxide is considered
less chemically stable than high-fired oxide because the lower
heat does not remove moisture and other impurities as
effectively.
low-income communities
A community where 25 percent or more of the population is
identified as living in poverty.
low-level waste
Radioactive waste not classified as high-level waste; the
wastes (mostly salts) remaining after removal of the highly
radioactive nuclides from the liquid high-level wastes for
immobilization.
MAXIGASP
A computer program used to calculate doses of airborne
releases of radioactivity to the maximally exposed member of
the public.
maximum contaminant levels (MCLs)
The maximum permissible level of a contaminant in water that
is delivered to a user of a public water system.
maximally exposed individual
A hypothetical person located to receive the maximum possible
dose by a given exposure scenario.
migration
The natural travel of a material through the air, soil, or groundwater.
mitigate
To take practicable means to avoid or minimize environmental
harm from a selected alternative.
monitoring
Continuing control and accountability, particularly of special
nuclear materials such as plutonium-239 and highly enriched
uranium, but also including oversight of hazardous or reactive
compounds before they are disposed of or converted to a stable
long-term storage form.
National Register of Historic Places
A list maintained by the National Park Service of
architectural, historic, archaeological, and cultural sites of
local, state, or national importance.
natural radiation or natural radioactivity
Background radiation. Some elements are naturally
radioactive, whereas others are induced to become radioactive
by bombardment in a reactor or accelerator.
NEPA
National Environmental Policy Act of 1969; it requires the
preparation of an eis for Federal projects that could present
significant impacts to the environment.
nonproliferation
The restriction of ability to easily access fissile materials
in concentrations sufficient to assemble a nuclear weapon.
NOx
Oxides of nitrogen, primarily nitrogen oxide (NO) and nitrogen
dioxide (NO2). These are produced in the combustion of fossil
fuels, and can constitute an air pollution problem.
NRC
Nuclear Regulatory Commission; the independent Federal
commission that licenses and regulates nuclear facilities.
nuclear energy
The energy liberated by a nuclear reactor (fission or fusion)
or by radioactive decay.
nuclear radiation
Radiation, usually alpha, beta, or gamma, that emanates from
an unstable atomic nucleus.
nuclear reaction
An interaction between a photon, particle, or nucleus and a
target nucleus, leading to the emission of one or more
particles and photons.
nuclear reactor
A device in which a fission chain reaction is maintained, used
for the irradiation of materials or the generation of
electricity.
nuclide
An atomic nucleus specified by atomic weight, atomic number,
and energy state; a radionuclide is a radioactive nuclide.
organic compounds
Chemical compounds containing carbon.
outfall
Place where liquid effluents enter the environment and are
monitored.
oxide
A compound in which an element chemically combines with
oxygen.
ozone
A compound of oxygen in which three oxygen atoms are
chemically attached to each other.
particulates
Solid particles and liquid droplets small enough to become
airborne.
passive safety system
A system that provides safety features requiring no human
intervention or adverse condition to actuate.
pH
A measure of the hydrogen ion concentration in aqueous
solution. Pure water has a pH of 7, acidic solutions have a pH
less than 7, and basic solutions have a pH greater than 7.
people of color communities
A population classified by the U.S. Bureau of the Census as
Black, Hispanic, Asian and Pacific Islander, American Indian,
Eskimo, Aleut, and other nonwhite persons, the composition of
which is at least equal to or greater than the state minority
average of a defined area or jurisdiction.
permeability
Ability of liquid to flow through rock, groundwater, soil, or
other substance.
person-rem
The radiation dose to a given population; the sum of the
individual doses received by a population segment.
physiographic
Geographic regions based on geologic setting.
plutonium (Pu)
A transuranic, heavy (average atomic mass about 244 atomic mass
units), silvery metal with 15 isotopes that is produced by the
neutron irradiation of natural uranium. Plutonium-239 is used
both in nuclear weapons and commercial nuclear power
applications. Plutonium-238 is used to power onboard
generators during manned and unmanned space flights.
plutonium solutions
Chemical solutions containing plutonium.
pollution
The addition of an undesirable agent to an ecosystem in excess
of the rate at which natural processes can degrade, assimilate,
or disperse it.
POPGASP
A computer mathematical model used to calculate doses of
airborne releases of radioactivity to the population within
80 kilometers (50 miles) of the SRS.
precipitate
A solid (used as a noun).
To form a solid substance in a solution by a chemical reaction
(used as a verb).
PUREX process
A chemical separation process to retrieve plutonium, uranium,
and other radionuclides from reactor fuel and targets.
radiation
The emitted particles and photons from the nuclei
of radioactive atoms; a shortened term for
ionizing radiation or nuclear radiation as distinguished from
nonionizing radiation (microwaves, ultraviolet rays, etc.).
radioactivity
The spontaneous decay of unstable atomic nuclei, accompanied
by the emission of radiation.
radioisotopes
Radioactive isotopes. Some radioisotopes are naturally
occurring (e.g., potassium-40) while others are produced by
nuclear reactions.
radiolysis
The decomposition of a material (usually water) into different
molecules due to ionizing radiation. In water, radiolysis
results in the production of hydrogen gas and oxygen.
repository
A place for the disposal of immobilized high-level waste in
isolation from the environment
resin
An ion-exchange medium; organic polymer used for the
preferential removal of certain ions
from a solution.
Richter Scale
A scale of measure used in the United States to quantify
earthquake intensity.
risk
In accident analysis, the probability weighted consequence of
an accident, defined as the accident frequency per year
multiplied by the dose. The term "risk" is also used commonly
in other applications to describe the probability of an event
occurring.
runoff
The portion of rainfall, melted snow, or irrigation water that
flows across the ground surface and eventually returns to streams.
Runoff can carry pollutants into receiving waters.
saltstone
Low-radioactivity fraction of high-level waste from the
in-tank precipitation process mixed with cement, flyash, and
slag to form a concrete block.
seismicity
The tendency for earthquakes to occur.
shield
Material used to reduce the intensity of radiation that would
irradiate personnel or equipment.
short-lived
A designation for radionuclides with relatively short
half-lives (i.e., they decay to stable materials relatively
quickly).
stabilization
The action of making a nuclear material more stable by
converting its physical or chemical form or placing it in a
more stable environment.
stack
A vertical pipe or flue designed to exhaust gases and
suspended particulates.
strontium
Naturally occurring element with 38 protons in its nucleus.
Some manmade isotopes of strontium are radioactive (e.g.,
strontium-89, strontium-90),
surface water
All water on the surface (streams, ponds, etc.), as
distinguished from underground water.
tank farm
An installation of interconnected underground tanks for the
storage of high-level radioactive liquid wastes.
target
In this eis, a tube of material placed in a reactor to absorb
neutrons and be changed to a desired end product.
transuranic waste
Waste material containing more than a specified concentration
of transuranic elements (presently, more than 10 nanocuries per
gram of waste).
tritium
A radioactive isotope of hydrogen; its nucleus contains one
proton and two electrons.
uninvolved worker
For this eis, an SRS worker who is not involved in the
operation of a facility when a radioactive release occurred,
and who is assumed to be 640 meters (2,100 feet) from the point
of release.
uranium (U)
A heavy (average atomic mass of about 238 atomic mass units),
silvery-white metal with 14 radioactive isotopes. One of the
isotopes, uranium-235, is most commonly used as fuel for
nuclear fission and another, uranium-238, is transformed into
fissionable plutonium-239 following its capture of a neutron in
a nuclear reactor.
vault
A reinforced concrete structure for storing strategic nuclear
materials used in national defense or other programmatic
purposes.
vitrification
Incorporation of a material into a glass form.
vulnerability
Condition or weakness that could lead to exposure to the
public, unnecessary or increased exposure to workers, or
release of radioactive materials to the environment.
waste, radioactive
Materials from nuclear operations that are radioactive or are
contaminated with radioactive materials and for which there is
no practical use or for which recovery is impractical.
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