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 that is 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).
°C
Degree Celsius. °C = ° (°F - 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 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 evaporator 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 ability of the various radiations), 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 general usage, however, "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 at a person's workplace. Population exposure
is the exposure to a number of persons who inhabit an area.
°F
Degree Fahrenheit. F = °C ¥ + 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
Safe and secure capacity in the near term to
support continuing operations in the interim period (10 years).
involved worker
For this EIS, an SRS worker who is involved in
the operation of a facility when a radioactive release occurs.
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.
Mark-x (Mk-x)
An historic naming system for a specific design
of fuel or target material used in SRS production reactors (e.g., Mk-31, Mk-42,
Mk-16).
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 (42 USC 4321);
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.
poison
A material that has an affinity for absorbing neutrons.
Poisons are added to nuclear materials with a potential criticality concern to
lessen the likelihood of an uncontrolled nuclear reaction.
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.
population
In this EIS, a collection of members of the public
who are located outside the boundaries of the SRS. Impacts in this EIS are
estimated for the population within a given area, depending on the appropriate
environmental pathways. For example, the affected population for liquid
releases to the Savannah River includes downstream residents.
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 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 neutrons.
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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