Section II - Definitions
II. DEFINITIONS
airborne radioactive material (airborne radioactivity): Radioactive
material in any chemical or physical form that is dissolved, mixed,
suspended, or otherwise entrained in air.
airborne radioactivity area: Any area where the measured concentration
of airborne radioactivity, above natural background, exceeds or is
likely to exceed 10 percent of the derived air concentration (DAC)
values listed in Appendix A or C of 10 CFR 835.
area: Any portion of a site or any facility inside or outside a
structure, building, or other enclosure.
as low as reasonably achievable (ALARA): The approach to radiation
protection to manage and control exposures (both individual and
collective) to the work force and to the general public to levels as low
as is reasonable, taking into account social, technical, economic,
practical, and public policy considerations. ALARA is not a dose limit
but a process which has the objective of attaining doses as far below
the applicable limits of 10 CFR 835 as is reasonably achievable.
background radiation: The radiation from:
(i) Naturally occurring
radioactive materials which have not been technologically enhanced;
(ii ) Cosmic sources;
(iii) Global fallout as it exists in the environment (such as from the
testing of nuclear explosive devices);
(iv) Radon and its progeny in concentrations or levels existing in
buildings or the environment which have not been elevated as a
result of current or prior activities; and
(v) Consumer products containing nominal amounts of radioactive
material or producing nominal amounts of radiation.
boundary: The line that defines the transition from one specified area
to another.
boundary identifier: A hazard identifier that is adequate to
distinguish between areas for purposes of radiation protection or which
is used to define the boundary of an area; it may be posting, physical
barricade, containment enclosure, or a combination of these.
contaminated material: Materials, equipment, or system components with
actual or potential radioactive material contamination.
contamination area: Any area where contamination levels are greater
than the values specified in Appendix D of 10 CFR 835, but less than or
equal to 100 times those levels.
controlled area: Any area to which access is managed in order to
protect individuals from exposure to radiation and/or radioactive
materials. Individuals who enter only the controlled area without
entering radiological areas are not expected to receive a total
effective dose equivalent of more than 100 mrem (0.001 Sv) in a year.
derived air concentration (DAC): For the radionuclides listed in
Appendix A of 10 CFR 835, the airborne concentration that equals the
annual limit for intake(ALI) divided by the volume of air breathed by an
average worker for a working year of 2000 hours (assuming a breathing
volume of 2400 m3). For the radionuclides listed in Appendix C of 10 CFR
835, the air immersion DACs were calculated for a continuous,
non-shielded exposure via immersion in a semi-infinite atmospheric
cloud. The value is based upon the derived airborne concentration found
in Table 1 of the U.S. Environmental Protection Agency (EPA),
EPA-520/1-88-020, "Limiting Values of Radionuclide Intake and Air
Concentration and Dose Conversion Factors for Inhalation, Submersion,
and Ingestion" Federal Guidance Report No. 11 (EPA, 1988).
dose equivalent (H): The product of the absorbed dose (D) in rads (or
gray) in tissue, a quality factor (Q), and other modifying factors (N).
Dose equivalent is expressed in units of rem (or sievert) (1 rem = 0.01
sievert).
fissile material symbol: The symbol designated in American National
Standards Institute (ANSI) Publication N12.1, "Fissile Material Symbol"
(ANSI, 1989a), used when marking fissile radioactive material. (See
Appendix B, for example)
fixed contamination: Radioactive material that cannot be readily
removed from surfaces by nondestructive means such as casual contact,
wiping, brushing, or washing.
fixed contamination area: Any area with detectable removable
contamination less than the removable contamination values of Appendix D
of 10 CFR 835 and fixed contamination at levels that exceed the total
contamination values of Appendix D of 10 CFR 835.
high contamination area: Any area where contamination levels are
greater than 100 times the values specified in Appendix D of 10 CFR 835.
high radiation area: Any area, accessible to individuals, in which
radiation levels could result in an individual receiving a deep dose
equivalent in excess of 0.1 rem (0.001 sievert) in 1 hour at 30
centimeters from the radiation source or from any surface that the
radiation penetrates.
hot particle: Small, discrete, highly radioactive particles that can
cause extremely high dose rates to a localized area.
hot spot: Any localized source of radiation or radioactive material,
normally within facility piping or equipment, which results in radiation
levels that exceed the general area radiation level by more than a
factor of five and are greater than 100 mrem (1 mSv) per hour on
contact. DOE Order 5400.5, Chapter IV, provides detailed guidance on
determining hot spots in soils.
locked barrier: A barrier that is secured with an industrial lock or other
closure that cannot be opened without a key or other hand tool.
monitoring: Actions intended to detect and quantify radiological
conditions.
personnel entrance: Any doorway, hatch, access hole, or other means of
access by which a person could be expected to achieve entry to an area
during operation of the site or facility.
physical barrier: A bounding physical obstruction that prevents
unimpeded access to an area.
radiation area: Any area accessible to individuals in which radiation
levels could result in an individual receiving a deep dose equivalent in
excess of 0.005 rem (0.05 millisievert) in 1 hour at 30 centimeters from
the source or from any surface that the radiation penetrates.
radiation-generating device (RGD): The collective term for devices
which produce ionizing radiation, sealed sources which emit ionizing
radiation, small particle accelerators used for single purpose
applications which produce ionizing radiation (e.g., radiography), and
electron generating devices that produce X-rays incidentally.
radiation symbol: The three-bladed symbol designated in ANSI N2.1,
"Radiation Symbol" (1989b), as the international symbol for designating
ionizing radiation. (See Figure 1, Appendix B, for example)
radioactive material area: An area where radioactive material is used,
handled or stored.
radioactive material contamination: Radioactive material that is
unwanted in a particular location.
radiological area: Any area within a controlled area which must be
posted as a "radiation area," "high radiation area," "very high
radiation area," "contamination area," "high contamination area," or
"airborne radioactivity area" in accordance with 10 CFR 835.603.
radiological buffer area (RBA): Any inter-mediate area established to
prevent the spread of radioactive contamination and to protect personnel
from radiation exposure.
radiological posting and labeling: Signs, labels, and other identifying
markings that warn of the presence or potential presence of ionizing
radiation or radioactive material.
removable contamination: Any radioactive material that can be removed
from surfaces by normal nondestructive means, such as casual contact,
wiping, brushing, or washing.
sealed radioactive source: Any radioactive material that is contained
in a sealed capsule, sealed between layers of nonradioactive material,
or firmly fixed to a nonradioactive surface by electroplating or other
means. The confining barrier prevents dispersion of the radioactive
material under normal and most accidental conditions related to use of
the source.
shall: Within the context of this Guide, the word "shall" is used to
designate requirements from 10 CFR 835, DOE Orders, the RCM, and
secondary documents invoked by them.
should and may: Within the context of this Guide, the words "should" and
"may" are used to represent optional program recommendations and allowable
alternatives, respectively. Deviations generally require no specific
approval or justification; however, exceptions or deviations to "should"
provisions referenced directly from the RCM require specific justification
and approval in accordance with Article 113.3 of that manual (i.e., RCM
113.3).
site: Any area, managed by DOE, where access can be limited for any
reason. The site boundary encompasses Controlled Areas.
soil contamination area: Any area where radioactive material
contamination exists in a matrix (e.g., soil) at levels exceeding
natural background and has not been released for unrestricted use in
accordance with DOE Order 5400.5, "Radiation Protection of the Public and
the Environment" (DOE, 1990).
underground radioactive material area: Any area having underground
items which contain radioactive material and has not been released for
unrestricted use according to DOE Order 5400.5.
unsealed radioactive source: Radioactive material that is not contained
in a sealed capsule, sealed between two layers of nonradioactive
material, or fixed in any way to a nonradioactive surface.
very high radiation area: Any area accessible to individuals in which
radiation levels could result in an individual receiving an absorbed
dose in excess of 500 rads (5 grays) in one hour at 1 meter from a
radiation source or from any surface that the radiation penetrates.
workplace monitoring: The measurement of radioactive material and/or
direct radiation levels in areas that could be routinely occupied by
workers.