[Code of Federal Regulations]
[Title 10, Volume 1]
[Revised as of January 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 10CFR20.1003]
[Page 323-330]
TITLE 10--ENERGY
CHAPTER I--NUCLEAR REGULATORY COMMISSION
PART 20--STANDARDS FOR PROTECTION AGAINST RADIATION--Table of Contents
Subpart A--General Provisions
Sec. 20.1003 Definitions.
As used in this part:
Absorbed dose means the energy imparted by ionizing radiation per
unit mass of irradiated material. The units of absorbed dose are the rad
and the gray (Gy).
Act means the Atomic Energy Act of 1954 (42 U.S.C. 2011 et seq.), as
amended.
Activity is the rate of disintegration (transformation) or decay of
radioactive material. The units of activity are the curie (Ci) and the
becquerel (Bq).
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Adult means an individual 18 or more years of age.
Airborne radioactive material means radioactive material dispersed
in the air in the form of dusts, fumes, particulates, mists, vapors, or
gases.
Airborne radioactivity area means a room, enclosure, or area in
which airborne radioactive materials, composed wholly or partly of
licensed material, exist in concentrations--
(1) In excess of the derived air concentrations (DACs) specified in
appendix B, to Secs. 20.1001-20.2401, or
(2) To such a degree that an individual present in the area without
respiratory protective equipment could exceed, during the hours an
individual is present in a week, an intake of 0.6 percent of the annual
limit on intake (ALI) or 12 DAC-hours.
Air-purifying respirator means a respirator with an air-purifying
filter, cartridge, or canister that removes specific air contaminants by
passing ambient air through the air-purifying element.
ALARA (acronym for ``as low as is reasonably achievable'') means
making every reasonable effort to maintain exposures to radiation as far
below the dose limits in this part as is practical consistent with the
purpose for which the licensed activity is undertaken, taking into
account the state of technology, the economics of improvements in
relation to state of technology, the economics of improvements in
relation to benefits to the public health and safety, and other societal
and socioeconomic considerations, and in relation to utilization of
nuclear energy and licensed materials in the public interest.
Annual limit on intake (ALI) means the derived limit for the amount
of radioactive material taken into the body of an adult worker by
inhalation or ingestion in a year. ALI is the smaller value of intake of
a given radionuclide in a year by the reference man that would result in
a committed effective dose equivalent of 5 rems (0.05 Sv) or a committed
dose equivalent of 50 rems (0.5 Sv) to any individual organ or tissue.
(ALI values for intake by ingestion and by inhalation of selected
radionuclides are given in table 1, columns 1 and 2, of appendix B to
Secs. 20.1001-20.2401).
Assigned protection factor (APF) means the expected workplace level
of respiratory protection that would be provided by a properly
functioning respirator or a class of respirators to properly fitted and
trained users. Operationally, the inhaled concentration can be estimated
by dividing the ambient airborne concentration by the APF.
Atmosphere-supplying respirator means a respirator that supplies the
respirator user with breathing air from a source independent of the
ambient atmosphere, and includes supplied-air respirators (SARs) and
self-contained breathing apparatus (SCBA) units.
Background radiation means radiation from cosmic sources; naturally
occurring radioactive material, including radon (except as a decay
product of source or special nuclear material); and global fallout as it
exists in the environment from the testing of nuclear explosive devices
or from past nuclear accidents such as Chernobyl that contribute to
background radiation and are not under the control of the licensee.
``Background radiation'' does not include radiation from source,
byproduct, or special nuclear materials regulated by the Commission.
Bioassay (radiobioassay) means the determination of kinds,
quantities or concentrations, and, in some cases, the locations of
radioactive material in the human body, whether by direct measurement
(in vivo counting) or by analysis and evaluation of materials excreted
or removed from the human body.
Byproduct material means--
(1) Any radioactive material (except special nuclear material)
yielded in, or made radioactive by, exposure to the radiation incident
to the process of producing or utilizing special nuclear material; and
(2) The tailings or wastes produced by the extraction or
concentration of uranium or thorium from ore processed primarily for its
source material content, including discrete surface wastes resulting
from uranium solution extraction processes. Underground ore bodies
depleted by these solution extraction operations do not constitute
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``byproduct material'' within this definition.
Class (or lung class or inhalation class) means a classification
scheme for inhaled material according to its rate of clearance from the
pulmonary region of the lung. Materials are classified as D, W, or Y,
which applies to a range of clearance half-times: for Class D (Days) of
less than 10 days, for Class W (Weeks) from 10 to 100 days, and for
Class Y (Years) of greater than 100 days.
Collective dose is the sum of the individual doses received in a
given period of time by a specified population from exposure to a
specified source of radiation.
Commission means the Nuclear Regulatory Commission or its duly
authorized representatives.
Committed dose equivalent (HT,50) means the dose
equivalent to organs or tissues of reference (T) that will be received
from an intake of radioactive material by an individual during the 50-
year period following the intake.
Committed effective dose equivalent (HE,50) is the sum of
the products of the weighting factors applicable to each of the body
organs or tissues that are irradiated and the committed dose equivalent
to these organs or tissues (HE,50 = [Sigma] wT
HT,50).
Constraint (dose constraint) means a value above which specified
licensee actions are required.
Controlled area means an area, outside of a restricted area but
inside the site boundary, access to which can be limited by the licensee
for any reason.
Critical Group means the group of individuals reasonably expected to
receive the greatest exposure to residual radioactivity for any
applicable set of circumstances.
Declared pregnant woman means a woman who has voluntarily informed
the licensee, in writing, of her pregnancy and the estimated date of
conception. The declaration remains in effect until the declared
pregnant woman withdraws the declaration in writing or is no longer
pregnant.
Decommission means to remove a facility or site safely from service
and reduce residual radioactivity to a level that permits--
(1) Release of the property for unrestricted use and termination of
the license; or
(2) Release of the property under restricted conditions and the
termination of the license.
Deep-dose equivalent (Hd), which applies to external
whole-body exposure, is the dose equivalent at a tissue depth of 1 cm
(1000 mg/cm\2\).
Demand respirator means an atmosphere-supplying respirator that
admits breathing air to the facepiece only when a negative pressure is
created inside the facepiece by inhalation.
Department means the Department of Energy established by the
Department of Energy Organization Act (Pub. L. 95-91, 91 Stat. 565, 42
U.S.C. 7101 et seq.) to the extent that the Department, or its duly
authorized representatives, exercises functions formerly vested in the
U.S. Atomic Energy Commission, its Chairman, members, officers, and
components and transferred to the U.S. Energy Research and Development
Administration and to the Administrator thereof pursuant to sections 104
(b), (c), and (d) of the Energy Reorganization Act of 1974 (Pub. L. 93-
438, 88 Stat. 1233 at 1237, 42 U.S.C. 5814) and retransferred to the
Secretary of Energy pursuant to section 301(a) of the Department of
Energy Organization Act (Pub. L. 95-91, 91 Stat 565 at 577-578, 42
U.S.C. 7151).
Derived air concentration (DAC) means the concentration of a given
radionuclide in air which, if breathed by the reference man for a
working year of 2,000 hours under conditions of light work (inhalation
rate 1.2 cubic meters of air per hour), results in an intake of one ALI.
DAC values are given in table 1, column 3, of appendix B to
Secs. 20.1001-20.2401.
Derived air concentration-hour (DAC-hour) is the product of the
concentration of radioactive material in air (expressed as a fraction or
multiple of the derived air concentration for each radionuclide) and the
time of exposure to that radionuclide, in hours. A licensee may take
2,000 DAC-hours to represent one ALI, equivalent to a committed
effective dose equivalent of 5 rems (0.05 Sv).
Disposable respirator means a respirator for which maintenance is
not
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intended and that is designed to be discarded after excessive breathing
resistance, sorbent exhaustion, physical damage, or end-of-service-life
renders it unsuitable for use. Examples of this type of respirator are a
disposable half-mask respirator or a disposable escape-only self-
contained breathing apparatus (SCBA).
Distinguishable from background means that the detectable
concentration of a radionuclide is statistically different from the
background concentration of that radionuclide in the vicinity of the
site or, in the case of structures, in similar materials using adequate
measurement technology, survey, and statistical techniques.
Dose or radiation dose is a generic term that means absorbed dose,
dose equivalent, effective dose equivalent, committed dose equivalent,
committed effective dose equivalent, or total effective dose equivalent,
as defined in other paragraphs of this section.
Dose equivalent (HT) means the product of the absorbed
dose in tissue, quality factor, and all other necessary modifying
factors at the location of interest. The units of dose equivalent are
the rem and sievert (Sv).
Dosimetry processor means an individual or organization that
processes and evaluates individual monitoring equipment in order to
determine the radiation dose delivered to the equipment.
Effective dose equivalent (HE) is the sum of the products
of the dose equivalent to the organ or tissue (HT) and the
weighting factors (wT) applicable to each of the body organs
or tissues that are irradiated (HE = [Sigma] wT
HT).
Embryo/fetus means the developing human organism from conception
until the time of birth.
Entrance or access point means any location through which an
individual could gain access to radiation areas or to radioactive
materials. This includes entry or exit portals of sufficient size to
permit human entry, irrespective of their intended use.
Exposure means being exposed to ionizing radiation or to radioactive
material.
External dose means that portion of the dose equivalent received
from radiation sources outside the body.
Extremity means hand, elbow, arm below the elbow, foot, knee, or leg
below the knee.
Filtering facepiece (dust mask) means a negative pressure
particulate respirator with a filter as an integral part of the
facepiece or with the entire facepiece composed of the filtering medium,
not equipped with elastomeric sealing surfaces and adjustable straps.
Fit factor means a quantitative estimate of the fit of a particular
respirator to a specific individual, and typically estimates the ratio
of the concentration of a substance in ambient air to its concentration
inside the respirator when worn.
Fit test means the use of a protocol to qualitatively or
quantitatively evaluate the fit of a respirator on an individual.
Generally applicable environmental radiation standards means
standards issued by the Environmental Protection Agency (EPA) under the
authority of the Atomic Energy Act of 1954, as amended, that impose
limits on radiation exposures or levels, or concentrations or quantities
of radioactive material, in the general environment outside the
boundaries of locations under the control of persons possessing or using
radioactive material.
Government agency means any executive department, commission,
independent establishment, corporation wholly or partly owned by the
United States of America, which is an instrumentality of the United
States, or any board, bureau, division, service, office, officer,
authority, administration, or other establishment in the executive
branch of the Government.
Gray [See Sec. 20.1004].
Helmet means a rigid respiratory inlet covering that also provides
head protection against impact and penetration.
High radiation area means an area, accessible to individuals, in
which radiation levels from radiation sources external to the body could
result in an individual receiving a dose equivalent in excess of 0.1 rem
(1 mSv) in 1 hour at 30 centimeters from the radiation source or 30
centimeters from any surface that the radiation penetrates.
Hood means a respiratory inlet covering that completely covers the
head
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and neck and may also cover portions of the shoulders and torso.
Individual means any human being.
Individual monitoring means--
(1) The assessment of dose equivalent by the use of devices designed
to be worn by an individual;
(2) The assessment of committed effective dose equivalent by
bioassay (see Bioassay) or by determination of the time-weighted air
concentrations to which an individual has been exposed, i.e., DAC-hours;
or
(3) The assessment of dose equivalent by the use of survey data.
Individual monitoring devices (individual monitoring equipment)
means devices designed to be worn by a single individual for the
assessment of dose equivalent such as film badges, thermoluminescence
dosimeters (TLDs), pocket ionization chambers, and personal (``lapel'')
air sampling devices.
Internal dose means that portion of the dose equivalent received
from radioactive material taken into the body.
Lens dose equivalent (LDE) applies to the external exposure of the
lens of the eye and is taken as the dose equivalent at a tissue depth of
0.3 centimeter (300 mg/cm\2\).
License means a license issued under the regulations in parts 30
through 36, 39, 40, 50, 60, 61, 63, 70, or 72 of this chapter.
Licensed material means source material, special nuclear material,
or byproduct material received, possessed, used, transferred or disposed
of under a general or specific license issued by the Commission.
Licensee means the holder of a license.
Limits (dose limits) means the permissible upper bounds of radiation
doses.
Loose-fitting facepiece means a respiratory inlet covering that is
designed to form a partial seal with the face.
Lost or missing licensed material means licensed material whose
location is unknown. It includes material that has been shipped but has
not reached its destination and whose location cannot be readily traced
in the transportation system.
Member of the public means any individual except when that
individual is receiving an occupational dose.
Minor means an individual less than 18 years of age.
Monitoring (radiation monitoring, radiation protection monitoring)
means the measurement of radiation levels, concentrations, surface area
concentrations or quantities of radioactive material and the use of the
results of these measurements to evaluate potential exposures and doses.
Negative pressure respirator (tight fitting) means a respirator in
which the air pressure inside the facepiece is negative during
inhalation with respect to the ambient air pressure outside the
respirator.
Nonstochastic effect means health effects, the severity of which
varies with the dose and for which a threshold is believed to exist.
Radiation-induced cataract formation is an example of a nonstochastic
effect (also called a deterministic effect).
NRC means the Nuclear Regulatory Commission or its duly authorized
representatives.
Occupational dose means the dose received by an individual in the
course of employment in which the individual's assigned duties involve
exposure to radiation or to radioactive material from licensed and
unlicensed sources of radiation, whether in the possession of the
licensee or other person. Occupational dose does not include doses
received from background radiation, from any medical administration the
individual has received, from exposure to individuals administered
radioactive material and released under Sec. 35.75, from voluntary
participation in medical research programs, or as a member of the
public.
Person means--
(1) Any individual, corporation, partnership, firm, association,
trust, estate, public or private institution, group, Government agency
other than the Commission or the Department of Energy (except that the
Department shall be considered a person within the meaning of the
regulations in 10 CFR chapter I to the extent that its facilities and
activities are subject to the licensing and related regulatory authority
of the Commission under section
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202 of the Energy Reorganization Act of 1974 (88 Stat. 1244), the
Uranium Mill Tailings Radiation Control Act of 1978 (92 Stat. 3021), the
Nuclear Waste Policy Act of 1982 (96 Stat. 2201), and section 3(b)(2) of
the Low-Level Radioactive Waste Policy Amendments Act of 1985 (99 Stat.
1842)), any State or any political subdivision of or any political
entity within a State, any foreign government or nation or any political
subdivision of any such government or nation, or other entity; and
(2) Any legal successor, representative, agent, or agency of the
foregoing.
Planned special exposure means an infrequent exposure to radiation,
separate from and in addition to the annual dose limits.
Positive pressure respirator means a respirator in which the
pressure inside the respiratory inlet covering exceeds the ambient air
pressure outside the respirator.
Powered air-purifying respirator (PAPR) means an air-purifying
respirator that uses a blower to force the ambient air through air-
purifying elements to the inlet covering.
Pressure demand respirator means a positive pressure atmosphere-
supplying respirator that admits breathing air to the facepiece when the
positive pressure is reduced inside the facepiece by inhalation.
Public dose means the dose received by a member of the public from
exposure to radiation or to radioactive material released by a licensee,
or to any other source of radiation under the control of a licensee.
Public dose does not include occupational dose or doses received from
background radiation, from any medical administration the individual has
received, from exposure to individuals administered radioactive material
and released under Sec. 35.75, or from voluntary participation in
medical research programs.
Qualitative fit test (QLFT) means a pass/fail fit test to assess the
adequacy of respirator fit that relies on the individual's response to
the test agent.
Quality Factor (Q) means the modifying factor (listed in tables
1004(b).1 and 1004(b).2 of Sec. 20.1004) that is used to derive dose
equivalent from absorbed dose.
Quantitative fit test (QNFT) means an assessment of the adequacy of
respirator fit by numerically measuring the amount of leakage into the
respirator.
Quarter means a period of time equal to one-fourth of the year
observed by the licensee (approximately 13 consective weeks), providing
that the beginning of the first quarter in a year coincides with the
starting date of the year and that no day is omitted or duplicated in
consecutive quarters.
Rad (See Sec. 20.1004).
Radiation (ionizing radiation) means alpha particles, beta
particles, gamma rays, x-rays, neutrons, high-speed electrons, high-
speed protons, and other particles capable of producing ions. Radiation,
as used in this part, does not include non-ionizing radiation, such as
radio- or microwaves, or visible, infrared, or ultraviolet light.
Radiation area means an area, accessible to individuals, in which
radiation levels could result in an individual receiving a dose
equivalent in excess of 0.005 rem (0.05 mSv) in 1 hour at 30 centimeters
from the radiation source or from any surface that the radiation
penetrates.
Reference man means a hypothetical aggregation of human physical and
physiological characteristics arrived at by international consensus.
These characteristics may be used by researchers and public health
workers to standardize results of experiments and to relate biological
insult to a common base.
Rem (See Sec. 20.1004).
Residual radioactivity means radioactivity in structures, materials,
soils, groundwater, and other media at a site resulting from activities
under the licensee's control. This includes radioactivity from all
licensed and unlicensed sources used by the licensee, but excludes
background radiation. It also includes radioactive materials remaining
at the site as a result of routine or accidental releases of radioactive
material at the site and previous burials at the site, even if those
burials were made in accordance with the provisions of 10 CFR part 20.
Respiratory protective device means an apparatus, such as a
respirator, used to
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reduce the individual's intake of airborne radioactive materials.
Restricted area means an area, access to which is limited by the
licensee for the purpose of protecting individuals against undue risks
from exposure to radiation and radioactive materials. Restricted area
does not include areas used as residential quarters, but separate rooms
in a residential building may be set apart as a restricted area.
Sanitary sewerage means a system of public sewers for carrying off
waste water and refuse, but excluding sewage treatment facilities,
septic tanks, and leach fields owned or operated by the licensee.
Self-contained breathing apparatus (SCBA) means an atmosphere-
supplying respirator for which the breathing air source is designed to
be carried by the user.
Shallow-dose equivalent (Hs), which applies to the
external exposure of the skin of the whole body or the skin of an
extremity, is taken as the dose equivalent at a tissue depth of 0.007
centimeter (7 mg/cm2).
Site boundary means that line beyond which the land or property is
not owned, leased, or otherwise controlled by the licensee.
Source material means--
(1) Uranium or thorium or any combination of uranium and thorium in
any physical or chemical form; or
(2) Ores that contain, by weight, one-twentieth of 1 percent (0.05
percent), or more, of uranium, thorium, or any combination of uranium
and thorium. Source material does not include special nuclear material.
Special nuclear material means--
(1) Plutonium, uranium-233, uranium enriched in the isotope 233 or
in the isotope 235, and any other material that the Commission, pursuant
to the provisions of section 51 of the Act, determines to be special
nuclear material, but does not include source material; or
(2) Any material artificially enriched by any of the foregoing but
does not include source material.
Stochastic effects means health effects that occur randomly and for
which the probability of the effect occurring, rather than its severity,
is assumed to be a linear function of dose without threshold. Hereditary
effects and cancer incidence are examples of stochastic effects.
Supplied-air respirator (SAR) or airline respirator means an
atmosphere-supplying respirator for which the source of breathing air is
not designed to be carried by the user.
Survey means an evalulation of the radiological conditions and
potential hazards incident to the production, use, transfer, release,
disposal, or presence of radioactive material or other sources of
radiation. When appropriate, such an evaluation includes a physical
survey of the location of radioactive material and measurements or
calculations of levels of radiation, or concentrations or quantities of
radioactive material present.
Tight-fitting facepiece means a respiratory inlet covering that
forms a complete seal with the face.
Total Effective Dose Equivalent (TEDE) means the sum of the deep-
dose equivalent (for external exposures) and the committed effective
dose equivalent (for internal exposures).
Unrestricted area means an area, access to which is neither limited
nor controlled by the licensee.
Uranium fuel cycle means the operations of milling of uranium ore,
chemical conversion of uranium, isotopic enrichment of uranium,
fabrication of uranium fuel, generation of electricity by a light-water-
cooled nuclear power plant using uranium fuel, and reprocessing of spent
uranium fuel to the extent that these activities directly support the
production of electrical power for public use. Uranium fuel cycle does
not include mining operations, operations at waste disposal sites,
transportation of radioactive material in support of these operations,
and the reuse of recovered non-uranium special nuclear and byproduct
materials from the cycle.
User seal check (fit check) means an action conducted by the
respirator user to determine if the respirator is properly seated to the
face. Examples include negative pressure check, positive pressure check,
irritant smoke check, or isoamyl acetate check.
Very high radiation area means an area, accessible to individuals,
in which radiation levels from radiation
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sources external to the body could result in an individual receiving an
absorbed dose in excess of 500 rads (5 grays) in 1 hour at 1 meter from
a radiation source or 1 meter from any surface that the radiation
penetrates.
Note: At very high doses received at high dose rates, units of
absorbed dose (e.g., rads and grays) are appropriate, rather than units
of dose equivalent (e.g., rems and sieverts)).
Week means 7 consecutive days starting on Sunday.
Weighting factor wT, for an organ or tissue (T) is the
proportion of the risk of stochastic effects resulting from irradiation
of that organ or tissue to the total risk of stochastic effects when the
whole body is irradiated uniformly. For calculating the effective dose
equivalent, the values of wT are:
Organ Dose Weighting Factors
------------------------------------------------------------------------
Organ or tissue wT
------------------------------------------------------------------------
Gonads......................................................... 0.25
Breast......................................................... 0.15
Red bone marrow................................................ 0.12
Lung........................................................... 0.12
Thyroid........................................................ 0.03
Bone surfaces.................................................. 0.03
Remainder...................................................... \1\ 0.3
0
Whole Body..................................................... \2\ 1.0
0
------------------------------------------------------------------------
\1\ 0.30 results from 0.06 for each of 5 ``remainder'' organs (excluding
the skin and the lens of the eye) that receive the highest doses.
\2\ For the purpose of weighting the external whole body dose (for
adding it to the internal dose), a single weighting factor, wT=1.0,
has been specified. The use of other weighting factors for external
exposure will be approved on a case-by-case basis until such time as
specific guidance is issued.
Whole body means, for purposes of external exposure, head, trunk
(including male gonads), arms above the elbow, or legs above the knee.
Working level (WL) is any combination of short-lived radon daughters
(for radon-222: polonium-218, lead-214, bismuth-214, and polonium-214;
and for radon-220: polonium-216, lead-212, bismuth-212, and polonium-
212) in 1 liter of air that will result in the ultimate emission of
1.3x10\5\ MeV of potential alpha particle energy.
Working level month (WLM) means an exposure to 1 working level for
170 hours (2,000 working hours per year/12 months per year=approximately
170 hours per month).
Year means the period of time beginning in January used to determine
compliance with the provisions of this part. The licensee may change the
starting date of the year used to determine compliance by the licensee
provided that the change is made at the beginning of the year and that
no day is omitted or duplicated in consecutive years.
[56 FR 23391, May 21, 1991, as amended at 57 FR 57878, Dec. 8, 1992; 58
FR 7736, Feb. 9, 1993; 60 FR 36043, July 13, 1995; 60 FR 48625, Sept.
20, 1995; 61 FR 65127, Dec. 10, 1996; 62 FR 4133, Jan. 29, 1997; 62 FR
39087, July 21, 1997; 63 FR 39481, July 23, 1998; 64 FR 54556, Oct. 7,
1999; 66 FR 55789, Nov. 2, 2001; 67 FR 16304, Apr. 5, 2002; 67 FR 20370,
Apr. 24, 2002; 67 FR 62872, Oct. 9, 2002]