| (23) Certification of mammography systems (state certification)--A
form of permission given by the agency to an applicant who has met
the requirements for mammography system certification set out in the
Act and this chapter.
(24) Collective dose--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.
(25) Commercial--Having financial profit as the primary
aim.
(26) Committed dose equivalent (HT,50
)--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.
(27) Committed effective dose equivalent (HE,50 )--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 each of these organs
or tissues (HE,50 = ΣWT HT.50 ).
(28) Consortium--An association of medical use licensees
and a Positron Emission Tomography (PET) radionuclide production facility
in the same geographical area that jointly own or share in the operation
and maintenance costs of the PET radionuclide production facility
that produces PET radionuclides for use in producing radioactive drugs
within the consortium for noncommercial distributions among its associated
members for medical use. The PET radionuclide production facility
within the consortium shall be located at an educational institution
or a medical facility.
(29) Constraint (dose constraint)--A value above which
specified licensee actions are required.
(30) Critical group--The group of individuals reasonably
expected to receive the greatest exposure to residual radioactivity
for any applicable set of circumstances.
(31) Curie (Ci)--A unit of measurement of radioactivity.
One curie (Ci) is that quantity of radioactive material that decays
at the rate of 3.7 x 1010 disintegrations
per second (dps). Commonly used submultiples of the curie are the
millicurie (mCi) and the microcurie (µCi). One mCi = 1 x 10-3 Ci = 3.7 x 107 dps.
One µCi = 1 x 10-6 Ci = 3.7 x 104 dps. One nanocurie (nCi) = 1 x 10-9 Ci = 3.7 x 101 dps.
One picocurie (pCi) = 1 x 10-12 Ci =
3.7 x 10-2 dps.
(32) Decommission--To remove a facility or site safely
from service and reduce residual radioactivity to a level that permits
the following:
(A) release of the property for unrestricted use and/or
termination of license; or
(B) release of the property under alternate requirements
for license termination.
(33) Deep dose equivalent (Hd ),
that applies to external whole body exposure--The dose equivalent
at a tissue depth of 1 centimeter (cm) (1,000 milligrams per square
centimeter (mg/cm2 )).
(34) Depleted uranium--The source material uranium
in which the isotope uranium-235 is less than 0.711 weight percent
of the total uranium present. Depleted uranium does not include special
nuclear material.
(35) Discrete source--A radionuclide that has been
processed so that its concentration within a material has been purposely
increased for use for commercial, medical, or research activities.
(36) Distinguishable from background--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 or equipment, in similar materials
using adequate measurement technology, survey, and statistical techniques.
(37) Distribution--The physical conveyance and authorized
transfer of commodities from producers to consumers and any intermediate
persons involved in that conveyance.
(38) Diversion--The unauthorized movement of radioactive
material subject to §289.252(ii) of this title to a location
different from the material's authorized destination inside or outside
of the site at which the material is used or stored.
(39) Dose--A generic term that means absorbed dose,
dose equivalent, effective dose equivalent, committed dose equivalent,
committed effective dose equivalent, total organ dose equivalent,
or total effective dose equivalent. For purposes of this chapter,
"radiation dose" is an equivalent term.
(40) Dose equivalent (HT )--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 sievert (Sv) and rem.
(41) Dose limits--The permissible upper bounds of radiation
doses established in accordance with this chapter. For purposes of
this chapter, "limits" is an equivalent term.
(42) Effective dose equivalent (HE )--The
sum of the products of the dose equivalent to each organ or tissue
(HT ) and the weighting factor (WT ) applicable to each of the body organs or
tissues that are irradiated (HE = ΣWT HT ).
(43) Embryo/fetus--The developing human organism from
conception until the time of birth.
(44) Entrance or access point--Any opening through
which an individual or extremity of an individual could gain access
to radiation areas or to licensed sources of radiation. This includes
portals of sufficient size to permit human access, irrespective of
their intended use.
(45) Escorted access--Accompaniment while in a security
zone by an approved individual who maintains continuous direct visual
surveillance at all times over an individual who is not approved for
unescorted access.
(46) Exposure--The quotient of dQ by dm where "dQ"
is the absolute value of the total charge of the ions of one sign
produced in air when all the electrons (negatrons and positrons) liberated
by photons in a volume element of air having mass "dm" are completely
stopped in air. The SI unit of exposure is the coulomb per kilogram
(C/kg). The roentgen is the special unit of exposure. For purposes
of this chapter, this term is used as a noun.
(47) Exposure rate--The exposure per unit of time.
(48) External dose--That portion of the dose equivalent
received from any source of radiation outside the body.
(49) Extremity--Hand, elbow, arm below the elbow, foot,
knee, and leg below the knee. The arm above the elbow and the leg
above the knee are considered part of the whole body.
(50) Fingerprint orders--The orders issued by the NRC
or the legally binding requirements issued by agreement states that
require fingerprints and criminal history records checks for individuals
with unescorted access to category 1 and category 2 quantities of
radioactive material or safeguards information-modified handling.
(51) Generally applicable environmental radiation standards--Standards
issued by the 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.
(52) Gray (Gy)--The SI unit of absorbed dose. One gray
is equal to an absorbed dose of 1 joule per kilogram (J/kg) or 100
rad.
(53) High radiation area--An area, accessible to individuals,
in which radiation levels from sources of radiation external to the
body could result in an individual receiving a dose equivalent in
excess of 0.1 rem (1 millisievert (mSv)) in one hour at 30 cm from
any source of radiation or from any surface that the radiation penetrates.
(54) Human use--The internal or external administration
of radiation or radioactive material to human beings for healing arts
purposes or research and/or development specifically authorized by
the agency.
(55) Individual--Any human being.
(56) Individual monitoring--The assessment of:
(A) dose equivalent to an individual by the use of
individual monitoring devices; or
(B) committed effective dose equivalent to an individual
by bioassay or by determination of the time-weighted air concentrations
to which an individual has been exposed, that is, DAC-hours. (See
the definition for DAC-hours in §289.202(c) of this title); or
(C) dose equivalent to an individual by the use of
survey data.
(57) Individual monitoring devices--Devices designed
to be worn by a single individual for the assessment of dose equivalent.
For purposes of this chapter, "personnel dosimeter" and "dosimeter"
are equivalent terms. Examples of individual monitoring devices include,
but are not limited to, film badges, thermoluminescence dosimeters
(TLDs), optically stimulated luminescence dosimeters (OSLs), pocket
ionization chambers (pocket dosimeters), electronic personal dosimeters,
and Cont'd... |
