| (III) be replaced if defaced or altered.
(C) Posting requirements.
(i) The registrant shall post each radiation area with
a conspicuous sign or signs bearing the radiation symbol and the words
"CAUTION, RADIATION AREA."
(ii) The registrant shall post each high radiation
area with a conspicuous sign or signs bearing the radiation symbol
and the words "CAUTION, HIGH RADIATION AREA" or "DANGER, HIGH RADIATION
AREA."
(iii) The registrant shall post each very high radiation
area with a conspicuous sign or signs bearing the radiation symbol
and words "GRAVE DANGER, VERY HIGH RADIATION AREA."
(D) Exceptions to posting requirements. A registrant
is not required to post caution signs in areas or rooms containing
radiation machines for periods of less than eight hours, if each of
the following conditions is met:
(i) the radiation machines are constantly attended
during these periods by an individual who takes the precautions necessary
to prevent the exposure of individuals to radiation in excess of the
limits established in this section; and
(ii) the area or room is subject to the registrant's
control.
(E) General surveys and monitoring.
(i) Each registrant shall make, or cause to be made,
surveys that:
(I) are necessary for the registrant to comply with
this section; and
(II) are necessary under the circumstances to evaluate:
(-a-) the magnitude and extent of radiation levels;
and
(-b-) the potential radiological hazards.
(ii) The registrant shall ensure that instruments and
equipment used for qualitative and quantitative radiation measurements,
for example, dose rate, are operable and calibrated:
(I) by a person licensed or registered by the agency,
another agreement state, a licensing state, or the United States Nuclear
Regulatory Commission to perform such service;
(II) at intervals not to exceed 24 months unless a
different time interval is specified in another section of this chapter;
(III) after each instrument or equipment repair;
(IV) for the types of radiation used and at energies
appropriate for use; and
(V) at an accuracy within 20 percent of the true radiation
level.
(iii) Record of the dosimetry system calibration shall
include:
(I) manufacturer's name, model and serial number of
each calibrated instrument;
(II) date of the calibration; and
(III) name of the individual recording the information.
(iv) All individual monitoring devices, except for
direct and indirect reading pocket dosimeters, electronic personal
dosimeters, and those individual monitoring devices used to measure
the dose to any extremity, that require processing to determine the
radiation dose and that are used by registrants to comply with paragraph
(3)(A) of this subsection, with other applicable provisions of this
chapter, shall be processed and evaluated by a dosimetry processor:
(I) holding current personnel dosimetry accreditation
from the National Voluntary Laboratory Accreditation Program (NVLAP)
of the National Institute of Standards and Technology; and
(II) approved in this accreditation process for the
type of radiation or radiations included in the NVLAP program that
most closely approximates the type of radiation or radiations for
which the individual wearing the dosimeter is monitored.
(F) Control of access to high radiation areas.
(i) The registrant shall ensure that each entrance
or access point to a high radiation area has one or more of the following
features:
(I) a control device that, upon entry into the area,
causes the level of radiation to be reduced below that level at which
an individual might receive a deep dose equivalent of 0.1 rem (1 mSv)
in one hour at 30 cm from the source of radiation from any surface
that the radiation penetrates;
(II) a control device that energizes a conspicuous
visible or audible alarm signal so that the individual entering the
high radiation area and the supervisor of the activity are made aware
of the entry; or
(III) entryways that are locked, except during periods
when access to the areas is required, with positive control over each
individual entry.
(ii) In place of the controls required by clause (i)
of this subparagraph for a high radiation area, the registrant may
substitute continuous direct or electronic surveillance that is capable
of preventing unauthorized entry.
(iii) The registrant may apply to the agency for approval
of alternative methods for controlling access to high radiation areas.
(iv) The registrant shall establish the controls required
by clauses (i) and (iii) of this subparagraph in a way that does not
prevent individuals from leaving a high radiation area.
(G) Control of access to very high radiation areas.
(i) In addition to the requirements in subparagraph
(F) of this paragraph, the registrant shall institute measures to
ensure that an individual is not able to gain unauthorized or inadvertent
access to areas in which radiation levels could be encountered at
500 rads (5 grays) or more in one hour at 1 m from a radiation machine
or any surface through which the radiation penetrates at this level.
(ii) The entry control devices required by clause (i)
of this subparagraph shall be established in such a way that no individual
will be prevented from leaving the area.
(H) Security and control of radiation machines.
(i) The registrant shall secure radiation machines
from unauthorized removal.
(ii) The registrant shall use devices and administrative
procedures to prevent unauthorized use of radiation machines.
(iii) Any person using hand-held veterinary radiation
machines shall ensure proper storage of the unit to include:
(I) securing the unit against theft or unauthorized
use; and
(II) storing the unit in locked cabinets, storage rooms
or work areas when not under immediate supervision of authorized users.
(5) Radiation machine requirements.
(A) Technique chart.
(i) A technique chart relevant to the particular radiation
machine shall be provided or electronically displayed in the vicinity
of the control panel and used by all operators.
(ii) Technique and exposure indicators.
(I) The technique factors to be used during an exposure
shall be indicated before the exposure begins except when automatic
exposure controls are used, in which case the technique factors that
are set before the exposure shall be indicated.
(II) On radiation machines having fixed technique factors,
the requirement of this paragraph may be met by permanent markings.
(III) The x-ray control shall provide visual or audible
indication of the production of x-rays observable at or from the operator's
protected position whenever x-rays are produced.
(IV) The indicated technique factors shall be accurate
to meet manufacturer's specifications. If these specifications are
not available from the manufacturer, the factors shall be accurate
to within plus or minus 10 percent of the indicated setting.
(B) Labeling radiation machines. Each registrant shall
ensure that each radiation machine is labeled in a conspicuous manner
that cautions individuals that radiation is produced when it is energized.
This label shall be affixed in a clearly visible location on the face
of the control unit.
(C) Mechanical support of tube head. The tube housing
assembly shall be adjusted to remain stable during an exposure unless
tube housing movement is a designed function of the radiation machine.
(D) Battery charge indicator. On battery-powered x-ray
generators, visual means shall be provided on the control panel to
indicate whether the battery is in a state of charge adequate for
proper operation.
(E) Beam quality. The following requirements apply
to beam quality.
(i) Half-value layer.
(I) The half-value layer of the useful beam for a given
x-ray tube potential shall not be less than the values shown in the
following Table I. If it is necessary to determine such half-value
layer at an x-ray tube potential that is not listed in Table I, linear
interpolation may be made.
Attached Graphic
(II) For capacitor energy storage equipment, compliance
with the requirements of subparagraph (I) of this paragraph shall
be determined with the maximum quantity of charge per exposure.
(ii) Filtration controls.
Cont'd... |
