Current through Register 1531, September 27, 2024
(A)
Safety Device. A device which prevents the entry of
any portion of an individual's body into the primary x-ray beam path or which
causes the beam to be shut off upon entry into its path shall be provided on
all open-beam configurations. A registrant [or licensee] may apply to the
Agency for an exemption from the requirement of a safety device. Such
application shall include:
(1) A description
of the various safety devices that have been evaluated;
(2) The reason each of these devices cannot
be used; and,
(3) A description of
the alternative methods that will be employed to minimize the possibility of an
accidental exposure, including procedures to assure that operators and others
in the area will be informed of the absence of safety devices.
(B)
Warning
Devices.
(1) Open-beam
configurations shall be provided with a readily discernible indication of:
(a) X-ray tube "on-off" status located near
the radiation source housing, if the primary beam is controlled in this manner;
and/or,
(b) Shutter "open-closed"
status located near each port on the radiation source housing, if the primary
beam is controlled in this manner.
(2) Warning devices shall be labeled so that
their purpose is easily identified. On equipment installed after the effective
date of 105 CMR 120.600, warning devices shall have fail-safe
characteristics.
(C)
Ports. Unused ports on radiation source housings shall
be secured in the closed position in a manner which will prevent casual
opening.
(D)
Labeling. All analytical x-ray equipment shall be
labeled with a readily discernible sign or signs bearing the radiation symbol
and the words:
(1) "CAUTION - HIGH INTENSITY
X-RAY BEAM", or words having a similar intent, on the x-ray source housing;
and,
(2) "CAUTION RADIATION - THIS
EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED", or words having a similar intent,
near any switch that energizes an x-ray tube if the radiation source is an
x-ray tube; or,
(3) "CAUTION -
RADIOACTIVE MATERIAL", or words having a similar intent, on the source housing
in accordance with
105 CMR 120.237 and
120.238 if
the radiation source is a radionuclide.
(E)
Shutters. On
open-beam configurations installed after the effective date of 105 CMR 120.600,
each port on the radiation source housing shall be equipped with a shutter that
cannot be opened unless a collimator or a coupling has been connected to the
port.
(F)
Warning
Lights.
(1) An easily visible
warning light labeled with the words "X-RAY ON", or words having a similar
intent, shall be located:
(a) Near any switch
that energizes an x-ray tube and shall be illuminated only when the tube is
energized; or,
(b) In the case of a
radioactive source, near any switch that opens a housing shutter and shall be
illuminated only when the shutter is open.
(2) On equipment installed after the
effective date of 105 CMR 120.600, warning lights shall have fail-safe
characteristics.
(G)
Radiation Source Housing. Each radiation source
housing shall be subject to the following requirements:
(1) Each x-ray tube housing shall be equipped
with an interlock that shuts off the tube if it is removed from the radiation
source housing or if the housing is disassembled.
(2) Each radioactive source housing or port
cover or each x-ray tube housing shall be so constructed that, with all
shutters closed, the radiation measured at a distance of five centimeters from
its surface is not capable of producing a dose in excess of 2.5 millirems
(0.025 mSv) in one hour. For systems utilizing x-ray tubes, this limit shall be
met at any specified tube rating.
(H)
Generator
Cabinet. Each x-ray generator shall be supplied with a protective
cabinet which limits leakage radiation measured at a distance of five
centimeters from its surface such that it is not capable of producing a dose in
excess of 0.25 millirem (2.5 µSv) in one hour.
