Current through Register Vol. 46, No. 19, March 20, 2024
(1)
Purpose and scope. This
rule provides special requirements for analytical X-ray equipment. The
requirements of this rule are in addition to, and not in substitution for,
641-Chapters 38, 39, and 40. The requirements of rules
641-45.1
(136C) to 641^5.4(136C) do not apply.
(2)
Definitions. For the
purpose of this subrule, definitions in 641-Chapter 38 may also apply. As used
in this rule, the following definitions apply:
"AnalyticalX-ray equipment" means equipment
used for X-ray diffraction or fluorescence analysis.
"Analytical X-ray system" means a group of
components utilizing X-rays or gamma rays to determine the elemental
composition or to examine the microstructure of materials.
"Fail-safe characteristics" means a design
feature which causes beam port shutters to close, or otherwise prevents
emergence of the primary beam, upon the failure of a safety or warning
device.
"Local components" means part of an analytical
X-ray system and includes X-ray areas that are struck by X-rays such as
radiation source housings, port and shutter assemblies, collimators, sample
holders, cameras, goniometers, detectors, and shielding, but does not include
power supplies, transformers, amplifiers, readout devices, and control
panels.
"Normal operating procedures" means
step-by-step instructions necessary to accomplish the analysis. These
procedures shall include sample insertion and manipulation, equipment
alignment, routine maintenance by the registrant or licensee, and data
recording procedures, which are related to radiation safety.
"Open-beam configuration" means an analytical
X-ray system in which an individual could accidentally place some part of his
body in the primary beam path during normal operation.
"Primary beam " means radiation which passes
through an aperture of the source housing by a direct path from the X-ray tube
or a radioactive source located in the radiation source housing.
(3)
Equipment
requirements.
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 ensure 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:
1. X-ray tube "on-off' status located near
the radiation source housing, if the primary beam is controlled in this manner;
or
2. Shutter "open-closed" status
located near each port on the radiation source housing, if the primary beam is
controlled in this manner.
(2) An easily visible warning light labeled
with the words "X-RAY ON," or words having a similar intent, shall be located:
1. Near any switch that energizes an X-ray
tube and shall be illuminated only when the tube is energized; or
2. 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.
(3)
Warning devices shall be labeled so that their purpose is easily identified. On
equipment installed after the effective date of these rules, 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
641-40.63
(136C) if the radiation source is a radionuclide.
e.
Shutters. On open-beam
configurations, 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.
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 5
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.
g.
Generator cabinet. Each
X-ray generator shall be supplied with a protective cabinet which limits
leakage radiation measured at a distance of 5 centimeters from its surface such
that it is not capable of producing a dose in excess of 0.25 millirem (2.5 mSv)
in one hour.
(4)
Area requirements.
a.
Radiation levels. The local components of an analytical X-ray
system shall be located and arranged and shall include sufficient shielding or
access control such that no radiation levels exist in any area surrounding the
local component group which could result in a dose to an individual present
therein in excess of the dose limits given in
641-40.26
(136C). For systems utilizing X-ray tubes, these levels shall be met at any
specified tube rating.
b.
Surveys.
(1) Radiation
surveys, as required by
641-40.36
(136C), of all analytical X-ray systems sufficient to show compliance with
45.5(4)
"a" shall be performed:
1. Upon installation of the equipment, and at
least once every 12 months thereafter;
2. Following any change in the initial
arrangement, number, or type of local components in the system;
3. Following any maintenance requiring the
disassembly or removal of a local component in the system;
4. During the performance of maintenance and
alignment procedures if the procedures require the presence of a primary X-ray
beam when any local component in the system is disassembled or
removed;
5. Anytime a visual
inspection of the local components in the system reveals an abnormal condition;
and
6. Whenever personnel
monitoring devices show a significant increase over the previous monitoring
period or the readings are approaching the limits specified in
641-40.15
(136C).
(2) Radiation
survey measurements shall not be required if a registrant or licensee can
demonstrate compliance with 45.5(4)"a" to the satisfaction of
the agency.
c.
Posting. Each area or room containing analytical X-ray
equipment shall be conspicuously posted with a sign or signs bearing the
radiation symbol and the words "CAUTION-X-RAY EQUIPMENT" or words having a
similar intent in accordance with 641-subrule 40.61(1).
(5)
Operating requirements.
a.
Procedures. Normal
operating procedures shall be written and available to all analytical X-ray
equipment workers. No individual shall be permitted to operate analytical X-ray
equipment in any manner other than that specified in the procedures unless such
individual has obtained written approval of the radiation safety
officer.
b.
Bypassing. No individual shall bypass a safety device or
interlock unless such individual has obtained the approval of the radiation
safety officer. Such approval shall be for a specified period of time. When a
safety device or interlock has been bypassed, a readily discernible sign
bearing the words "SAFETY DEVICE NOT WORKING," or words having a similar
intent, shall be placed on the radiation source housing.
c.
Repair or modification of X-ray
tube systems. Except as specified in 45.5(5)"b, " no
operation involving removal of covers, shielding materials or tube housings or
modifications to shutters, collimators, or beam stops shall be performed
without ascertaining that the tube is off and will remain off until safe
conditions have been restored. The main switch, rather than interlocks, shall
be used for routine shutdown in preparation for repairs.
d.
Radioactive source replacement,
testing, or repair. Radioactive source housings shall be opened for
source replacement, leak testing, or other maintenance or repair procedures
only by individuals authorized to specifically conduct such procedures under a
license issued by the U.S. Nuclear Regulatory Commission, an agreement state,
or a licensing state.
(6)
Personnel requirements.
a.
Instruction. No
individual shall be permitted to operate or maintain analytical X-ray equipment
unless such individual has received instruction in and demonstrated competence
as to:
(1) Identification of radiation hazards
associated with the use of the equipment;
(2) Significance of the various radiation
warnings, safety devices, and interlocks incorporated into the equipment, or
the reasons they have not been installed on certain pieces of equipment and the
extra precautions required in such cases;
(3) Proper operating procedures for the
equipment;
(4) Recognition of
symptoms of an acute localized exposure; and
(5) Proper procedures for reporting an actual
or suspected exposure.
b.
Personnel monitoring.
(1) Finger or wrist dosimetry devices shall
be provided to and shall be used by:
1.
Analytical X-ray equipment workers using systems having an open-beam
configuration and not equipped with a safety device; and
2. Personnel maintaining analytical X-ray
equipment if the maintenance procedures require the presence of a primary X-ray
beam when any local component in the analytical X-ray system is disassembled or
removed.
(2) Reported
dose values shall not be used for the purpose of determining compliance with
641-subrule 40.2(1) unless evaluated by a qualified expert.
