Current through Register Vol. 47, No. 6, September 18, 2024
(1) This rule
applies to licensees with sources of radiation in non-self-shielded
irradiators. This rule does not apply to sources of radiation that are used in
teletherapy, in industrial radiography, or in completely self-shielded
irradiators in which the source of radiation is both stored and operated within
the same shielding radiation barrier and, in the designed configuration of the
irradiator, is always physically inaccessible to any individual and cannot
create high levels of radiation in an area that is accessible to any
individual.
(2) Each area in which
there may exist radiation levels in excess of 500 rad (5 Gy) in 1 hour at 1
meter from a source of radiation that is used to irradiate materials shall meet
the following requirements:
a. Each entrance
or access point shall be equipped with entry control devices which:
(1) Function automatically to prevent any
individual from inadvertently entering a very high radiation area;
and
(2) Permit deliberate entry
into the area only after a control device is actuated that causes the radiation
level within the area, from the source of radiation, to be reduced below that
at which it would be possible for an individual to receive a deep dose
equivalent in excess of 0.1 rem (1 mSv) in 1 hour; and
(3) Prevent operation of the source of
radiation if it would produce radiation levels in the area that could result in
a deep dose equivalent to an individual in excess of 0.1 rem (1 mSv) in 1
hour.
b. Additional
control devices shall be provided so that, upon failure of the entry control
devices to function as required by 40.44(2)
"a":
(1) The radiation level within the area, from
the source of radiation, is reduced below that at which it would be possible
for an individual to receive a deep dose equivalent in excess of 0.1 rem (1
mSv) in 1 hour; and
(2) Conspicuous
visible and audible alarm signals are generated to make an individual
attempting to enter the area aware of the hazard and at least one other
authorized individual, who is physically present, familiar with the activity,
and prepared to render or summon assistance, aware of the failure of the entry
control devices.
c. The
licensee shall provide control devices so that, upon failure or removal of
physical radiation barriers other than the sealed source's shielded storage
container:
(1) The radiation level from the
source of radiation is reduced below that at which it would be possible for an
individual to receive a deep dose equivalent in excess of 0.1 rem (1 mSv) in 1
hour; and
(2) Conspicuous visible
and audible alarm signals are generated to make potentially affected
individuals aware of the hazard and the licensee or at least one other
individual, who is familiar with the activity and prepared to render or summon
assistance, aware of the failure or removal of the physical barrier.
d. When the shield for stored
sealed sources is a liquid, the licensee shall provide means to monitor the
integrity of the shield and to signal, automatically, loss of adequate
shielding.
e. Physical radiation
barriers that comprise permanent structural components, such as walls, that
have no credible probability of failure or removal in ordinary circumstances
need not meet the requirements of 40.44(2)"c" and
40.44(2)"d. "
f.
Each area shall be equipped with devices that will automatically generate
conspicuous visible and audible alarm signals to alert personnel in the area
before the source of radiation can be put into operation and in time for any
individual in the area to operate a clearly identified control device, which
must be installed in the area and which can prevent the source of radiation
from being put into operation.
g.
Each area shall be controlled by use of such administrative procedures and such
devices as are necessary to ensure that the area is cleared of personnel prior
to each use of the source of radiation.
h. Each area shall be checked by a radiation
measurement to ensure that, prior to the first individual's entry into the area
after any use of the source of radiation, the radiation level from the source
of radiation in the area is below that at which it would be possible for an
individual to receive a deep dose equivalent in excess of 0.1 rem (1 mSv) in 1
hour.
i. The entry control devices
required in 40.44(2)
"a" shall be tested for proper
functioning. See 40.89(136C) for record-keeping requirements.
(1) Testing shall be conducted prior to
initial operation with the source of radiation on any day, unless operations
were continued uninterrupted from the previous day; and
(2) Testing shall be conducted prior to
resumption of operation of the source of radiation after any unintentional
interruption; and
(3) The licensee
or registrant shall submit and adhere to a schedule for periodic tests of the
entry control and warning systems.
j. The licensee or registrant shall not
conduct operations, other than those necessary to place the source of radiation
in safe condition or to effect repairs on controls, unless control devices are
functioning properly.
k. Entry and
exit portals that are used in transporting materials to and from the
irradiation area, and that are not intended for use by individuals, shall be
controlled by such devices and administrative procedures as are necessary to
physically protect and warn against inadvertent entry by any individual through
these portals. Exit portals for irradiated materials shall be equipped to
detect and signal the presence of any loose radioactive material that is
carried toward such an exit and to automatically prevent loose radioactive
material from being carried out of the area.
(3) Licensees, registrants, or applicants for
licenses or registrations for sources of radiation within the purview of
40.44(2) which will be used in a variety of positions or in locations, such as
open fields or forests, that make it impracticable to comply with certain
requirements of 40.44(2), such as those for the automatic control of radiation
levels, may apply to the Agency for approval of alternative safety measures.
Alternative safety measures shall provide personnel protection at least
equivalent to those specified in 40.44(2). At least one of the alternative
measures shall include an entry-preventing interlock control based on a
measurement of the radiation that ensures the absence of high radiation levels
before an individual can gain access to the area where such sources of
radiation are used.
(4) The entry
control devices required by 40.44(2) and 40.44(3) shall be established in such
a way that no individual will be prevented from leaving the area.
