A. Section D.1603 applies to licensees or
registrants with sources of radiation in non-self-shielded irradiators. Section
D.1603 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.
B. Each area in which there may exist
radiation levels in excess of 5 Gy (500 rad) in one hour at 1 meter from a
source of radiation that is used to irradiate materials shall meet the
following requirements:
(1) Each entrance or
access point shall be equipped with entry control devices which:
(a) Function automatically to prevent any
individual from inadvertently entering a very high radiation area;
and
(b) 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 1 mSv (0.1 rem) in one hour; and
(c) 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 1 mSv (0.1 rem) in one
hour.
(2) Additional
control devices shall be provided so that, upon failure of the entry control
devices to function as required by D.1603.B(1):
(a) 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 1 mSv (0.1
rem) in one hour; and
(b)
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.
(3) The licensee or registrant shall provide
control devices so that, upon failure or removal of physical radiation barriers
other than the sealed source's shielded storage container:
(a) 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 1 mSv (0.1 rem) in one hour;
and
(b) Conspicuous visible and
audible alarm signals are generated to make potentially affected individuals
aware of the hazard and the licensee or registrant 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.
(4) When the shield for stored
sealed sources is a liquid, the licensee or registrant shall provide means to
monitor the integrity of the shield and to signal, automatically, loss of
adequate shielding.
(5) 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 D.1603.B(3) and (4).
(6) 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.
(7) 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.
(8) 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 1 mSv (0.1 rem) in one hour.
(9) The entry control devices required in
D.1603.B(1) shall be tested for proper functioning. See D.2109 for record
keeping requirements.
(a) 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
(b) Testing shall be conducted
prior to resumption of operation of the source of radiation after any
unintentional interruption; and
(c)
The licensee or registrant shall submit and adhere to a schedule for periodic
tests of the entry control and warning systems.
(10) 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.
(11) 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 automatically to prevent loose radioactive
material from being carried out of the area.
C. Licensees, registrants, or applicants for
licenses or registrations for sources of radiation within the purview of
D.1603.B 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 D.1603.B, 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 D.1603.B. 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.
D. The entry
control devices required by D.1603.B and C shall be established in such a way
that no individual will be prevented from leaving the area.
