Current through Register Vol. 24-18, September 15, 2024
(1) This section
applies to licensees or registrants with sources of radiation in
nonself-shielded irradiators. This section 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 a radiation level of five Gy (500 rad) or more
in one hour at one meter in an area that is accessible to any
individual.
(2) Each area in which
there may exist radiation levels in excess of five Gy (500 rad) in one hour at
one 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:
(i) Function automatically to prevent any
individual from inadvertently entering a very high radiation area;
and
(ii) 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 one mSv (0.1 rem) in one hour; and
(iii) 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 one mSv (0.1 rem) in one
hour.
(b) Additional
control devices shall be provided so that, upon failure of the entry control
devices to function as required by (a) of this subsection:
(i) 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 one mSv (0.1
rem) in one hour; and
(ii)
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 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:
(i) 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 one mSv (0.1 rem) in one hour;
and
(ii) 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.
(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 (c) and (d) of this subsection.
(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 one mSv (0.1 rem) in one hour.
(i) 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.
(3) The entry
control devices required in subsection (2)(a) of this section shall be tested
for proper functioning:
(a) Prior to initial
operation with the source of radiation on any day, unless operations were
continued uninterrupted from the previous day; and
(b) Prior to resumption of operation of the
source of radiation after any unintentional interruption; and
(c) In accordance with a schedule for
periodic tests of the entry control and warning systems submitted by the
licensee or registrant and approved by the department.
(4) 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.
(5)
Licensees, registrants, or applicants for licenses or registrations for sources
of radiation within the purview of subsection (2) of this section 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 subsection
(2) of this section, such as those for the automatic control of radiation
levels, may apply to the department for approval of alternative safety
measures. Alternative safety measures shall provide personnel protection at
least equivalent to those specified in subsection (2) of this section. 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.
(6) The entry control devices required by
subsections (2) and (3) of this section shall be established in such a way that
no individual will be prevented from leaving the area.
(7) The licensee shall maintain records of
tests made pursuant to subsection (3) of this section on entry control devices
for very high radiation areas. These records shall include the date, time, and
results of each such test of function.
Statutory Authority:
RCW
70.98.050. 94-01-073, § 246-221-106,
filed 12/9/93, effective 1/9/94.
