Configuration Control Policy & Procedure
Scope: This policy describes requirements and authorizations necessary to initiate and perform work on radiation safety systems. It addresses mainly
the administrative controls that the APS has put into place to ensure the
integrity of beamline shielding.
APS Configuration Controls are the
administrative controls (i.e., the policies and procedures) that the APS
has placed on beamline shielding components.
White beam is an x-ray beam whose
spectral characteristics have not been modified from those produced by
an insertion device or bending magnet source, except through the introduction
of filters. For the purposes of this policy, the term white beam
includes those x-ray beams that have been reflected from a mirror but have
not passed through a monochromator.
Monochromatic beam is an x-ray beam
whose spectral properties have been defined by the use of a monochromator
to select an energy range (and corresponding harmonics) with a relatively
narrow bandwidth, typically less than a few percent.
Under prior APS Configuration Controls, components
fell into two categories:
Critical components: Beamline components
used to stop, for shielding purposes, the white synchrotron and bremsstrahlung
radiation. These include:
Portions of the shielding system that are not directly exposed to the white
synchrotron or bremsstrahlung radiation. These include:
White beam stops and shutters
Bremsstrahlung stops and collimators
Masks that protect the above components
The APS will verify the alignment of these
components, and their radiation shielding integrity will be verified by a radiation
Shielded beam transport
Temporary local station shielding
The APS will verify the shielding integrity
of these components with a radiation survey.
NOTE: All components are now referred to as "Radiation Shielding Systems" or components under "Configuration Control." They are no longer tagged as "critical" and "non-critical" components. This is old terminology but is, at times, still referenced. All RSS components are now tagged with a red sign reading " APS Radiation Safety - Do not remove or change this component without an approved work permit. Contact 2-0101."
Because of the higher risks associated
with exposure to white synchrotron radiation, it is the APS policy that
the alignment of components once deemed "critical" be verified by the APS.
Functionally, each white beam shutter and
stop must stop the x-radiation as well as manage the thermal load of the
white beam. Though the mechanical assemblies that perform these functions
may be physically separated and may have different alignment tolerances,
both parts of the assembly shall be treated as critical components.
In addition to critical components, there
are many components that are exposed to the direct white synchrotron beam
but whose presence and performance does not impact personnel safety. Such
components include, but are not limited to, filters, white beam slits,
monochromators, and mirrors.
As part of the beamline commissioning process:
1. The CAT prepares a list of components
under APS Configuration Control, which is consistent with the approved
operation envelope of the beamline; the list is approved by the APS and
posted in the beamline cabinet at the end of the sector.
2. Components under APS Configuration Control will be tagged by a Floor Coordinator.
Each white beam transport is to be tagged
as under APS Configuration Control. For transport designs with the vacuum
pipe mounted within a shielding enclosure, each removable cover shall be
tagged. For transports with lead shielding as an integral part of the vacuum
spool pieces, the control tags shall be installed on each section of shielded
transport and on each exposed flange or flange cover.
All of the front-end components housed
in the FOE will be put under APS Configuration Control and a tag placed
on the support table.
Before a component under APS Configuration
Control may be moved or worked on, a Configuration Control Work Permit
must be completed, approved by a Floor Coordinator, and posted in the beamline
cabinet. Refer to the Configuration Control Work Permit Policy and Procedure
for further details.
Patti Pedergnana or
Nena Moonier for information or problems relating to this web page.