SIGMA 150Ci - Manual (Page 33)

4.3
MAINTENANCE INSTRUCTIONS
Annual maintenance requirements
Radiographic exposure devices used under normal environmental conditions should only
require complete maintenance once a year. Complete maintenance on the associated
equipment including the remote controls and source guide tubes should be performed every
three months to detect deficiencies and to prevent corrosion and wear related problems.
The complete maintenance of the exposure device requires the disassembly of the exposure
device to enable a detailed inspection of all major components. Therefore, the inspection
and maintenance requires transfer of the source assembly from the exposure device into
a source changer performed inside of a restricted area. The annual inspection and
maintenance must be performed by individuals specifically trained, qualified and
authorized for this work.
Perform the following steps to transfer the sealed source from the exposure device into a
source changer:
1 Perform a survey of the exposure device to ensure measurable dose rates are less than
200mR/hr (2mSv/hr) when loaded to maximum capacity. Perform a radiation survey and an
inspection of the source changer to be used according to the source changer's operating
instructions manual.
2 Perform a daily inspection of the remote controls, source guide tube(s) and exposure
device according to the daily inspection section of this manual. If the source assembly
connector fails the NO GO gauge test, do not proceed with transfer of the source assembly.
Contact an AEA Technology QSA service center for advice on disposal of the source assembly.
Use the Model 550 NO GO gauge to check the remote control cable connector before and
after a connection to the source assembly connector. For complete instructions to use the
NO GO gauge and points tested, review the daily inspection instructions. (See page 3.8)
Do not use remote controls that do not meet the inspection criteria described in the
daily inspection.
3 Set up the equipment within a restricted area before transferring the source assembly
into the source changer according to the instructions supplied with the source changer.
The transfer must be performed by properly trained and licensed personnel. Use a survey
meter to perform confirmatory surveys of the exposure device, source guide tube and
source changer to confirm that the sealed source is properly secured. Engage the lock
on the source changer to lock the sealed source within the source changer.
Remove the source identification tag from the exposure device and fasten it to the
source changer.
Attach a Model 550 connector gauge (jumper) to the end of the remote control cable
connector found inside of the protective cover of the locking mechanism. The jumper will
allow removal of the remote controls from the locking mechanism of the device after the
remote control cable connector is returned to the exposure device lock.
Leak testing
Leak test of the radioactive sealed source
Periodic leak tests of the radioactive sealed source are required by most national regulations.
The leak test provides a confirmation of the integrity of the hermetically welded sealed
source by determining the amount of removable contamination. In most regulatory
jurisdictions, a leak test of a sealed source must be performed every 6 months or prior to
its first use after removal from storage. Acceptable results of a radio-assay must indicate
removable contamination is less than 0.005µCi (<185Bq). To perform a wipe of the
radioactive sealed source, perform the following steps:
1 Survey the exterior surface of the Model 880 exposure device to ensure the dose/rates are
less than 200mR/hr (2mSv/hr).