Annual Maintenance For The Sentinel Sentry 110 & Sentinel Sentry 330 Gamma-Ray Source Projectors - QSA Global SENTINEL SENTRY 330 Manual

d. Fully insert the wipe test swab into the 'S' tube and move back and forth to obtain the sample.
e. Carefully withdraw the wipe test swab from the outlet port while observing the survey instrument.
Withdraw the plastic bag over the wipe test wand without touching. Always assume the sample is
contaminated.
f. Remove the service bayonet fitting from the outlet port and rotate the outlet port cover into the closed
position.
g. In a low background (no radiation) area, switch the survey meter to the lowest scale and obtain a
background measurement. Leaving the survey meter stationary, move the plastic wrapped swab
towards the survey meter's detector to determine if a gross quantity of contamination is on the wipe
test. If the survey meter measures greater than 1 µSv/hr (0.1 mR/hr), contact QSA Global, Inc. for
instructions. If there is no measurable increase above background, the sample may be sent to the
SENTINEL™ laboratory for radio-assay. The SENTINEL™ laboratory will send a leak test certificate
after performing the radio-assay. Retain this certificate in your records.
In the event you are informed by the radio-assay laboratory that your leak test results indicate greater
than >185 Bq (0.005 µCi), you must immediately remove from service the radioactive sealed source,
the gamma-ray source projector and all remote controls, source guide tubes, collimators, lab stands,
etc. that were used in conjunction with that sealed source. You must cause the equipment to be
repaired or decontaminated and notify the regulatory agency (USA) within 5 days (check local
regulations for reporting requirements). Contact the sealed source manufacturer for assistance.
4.2.2 Leak Test for Depleted Uranium (DU)
Some regulatory jurisdictions require periodic leak tests every twelve months of all projection-type
gamma-ray source projectors that utilize DU for shielding. The purpose of the leak test is to detect the
long-term wear through of the device's source tube that may consequently expose the DU shielding. A
wipe-test wand that is both flexible and long enough to reach a bend radius or a wear point is required to
perform a leak test. The wand enables direct contact with the DU where the device's source tube has
worn through. A direct wipe of the DU is required due to the low specific activity of depleted uranium. The
wipe test for DU is obtained in the same fashion as a leak test of a sealed source utilizing the same
radiation safety procedures.
The analysis performed on the wipe test must be capable of detecting the presence of 0.005 µCi (185 Bq)
of radioactive material on the test sample. If the test sample reveals 185 Bq (0.005 µCi ) or more of
removable DU contamination, the gamma-ray source projector must be removed from service until an
evaluation of the wear on the 'S' tube has been made. Should the evaluation reveal that the source tube
is worn through, the gamma-ray source projector may not be used again.
DU shielded devices do not have to be tested for DU contamination while in storage and not in use.
Before using or transferring a device that has been in storage for more than 12 months, the gamma-ray
source projector must be leak tested for DU contamination prior to use or transfer. Please contact a QSA
Global, Inc. service center if you require leak test kits, radio-assay services or assistance in the disposal
of worn through gamma-ray source projectors.
4.3 Annual Maintenance for the SENTINEL SENTRY 110 &
SENTINEL SENTRY 330 Gamma-Ray Source Projectors
4.3.1 Maintenance Tools

Allen wrenches: 3/16, 9/64 and 3/32.

Calibrated torque wrench (inch/lbs) for ¼-20 socket head screws and 5/16 x 1½ long security
screw (SCR154).
QSA Global, Inc.  40 North Avenue Burlington, MA 01803
Operations Manual  MAN-038 March 2019
 888.272.2242  781.272.2000
 Page 42 of 100
 qsa-global.com