CLIMP-08
Rev. 1
Approved:______ 01/09/2015
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PARALLEL POLISHING
A.
Precautions
Review the PPE operational procedure (CLIMP-05) as Level 3 protections such as lab coats and
double-layer gloves shall be worn while working in the radioactive materials lab. Ensure
personal and finger ring dosimeters are worn. A disposal bag for storing any gloves, wipes, or
other material that ends up with contamination will be available during this procedure. Review
operating procedures for radiation detection (CLIMP-03) and contamination surveys (CLIMP04). Ensure radiation monitoring equipment is available and in working condition. Hands, shoes,
and lab coats must be surveyed and determined non-contaminated before leaving the lab.
With this procedure, the potential for spreading loose contamination is high but can be well
controlled. After any contact with the radioactive sample material, contaminated lapping
sheet, or contaminated lubricant the outer-layer gloves must be replaced with a new pair
before contact with device front panel interface. The sample preparation will be performed in
the fume hood in the Mechanical Engineering building, room B1215.
B.
Procedure
The use of parallel polishing is critical to sample preparation by mechanically polish specimens
down to thicknesses of 100 µm. By orientating the stage so its face is parallel with the polishing
surface, the polisher will reduce the overall thickness of the specimen and result in a uniform
smooth surface.
Figure 1: Picture of Parallel polisher
Figure 2: Close-up of securing mechanism
CLIMP-08
Rev. 1
Approved:______ 01/09/2015
Figure 3: Close-up of calibrating dial
and screws.
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Figure 4: Picture of fluid dispenser
1. Prepare the parallel polisher by calibrating the head. Calibration is essential because this
will create a parallel surface to the polishing surface. Secure the attachment to the end of
the head as in figure 2. By using the calibrating dial and screws in figure 3, the head can be
turned to provide the surface at any angle, in this case, the surface needs to be perfectly
flat. The calibration devices will have no direct contact with the contaminated samples.
2. The specimen is glued onto a thinning fixture with crystal bond which will then be attached
to the head.
3. A fluid dispenser (figure 4) will be attached to the polisher to allow controlled amounts of
suspensions or lubricants to be applied to the polishing surface. A nozzle supplies water (for
UO2) or blue lube (for UN, UN-UO2 composite) to the polishing surface which collects
particles from the specimen and prevents dust from spreading. A closed lubricant circuit will
be implemented to contain all fluids. The contaminated liquid will be funneled by a bowl
under the polishing wheel to be collected in a separate small plastic container (250-500 ml).
Before use, make sure the container is secured to the funnel hose and is labeled with the
radioactive material used.
4. A 30 µm grit lapping sheet is installed first and used to flatten the two faces of the
specimen: At 20 rpm and having the head oscillate, lower the head so that the specimen is
contacting the polishing surface. Once the surface is uniformly flat, the specimen is flipped
over and re-glued to the fixture. The specimen is flattened again so surface is uniform. In
this process, a layer of water will be covering the lapping sheet and the specimen will be
submerged in water. The particles from the specimen will be trapped in the water and no
dust will be generated.
5. The 30 µm grit lapping sheet will be manually removed, cleaned, and stored in the
designated storage box. A 15 µm grit lapping sheet is installed and 90 µm of the specimen is
removed by referencing the digital dial indicator.
CLIMP-08
Rev. 1
Approved:______ 01/09/2015
Page 3 of 4
6. The 15 µm grit lapping sheet will be manually removed, cleaned, and stored in the
designated storage box. A 9 µm grit lapping sheet is installed and 45 µm of the specimen is
removed by referencing the digital dial indicator.
7. The 9 µm grit lapping sheet will be manually removed, cleaned, and stored in the
designated storage box. A 6 µm grit lapping sheet is installed and 27 µm of the specimen is
removed by referencing the digital dial indicator.
8. The 6 µm grit lapping sheet will be manually removed, cleaned, and stored in the
designated storage box. A 3 µm grit lapping sheet is installed and 18 µm of the specimen is
removed by referencing the digital dial indicator.
9. The 3 µm grit lapping sheet will be manually removed, cleaned, and stored in the
designated storage box. A 1 µm grit lapping sheet is installed and 9 µm of the specimen is
removed by referencing the digital dial indicator.
10. The 1 µm grit lapping sheet will be manually removed, cleaned, and stored in the
designated storage box. A 0.5 µm grit lapping sheet is installed and 3 µm of the specimen is
removed by referencing the digital dial indicator.
11. The specimen’s surface is now mirror polished. The specimen is flipped over so that the
mirrored face is now glued to the fixture. Install a 30 µm grit lapping sheet and polish down
sample to desired thickness.
12. Once the specimen is at correct thickness, the polisher instrument is turned off, the sample
stage is removed from the polishing head, and samples are collected from the stage by
melting the crystal bond.
13. The lapping film is removed, cleaned with Kimwipes, and stored in the designated storage
box. The polishing surface and bowl are wiped down with Kimwipes to remove all
contaminated liquid. All wipes used for cleaning will be disposed of in the appropriate
contamination waste basket – make sure segregation of uranium and non-uranium waste is
observed.
CAUTION:
There is a significant risk of spreading contamination in the following step. Use
extreme caution.
14. The labeled container that has collected (at the back of the polisher, 250-500 ml) all
contaminated water or blue lube is removed from the system (detached from hose), left
open in a fume hood for contaminated liquid to evaporate. Replace the container left for
evaporating with a new plastic container behind the polishing instrument.
CLIMP-08
Rev. 1
Approved:______ 01/09/2015
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15. Conduct a survey of the work space, including the calibration needle, samples holder,
polisher platen, hot plate, and crystal bond stick, to ensure no contamination is present.
Follow the operation procedure discussing proper radiation contamination survey for
reference.
16. Update the sample inventory. After usage, wipe the scale with a Kimwipe and survey it.
Careful accounting must be made of the polished sample as well as material lost to the
lubricant and cleaning waste.