Description of the Pre Irradiation sample preparation for activated samples
Zelimir Djurcic and Andreas Piepke
University of Alabama
We describe here the procedures on how to prepare PPO samples for irradiation. Clean PPO samples
sent by manufacturer to our clean room facility are always subjected to the same procedure to
achieve reproducible clean conditions. The following procedure is used:
Upon receipt all samples are stored in our clean room as received. All packages are carefully
inspected to exclude possible mechanical damage and visible sample contamination.
Clean 4 ml polyethylene (PE) vials, screw cap type, with high resistivity to chemicals and high
temperatures were always used in this procedure. Prior to PPO filling, all PE vials were
additionally cleaned in new glass beakers using double-ionized (DI) water, high purity
(U/Th < 1·10-10 g/g, K < 2·-10 g/g), and
ultra-high purity HNO3 (U/Th < 1·10-13 g/g, K < 2·-11
First step is cleaning of new glass beakers with 30% HNO3 (high pure grade). They are
rinsed, then, with DI water and finally dried in the clean room oven at 1050C. Beakers
prepared in this way can be used for vial cleaning.
Clean glass beakers were filled with 50% high purity HNO3. PE vials were unscrewed and
both vials and corresponging caps submerged into a beaker. These parts were kept in for 1 hour.
The parts have been rinsed with DI water.
Second acid wash of the vials was performed with ultra pure HNO3 for 1 hour as well.
Again, parts were rinsed with DI water and then dried in a clean room oven at 600C.
New acid cleaned Teflon spatulas were used to fill PPO into PE vials from original packages.
Vials were closed carefully.
Mass of the vials was determined before and after PPO filling using precise analytic balance
with sensitivity of 10-4g.
The vials were melted shut with acid cleaned soldering iron used for this purpose only.
Mass was measured again on the analytic balance.
Following step is welding vials into secondary containment bag to prevent accidental vial
contamination during irradiation and hold PPO if leaks out of the vial.
Nothing was touched without new Nitrile gloves and Teflon twezeers. All preparation was
done in class 500 clean room at University of Alabama.