Description of the Pre Irradiation sample preparation for activated samples

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 g/g).

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.