Investigating the Effect of Force Input on the Pick-Up Factor of Loose Contamination - 21093

This paper details investigations in to the effects of force input on the removal of loose contamination from a surface. Dry swabbing is a common technique used in the characterisation of radioactive environments, however there is a large amount of uncertainty in the removal of contamination from dry swabbing. This uncertainty is often largely attributed to variability in the force input while swabbing, however no studies have yet quantified this effect. This paper demonstrates the effect that force input has on the removal of an idealised contaminant so that we can better understand the sources of uncertainty in pick-up factor. This paper finds that pick-up factor was dependent on the swabbing force, and that controlling the swabbing force can reduce the overall uncertainty in pick-up factor across multiple swabs. This paper found that force-controlled swabbing produced a much smaller standard deviation, (σ = 3.3), than uncontrolled swabbing (σ = 13.4 ). This paper also finds that there is reduced pick-up with higher swabbing forces. While a mean pick-up factor of > 20% was achieved for a 20 N swabbing force, this figure reduced sharply to < 10% for a 30 N swabbing force. (authors)