Following critiques of multiple personal contamination events from entries into the Oak Ridge National Laboratory’s Spallation Neutron Source Transfer Bay, it was considered that the most likely causes for contamination were personal protective clothing doffing errors or moisture (sweat) allowing contamination to wick through the protective clothing. Radiological protection staff looked more closely, however, at the specific area of the clothing where contamination was highest; under enhanced lighting and photochromic manipulation, there appeared to have been some type of moisture in the area. Recognizing the possibility that moisture may have allowed for migration of contamination through the clothing, further experiments were undertaken to determine under which conditions this transport might have occurred.
The objective for this work was to identify the susceptibility of different types of personal protective clothing to various liquids encountered in the workplace.
Several tests were performed to determine if perspiration had enabled migration of contamination and to identify what other liquids might have affected contamination transport. Two layers of personal protective clothing were subjected to static conditions and dynamic conditions to include active rubbing of the materials while wet. Food dye added to each of the liquids tested enabled visual indications of liquid breakthrough. Additional tests were conducted to see if solid contamination could be transported through the materials along with the liquids.
All but one type of non-rubberized personal protective clothing in use at Oak Ridge National Laboratory were permanently compromised to some extent by the solvents used for decontamination.
It was determined that most common cleaning agents immediately and permanently destroyed the hydrophobic nature of several of the tested protective clothing materials, potentially allowing for radioactive contamination to penetrate through the material to the worker. Work around wet surfaces or performing wet decontamination will only be performed in protective clothing known to prevent transport of the wetting agent.