Sampling and characterization of aerosols formed in the atmospheric hydrolysis of UF6

When gaseous UF6 is released into the atmosphere, it rapidly reacts with ambient moisture to form an aerosol of uranyl fluoride and HF. As part of the Safety Analysis program, the authors performed several experimental releases of UF6 (from natural uranium) in contained volumes in order to investigate techniques for sampling and characterizing the aerosol materials. The aggregate particle morphology and size distribution have been found to be dependent upon several conditions, including the relative humidity at the time of the release and the elapsed time after the release. Aerosol composition and settling rate have been investigated using isokinetic samplers for the separate collection of UO2F2 and HF, and via laser spectroscopic remote sensing (Mie scatter and infrared spectroscopy)