AEROSOL SIZE DISTRIBUTION IN URANIUM PROCESSING FACILITY FOR APPLICATION IN THE ASSESSMENT OF INTERNAL EXPOSURE

In circumstances of inhalation exposure the radiotoxicity of radionuclide depends on the fractional deposition of inhaled activity, which is governed by the aerodynamic characteristics of the particles. Although International Commission on Radiological Protection (ICRP) provides default size distribution parameters for work place aerosols, inhaled aerosol characteristics may be different depending on the physical and chemical conditions of aerosol generation process. The present study is undertaken to determine the particle activity-size distribution during operation of various significant processes of uranium metal production facility of Bhabha Atomic Research Centre (BARC). Activity median aerodynamic diameter (AMAD) and its geometric standard deviation (GSD) were estimated for these process areas for uranium aerosol particles. The AMAD varied from 3.2 to 10.06 µm and GSD ranged from 1.5 to 3.0. Also, the obtained size distribution was tested by Pearson's chi-squared distribution test method to ascertain the assumption that the particle size distribution is best described by log-normal relationship.