Determination of the Size Distribution of Radioactive Aerosols in the IVV-2M Reactor Room Atmosphere

Abstract

The results of a determination of the particle size of radioactive aerosols in the reactor room of the IVV-2M reactor facility at the Institute of Reactor Materials are presented. A four-stage diffusion battery with mesh catching elements and a five-stage setup was used to determine the size of aerosol particles. This sampling arrangement makes it possible to study the distribution of radioactive aerosols in the size range 0.5 nm to 23 μm. The gas–aerosol mixture studied in the reactor room contains the radioactive noble gases ¹³⁸Xe and ⁸⁸Kr, their decay products ¹³⁸Cs and ⁸⁸Rb, and the fission product ¹³²Te. Three basic modes in the range of ultrafine aerosols with active median thermodynamic diameter 0.7, 6, and 35 nm were obtained for this mixture. The relative amount of the aerosols of size <50 nm is 25–30%. No radioactive aerosols with particle size >0.5 μm were detected.