Specialized computer codes that model the behavior of aerosol particles propagating through a system of pipes or air ducts are used for assessment of aerosol particle deposition. Developed in Russia, SOCRAT/V3 is one such code. SOCRAT/V3 was used for modeling of the transport of radioactive aerosols containing the 137Cs radionuclide through an air duct during a real emergency. The obtained results of the modeling were used to estimate the exposure dose rate (EDR) of gamma radiation near the air duct. The results of the estimation were compared with data of real measurements of the gamma-radiation EDR along the air duct.

This paper proposes an approach to assessment of source term in the case of radioactive aerosol releases using (1) a thermophysical code (SOCRAT/V3), allowing modeling of physical processes that influence the formation and transport of aerosols, and (2) data of in situ measurements for the external EDR from contaminated air ducts.