AIRSOURC code aerosol model in radioactive waste tanks

An aerosol model was developed for a radioactive waste tank vapor space and ventilation system. The source of aerosol formation was modeled from gas bubble bursts at the liquid surface. The gases contained in these bubbles are formed by radiolytic breakdown of liquid and organic materials in the radioactive tank contents. The model accounts for the rate of radiolytic gas formation and the rate of tank liquids that are released as aerosols. The concentration of particles in the tank vapor are modeled as a function of the deposition rate of dry particles and the vapor removal rate by ventilation. The ventilation rate in tanks without an active ventilation system has a threshold level that is driven by atmospheric pressure variation. The model predictions are compared to measurements in several typical waste tank vapors of the Hanford Site waste storage tanks