The Analysis of Sedimentation Rate of Sodium Aerosol in a Hypothetical Accident of CEFR

The present work was undertaken to evaluate the sedimentation rate of the sodium aerosol in a hypothetical sodium fire accident of China Experimental Fast Reactor (CEFR). In the sodium fire accident, sodium aerosol which was hazardous for facility and people as a result of its chemical property and radioactivity, must be carefully evaluated. In this publication, the chemical and physical characteristics of sodium aerosol particles as well as factors that influence the sedimentation rate of sodium aerosol during its transport is attempted to be analysed. Besides, a simplified model is given to calculate the sedimentation rate when aerosol getting through the sodium fire ventilation system of CEFR. It has been found that the sedimentation rate is largely determined by gravity and turbulent diffusion; other factors, such as Brownian movement and thermophoretic force, could be ignored, since they almost have little effect. Using the model, we find that the loss through the ventilation system is about 5%.