Experimental study of AESOP code for aerosol removal behavior from a rising gas bubble in water pool and parametric study for application to sodium pool system

Miyahara, Shinya*  ; Koie, Ryusuke*; Uno, Masayoshi*; Kawaguchi, Munemichi*; Sato, Rika; Seino, Hiroshi 

In a postulated accident of fuel pin failure of a sodium-cooled fast reactor, a fission product of cesium will be released from the failed pin as an aerosol such as cesium iodide and/or cesium oxide together with a fission product noble gas such as xenon and krypton. The xenon and krypton released with the cesium aerosols into the sodium coolant as bubbles have an influence on the removal of cesium aerosols by the sodium pool in a period of bubble rising to the sodium pool surface. Then, the cesium aerosols could transfer into the containment vessel as an initial inventory of a source term. To meet this phenomenon, the computer program AESOP (AErosol scrubbing in SOdium Pool) has been developed to deal with the expansion and the deformation of the bubble together with the aerosol absorption considering the effects of the particle size distribution and the agglomeration in aerosols. In this study, simulation experiments have been conducted using simulant particles under the condition of room temperature in water pool and nitrogen gas bubble systems and the experimental results were compared with the analysis results calculated under the same condition by the AESOP code. Furthermore, to examine the applicability of the AESOP code to the sodium pool system, the sensitivities of the physical parameters on decontamination factor (DF) of fission product aerosols such as the initial bubble diameter, the sodium pool depth and the temperature, the aerosol particle diameter and the density, the initial aerosol concentration in the bubble had been studied and the analysis results were discussed for the sensitivities of the parameter as same as DF of the aerosol.