EVALUATION OF AEROSOL POOL SCRUBBING EFFICIENCIES IN FUKUSHIMA DAIICHI UNIT 1

摘要

Simulations with MELCOR and ECART mechanistic computer codes were performed to analyze the efficiency of aerosol pool scrubbing phenomena in the Fukushima Daiichi-Unit 1 scenario. The thermal-hydraulic boundary conditions and the fission product releases into the suppression pool were determined with MELCOR referring to the in-vessel phase, while sensitivity analyses on the aerosol scrubbing into the water were carried out both with MELCOR and ECART. The actual pool depth, as well as aerosol particle material density and geometric aerosol parameters, were considered as parameters having significant influence on the aerosol decontamination factor. The study confirms the great importance of scrubbing in the mitigation of source term associated to radionuclide inform of particles and shows a good agreement between the two code models.