Abstract
The MELCOR 2.1 computer code has been used to simulate the large-scale aerosol behavior experiment in the Containment System Test Facility (CSTF) vessel. The test LA2 of the Light Water Aerosol Containment Experiments (LACE) was designed to simulate the containment conditions and aerosol behaviors in the high-steam-concentration environment under a postulated severe accident. In this study, the Aerosol Condensation model’s (ACD) and Hygroscopic Model’s (HM) ability of the aerosol behavior prediction has been evaluated by the simulation of LA2 based on MELCOR 2.1 code. It has been found that the size distribution and depletion rate of dry aerosols are affected by the mass of water aerosol. The different masses of water aerosol in ACD and HM models are due to the different relative humidity calculated by these two models. The simulation models with different control volumes setup were evaluated to study the effect of water aerosol mass on aerosol depletion rate. The results show that higher water aerosol mass results are calculated and better airborne aerosol masses are predicted under the multi-control volume models. Based on this research①, it can be concluded that good results of aerosol deposition in the vessel are severely affected by the accuracy of water aerosol mass. The improvement of water aerosol mass results by the MELCOR code’s simulation should be thoroughly studied.
