VALIDATION OF SPARC-90 POOL SCRUBBING MODEL IN SEVERE ACCIDENT CODE

During the decommissioning of the Fukushima Daiichi Nuclear Power Plant (NPP), the radioactive aerosols generated by the crushing works such as laser cutting and drilling fuel debris. Severe accidents in NPP also release the fission products (FP) in the form of aerosols into the containment. In boiling water reactor (BWR), the gas containing small aerosol particles is transported into the suppression chamber (S/C) and with the removal effect called pool scrubbing, the aerosols are trapped from the gas to the liquid. Due to the complex phenomena during the pool scrubbing, many assumptions and empirical formula of the thermal-hydraulics and aerosol physics are applied in the severe accident codes. The validation of prediction performance of these codes is crucial to the establishing the benchmark of the source term calculation. A number of experimental studies have been conducted before to evaluate the affecting factors such as the submergence, gas flow rate, particle diameter. In this paper, the code modelling of SPARC-90 in MECLOR is reviewed and a comparison on the decontamination factor between the calculation results of code and the experimental data without steam is discussed. The limitations of the MELCOR estimation are pointed out and the suggestions on modification and improvement of the pool scrubbing model in severe accident code are given.