Validation of a Model for Estimating the Retention Efficiency in Pool Scrubbing

Abstract

For the estimation of particle retention in a liquid pool, a model is developed that is suitable to be implemented in the software package AC² developed by the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH. Within AC², the Containment Code System COCOSYS is used for the simulation of ex-vessel phenomena in the frame of postulated severe accident scenarios in light water reactor containments. As a lumped parameter code COCOSYS is characterized by a low simulation time compared to other simulation methods such as CFD. Validation works show an underestimation of the retention efficiency by the pool scrubbing model available in COCOSYS compared to experimental data. For the validation of the newly developed model APVOR experiments conducted in the SAAB test facility, EPRI experiments performed in the Phase I scrubbing facility and experiments from the SAPOS test facility at Shanghai Jiao Tong University are used. The results show a high agreement between the calculated retention efficiencies and the data obtained in the experiments. With a few exceptions, the deviation is less than ±10 %. A high uncertainty can be traced back to the used condensation model, which should be optimized in future activities. Compared to existing correlative approaches, the developed model shows high agreement with experimental data. The input parameters of the new model can be provided by COCOSYS and a calculation of the particle retention is possible without significant user influence.