Aerosol pool scrubbing phenomena during the containment depressurization venting. Part I: Scaling analysis

•Aerosol Spent Fuel Pool scrubbing phenomena was analyzed.•PIRT of containment depressurization venting process was developed.•H2TS was used to complete the scaling analysis of SFP scrubbing phenomena. For the Chinese Advanced Passive Pressurized Water Reactor, one of the possible containment depressurization measures is to discharge to the Spent Fuel Pool (SFP) during severe accidents. During containment depressurization venting process, carrier gas with aerosol is injected into the SFP from the containment through a discharge sparger. To obtain the aerosol retention effect during this process, a scaled-down test facility have been designed and built. In this paper, the Phenomena Identification and Ranking Tables (PIRT) in the discharge pipe and the SFP is developed. Then, based on the Hierarchical Two-tiered Scaling analysis (H2TS) method, the scaling analysis of SFP scrubbing phenomena is completed. A jet flow model and a particle retention model are developed to analyze these important phenomenon, and a series of similarity criteria are obtained. Based on these similarity criteria, the CASSI test facility is designed, and the scaling rationality is evaluated.