Vapor condensation and thermophoretic aerosol deposition of cesium iodide in horizontal thermal gradient pipes

The aerosol deposition test series is being performed to investigate the de position of FP vapor and aerosol onto the inner surface of reactor coolant piping during a severe accident of a light water reactor. Vapor and aerosol of CsI as an FP simulant was introduced into the horizontal test section p ipes. No substantial decomposition of CsI was identified to occur both in t he high temperature inert and superheated steam environments. The compariso n between the results of the aerosol deposition test series and the thermo- fluiddynamic analysis with WINDFLOW implied that a profile of the CsI depos ition due to vapor condensation and thermophoretic aerosol deposition was i nfluenced hy local thermo-fluiddynamic conditions. Deposition velocities we re evaluated for CsI vapor and aerosol based on the deposition characterist ics of CsI and the thermo-fluiddynamic analysis.