Investigation of differences of phenomena of diffusiophoresis and thermophoresis from aerosol deposition in modified ART Mod 2 code

Abstract

Fission product behavior assessment in containment vessel (CV) is one of the important areas in safety analyses because the CV is the final release protection. Modified ART Mod 2 code is used to study aerosol deposition phenomena in the CV. From Phébus FPT experiments, the phenomena of diffusiophoresis and thermophoresis on wet condensers were occurred in the CV. The two phenomena are recognized to be the same thing. However, this is not a universal view on these phenomena, which are evaluated separately in the modified ART Mod 2 code. In previous study on the modified ART Mod 2 calculation of Economic Simplified Boiling Water Reactor (ESBWR) and Phébus FPT experiments, there was more diffusiophoresis than thermophoresis in the case of simulating single volume of the CV while there was more thermophoresis for multiple volume case. This research aim is to conduct a ceteris paribus sensitivity analysis of representative parameters affecting diffusiophoresis and thermophoresis namely aerosol size, pressure, and gas temperature, under different nodalizations in the modified ART Mod 2 code using the Phébus FPT experiments to investigate the differences. As a result, differences of gas temperature between atmosphere and wall in single volume most affect diffusiophoresis while differences of temperature between atmosphere and wall of multiple volumes most affect thermophoresis.