An Integrated Small Modular Reactor is an Integral Pressurized-Water Reactor (iPWR) with a relatively high surface-area-to-volume ratio. It has been hypothesized that a higher surface-area-to-volume ratio aids passive aerosol decontamination through various deposition phenomena, namely thermophoresis, diffusiophoresis and gravitational settling. Accordingly, particle deposition was studied within a range of thermal-hydraulic parameters, namely pressure, temperature and A/V ratios, in the presence as well as the absence of steam. It was found that presence of steam, an increasing thermal gradient between the Reactor Vessel (RV) and Containment Vessel (CV) walls, an increasing A/V ratio, and an increasing initial pressure enhance particle deposition. As part of this study, a Computational Fluid Dynamics (CFD) model with the capability to predict particle deposition, particle velocities and steam condensation was developed using User-Defined Functions for the 3-D CFD commercial code CONVERGE. It was found that the CFD results qualitatively agreed with the experimental data in the context of predicting particle deposition with respect to varying thermal-hydraulic parameters. Overall, the aerosol removal mechanisms are sensitive to varying thermal-hydraulic parameters.