In this book, the parametric performance of self-priming venturi scrubber is analysed for submerged operating condition, primarily for pressure drop and Iodine removal efficiency, using series of experiments. To remove the gaseous pollutants (Iodine) from contaminated gas during severe accidents, the venturi scrubber is used in Containment Filtered Venting System (CFVS) of Nuclear Power Plants (NPP). By measuring the quantity of Iodine in water, from iodometric titration, with distinct pH of water, the iodine removal efficiency of venturi scrubber is determined. The effect of Pool swelling is also deliberated by using hydrodynamic study.