Kinetics of Gaseous Iodine Uptake onto Stainless Steel during Iodine-Assisted Corrosion

Abstract

Previous experimental work led to the development of a kinetic model that can be used to quantify iodine sorption behavior on a stainless steel surface. The kinetic model, based on the mechanism proposed in earlier work, consists of four chemical reactions. The model has reproduced the time-dependent adsorbed iodine concentration data on the coupons observed under various atmospheric conditions and different cycles of loading and purging. The iodine adsorption kinetics were then incorporated into a mass transport equation to simulate iodine sorption behavior from a flowing air stream through a length of stainless steel tubing. Discussed are the model, the simulation results, and their implications regarding the calibration of iodine transmission through long stainless steel sampling lines used for radiological monitoring of airborne iodine in a reactor containment building following an accident.