Mechanistic model of iodine mass transfer at pool surfaces

摘要

Mass transfer of molecular iodine (I_2) at the water pool-gas interface can be modeled by means of a water surface film renewal model superimposed to the established two-film theory, where the water-side I_2 mass transfer coefficient k_w is related to the I_2 molecular diffusivity in water D and the air-water contact time a according to The present paper describes a mechanistic approach to determine the contact time from the water flow distribution. The method makes use of a numerical simulation of the poolwater flow, and a numerical evaluation of the contact time distribution at the pool surface. Owing to the numerical treatment it can be applied to pool geometries of any kind, which makes it applicable for nuclear reactor safety studies in general k_w = (D/πa)~(1/2) The present paper describes a mechanistic approach to determine the contact time from the water flow distribution. The method makes use of a numerical simulation of the poolwater flow, and a numerical evaluation of the contact time distribution at the pool surface. Owing to the numerical treatment it can be applied to pool geometries of any kind, which makes it applicable for nuclear reactor safety studies in general.