Reactions between reactive metals and iodine in aqueous solutions

Abstract Volatile I 2 is likely to be released from the core and primary system to the reactor containment in the event of a severe nuclear reactor accident. Within the containment, I 2 will be distributed between the aqueous and gas phases which makes it very important to study how I 2 will interact with containment surfaces in order to determine which processes might reduce the concentration of volatile I 2 . This study focused on the reactions of I 2 with some reactive metals available in the aqueous phase of the containment. The experiments were done under conditions similar to those in the containment of a boiling water reactor in a severe accident situation. Copper, zinc and aluminium are all capable of reducing the concentration of I 2 in the aqueous phase either by adsorption or by conversion of I 2 to I − . Copper binds I 2 on the surface as CuI, while zinc and aluminium converts I 2 to I − . Rate constants were determined for the adsorption of I 2 on Cu in the temperature range of 25–85 °C and for the conversion of I 2 to I − on Zn and Al in the temperature range of 25–140 °C. The rates of adsorption and conversion increased with temperature.