Absorption of iodine from aqueous solutions on nuclear reactors alloys

Iodide ions I-, molecular iodine I-2 and iodate ions IO3- absorption has be en studied on the three alloys which are present, in majority, in french nu clear reactors: Inconel 600, Zircaloy and 304 L stainless steel. Iodide and iodate anions are not absorbed on the three considered alloys and contribu te only for a negligible quantity to iodine retention on the nuclear reacto rs materials. Molecular iodine is absorbed according to: 304 stainless steel < Zircaloy < Inconel 600 Influence of pH has been studied: absorption increases in acidic medium and decreases in basic medium. Molecular iodine absorption increases with temp erature. Phenomenons which occur with iodine during the cold shut-down of a nuclear reactor and during its restart are discussed From the point of vue of iodin e volatilization risk.