Photochemcial Removal of Radioactive Iodine from Air

Abstract

An advanced method of removing both organic (RI) and inorganic (I2, HI) forms of radioactive iodine from air, developed by AECL Research is reviewed. The method employs ultraviolet light (200-300 nm) to convert RI and BI to molecular iodine (I2) and the corresponding oxidized forms of the free radical R (alcohols, aldehydes, and ketones) and the hydrogen atom H (H20). Molecular iodine can be further converted by reaction with ozone to iodine oxide solids, which can react with water vapour to form solid and nonvolatile iodine oxyacids or, in the presence of water, dissolve to form nonvolatile iodates. This paper discusses applications of the photochemical method to the construction of scrubbers that can be used to remove volatile radioiodine in air inside a reactor containment or in air released during venting of a reactor containment following an accident.