Affinity of charcoals for different forms of radioactive organic iodine

Abstract

During a serious nuclear reactor accident a large fraction of the radioactive iodine in the fuel can escape from the core and subsequently from the plant. While the noble gases in reactor fuel are more mobile than iodine, the iodine is often of greater concern as its chemistry and biology causes it to be more radiotoxic. Iodine has the potential to be re-concentrated in vivo in the thyroid. Filters containing charcoals are used both under normal operating conditions and during emergencies to retain iodine species, they are used in environmental sampling to estimate radioactive iodine and in respiratory protection systems such as air purifying filter respirators. During a nuclear accident iodine can exist in many forms. As the formation of organic iodine compounds other than methyl iodide has been observed in nuclear plants it can be reasoned that a failure of a charcoal to retain other organoiodines than methyl iodide could have adverse consequences. In this paper, the ability of different charcoals to capture various forms of radioactive organic iodine compounds has been explored. Besides elemental iodine used as reference methyl, chloromethyl, ethyl and isopropyl iodides have been studied together with iodoacetylene.