SURFACE EFFECTS IN THE TRANSPORT OF AIRBORNE RADIOIODINE AT LIGHT WATER NUCLEAR POWER PLANTS.

It has long been noted that changes occur during the transport of radioiodine in ventilation systems from the location of material escape to plant discharge. These changes are explainable in terms of simple transport by air streams. This study was conducted to verify the effects of surfaces on airborne radioiodine, and to determine if they can be applied in an engineering sense to reduce the radiological impact of radioiodine released from plants. The surfaces applied were aluminum, galvanized steel, concrete, and paints. The results indicated that surface interactions do shift the chemical forms of radioiodine from the more reactive elemental form to the less reactive organic form, and that the iodine can be retained for a sufficient length of time to affect the concentration ratios of long-lived isotopes relative to those with shorter half-lives. Concrete and painted surfaces were found to be most effective.