Radiolysis of Cesium Iodide Solutions in Conditions Prevailing in a Pressurized Water Reactor Severe Accident

Measurements were made of I₂ formed when aqueous cesium iodide (CsI) solutions were exposed to two temperatures, 43 and 95°C, with irradiation. Iodine partition coefficients were obtained from the experiments. The parameters varied were dose, CsI concentration, and Cs₂CO₃ concentration, in the presence of air-carbon dioxide and air-carbon dioxide-hydrogen mixtures, to provide information to calculate the form in which iodine released from fuel as CsI in a reactor accident might reach the environment. In a series of experiments, a two-compartment cell was used to trap the gaseous iodine produced. In this case, it was found that the quantity of gaseous iodine produced increased approximately linearly with the dose (at the dose rate used).