Effects of temperature and solution composition on evaporation of iodine as a part of estimating volatility of iodine under gamma irradiation

As a part of evaluating the volatility of iodide ions subjected to gamma irradiation, I2 evaporation experiments were performed with I2 and I- mixed solutions in the temperature range 26-80°C in an open, well-ventilated space. The evaporation of I2 was observed to follow primarily first order kinetics, depending on the I2 concentration. The evaporation rate constant increased rapidly with increase in temperature. The presence of I- slightly reduced the evaporation rate of I2 by forming relatively stable I3−. The effect of Cl- at <1.0 wt% on I2 evaporation was insignificant. The evaporation rate constants of I2 were 1.3 × 10−3 min−1 cm−2, 2.4 × 10−2 min−1 cm−2, and 8.6 × 10−2 min−1 cm−2, at 26°C, 50°C, and 80°C, respectively.