Simulating Gaseous 131I Distribution in a Silver Zeolite Cartridge Using Sodium Iodide Solution

131I is one of the most significant gaseous fission products in a nuclear power plant. Because of its high volatility at room temperature, iodine can be easily inhaled by radiation workers following release of radioiodine into the atmosphere. The thyroid gland is the critical organ for iodine uptake and is subject to radioiodine carcinogenesis. Hence, monitoring systems are provided in nuclear power plants to sample and evaluate ambient air for gaseous radioiodine content. Due to a highly preferential retention efficiency for iodine gas compared to noble gases, silver zeolite cartridges are typically used in nuclear power plants to adsorb gaseous iodine for sampling purposes. To obtain accurate measurements, preparation of a proper calibration standard to simulate the gaseous radioiodine distribution in the cartridge is essential. This project developed a silver zeolite cartridge calibration standard that uses sodium iodide solution to simulate gaseous iodine distribution. This calibration standard appears to satisfactorily simulate the gaseous radioiodine distribution in the silver zeolite cartridge.