Experiment for evaluation of radioactive iodine transfer rate into the exhaust gas in the sodium removal process

not registered; not registered; Nakasuji, Takashi

Radioactive sodium removal is required to primary system components of sodium cooled fast reactor for inspection, repair or maintenance. A steam and an alcohol process are generally used to removal of this sodium from the components. In order to evaluate safety of the facility in which radioactive sodium is removed from the components by using alcohol, it was required to determine transfer rates of radioactive Iodine into gas phase and liquid phase, when the sodium was dissolved with alcohol. Based upon above requirement, a study was conducted. This report has been described experimental procedure and measuring results of Iodine transfer rates. Measurement of the transfer rates have been done by counting iodine activity distributed between the gas phase and the liquid alcohol phases, after dissolving sodium into the alcohol containing radio Iodine, scince preparation of sodium contained radio Iodine in phomogeneous is difficult. Transfer rate of Iodine-131 into the gas phase was below 10, when bubbling gas was introduced into alcohol in a reaction vessel. Transfer rate, however, into the gas phase indicated 10 level when cover gas flowing was introduced into a upper space in the reaction vessel with conbination of the bubbling gas flow. Transfer rate of Iodine-131 into the liquid phase was 1.0. So it was found that Iodine-131 is near completely retained in the liquid phase under this experimental conditions.