Safe-handling of tritiated water

The systems for safe-handling of tritiated water have been developed and used on time-sharing basis in the University of Tokyo. In these systems, an effective radiation protection has been achieved by the use of two kinds of hoods. One is a hood for various biological experiments and the other is a combined hood for decontamination procedure and storage procedure including pre-treatment of high level waste. The leakage of tritiated water vapor from these hoods was negligible small under the different experimental conditions. The inner boxes were put inside the cabinet and were used for the experiments when high levels of radioactivities were handled. Tritium monitors and samplers were used for monitoring the tritium concentration of the air in the hoods, in the room and in the exhaust from the hoods. The expiratory air monitor was used for monitoring the tritium intake by the researchers during and after the experiments. The inventory of tritiated water in the biological experiments was obtained. The data of tritium monitoring and inventory showed that the present systems are very efficient for the safe-handling of tritiated water. (author)