Performance tests of the emergency room air tritium removal system for the Tritium Systems Test Assembly

One of the major safety components of the Tritium Systems Test Assembly (TSTA) is the Emergency Tritium Cleanup System (ETC). It will remove tritium from the air of the tritium handling areas at TSTA should an accidental release occur. Measurements have been made on the efficiency of the ETC to remove hydrogen isotopes from room air. The ETC removes tritium from room air by the catalytic conversion of gaseous tritium (T2) to the oxide form (T2O) and then subsequent removal of the water by condensation and further drying by passing the air stream through molecular sieve. The major components of the system are: Compressors, which collect room air and compress it to 50 psia; Catalyst bed, which converts hydrogen isotopes to water and is operated at approximately 3000F; Condenser, which cools the process air to 350F condensing water and reducing the water concentration to approximately 2000 ppm; Water Storage Tanks, in which the condensed water is collected; and Molecular Sieve Beds, which dry the air to a moisture level of about ppm water. The temperature of the catalyst bed is maintained by the heat of compression from the compressor. During the initial warm up of the bed, hydrogen can be added to provide local heating on the catalyst surface thus maintaining the efficient conversion of tritium gas to the water form. Hydrogen can also be added to the input of the ETC to provide a dilution of the tritium to maintain a higher conversion efficiency. In addition, water can be added between molecular sieve beds to provide a dilution and more efficient removal of tritiated water by the molecular sieve. The following parameters were determined: catalyst bed heat up time and efficiency to convert hydrogen isotopes to the oxide form; water removal efficiency of the refrigerated dryer and molecular sieve beds; and the effect hydrogen and water addition on the efficiency of hydrogen removal