The sampling and removal of tritiated water vapor in Taiwan research reactor

The Taiwan Research Reactor (TRR) is a research facility in Taiwan. TRR is a heavy water reactor designed based on the National Research Experiment (NRX) with output thermal power 40 MW. On January 3, 1973, it reach criticality. TRR had been operated for 15 years and was permanently shut down in early 1988. TRR uses heavy water moderation and light water cooling. Hence, some tritium was created when deuterium captures a neutron. The inside of the Calandria has been washed with clean water after shutdown. After draining the water in the interior, it is inevitable that some residual water would remain at the bottom of the Calandria. Air sampling and analysis techniques were employed to detect and quantify tritiated water vapor. The investigation of tritiated water vapor in the TRR Calandria proved potential tritium contamination risks. Adopting the vapor condensation drying technique proved effective in removing tritiated water vapor from the TRR Calandria. After the removal of tritiated water vapor, the air in the Calandria no longer contains rich concentration of tritiated water vapor. That will help to ensure a safe environment for decommissioning operations.