Tritium Behavior Intentionally Released in the Radiological Controlled Room under the US-Japan Collaboration at TSTA/LANL

A series of planned tritium release experiments into the Tritium Systems Test Assembly (TSTA) tritium processing rooms (3000 m³), were performed under the US-Japan collaboration program at Los Alamos National Laboratory (LANL). These experiments were carried out to acquire data on the behavior of tritium in an actual tritium facility. These experiments were performed safely with no impact on the environment or worker safety using 37 GBq (1 Ci). The results showed that the migration of tritium within the facility was dominated by the residual airflow in the room and reached a uniform value in 30 ~ 40 minutes. After restoring the normal once through ventilation (5 air changes per hour), room tritium levels decreased to background in less than 1 hour. Residual surface contamination was detected (max. 1 Bq/cm² level). Residual contamination levels were found to be in order of decreasing contamination: linoleum > epoxy coating > acrylic resin > butyl rubber > stainless steel, from soaking results. The surface contamination increase as a result of the tritium release, was reduced to background with the normal ventilation within a few days.