Validation of Tritium Protection Factors of Respiratory Protective Equipment: Setup and Initial Tests

Several types of radiological respiratory protective equipment (RPE) are used in tritiated environments at nuclear facilities and nuclear power plants to protect workers in those environments. It is crucial that the level of protection the RPE provides is well understood. A tritium protection factor (PF) may be assigned to RPE. The PF is often defined as the ratio of the tritium concentration in the ambient air to the tritium concentration in the breathing air. Field observations at Canada Deuterium Uranium (CANDU) nuclear plants indicate that the in-use PFs are too conservative and do not represent actual internal uptakes following work in tritiated atmospheres. To improve radioactive work planning and work execution efficiency, more accurate tritium PFs are needed to cover the variety of personal radiological RPE currently in use. In order to test PFs of RPE, Kinectrics has designed, manufactured, and commissioned a tritium facility, referred to as the tritium exposure box (TEB), through support from the CANDU Owners Group. The TEB is a self-contained enclosure that permits the use of a full-sized mannequin with RPE for testing in a tritium oxide atmosphere. Tritium concentrations of up to 3.7 × 10⁸ Bq/m³ may be achieved and maintained inside the TEB. The clean airflow to an air-supplied suit may range from 420 to 800 standard liters per minute. Following the successful commissioning of the TEB, Kinectrics has performed testing of an air-supplied plastic suit to determine the protection provided.