Tritium contamination prevention using sacrificial materials

Tritium is produced by irradiating Tritium Producing Burnable Absorber Rods (TPBARs) in a Commercial Light Water Reactor at the Tennessee Valley Authority Watts Bar Reactor 1. The TPBARs are manufactured with strict materials specification for contaminants for all of the components. Despite meeting these requirements, gamma emitting contamination in the form of ⁶⁵Zn was detected in a glovebox that was designed to contain tritium. A forensic examination of the piping revealed that the zinc was borne fromnatural zinc. This zinc deposits at an anomalous distance from the extraction furnace based on vapor pressure. A method to capture the zinc was developed that is intended to prevent the further spread of the ⁶⁵Zn. This method relies on operating filter media at a specific temperature and location. While this approach is acceptable for the facility while it is in limited operation, as the facility undergoes increased utilization, there is a possibility of scheduling conflicts for maintenance and increasing dose to workers. In order to preclude these issues, methods to contain the zinc within the furnace module, an area designed for high radiation dose, were examined and experimental approaches were developed. These approaches used bulkmaterials and nano-materials deposited on various substrates that are compatible with tritium and the extraction process. These materials were tested to ascertain their zinc capturing capability, capacity, and characteristics. The first generation material was optimized and a process lid has been fabricated for testing.