Handling Radioactive Tritium: Inside a Specialized Laboratory
0:00 Introduction to Tritium: Tritium, a radioactive hydrogen isotope, is used in various applications, including self-luminous devices. This video explores a laboratory authorized to handle significant amounts of tritium (40g).
0:40 Calorimetry for Tritium Measurement in Contaminated Objects: Due to tritium's ability to penetrate materials and its weak beta radiation, traditional surface measurements are ineffective. Calorimetry is used to determine tritium content by measuring the heat generated from radioactive decay within a sealed container.
1:07 Atmospheric Monitoring with Ionization Chambers: Ionization chambers continuously monitor the lab's atmosphere for tritium leaks. Air is passed through the chamber, and any tritium decay creates a measurable signal, providing immediate leak detection. Additionally, a bubbler bottle collects tritiated water vapor for more sensitive, integral measurements over time.
7:46 Tritium Laboratory Infrastructure: The laboratory uses glove boxes with underpressure to contain tritium and protect operators. Experiments are built as complete as possible before being enclosed within the glove boxes to minimize the risk of tritium release during setup modifications.
8:13 TP2 Experiment: IR Spectroscopy of Tritium: This new experiment aims to study tritium's properties through infrared spectroscopy. It involves cooling tritium gas to high densities (liquid or solid state) to induce IR activity. A catalyst is used to control the conversion between different hydrogen/tritium isomers (ortho and para) which have distinct properties.
17:53 Glove Box Design and Material Considerations: Glove boxes are designed with safety in mind, featuring inward-facing gloves and covers for unused glove ports. Fluorinated polymers are avoided due to tritium's ability to react with them, forming corrosive hydrofluoric acid and damaging the material. Metal and ceramic components are preferred for their resistance to tritium.
23:29 Tritium Retention System: A closed-loop system continuously removes tritium from the glove box atmosphere. It converts tritium gas into tritiated water using a catalyst, then removes the water vapor using molecular sieves. The sieves are periodically regenerated, and the collected tritiated water is stored separately.
25:43 Specialized Vacuum Pumps: Tritium-compatible vacuum pumps are crucial. The lab utilizes metal bellows pumps for the higher pressure range and specialized scroll pumps with tight tolerances for lower pressures. These pumps avoid the use of hydrocarbons that could react with tritium.
32:01 Tritiated Water Recovery and Storage: The molecular sieves containing tritiated water are heated in a dedicated facility to release the water vapor, which is then condensed and stored. Tritiated water is considered more hazardous than tritium gas due to its higher biological incorporation and potential for DNA damage. Urine samples from personnel are regularly tested to monitor for tritium uptake.
35:48 Tritium Storage with Uranium Getters: Tritium is stored long-term by absorbing it into depleted uranium metal, forming stable uranium hydrides. This method ensures safe containment, even during power outages. The tritium can be released by heating the uranium to several hundred degrees Celsius.
43:00 Tritium Distribution System: A network of interconnected pipes allows for safe tritium transfer between glove boxes and experiments, minimizing the need for manual handling of containers.
44:14 Katrin Experiment (Brief Mention): The lab's tritium is also used in the Katrin experiment, which aims to determine the mass of the anti-neutrino.
44:35 Conclusion: The video highlights the impressive safety measures, specialized equipment, and closed-loop systems employed in the tritium laboratory to enable safe handling and research of this radioactive isotope.