Tritium Management and Control Using Carbon in a Fluoride-Salt-Cooled High-Temperature Reactor

Research characterizing hydrogen behavior on carbon has been primarily focused on collecting data at near-ambient temperatures and pressures for storage or for high volume applications such as fusion. Transport models of a pre-conceptual 236 MWt pebble-bed fluoride-salt-cooled, high-temperature reactor (PB-FHR) estimate that the production of tritium is relatively low resulting in partial pressures ranging between 0 and 20 Pa. Operating temperatures in an FHR range from 600 to 700 degrees C. Under these operating conditions, the interaction between hydrogen and carbon is currently undefined. Since an FHR contains large quantities of carbon (reflectors, fuel, structures), the tritium behavior in carbon must be investigated in order to develop methods to control tritium release rates to the environment and material corrosion. Preliminary modeling and experiments demonstrate high performance is achieved in a carbon adsorption tower, which can reduce system release rates by greater than 99%. This research aims to (1) accurately measure hydrogen uptake and kinetics on different types of carbon at prototypic conditions and (2) use tritium transport modeling to demonstrate the potential of carbon materials for tritium capture and control.