Development of a Catalytic Water Gas Shift Reactor for Fusion Fuel Exhaust Streams

Catalytic reactors based on the water gas shift reaction were designed, built and tested to provide data for the design of a prototype reactor as an alternative to the uranium hot metal beds in a Fusion Fuel Clean Up (FCU) system. The reactor was designed so it could be implemented into a FCU using only existing technology. A closed loop system was chosen so that safety and net efficiency would not be compromised during upset conditions. The system uses only pure reactants thus eliminating the requirement for a carrier gas. The prototype reactor contains only 10 g of catalyst and is expected to last at least five years. The reactor is small and operates at ∼490 K. It will convert water to hydrogen, at a CO/H₂O ratio of 1.5 with greater than 98% efficiency and with an estimated 95% efficiency for a tritiated stream of 90 000 Ci/day. This small decrease in efficiency is not expected to be a concern in the closed loop system proposed. Results show that the reactor performance is very stable even during upset conditions, wide ranges of flow, CO/H₂O variance upward from 1.3, and the presence of various contaminants. The maximum tritium inventory during operation in a FCU system is calculated to be 10.4 Ci. The expected waste disposal inventory of the reactor is 3.2 Ci.