Abstract: The invention provides a new high temperature isotopic exchange fuel processing loop for tritium recovery in which tritium is exchanged out of impurities such as tritiated ammonia, methane and water by swamping with H.sub.2 and isotopically equilibrating the mixture in a high temperature reactor. Downstream of the reactor is a Pd/Ag permeator for separation of the hydrogen from the impurities, the separated hydrogen being sent to an isotope separation system for tritium recovery and the residual impurities being recycled. The process eliminates the need for impurity oxidation and electrolysis of DTO and does not rely on complicated catalytic decomposition reactions.