[en] HTGR graphite-based spent fuel has been thermally analyzed to provide data for a reprocessing design. Steps include crushing, burning in fluidized beds, size classification, dissolution, and solvent extraction. The principal problem is that the bunkers holding feed and product between steps need sizing for decay heat. Constraints have been set for different modes of cooling. However, criticality may prove stricter. Adverse effects of solvent degradation products in the Acid--Thorex process, mainly dibutyl phosphate (DBP), are reduced by using a partition flowsheet and by adding fluoride ions to the 1BX and 1CX columns