A grind-leach method for the recovery of uranium from high-density graphite fuel elements containing greater than 5 weight per cent uranium has been developed on a laboratory scale as a head-end treatment for standard tributyl phosphate solvent extraction processes. With fuel ground to −16 mesh, greater than 99.8% of the uranium can be recovered by leaching twice with boiling 15.8 M nitric acid. Uranium recoveries were lower with less concentrated acid, and with fuel of larger particle size or lower uranium concentration. The grind-leach method is not applicable to fuels containing less than 3% uranium. Leaching −16+30 mesh samples of a fuel containing 1.5% uranium and 7.2% thorium with either boiling 15.8 M nitric acid or 15.8 M nitric acid−0.04 M sodium fluoride, resulted in uranium and thorium recoveries of 90 and 86%, respectively.