Recovering Uranium from Graphite Fuel Elements

S>A method for the recovery of uranium from high-density, graphitized uranium-graphite fuel elements was developed on a laboratory scale as a head-end treatment for tributyl phosphate solvent extraction processes. Simultaneous disintegration and leaching of the uranium occur when the fuel is contacted with 90% HNO/sub 3/, either at room temperature or at the boiling point. More than 99.8% uranium was recovered when the fuel contained at least 5% (weight) uranium, but only 97% was recovered from fuel containing 0.7% (weight). Alternative techniques involve disintegration with bromine, ICl, or lBr prior to leaching with boiling 15.8M HNO/sub 3/. After bromine disintegration, 96 and 99.8% of the uranium were recovered from fuels containing 0.7 and 9% (weight) uranium, respectively. Both ICl and IBr were better disintegrating agents than bromine; however, uranium recovery after ICl disintegration was lower. (auth)