Abstract: In the processes of nuclear fuel manufacture, scrap material such as uncontaminated reject powder and reject pellets, which would previously have been reprocessed chemially in conversion of the uranium values by dissolution into liquid form, is now mechanically reduced by crushing in a substantially inert atmosphere and converted to a slurry having between about 70 to 85 weight per cent solids, and then attrition milled utilizing scrap sintered UO.sub.2 pellets as the reducing medium. Grinding swarf generated during the centerless grinding of UO.sub.2 pellets may also be recycled provided it is sufficiently pure.