Extensive recycle of nitric acid and water in a nuclear fuel reprocessing plant can result in the buildup of deleterious trace impurities; identified materials of serious concern include fluoride, chloride, and organic materials. Methods for removal of these deleterious materials must be developed to allow increased aqueous recycle. Fluoride at 10 to 100 µg/ml can be removed from 10 M HNO3 using a silica gel column. Chloride can be removed from 10 M HNO3 by sparging with ozonized air, a method that is rapid even at room temperature. Carbonaceous material can be removed by pressurized aqueous combustion and by ozonation and the latter can be greatly accelerated by the presence of Ag+ ions.