For presentation at the American Chemical Society's Nuclear Technology Symposium, Boston, Apr. 5-10, Information is presented from studies with materials and conditions simulating those expected in anm aqueous homogeneous reactor for the formation of insoluble corrosion and fission products in aqueous UO/sub 2/ SO/sub 4/ solutions used as a reactor fuel. Sulfate salts which become insoluble as the temperature inereases deposited preferentially and reversibly on hot walls. Oxides from hydrolysis of sulfate salts deposit on any surfaces while insoluble corrosion products released into the solution show variable degrees of circulation. (auth)