Laboratory Development Of A Tributyl Phosphate Solvent Extraction Process For Processing 20 Enriched Uranium Alloy Fuel PDF Download

For presentation at the 5th Nuclear Congress, Clevelands Apr. 7, 1959. Increasing emphasis has been placed recently on the application of solvent extraction to the recovery of uranium and plutonium from spent power reactor fuels. Zircaloy-2 jackets were removed from PWR blankettype fuels by dissolution with the Zirflex Process, and the UO/sub 2/ cores were dissolved in 10 M HNO/sub 3/. Zirflex treatment of prototype samples irradiated to 2500 Mwd/ ton resulted in satisfactory dissolution rates and losses to the dejacketing solution generally less than 0.2% for U and Pu. U-Zr alloy fuels were dissolved in 6 M NH/sub 4/F and adjusted for solvent extraction by the addition of ride was recycled by metathesis and precipitation. Stainless steel jackets were removed from Consolidated Edisontype fuels by dissolution in 6 M H/sub 2/SO/sub 4/ (Sulfex Process), and the ThO/sub 2/-UO/sub 2/ core was dissolved in 13 M HNO/sub 3/0.04 M F-0.04 M Al. Dejacketing losses in unirradiated samples were about 0.02%. Use of the ORNL Reference Darex flowsheet for APPR processing resulted in solvent extraction feed containing 30 ppm chloride. Mechanical equipment was designed to declad SRE fuels and chop and leach techniques are being developed to treat stainless and Zr clad ceramic fuel. A solvent extraction flowsheet was developed for Foreign Research Reactor Fuels, (Al-20% enriched U alloy) using a revised tributyl phosphate extraction system for the separation of Pu from U. Feasibility tests were carried out on the coupling of Redox solvent extraction with Darex and Niflex head-end treatments. New solvents for the reprocessing of power reactor fuels are being studied. Among these, the amines show an order of magnitude greater radiation stability than does tributyl phosphate. A primary amine was proposed for the recovery of U and Pu from Sulfex decladding wastes. (auth).