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U.S. Department of Energy
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RECENT DEVELOPMENTS IN FEED PREPARATION AND SOLVENT EXTRACTION

Technical Report ·
OSTI ID:4129919

Increasing emphasis has been placed recently on the application of solvent extraction to the recovery of uranium and plutonium from spent power- reactor fuels. Zircaloy2 jackets were removed from PWR blanket type 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 uranium and plutonium. Zr-U alloy fuels were dissolved in 6 M NH/sub 4/F and adjusted for solvent extraction by the addition of Al(NO/sub 3/)/sub 3/ and HNO/sub 3/. In an alternative procedure, fluoride was recycled by metathesis and precipitation. Stainlesssteel jackets were removed from Consolidated Edison type fuels by dissolution in 6 M H/sub 2/SO/ sub 4/ (Sulfex process), and the ThC/sub 2/-UO/sub 2/ core was dissolved in l3 M HNO/sub 3/-0.04 M F0.04 M Al. Dejacketing losses in unirradiated samples were about 0.02%. Use of the ORNL Deference Darex flowsheet for APPR processing resulted in solventextraction feed containing 10 ppr chloride. Mechanical equipment was designed to declad SRE fuel, and chop and leach techniques are being developed to treat stainlessand zirconium-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 plutonium from uranium. 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 uranium and plutonium from Sulfex decladding wastes. (auth)

Research Organization:
Oak Ridge National Lab., Tenn.
NSA Number:
NSA-15-000272
OSTI ID:
4129919
Report Number(s):
CF-58-11-91(Rev.)
Country of Publication:
United States
Language:
English