Actinide recovery from combustible waste: the Ce(IV)-NHO/sub 3/ system. Final report

Technical Report · Fri Sep 14 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/5806463· OSTI ID:5806463

Thompson, G. H.; Childs, E. L.; Kochen, R. L.; Schmunk, R. H.; Smith, C. M.

Actinides in ash can be leached effectively by refluxing with Ce(IV) in HNO/sub 3/; solubilization of actinide in ash was greater than or equal to 95% at ash concentrations to 30 g/l in stirred leachant. Plutonium and americium were the actinides present in the ash. Solubilized plutonium and americium were recovered from Ce(IV)-HNO/sub 3/ solution by solvent extraction. Extraction of plutonium into 30% tributyl phosphate in n-dodecane gave 99.99% recovery. The plutonium-depleted solution was then extracted with 30% dihexyl-N,N-diethylcarbamolylmethylenephosphonate (DHDECMP). Americium recovery was 99.64%. The Ce(IV)-HNO/sub 3/ system was compared with the HF-HNO/sub 3/ system now in common use. Advantages of the former included less equipment corrosion, no volatilization of silica, safe oxidation of carbon residues, minimal secondary waste (Ce is recycled), and better solubilization of actinide in the initial contact. However, additional contacts do not significantly improve solubilization, and a small fraction of actinide is not solubilized with Ce(IV)-HNO/sub 3/ that can be solubilized by HF-HNO/sub 3/. The effect of the fission product ruthenium on the dissolution of actinides in the Ce(IV)-HNO/sub 3/ system was investigated briefly, and a method for removing the ruthenium electrolytically was developed. Several process flowsheets were also considered. Actinide recovery requirements will suggest which of these might best be used. 6 figures, 7 tables.

• Research Organization: Rockwell International Corp., Canoga Park, CA (USA). Energy Systems Group
• Sponsoring Organization: USDOE
• DOE Contract Number: EY-76-C-04-3533
• OSTI ID: 5806463
• Report Number(s): RFP-2907
• Country of Publication: United States
• Language: English

Related Subjects

052001* -- Nuclear Fuels-- Waste Processing
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACTINIDES
ASHES
CERIUM COMPOUNDS
DIAGRAMS
DISSOLUTION
ELEMENTS
FLOWSHEETS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
LEACHING
MANAGEMENT
METALS
NITRIC ACID
PLATINUM METALS
PROCESSING
RADIOACTIVE WASTE PROCESSING
RARE EARTH COMPOUNDS
RECOVERY
REFRACTORY METALS
RESIDUES
RUTHENIUM
SEPARATION PROCESSES
TRANSITION ELEMENTS
WASTE MANAGEMENT
WASTE PROCESSING