Demonstration of the UNEX Process for the Simultaneous Separation of Cesium, Strontium, and the Actinides from Actual INEEL Sodium-Bearing Waste

Technical Report · Mon Nov 01 04:00:00 EST 1999

DOI:https://doi.org/10.2172/911483· OSTI ID:911483

Law, Jack Douglas; Herbst, Ronald Scott; Todd, Terry Allen; Romanovskiy, V; Smirnov, I; Babain, V; Zaitsev, B; Esimantovskiy, V

A universal solvent extraction (UNEX) process for the simultaneous separation of cesium, strontium, and the actinides from actual radioactive acidic tank waste was demonstrated at the Idaho National Engineering and Environmental Laboratory. The waste solution used in the countercurrent flowsheet demonstration was obtained from tank WM-185. The UNEX process uses a tertiary solvent containing 0.08 M chlorinated cobalt dicarbollide, 0.5% polyethylene glycol-400 (PEG-400), and 0.02 M diphenyl-N,N-dibutylcarbamoyl phosphine oxide (Ph2Bu2CMPO) in a diluent consisting of phenyltrifluoromethyl sulfone (FS-13). The countercurrent flowsheet demonstration was performed in a shielded cell facility using 24 stages of 2-cm diameter centrifugal contactors. Removal efficiencies of 99.4%, 99.995%, and 99.96% were obtained for 137Cs, 90Sr, and total alpha, respectively. This is sufficient to reduce the activities of 137Cs, 90Sr, and actinides in the WM-185 waste to below NRC Class A LLW requirements. Flooding and/or precipitate formation were not observed during testing. Significant amounts of the Zr (87%), Ba (>99%), Pb (98.8%), Fe (8%), Ca (10%), Mo (32%), and K (28%) were also removed from the feed with the universal solvent extraction flowsheet. 99Tc, Al, Hg, and Na were essentially inextractable (<1% extracted).

• Research Organization: Idaho National Laboratory (INL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC07-99ID13727
• OSTI ID: 911483
• Report Number(s): INEEL/EXT-99-00954
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACTINIDES
CESIUM
COBALT
EXTRACTION APPARATUSES
FLOWSHEETS
LIQUID WASTES
PHOSPHINE OXIDES
POLYETHYLENES
REMOVAL
SOLVENT EXTRACTION
SOLVENTS
STRONTIUM
SULFONES
TANKS
TESTING
WASTES
actinide
centrifugal contactors
cesium
radioactive waste processing
separation processes
solvent extraction
strontium