Zirconium and fission product management in the ALSEP process

Conference · Mon Jul 01 04:00:00 EDT 2013

OSTI ID:22264129

Lumetta, G. J.; Carter, J. C.; Niver, C. M. ^[1]

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1. Pacific Northwest National Laboratory: P.O. Box 999, MSIN P7-25, Richland, WA 99352 (United States)

Solvent extraction systems that combine neutral donor extractants and acidic extractants are being investigated to provide a single process solvent for separating Am and Cm from acidic high-level liquid waste, including their separation from the trivalent lanthanides. This approach of combining extractants is collectively referred to as the Actinide-Lanthanide Separation (ALSEP) process. Managing Zr and other fission products is one of the critical factors in developing the ALSEP process. In this work, a strategy has been developed in which Zr(IV) is extracted into the process solvent, then it is stripped from the solvent after the actinides have been selectively stripped. The ALSEP solvent contains a bifunctional neutral donor extractant that extracts the minor actinides and the trivalent lanthanides (Ln) from nitric acid media. In this work, two such extractants were considered: N,N,N',N'- tetraoctyl-diglycolamide (TODGA) and N,N,N',N'-tetra(2- ethylhexyl)diglycolamide (T2EHDGA). Molybdenum is strongly extracted into ALSEP solvents. Scrubbing the solvent with a citrate buffer before the actinide stripping step effectively removes Mo. Distribution ratios for Ru and Fe are low for extraction from HNO{sub 3}, so these components can easily be routed to the high-level waste raffinate. (authors)

• Research Organization: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22264129
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
ACTINIDES
CITRATES
FISSION PRODUCTS
HIGH-LEVEL RADIOACTIVE WASTES
MANAGEMENT
MOLYBDENUM
NITRIC ACID
NUCLEAR FUELS
RARE EARTHS
SOLVENT EXTRACTION
SOLVENTS
STRIPPING
ZIRCONIUM