skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Caustic-Side Solvent Extraction Chemical and Physical Properties Progress in FY 2000 and FY 2001.

Technical Report ·
DOI:https://doi.org/10.2172/814534· OSTI ID:814534

The purpose of this work was to provide chemical- and physical-property data addressing the technical risks of the Caustic-Side Solvent Extraction (CSSX) process as applied specifically to the removal of cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site. As part of the overall Salt Processing Project, this effort supported decision-making in regards to selecting a preferred technology among three alternatives: (1) CSSX, (2) nonelutable ion-exchange with an inorganic silicotitanate material and (3) precipitation with tetraphenylborate. High risks, innate to CSSX, that needed specific attention included: (1) chemical stability of the solvent matrix, (2) radiolytic stability of the solvent matrix, (3) proof-of-concept performance of the proposed process flowsheet with simulated waste, and (4) performance of the CSSX flowsheet with actual SRS high-level waste. This body of work directly addressed the chemical-stability risk and additionally provided supporting information that served to plan, carry out, and evaluate experiments conducted by other CSSX investigators addressing the other high risks. Information on cesium distribution in extraction, scrubbing, and stripping served as input for flowsheet design, provided a baseline for evaluating solvent performance under numerous stresses, and contributed to a broad understanding of the effects of expected process variables. In parallel, other measurements were directed toward learning how other system components distribute in the flowsheet. Such components include the solvent components themselves, constituents of the waste, and solvent-degradation products. Upon understanding which components influence flowsheet performance, it was then possible to address in a rational fashion how to clean up the solvent and maintain its stable function.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
AC05-00OR22725
OSTI ID:
814534
Report Number(s):
ORNL/TM-2001/285; TRN: US200317%%278
Resource Relation:
Other Information: PBD: 17 Apr 2002
Country of Publication:
United States
Language:
English