Interim report on a multi-day test of the caustic-side solvent extraction flowsheet for cesium removal from a simulated SRS tank waste.

Potential for the Precipitation of Uranium and Plutonium Solids upon Addition of Nitric Acid to Waste Solutions in a Caustic-Side Solvent Extraction Process

“…11,12 Similar residence times are expected in the larger pilot-scale and full-scale equipment. As a consequence of the short residence times non-equilibrium conditions will most likely prevail upon mixing the scrub acid solution with the alkaline waste in the contactors.…”

Savannah River Site Salt Processing Project: FY2002 Research and Development Program Plan

“…Tests at ANL and SRTC during FY01 demonstrated solvent washing and recycle using a single centrifugal contactor stage with 0.01-M NaOH as the wash solution. 21,41 In the planned test, solvent will be washed in one contactor stage with 0.010 M NaOH, but may include reuse of NaOH recycled to minimize waste. However, these conditions could be changed depending on results of tasks described in Section 7.2.2.11.…”

“…ORNL will complete characterization of the solvent and solvent wash solution from the ANL March 2001 multi-day test, where the solvent was recycled a total of 40 times. 41 Since this test was conducted with waste simulant, the identity of compounds of interest are known; however, method development and or modification will be required to determine the concentrations of the compounds in the respective solutions. This task complements work that SRTC performed on similar solutions obtained from the actual waste test.…”

“…10,41 Emulsifiers may be formed as a result of chemical or radiolytic degradation of solvent components. Emulsions could also be a result of the smaller density difference between the liquids and low concentration of NaOH.…”

Demonstration of Caustic-Side Solvent Extraction with Savannah River Site High-Level Waste: Results of Organic and Trace Component Analyses

“…2 This solvent consists of an extractant, calix [4]arene-bis-(tert-octylbenzo-crown-6) (BOBCalixC6), dissolved in an inert hydrocarbon matrix. An alkylphenoxy alcohol modifier, 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs7SB modifier), is added to the solvent to enhance the extraction power of the calixarene and to prevent the formation of a third phase.…”