Solvent Extraction Batch Distribution Coefficients with Savannah River Site Dissolved Salt Cake

Researchers characterized high-level waste derived from dissolved salt cake from the Savannah River Site (SRS) tank farm and measured the cesium distribution coefficients (DCs) for extraction, scrub, and stripping steps of the caustic-side solvent extraction (CSSX) flowsheet. The measurements used two SRS high-level waste samples derived entirely or in part from salt cake. The chemical compositions of both samples are reported. Dissolved salt cake waste contained less Cs-137 and more dianions than is typical of supernate samples. Extraction and scrub DCs values for both samples exceeded process requirements and agreed well with model predictions. Strip DCs values for the Tank 46F sample also met process requirements. However, strip DCs values could not be calculated for the Tank 38H sample due to the poor material balance for Cs-137. Potential explanations for the poor material balance are discussed and additional work to determine the cause is described.