Solvent Blending Strategy to Upgrade MCU CSSX Solvent to Equivalent Next-Generation CSSX Solvent

Delmau, Laetitia Helene ; Moyer, Bruce A

Oak Ridge National Laboratory

关键词: Cesium;    Solvent Extraction;    Nuclear Waste;   

DOI  :  10.2172/1057946
RP-ID  :  ORNL/TM-2012/580
RP-ID  :  DE-AC05-00OR22725
RP-ID  :  1057946

美国|英语

来源: UNT Digital Library

【 摘 要 】

The results of the present study have validated an equal-volume blending strategy for upgrading freshly prepared CSSX solvent to a blended solvent functionally equivalent to NG-CSSX solvent. It is shown that blending fresh CSSX solvent as currently used in MCU with an equal volume of an NG-CSSX solvent concentrate of appropriate composition yields a blended solvent composition (46.5 mM of MaxCalix, 3.5 mM of BOBCalixC6, 0.5 M of Cs-7SB, 3 mM of guanidine suppressor, and 1.5 mM of TOA in Isopar L) that exhibits equivalent batch ESS performance to that of the NG-CSSX solvent containing 50 mM of MaxCalix, 0.5 M of Cs-7SB, and 3 mM of guanidine suppressor in Isopar L. The solvent blend composition is robust to third-phase formation. Results also show that a blend containing up to 60% v/v of CSSX solvent could be accommodated with minimal risk. Extraction and density data for the effect of solvent concentration mimicking diluent evaporation or over-dilution of the equal-volume blended solvent are also given, providing input for setting operational limits. Given that the experiments employed all pristine chemicals, the results do not qualify a blended solvent starting with actual used MCU solvent, which can be expected to have undergone some degree of degradation. Consequently, further work should be considered to evaluate this risk and implement appropriate remediation if needed.