Batch-Equilibrium Hot-Cell Tests of Caustic-Side Solvent Extraction (CSSX) with SRS Simulant Waste and Internal 137Cs Irradiation

Spence, R. D.

Oak Ridge National Laboratory

关键词: 12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Organic Solvents;    Chemical Radiation Effects;    Radioactive Waste Processing;    38 Radiation Chemistry, Radiochemistry, And Nuclear Chemistry;   

DOI  :  10.2172/788355
RP-ID  :  ORNL/TM-2001/49
RP-ID  :  AC05-00OR22725
RP-ID  :  788355

美国|英语

来源: UNT Digital Library

【 摘 要 】

The solvent was loaded with {sup 137}Cs and subsamples were stored on a shaker table while in contact with the extract, scrub, or strip aqueous phases. Evidence of solvent degradation was evaluated at exposure times of 0, 20, 54, and 83 days. This resulted in estimated solvent doses ranging up to 1.24 Mrad, equivalent to the dose expected to be received during 16.5 years of operation at the plant proposed for the Savannah River Site. The break times and distribution of cesium of the batch samples remained constant within experimental error; in addition, no third-phase formation was observed. The solvent concentrations of calix[4]arene-bis-(tert-octylbenzo-crown-6) and 1-(2,2,3,3-tetra-fluoroproproxy)-3-(4-sec-butylphenoxy)-2-propanol remained constant within experimental error. Solvent degradation with irradiation was evidenced by a decrease in the trioctylamine (TOA) concentration in the solvent and an increase in the solvent concentration of the degradation product 4-sec-butylphenol. No decline in extraction or scrubbing performance of the irradiated solvents was observed. The stripping performance of the solvent was seriously impaired with irradiation; however, a mild caustic wash and replenishment of the TOA concentration restored the ability to strip the irradiated solvent.