Skip to main content
Open Access Publications from the University of California

Chemical behavior of U(VI), Am(III) and Sr(II) in the washing of HLW sludges


To understand the behavior of radionuclides during alkaline pretreatment of tank sludges, simulants were prepared according to the BiPO4, Redox and PUREX processes and incorporated with U-233, U-238, Am-243 or Sr-90. The simulated sludges were washed with solutions of various compositions - acidic, alkaline, or with chelating agents. Spectroscopic techniques including UV/Vis, fluorescence, NMR and EXAFS provided additional information on the speciation. A combination of selective leaching of uranium in the presence of oxalate and malonate and NMR experiments demonstrated the competition between complexation and hydrolysis. Limited experiments with Co-60 radiation were performed to evaluate the effect of radiolysis on the leaching. Preliminary experiments were conducted to study the oxidative leaching of americium from the sludge, using S2O82- as the oxidant. These data help to predict the behavior of radionuclides in sludge washing and improve the washing strategies.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View