Characterization of Actinides in Simulated Alkaline Tank Waste Sludges and Leachates

Nash, Kenneth L. ; Jensen, Mark P. ; Rao, Linfeng

Argonne National Laboratory

关键词: Leaching;    Decision Making;    Oxidizers;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Wastes;   

DOI  :  10.2172/834983
RP-ID  :  EMSP-81940-2002
RP-ID  :  834983

美国|英语

来源: UNT Digital Library

【 摘 要 】

During sludge washing procedures associated with tank waste remediation, actinide ions are expected to remain with the insoluble metal oxide/hydroxide residue as the sludges are scrubbed to remove Cr, P, Al, S, and thus to be transmitted conveniently to the vitrification plant. Unfortunately, in laboratory tests with actual sludge samples alkaline sludge treatment has proven less efficacious for Al and Cr removal than was hoped. To improve removal of Al and Cr, more aggressive treatments of sludges are anticipated, including contact with oxidants targeting Cr(III). In addition, our prior research on the alkaline scrubbing of sludge simulants indicated higher than expected ''solubilization'' of Np and U into concentrated alkali, and some tendency for Am to be mobilized in contact with oxidants. In this project, we are investigating the fundamental chemistry of actinides in sludge simulants under representative oxidative leaching conditions. We are also examining acidic leaching with concurrent secondary separations to enhance Al removal. Our objective is to provide adequate insight into actinide behavior under these conditions to enable prudent decision making as tank waste treatment protocols develop. We expect to identify those components of sludges that are likely to be problematic in the application of oxidative leaching protocols.