Tc Chemistry in HLW: Role of Organic Complexants

Hess, Nancy S. ; Conradsen, Steven D.

Los Alamos National Laboratory

关键词: Removal;    Research Programs;    Radioactive Wastes;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Sludges;   

DOI  :  10.2172/834842
RP-ID  :  EMSP-81921-2003
RP-ID  :  834842

美国|英语

来源: UNT Digital Library

【 摘 要 】

Tc complexation with organic compounds in tank waste plays a significant role in the redox chemistry of Tc and the partitioning of Tc between the supernatant and sludge components in waste tanks. These processes need to be understood so that strategies to effectively remove Tc from high-level nuclear waste prior to waste immobilization can be developed and so that long-term consequences of Tc remaining in residual waste after sludge removal can be evaluated. Only limited data on the stability of Tc-organic complexes exists and even less thermodynamic data on which to develop predictive models of Tc chemical behavior is available. To meet these challenges we are conducting a research program to study to develop thermodynamic data on Tc-organic complexation over a wide range of chemical conditions. We will attempt to characterize Tc-speciation in actual tank waste using state-of-the-art analytical organic chemistry, separations, and speciation techniques to validate our model. On the basis of such studies we will develop credible model of Tc chemistry in HLW that will allow prediction of Tc speciation in tank waste and Tc behavior during waste pretreatment processing and in waste tank residuals.