Speciation and Oxidative Stability of Alkaline Soluble, Non-Pertechnetate Technetium
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
The long half-life, complex chemical behavior in tank waste, limited incorporation in mid- to high-temperature immobilization processes, and high mobility in subsurface environments make technetium (Tc) one of the most difficult contaminants to dispose of and/or remediate. Technetium exists predominantly in the liquid tank waste phase as the relatively mobile form of pertechnetate, TcO4-. However, based on experimentation to date a significant fraction of the soluble Tc cannot be effectively separated from the wastes and may be present as a non- pertechnetate species. The presence of a non-pertechnetate species significantly complicates disposition of low-activity waste (LAW), and the development of methods to either convert them to pertechnetate or to separate directly is needed. The challenge is the uncertainty regarding the chemical form of the alkaline-soluble low-valent non-pertechnetate species in the liquid tank waste. This report summarizes work done in fiscal year (FY) 2014 exploring the chemistry of a low-valence technetium(I) species, [(CO)3Tc(H2O)3]+, a compound of interest due to its implication in the speciation of alkaline-soluble technetium in several Hanford tank waste supernatants.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Management (EM)
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1378055
- Report Number(s):
- PNNL-23654; EMSP-RPT-024; 47928; EY4049110
- Country of Publication:
- United States
- Language:
- English
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