Executive SummaryThe purpose of this report is twofold: first, to propose a test protocol for identifying the presence of soluble, non-pertechnetate Tc (n-Tc) in alkaline, high ionic strength, Hanford tank supernatants, and second, to evaluate various methods of obtaining information about the nature of the identified, non-pertechnetate species.The proposed protocol addresses three questions: 1) is n-Tc present and what fraction of the total soluble Tc is present in this form, 2) is there an interference at m/e 99 in the inductively coupled plasma mass spectrometry (ICP-MS) that gives false positives in a test for n-Tc, and 3) is there another isotope that could act as an interference in a test for n-Tc by liquid scintillation counting.For ALARA (as low as reasonably achievable) reasons, the protocol involves an initial Cs decontamination by contact with the Cs selective IE-911 ion exchanger. It is recommended that the Cs-depleted supernatant be spiked with a non-Tc-99 source (likely Tc-99m) of pertechnetate to allow an independent assessment of pertechnetate and total technetium behaviors during the test. The solution is then passed through a column containing a pertechnetate getter. Because of its extensive use with Hanford tank waste supernatants, SuperLig® 639 is recommended as the pertechnetate getter. The resulting effluent is sampled for analysis by gamma energy analysis, liquid scintillation counting for beta activity, and ICP-MS for its mass 99 concentration.Should there be a significant difference in pertechnetate versus total technetium behavior, the effluent is exhaustively oxidized by a persulfate/microwave digestion, adjusted as needed in composition, passed again through an appropriate pertechnetate getter, and resampled. From analysis of these sample results, the questions posed above can be addressed.The report concludes with an evaluation of a variety of spectroscopic methods that might be used either to identify n-Tc spectroscopically in Hanford tank waste supernatant or to gain insight into the chemical structure of n-Tc. It is concluded that most methods evaluated either are unsuitable, sufficiently insensitive to preclude use at the technetium concentrations present in Hanford tank waste supernatant, or would require significant methods development before they might be effective in n-Tc species analysis. The two methods currently available that can supply useful speciation information are X-ray absorption spectroscopy (of various types) and Tc-99 nuclear magnetic resonance spectroscopy.