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Low-activity tank wastes will be generated during cleanup of high-level radioactive tank wastes on the Hanford site. The low-activity tank waste will be among the largest volumes of radioactive waste within the U.S. Department of Energy (DOE) complex and is one of the largest inventories of long-lived radionuclides planned for disposal in a low-level waste facility. The Department of Energy's Office of River Protection is evaluating several options for immobilization of low-activity tank wastes for eventual disposal in a shallow subsurface facility at the Hanford Site. A significant portion of the waste will be converted into low-activity waste (LAW) glass with a conventional Joule-heated ceramic melter. In addition, three supplemental treatment processes are presently under consideration by the DOE to treat wastes in selected tanks with the goal of accelerating the overall cleanup mission at the Hanford site. These are: 1) bulk vitrification (BV), 2) cementation or the cast stone (CS) process, and 3) steam reformation (SR). The DOE is expected to select by October 2003 one or more of these supplemental treatment technologies for more detailed evaluation. As part of the selection process, a preliminary risk assessment is being performed to evaluate the impacts of the disposal facility on public health and environmental resources. The purpose of this report is to document the laboratory testing that was conducted on BV and SR waste forms to supply the input parameters needed for reactive chemical transport calculations with the Subsurface Transport Over Reactive Multiphases (STORM) code. This same code was used to conduct the 2001 ILAW performance assessment. The required input parameters for BV and SR waste forms are derived from a mechanistic model that describes the effect of solution chemistry on contaminant release rates. The single-pass flow-through test is the principal method used to obtain these input parameters, supplemented by product consistency test measurements and physical property measurements. v 2.1.1.1 X-ray Microtomagraphy (XMT) X-ray microtomography provided a novel way to characterize the froth layer glass properties. Characterization was principally done on a piece of froth-layer glass broken off the sample shown in Figure 2. This sampled was labeled BKV5. The XMT system at PNNL, shown in Figure 5, is an ACTIS 200/160 KXR unit manufactured by Bio-Imaging Research, Inc. The x-ray generator is a Kevex KM16010E-A X-ray tube with spot sizes of 10, 20, 65, 250 µm at power levels 5, 10, 50, and 160 watts. The microfocus X-ray source allows variable slice widths over a nominal range of 10 to 150 µm and can achieve resolution in the focal plane of one one-thousandth of the object diameter. A computer-controlled sample manipulator with a 75-mm diameter turntable allows 365° of continuous rotation and a maximum vertical travel of 150 mm The detection system is a BIR RLS 2048-100 discrete element solid-state detector system consisting of gadolinium oxysulfide scintillator and EG & G Reticon photodiodide...

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