Washington River Protection Solutions is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at the Hanford Site. The ETF is a Resource Conservation and Recovery Act-permitted, multi-waste, treatment and storage unit that can accept dangerous, low-level, and mixed wastewaters for treatment. The STU needs to be operational by 2018 to receive secondary liquid wastes generated during operation of the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The STU will provide the additional capacity needed for ETF to process the increased volume of secondary wastes expected to be produced by the WTP. Pacific Northwest National Laboratory is conducting a secondary waste form screening program to support the evaluation and selection of waste forms to stabilize and solidify the liquid secondary waste stream from the WTP. The following monolith waste forms are being evaluated for immobilizing the secondary wastes: 1) Cast Stone; 2) DuraLith alkali aluminosilicate geopolymer; 3) Ceramicrete phosphate-bonded ceramic; and 4) THOR ® fluidized bed steam reforming waste product encapsulated in geopolymer. This report documents work to further develop and characterize the Cast Stone waste form. Other reports will cover the development and characterization of the other three waste forms. Follow-on activities will address the mechanisms of radionuclide retention to support disposal-system performance assessments, and regulatory and waste acceptance testing to demonstrate the waste forms will meet requirements for disposal at the Hanford Integrated Disposal Facility. Cast Stone (also called-Containerized Cast Stone‖) is a cementitious waste form that is essentially a mixture of Class F fly ash, Grade 100 or 120 blast furnace slag, and Type I/II Portland cement. CH2M Hill Hanford Group Inc. developed this waste form to solidify numerous waste streams, including secondary waste generated at the Hanford Site. The Cast Stone cementitious waste form is the current baseline for solidifying the liquid secondary wastes from the WTP. Pierce et al. (2010) demonstrated that the Cast Stone is a viable waste form for immobilizing WTP secondary wastes. This statement is based on the leachability of technetium-99 (99 Tc) as determined using draft U.S. Environmental Protection Agency (EPA) test methods examining contaminant diffusivity (Method 1315) and the impacts of solution pH (Method 1313) and liquid-to-solids ratio (Method 1316). 1 The Cast Stone testing reported here focused on optimizing waste loading and evaluating the robustness of the waste form to waste stream variability. Because of the extensive work on the Cast Stone formulation and the similar Saltstone formulation used at the Savannah River Site for low-level tank waste immobilization, testing conducted as part of this current test plan relied on those previous testing studies and did not aim to optimize the dry-blend material components or mix ratios beyond what has already been accomplished.

One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex.Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce.To address these technical areas, small-and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and net generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of antifoam agents was assessed with most of the simulants. Orifices included round holes and rectangular slots. For the combination of both test stands, the round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width × length) 0.3 × 5 to 2.74 × 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the much larger flow rates and equipment that would be required.This report presents the experimental results and analyses for the aerosol measurements obtained in the small-scale test stand. It includes a description of the simulants used and their properties, equipment and operations, data analysis methodologies, and test results. The results of tests investigating the role of slurry particles in plugging small breaches are reported in Mahoney et al. (2012). The results of the...

One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities, is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations published in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials present in the WTP and across processing facilities in the DOE complex.Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty introduced by extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches in which the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are largely absent.To address these technical areas, small-and large-scale test stands were constructed and operated with simulants to determine the aerosol release fractions and aerosol generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents (AFA) was assessed with most of the simulants. Orifices included round holes and rectangular slots. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the much larger flow rates and equipment that would be required.The purpose of the study described in this report is to provide experimental data for the first key technical area, potential plugging of small breaches, by performing small-scale tests with a range of orifice sizes and orientations representative of the WTP conditions. The simulants used were chosen to represent the range of process stream properties in the WTP. Testing conducted after the plugging tests in the small-and large-scale test stands addresses the second key technical area, aerosol generation. The results of the small-scale aerosol generation tests are included in Mahoney et al. (2012). The area of spray generation from large breaches is covered by large-scale testing in Schonewill et al. (2012). S.1 Objective S.2 Results and Performance Against Success Criteria...

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