Executive SummaryThe Hanford Site in Washington State manages 177 underground storage tanks containing approximately 250,000 m 3 of waste generated during past defense reprocessing and waste management operations. These tanks contain a mixture of sludge, saltcake and supernatant liquids. The insoluble sludge fraction of the waste consists of metal oxides and hydroxides and contains the bulk of many radionuclides such as the transuranic components and 90 Sr. The saltcake, generated by extensive evaporation of aqueous solutions, consists primarily of dried sodium salts. The supernates consist of concentrated (5-15 M) aqueous solutions of sodium and potassium salts. The 177 storage tanks include 149 single-shell tanks (SSTs) and 28 double-shell tanks (DSTs).Ultimately the wastes need to be retrieved from the tanks for treatment and disposal. The SSTs contain minimal amounts of liquid wastes, and the Tank Operations Contractor is continuing a program of moving solid wastes from SSTs to interim storage in the DSTs. The Hanford DST system provides the staging location for waste feed delivery to the Department of Energy (DOE) Office of River Protection's (ORP) Hanford Tank Waste Treatment and Immobilization Plant (WTP). The WTP is being designed and constructed to pretreat and then vitrify a large portion of the wastes in Hanford's 177 underground waste storage tanks.The retrieval, transport, treatment and disposal operations involve the handling of a wide range of slurries. Solids in the slurry have a wide range of particle size, density and chemical characteristics. Depending on the solids concentration the slurries may exhibit a Newtonian or a non-Newtonian rheology.The extent of knowledge of the physical and rheological properties is a key component to the success of the design and implementation of the waste processing facilities. These properties are used in engineering calculations in facility designs. Knowledge of the waste properties is also necessary for the development and fabrication of simulants that are used in testing at various scales. The expense and hazards associated with obtaining and using actual wastes dictates that simulants be used at many stages in the testing and scale-up of process equipment. The results presented in this report should be useful for estimating process and equipment performance and provide a technical basis for development of simulants for testing.The purpose of this document is to provide an updated summary of the Hanford waste characterization data pertinent to safe storage, retrieval, transport and processing operations for both the tank farms and the WTP and thereby identify gaps in understanding and data. Important waste parameters for these operations are identified by examining examples of relevant mathematical models of selected phenomena including: The data sets in (UDS composition and particle density, UDS primary particle size and shape, UDS particle size distributions [PSDs], and estimated particle size and density distributions [PSDDs]) and Poloski et al. (2007) ...

The actual testing activities were performed and reported separately in referenced documentation. Because of this, many of the required topics below do not apply and are so noted. Test ObjectivesThis section is not applicable. No testing was performed for this investigation. Test ExceptionsThis section is not applicable. No test specification as well as test exception applies to this investigation as there was no testing was performed. Results and Performance Against Success CriteriaThis section is not applicable. No success criteria were established as there was no testing performed for this investigation. Quality RequirementsSince This report is based on data from testing as referenced. The PNNL assumes that the data from these references has been fully reviewed and documented in accordance with the analysts' QA Programs. PNNL only analyzed data from the referenced documentation. At PNNL, the performed calculations, the documentation and reporting of results and conclusions were performed in accordance with the RPP-WTP Quality Assurance Manual (RPP-WTP-QA-003, QAM). Internal verification and validation activities were addressed by conducting an independent technical review of the final data report in accordance with PNNL procedure QA-RPP-WTP-604. This review verifies that the reported results are traceable, that inferences and conclusions are soundly based, and that the reported work satisfies the Test Specification Success Criteria. This review procedure is part of PNNL's RPP-WTP Quality Assurance Manual). Test ConditionsThe scope of the RWG effort is specified in the approved WTP issue response plan (24590-WTP-PL-ENG-06-0013) and defined in subcontractor change notice (SCN) 007 and Test Specification 24590-PTF-TSP-RT-06-007, Rev 0.Demonstrate the simulant properties used for testing bracket expected actual waste properties. For non-cohesive solids (Phase 1) this includes particle size, solids density, solids concentration, liquid density, and liquid viscosity. For cohesive solids (Phase 2) this includes bulk slurry density, particle size, particle density, slurry rheology (such as consistency and yield stress) and shear strength of settled, aged sediments, as well as settled layer (heel) thickness.Waste received at the WTP will be subject to a feed specification supporting plant design and as agreed to in an Interface Control Document. This report compiles the existing Hanford Tank Farm rheological data addressed in italicized text above and establishes expected ranges for these properties for as-retrieved Hanford Tank Farm wastes. Various processes will be performed on these retrieved wastes which are expected to alter these property ranges from the as-retrieved conditions. Simulant development activities should focus on the expected properties of the waste streams under such processing conditions. v Simulant UseThis section is not applicable. No testing was performed for this investigation.

ph: (865) 576-8401 fax: (865) 576-5728 email: reports@adonis.osti.gov Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161 ph: (800) 553-6847 fax: (703) 605-6900 email: orders@ntis.fedworld.gov online ordering: http://www.ntis.gov/ordering.htm AbstractBuoyant displacement gas release events (BDGRE) are spontaneous gas releases that occur in a few of the Hanford radioactive waste storage tanks when gas accumulation makes the sediment layer buoyant with respect to the liquid. BDGREs are assumed to be likely if the ratio of the predicted sediment gas fraction and neutral buoyancy gas fraction, or buoyancy ratio, exceeds unity. Based on the observation that the buoyancy ratio is also an empirical indicator of BDGRE size, a new methodology is derived that formally correlates the buoyancy ratio and the peak headspace hydrogen concentration resulting from BDGREs. The available data on the six historic BDGRE tanks, AN-103, AN-104, AN-105, AW-101, SY-103, and SY-101, are studied in detail to describe both the waste state and the corresponding distribution of BDGREs. The range of applicability of the buoyancy ratio-based models is assessed based on the modeling assumptions and availability of tank data. Recommendations are given for extending the range of the models' applicability.iv v

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...

range from 70 to 85 wt%; the reported water content is somewhat higher in Tank T-111 (85 to 90 wt%) and lower in a few samples from T-201 (~65 wt%). Most of the data for bulk solids samples, a matrix of waste solids and interstitial liquid, show bulk densities of 1.15 to 1.30 g/mL, and the density generally increases with decreasing water content. The shear strength estimates obtained from the extrusion methods were compared with the water content and bulk density of waste samples from the same core segments. The shear strength and, to a lesser extent, the density show some tendency to decrease with increasing water, but significant scatter exists in the data. The physical properties of in situ and diluted SST TRU waste described in this report and summarized in the discussion above are tabulated in Table ES.1. In many cases, the expected range of properties is estimated from limited data. However, in those instances where data are available for many tanks and multiple locations within tanks, the data do not indicate major differences among individual tanks. Therefore, it appears reasonable to treat individual tank results as typical of Hanford SST TRU waste. Table S.1. Expected Range of Physical Properties of In Situ and Diluted SST TRU Waste Property Expected Range Comments Shear strength 200 to 2,000 Pa (majority of waste) 0 to 4,000 Pa (range, including liquid) Estimated from data obtained from core extrusions (Sections 3.1 and 3.2) and reported shear vane measurements (Section 4.1). Viscosity 2 to 25 cP at 10 s-1 2 to 15 cP at 100 s-1 Results for 1:1 dilution with water; higher viscosities expected for waste diluted less and at lower strain rates. Waste exhibited pseudoplastic rheology. Section 4.1. Waste settling ~0 vol% free liquid (1 G) 2 to 40 vol% free liquid (>1000 G, 1 hr) Undiluted waste, >200 Pa shear strength. Weaker waste (liquid in the extreme) is expected to produce more free liquid on settling. Section 4.2. Waste settling 5 to 25 vol% free liquid (1 G, ~2 days) 40 to 60 vol% free liquid (>1000 G, 1 hr) 1:1 diluted waste, >200 Pa shear strength prior to dilution. See comment above. Section 4.2. Waste settling 40 to 65 vol% free liquid (1 G, ~2 days) 70 to 85 vol% free liquid (>1000 G, 1 hr) 3:1 diluted waste, >200 Pa shear strength prior to dilution. See comment above. Section 4.2. Particle size, mean 7 to 70 µm (volume density) < 2 µm (number density) Section 4.3. Water content 70 to 85 wt% (majority of waste) 65 to 90 wt% (range) Section 5.1. Liquid Density ~1.05 g/mL Section 5.2 Bulk Density 1.15 to 1.3 g/mL (majority of waste) 1.1 to 1.4 g/mL (range) Section 5.2 vii

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Radioactive waste is scheduled to be retrieved from Hanford double-shell tanks AN-103, AN-104, AN-105 and AW-101 and transferred to the vitrification plant beginning in about 2009. Retrieval may involve decanting the supernatant liquid and/or mixing the waste with jet pumps. In these four tanks, which contain relatively large volumes of retained gas, both operations are expected to induce buoyant displacement gas releases that can potentially raise the tank headspace hydrogen concentration to a level very near the lower flammability limit. This report describes the theory and detailed physical models for both the supernatant decant and jet mixing processes and presents the results from applying the models to these operations in the four tanks. The technical bases for input parameter distributions are elucidated.