Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xix, 219 p.: ill. (some col.). Includes abstract and vita. Advisor: Samuel J. Traina, Environmental Science Graduate Program. Includes bibliographical references (p. 201-219).

The 53 million gallons (240,000 tons) of nuclear waste stored at the Hanford site comprises approximately 60% of the nation¡¯s legacy nuclear waste. Previously, processing of the saltcake phases of tank wastes dominated disposal efforts at Hanford. Interest is now being directed at the processing and pretreatment of the sludge phases of the waste. These sludges, consisting of complex combinations of insoluble metal compounds, present many challenges. This thesis deals with experimentation pertaining primarily to aluminum chemistry and the role it plays in pretreatment of Hanford waste sludge. Included is a statistical analysis of an inventory of components within Hanford tanks. A recipe was followed to produce a simulant sludge for further experimentation. The solubility of the aluminum species, gibbsite, thought to be the most common aluminum species in the Hanford tanks, was studied. In addition, the reaction by which gibbsite is transformed to a much less soluble phase, boehmite, was studied in depth. Gibbsite¡¯s transformation to boehmite begins at about 200 ¡ÆC, a temperature higher than that seen by Hanford tanks. However, recent literature suggests that it may be converted to boehmite at lower temperatures. A study of the rate of boehmite formation at temperatures ranging from 80 to 150 ¡ÆC using caustic concentrations of 1.5, 3, and 5 molal is reported. In such a way, the effects of both temperature and caustic loading on the rate of boehmite formation were sought. It was determined that boehmite formed readily at temperatures 120 ¡ÆC and higher. These data supplement existing aluminum chemistry knowledge and will increase the efficiency with which sludge pretreatment and disposal procedures are designed.

Intercommunication has been identified between the unconfined and uppermost confined aquifer systems underlying a portion of the U.S. Department of Energy's Hanford Site. Erosional thinning and fracturing of the basalt confining layer within the study area allows physical contact between the two aquifers, but the vertical hydraulic gradient (a required driving force) is small. To better conceptualize the distribution and volume of the leakage occurring between the aquifer systems, this study investigates the confined Rattlesnake Ridge Aquifer flow system, which appears to be more sensitive to the vertical leakage than the overlying unconfined aquifer.

Batch microcosm studies were carried out to screen for microorganisms from the subsurface of Hanford DOE site that could cometabolically transform chloroform (CF) under aerobic conditions. The potential need for CF bioremediation at the Hanford site has resulted from the large release of carbon tetrachloride (CT) to the subsurface, of which a fraction anaerobically transformed to CF. Potential cometabolic substrates were screened for their ability to promote aerobic cometabolism of CF. The potential cometabolic substrates tested were isoprene, propene, octane, ammonia, methane, propane, and butane. Microcosms were constructed with 125 ml batch serum bottles filled with 25 g of aquifer solids, 50 ml of synthetic groundwater, and 60 ml of headspace air. Consumption of methane, butane, propane, and propene was slow, while the consumption of ammonia was very slow. Microorganisms stimulated on propene and octane showed no ability to transform CF. Limited CF was transformed in microcosms stimulated on ammonia and methane. Over 90% transformation of CF was observed in microcosms stimulated on either butane or propane during the initial incubation. Successive addition studies with methane, propane, and butane microcosms were conducted, because these substrates showed the most potential for driving CF cometabolism. The studies indicated that the most effective CF transformation was achieved by butane-utilizers. CF transformation was correlated with the consumption of the primary substrate. Propane- and butane-utilizers grown in the absence of CF showed transformation yields 3 times greater than those grown in the presence of CF. In butane fed microcosms, CF transformation was linked with butane and oxygen consumption, indicating that an oxygenase enzyme of the butane-utilizers was likely responsible for CF transformation. The butane-utilizers showed no ability to transform CT, which also suggests the possibility of CF transformation by an oxygenase enzyme. In butane microcosms, complete transformation of 55 pg of CF (1200 ��g/L of CF in aqueous solution) was observed. The maximum transformation yield of 0.03 g CF transformed/g substrates consumed was achieved by the butane-utilizers. A stoichiometric amount of chloride was released to solution from CF during CF transformation, indicating that complete dehalogenation of CF was achieved by butane-utilizers. In our knowledge, these were the first observations, demonstrating butane as a cometabolic substrate for CF transformation. / Graduation date: 1997

Thesis (M.S. in environmental science)--Washington State University, December 2009. / Title from PDF title page (viewed on Jan. 26, 2010). "School of Earth and Environmental Sciences." Includes bibliographical references (p. 48-51).

Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2007. / Committee Chair: Dr. Ronald W. Rousseau; Committee Member: Dr. Amyn S, Teja; Committee Member: Dr. Wm. James Frederick Jr.

The Hanford nuclear reservation in Washington state was initially created during World War II for the production of plutonium to be used in atomic bombs. A perceived need for a large increase in the number of nuclear weapons spurred expansions in production facilities at Hanford through the 1960's, and production was continued through the mid 1980's. The production process included irradiation of uranium fuel in reactors followed by chemical separation of the plutonium from the other fuel constituents, and finally transformation of plutonium nitrate to plutonium metal. The various steps in the process produced large amounts of radioactive as well as chemical hazardous waste. Some of this waste was released to the environment either through deliberate disposal methods or by leaks in transfer and storage systems. As a result, the soil at many areas of Hanford is contaminated to a point at which it would be unsafe for human contact for more than a short period of time. The current focus of efforts at Hanford is cleanup of the environment as well as decommissioning of the facilities. As part of the cleanup process, future land use must be determined which will then affect the scale of the remediation effort. The proposed land use will determine the residual contamination which will be left after all remediation is complete and access is allowed to the site. This document details the process for determining the residual contamination levels associated with various land use options. Some possible land use options are explained in the form of exposure scenarios. These scenarios give data in the form of exposure factors which describe the possible exposure level of an individual to contaminated media. Once the exposure factors are determined, they can be used in the equations outlined in the Hanford Site Risk Assessment Methodology to calculate preliminary remediation goals. These goals are presented as contaminant concentrations in environmental media which are the maximum allowable in order to meet regulatory limits. The limits are expressed either as a risk for carcinogens, or as a hazard quotient for non-carcinogens. / Graduation date: 1997

Concentration ratios are used to determine the transfer of nuclides from soil to biota to fauna. Some nuclides have limited associated data though, this has not prevented predictions from being performed at sites without associated data. These ratios are site specific and are not fully applicable when applied to other locations. A recent literature review for a waste repository performance assessment determined that a significant portion of the environmental data was based on recursively published material. To address this deficiency neutron activation analysis (NAA) was used to determine concentration ratios of certain biota. Three sites, two riparian and one shrub steppe, were sampled in the eastern Washington Columbia basin, near the Hanford site. Two hundred and fifty eight samples of opportunity were collected. This included 15 soil samples, 10 water and sediment samples, 40 different species of biota, and 2 terrestrial animal species and 3 aquatic animal species. These samples were prepared for NAA by drying, weighing, and in certain cases ashing to improve detection efficiency. After activation, the samples were placed in a HPGe detector to perform spectral analysis. The concentration results of 26 elements of interest are presented, along with newly established concentration ratios for all of the species sampled. / Graduation date: 2013

The decision to bury high level nuclear wastes in deep geological formations led to the study of the Hanford Nuclear Reservation as one of three possible sites for the first nuclear waste repository in the United States. To adequately evaluate the environmental impact of siting nuclear waste repositories in basalt aquicludes, it is essential to know the effects on parameter identification algorithms of thermal gradients that exist in these basaltic aquicludes. Temperatures of approximately 60° C and pressures of approximately 150 atms can be expected at potential repository sites located at depths of approximately 1000m. The phenomenon of over-recovery has been observed in some pumping tests conducted at the Hanford Nuclear Reservation. This over-recovery phenomenon may possibly be due to variations in the fluid density caused by thermal gradients. To asses the potential effects of these thermal gradients on indirect parameter identification algorithms, a systematic scaling of the governing field equations is required in order to obtain dimensionless equations based on the principle of similarity. The constitutive relationships for the specific weight of the fluid and for the porosity of the aquiclude are assumed to be exponentially dependent on the pressure gradient. The dynamic pressure is converted to the piezometric head and the flow equation for the piezometric head is then scaled in radial coordinates. Order-ofmagnitude estimates are made for all variables in unsteady flow for a typical well test in a basaltic aquiclude. Retaining all nonlinear terms, the parametric dependency of the flow equation on the classical dimensionless thermal and hydraulic parameters is demonstrated. These classical parameters include the Batchelor, Fourier, Froude , Grashof, and Reynolds Numbers associated with thermal flows. The flow equation is linearized from order-of-magnitude estimates based on these classical parameters for application in the parameter identification algorithm. Two numerical solutions are presented which predict hydraulic head given a continuous set of flow parameters. The first solution uses a totally numerical finite difference scheme while the second combines an analytical solution with a numerical solution. A radial coordinate system is utilized for describing an anisotropic confined aquifer. The classical inverse parameter identification problem is solved using an indirect method. This method is based on the minimization of a objective function or error criterion consisting of three parts: 1) least-squares error of head residuals; 2) prior information of flow parameters; and 3) regularization. An adjoint equation is incorporated into the method to eliminate the need to differentiate the heads with respect to the parameters being identified, increasing the stability of the algorithm. Verification of the parameter identification algorithm utilizes both "synthetic", computed generated input data and field data from a well test for a confined aquifer within the Columbia Plateau near Stanfield, Oregon. The method used is found to give parameter estimates which are both stable and unique. / Graduation date: 1992

Thesis (M.S. in environmental Science)--Washington State University, December 2007. / Includes bibliographical references (p. 27).