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Hydrogen Transport in Copper

Description: Hydrogen interaction with oxygen in copper exerts a significant influence on the apparent hydrogen diffusivity and the quantity of hydrogen absorbed. Correlation of the amount of absorbed tritium with oxygen content and dependence of permeation transients on both oxygen content and prior treatment indicate that both reversible and irreversible interactions occur between hydrogen and dissolved oxygen. This paper discusses results of that study.
Date: October 23, 2001
Creator: Caskey, G. R., Jr.
Partner: UNT Libraries Government Documents Department

The U-tube: A new paradigm in borehole fluid sampling

Description: Fluid samples from deep boreholes can provide insights into subsurface physical, chemical, and biological conditions. Recovery of intact, minimally altered aliquots of subsurface fluids is required for analysis of aqueous chemistry, isotopic composition, and dissolved gases, and for microbial community characterization. Unfortunately, for many reasons, collecting geofluids poses a number of challenges, from formation contamination by drilling to maintaining integrity during recovery from depths. Not only are there substantial engineering issues in retrieval of a representative sample, but there is often the practical reality that fluid sampling is just one of many activities planned for deep boreholes. The U-tube geochemical sampling system presents a new paradigm for deep borehole fluid sampling. Because the system is small, its ability to integrate with other measurement systems and technologies opens up numerous possibilities for multifunctional integrated wellbore completions. To date, the U-tube has been successfully deployed at four different field sites, each with a different deployment modality, at depths from 260 m to 2 km. While the U-tube has proven to be highly versatile, these installations have resulted in data that provide additional insights for improving future U-tube deployments.
Date: October 1, 2009
Creator: Freifeld, B. M.
Partner: UNT Libraries Government Documents Department

Atlantic Coastal experiment III, FRV Delaware II cruise, 17-27 May 1977 and R/V ONRUST cruise, 28-30, June 1977. Data report

Description: The DELAWARE II and ONRUST cruises, continuations of Atlantic Coastal Experiment III, were made during May and late June, 1977, to compare seasonal changes in chlorophyll a, nitrogen nutrient, dissolved oxygen and phytoplankton composition within the mid-Atlantic and New York Bights. Data from 106 stations and 3300 km of surface mapping are reported as classical hydrographic listings, areal and/or vertical contours of chlorophyll a, inorganic nitrogen and salinity, and listings of phytoplankton species abun- dance. Temperature profiles from 100 stations are included, as well as res- piration experiments [ETS assay] for the dinoflagellate, Ceratium tripos.
Date: September 1, 1980
Creator: Malloy, S.; Stoddard, A. & von Bock, K. (eds.)
Partner: UNT Libraries Government Documents Department

Erosion/corrosion of machinable Tungsten in water.

Description: It was recently discovered that significant erosion/corrosion occurs with machinable tungsten when exposed to water, particularly when the water has dissolved oxygen present. The problem was first discovered about 1 1/2 years ago when extensive corrosion was found inside the cooling channels of the L5-80 white-beam slits located in sector 3-ID-A. Figure 1 and Figure 2 show cut-away sections of the tungsten slit; the water passages are severely corroded from the cooling water used to cool the slit. The problem was brought to the attention of the world's two largest manufacturers of machinable tungsten, Mi-Tech Metals from Indianapolis, IN and Kulite Tungsten Corp. from East Rutherford, NJ. Neither company had any experience with this problem and were unaware that water could cause such significant corrosion, apparently the APS was the first customer to ever use the material in this fashion.
Date: December 20, 2000
Creator: Collins, J. T.
Partner: UNT Libraries Government Documents Department

Oceanic CO{sub 2} measurements for the WOCE hydrological survey in the Pacific Ocean; Shipboard alkalinity analyses during 1991 and 1992. Final technical report, February 1, 1992--July 31, 1994

Description: This research group contributed titration alkalinity analyses to transects of the WOCE Hydrological Survey during 1991 and 1992. The results have been transmitted to the Carbon Dioxide Information and Analysis Center (CDIAC) of the Department of Energy in a technical data report having two parts: Oceanic CO{sub 2} Measurements for the WOCE Hydrographic Survey of the Pacific Ocean, 1990--1991: Shipboard Analyses During 1991 and 1992, Part 1. Alkalinity Measurements on TUNES, Leg 3, 1991. Oceanic CO{sub 2} Measurements for the WOCE Hydrographic Survey of the Pacific Ocean, 1990--1991: Shipboard Analyses During 1991 and 1992, Part 2. Alkalinity Measurements on CGC92, Legs 1 and 2, 1992. This report contains a paper entitled, ``Total dissolved inorganic carbon measurements made on WOCE leg P13`` by Andrew G. Dickson. A brief description of how these measurements were made and calibrated has been provided along with a statement of the quality of the measurements. The data themselves have been sent to ORNL CDIAC for archival and distribution.
Date: July 1, 1998
Creator: Keeling, C.D.
Partner: UNT Libraries Government Documents Department

Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

Description: The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.
Date: February 24, 2004
Creator: Molloy, Daniel P.
Partner: UNT Libraries Government Documents Department

Effects of Total Dissolved Gas on Chum Salmon Fry Incubating in the Lower Columbia River

Description: This report describes research conducted by Pacific Northwest National Laboratory in FY 2007 for the U.S. Army Corps of Engineers, Portland District, to characterize the effects of total dissolved gas (TDG) on the incubating fry of chum salmon (Onchorhynchus keta) in the lower Columbia River. The tasks conducted and results obtained in pursuit of three objectives are summarized: * to conduct a field monitoring program at the Ives Island and Multnomah Falls study sites, collecting empirical data on TDG to obtain a more thorough understanding of TDG levels during different river stage scenarios (i.e., high-water year versus low-water year) * to conduct laboratory toxicity tests on hatchery chum salmon fry at gas levels likely to occur downstream from Bonneville Dam * to sample chum salmon sac fry during Bonneville Dam spill operations to determine if there is a physiological response to TDG levels. Chapter 1 discusses the field monitoring, Chapter 2 reports the findings of the laboratory toxicity tests, and Chapter 3 describes the field-sampling task. Each chapter contains an objective-specific introduction, description of the study site and methods, results of research, and discussion of findings. Literature cited throughout this report is listed in Chapter 4. Additional details on the study methdology and results are provided in Appendixes A through D.
Date: January 30, 2008
Creator: Arntzen, Evan V.; Hand, Kristine D.; Geist, David R.; Murray, Katherine J.; Panther, Jenny; Cullinan, Valerie I. et al.
Partner: UNT Libraries Government Documents Department

A Conceptual model of coupled biogeochemical and hydrogeologicalprocesses affected by in situ Cr(VI) bioreduction in groundwater atHanford 100H Site

Description: The overall objective of this presentation is to demonstratea conceptual multiscale, multidomain model of coupling of biogeochemicaland hydrogeological processes during bioremediation of Cr(VI)contaminated groundwater at Hanford 100H site. A slow releasepolylactate, Hydrogen Release Compound (HRCTM), was injected in Hanfordsediments to stimulate immobilization of Cr(VI). The HRC injectioninduced a 2-order-of-magnitude increase in biomass and the onset ofreducing biogeochemical conditions [e.g., redox potential decreased from+240 to -130 mV and dissolved oxygen (DO) was completely removed]. Athree-well system, comprised of an injection well and upgradient anddowngradient monitoring wells, was used for conducting the in situbiostimulation, one regional flow (no-pumping) tracer test, and fivepumping tests along with the Br-tracer injection. Field measurements wereconducted using a Br ion-selective electrode and a multiparameter flowcell to collect hourly data on temperature, pH, redox potential,electrical conductivity, and DO. Groundwater sampling was conducted bypumping through specially designed borehole water samplers.Cross-borehole radar tomography and seismic measurements were carried outto assess the site background lithological heterogeneity and themigration pathways of HRC byproducts through groundwater after the HRCinjection.
Date: September 6, 2006
Creator: Faybishenko, B.; Long, P.E.; Hazen, T.C.; Hubbard, S.S.; Williams, K.H.; Peterson, J.E. et al.
Partner: UNT Libraries Government Documents Department

A decision support system for real-time management of dissolvedoxygen in the Stockton deep water ship channel

Description: A decision support system(DSS)is under development to assistin the control and management of episodes of dissolved oxygen sag in aDeep Water Ship Channel (DWSC), located in Stockton, California. The DWSCwas formed by excavating the bed of the San Joaquin River in the 1950'sto allow navigation by ocean-going cargo ships to the Port of Stockton.The deepened channel has the effect of increasing hydraulic residencetime by a factor of ten. allowing accumulation of decaying algae andother oxygen demanding substances - which creates a barrier to themigration of anadromous fish. This problem, which manifests itself inlate summer and early autumn, is an impediment to a multimillion dollarhabitat restoration effort for the salmon fishery in the San JoaquinRiver basin (SJRB). A hydrodynamic and water quality model of the Deltaand San Joaquin River forms the basis of the DSS which will provideforecasts of dissolved oxygen sag in the DWSC and provide modelingsupport for management actions such as forced aeration to improvedissolved oxygen concentrations in the Ship Channel. A graphical userinterlace, currently used for displaying flow and salinity forecasts onthe San Joaquin River, is being adapted to allow the display of dissolvedoxygen forecasts and to encourage the formation of a stakeholder-ledentity or institution to adaptively manage the problem.
Date: July 16, 2003
Creator: Quinn, N. W. T.; Chen, Carl W. & Stringfellow, William T.
Partner: UNT Libraries Government Documents Department

Demonstration of membrane aeration panels: City of Geneva Wastewater Treatment Plant. Final report

Description: This report describes the design, construction, and testing of membrane aeration panels at the Marsh Creek wastewater treatment plant (WWTP) in Geneva, NY. The operators at the Geneva plant have undertaken a long-term program to upgrade wastewater treatment processes and lower operating costs. The aging mechanical surface aerators at the Marsh Creek treatment plant were replaced by a state-of-the-art membrane panel system. This fine-bubble diffused air system offers higher oxygen transfer efficiency than surface aerators or other types of fine-bubble diffused-air systems. The project had four objectives: to decrease the amount of electricity used at the plant for aeration; to enable the plant`s existing aeration basins to accommodate higher organic loads and/or nitrify the wastewater should the need arise; to provide an even distribution of dissolved oxygen within the aeration basins to enhance biological wastewater treatment activity; and to provide technical data to assess the performance of the membrane panel system versus other forms of wastewater aeration.
Date: January 1, 1995
Partner: UNT Libraries Government Documents Department

Retained gas sampler extractor mixing and mass transfer rate study: Experimental and simulation results

Description: Research staff at Pacific Northwest National Laboratory conducted experimental testing and computer simulations of the impeller-stirred Retained Gas Sampler (RGS) gas extractor system. This work was performed to verify experimentally the effectiveness of the extractor at mixing viscous fluids of both Newtonian and non-Newtonian rheology representative of Hanford single- and double-shell wastes, respectively. Developing the computational models and validating their results by comparing them with experimental results would enable simulations of the mixing process for a range of fluid properties and mixing speeds. Five tests were performed with a full-scale, optically transparent model extractor to provide the data needed to compare mixing times for fluid rheology, mixer rotational direction, and mixing speed variation. The computer model was developed and exercised to simulate the tests. The tests demonstrated that rotational direction of the pitched impeller blades was not as important as fluid rheology in determining mixing time. The Newtonian fluid required at least six hours to mix at the hot cell operating speed of 3 rpm, and the non-Newtonian fluid required at least 46 hours at 3 rpm to become significantly mixed. In the non-Newtonian fluid tests, stagnant regions within the fluid sometimes required days to be fully mixed. Higher-speed (30 rpm) testing showed that the laminar mixing time was correlated to mixing speed. The tests demonstrated that, using the RGS extractor and current procedures, complete mixing of the waste samples in the hot cell should not be expected. The computer simulation of Newtonian fluid mixing gave results comparable to the test while simulation of non-Newtonian fluid mixing would require further development. In light of the laboratory test results, detailed parametric analysis of the mixing process was not performed.
Date: November 1, 1997
Creator: Recknagle, K.P.; Bates, J.M. & Shekarriz, A.
Partner: UNT Libraries Government Documents Department

Effects of LWR coolant environments on fatigue lives of austenitic stainless steels.

Description: Fatigue tests have been conducted on Types 304 and 316NG stainless steels to evaluate the effects of various material and loading variables, e.g., steel type, strain rate, dissolved oxygen (DO) in water, and strain range, on the fatigue lives of these steels. The results confirm significant decreases in fatigue life in water. Unlike the situation with ferritic steels, environmental effects on Types 304 and 316NG stainless steel are more pronounced in low-DO than in high-DO water. Experimental results have been compared with estimates of fatigue life based on a statistical model. The formation and growth of fatigue cracks in air and water environments are discussed.
Date: January 13, 1998
Creator: Chopra, O. K.
Partner: UNT Libraries Government Documents Department

Fatigue crack initiation in carbon and low-alloy steels in light water reactor environments : mechanism and prediction.

Description: Section 111 of the ASME Boiler and Pressure Vessel Code specifies fatigue design curves for structural materials. The effects of reactor coolant environments are not explicitly addressed by the Code design curves. Recent test data illustrate potentially significant effects of light water reactor (LWR) coolant environments on the fatigue resistance of carbon and low-alloy steels. Under certain loading and environmental conditions, fatigue lives of test specimens may be shorter than those in air by a factor of {approx}70. The crack initiation and crack growth characteristics of carbon and low-alloy steels in LWR environments are presented. Decreases in fatigue life of these steels in high-dissolved-oxygen water are caused primarily by the effect of environment on growth of short cracks < 100 {micro}m in depth. The material and loading parameters that influence fatigue life in LWR environments are defined. Fatigue life is decreased significantly when five conditions are satisfied simultaneously, viz., applied strain range, service temperature, dissolved oxygen in water, and S content in steel are above a threshold level, and loading strain rate is below a threshold value. Statistical models have been developed for estimating the fatigue life of these steels in LWR environments. The significance of the effect of environment on the current Code design curve is evaluated.
Date: January 27, 1998
Creator: Chopra, O. K. & Shack, W. J.
Partner: UNT Libraries Government Documents Department

Mechanism of fatigue crack initiation in austenitic stainless steels in LWR environments.

Description: This paper examines the mechanism of fatigue crack initiation in austenitic stainless steels (SSs) in light water reactor (LWR) coolant environments. The effects of key material and loading variables, such as strain amplitude, strain rate, temperature, level of dissolved oxygen in water, and material heat treatment on the fatigue lives of wrought and cast austenitic SSs in air and LWR environments have been evaluated. The influence of reactor coolant environments on the formation and growth of fatigue cracks in polished smooth SS specimens is discussed. Crack length as a function of fatigue cycles was determined in air and LWR environments. The results indicate that decreased fatigue lives of these steels are caused primarily by the effects of the environment on the growth of cracks <200 {micro}m and, to a lesser extent, on enhanced growth rates of longer cracks. A detailed metallographic examination of fatigue test specimens was performed to characterize the fracture morphology. Exploratory fatigue tests were conducted to enhance our understanding of the effects of surface micropits or minor differences in the surface oxide on fatigue crack initiation.
Date: March 27, 2002
Creator: Chopra, O. K.
Partner: UNT Libraries Government Documents Department

Gas Bubble Trauma Monitoring in the Clearwater River Drainage, Idaho 1998.

Description: Select portions of the Clearwater and North Fork of the Clearwater rivers were electroshocked to estimate the incidence of gas bubble trauma (GBT) occurring in resident fish populations for the spring and summer months of 1998. The study area was divided into four sections and sampled weekly during periods of spill and non-spill from Dworshak Dam. Five thousand five hundred and forty one fish, representing 22 different species, were captured and examined for GBT. Two fish were detected with signs of GBT; exhibiting the lowest incidence of GBT in the last four years (0.04%). Reduced discharge and lower levels of total dissolved gases may have resulted in lower incidence of GBT in the 1998 monitoring period.
Date: December 1, 1998
Creator: Cochnauer, Tim
Partner: UNT Libraries Government Documents Department

Static and Transient Cavitation Threshold Measurements for Mercury

Description: Transient and static cavitation thresholds for mercury as a function of the cover gas (helium or air), and pressure are reported. Both static and transient cavitation onset pressure thresholds increase linearly with cover gas pressure. Additionally, the cavitation thresholds as a function of dissolved gases were also measured and are reported.
Date: November 14, 1999
Creator: Moraga, F. & Taleyarkhan, R.P.
Partner: UNT Libraries Government Documents Department


Description: Combustion-produced soot (carbonaceous) particles have been found to be efficient catalysts for SO{sub 2} oxidation, especially in the presence of liquid water. A kinetic study of the catalytic oxidation of SO{sub 2} on carbon particles suspended in solution has been carried out. The reaction was found to be first order with respect to the concentration of carbon particles, 0.69th order with respect to dissolved oxygen, between zero and second order with respect to S(IV) concentrations, and independent of the pH. Temperature studies were carried out, and an activation energy for this reaction was determined. A four-step mechanism is proposed for this carbon-catalyzed oxidation reaction.
Date: February 1, 1980
Creator: Brodzinsky, R.; Chang, S.G.; Markowitz, S.S. & Novakov, T.
Partner: UNT Libraries Government Documents Department


Description: In early 2004, the U.S. Department of Energy (DOE) Richland and Fluor Hanford requested technical assistance from the DOE Headquarters EM-23 Technical Assistance Program to provide a team of technical experts to develop recommendations for mending the In Situ Redox Manipulation (ISRM) Barrier in the 100-D Area of the Hanford Site in Washington State. To accommodate this request, EM-23 provided support to convene a group of technical experts from industry, a national laboratory, and a DOE site to participate in a 2 1/2-day workshop with the objective of identifying and recommending options to enhance the performance of the 100-D Area reactive barrier and of a planned extension to the northeast. This report provides written documentation of the team's findings and recommendations. In 1995, a plume of dissolved hexavalent chromium [Cr(VI)], which resulted from operation of the D/DR Reactors at the Hanford site, was discovered along the Columbia River shoreline and in the 100-D Area. Between 1999 and 2003, a reactive barrier using the In Situ Redox Manipulation (ISRM) technology, was installed a distance of 680 meters along the river to reduce the Cr(VI) in the groundwater. The ISRM technology creates a treatment zone within the aquifer by injection of sodium dithionite, a strong reducing agent that scavenges dissolved oxygen (DO) from the aquifer and reduces ferric iron [Fe(III)], related metals, and oxy-ions. The reduction of Fe(III) to ferrous [Fe(II)] iron provides the primary reduction capacity to reduce Cr(VI) to the +3 state, which is less mobile and less toxic. Bench-scale and field-scale treatability tests were initially conducted to demonstrate proof-of principle and to provide data for estimation of barrier longevity. These calculations estimated barrier longevity in excess of twenty years. However, several years after initial and secondary treatment, groundwater in a number of wells has been found to contain elevated ...
Date: February 6, 2006
Creator: PETERSEN, S.W.
Partner: UNT Libraries Government Documents Department

Total Dissolved Gas Monitoring in Chum Salmon Spawning Gravels Below Bonneville Dam

Description: At the request of the U.S. Army Corps of Engineers (Portland District), Pacific Northwest National Laboratory (PNNL) conducted research to determine whether total dissolved gas concentrations are elevated in chum salmon redds during spring spill operations at Bonneville Dam. The study involved monitoring the total dissolved gas levels at egg pocket depth and in the river at two chum salmon spawning locations downstream from Bonneville Dam. Dissolved atmospheric gas supersaturation generated by spill from Bonneville Dam may diminish survival of chum (Oncorhynchus keta) salmon when sac fry are still present in the gravel downstream from Bonneville Dam. However, no previous work has been conducted to determine whether total dissolved gas (TDG) levels are elevated during spring spill operations within incubation habitats. The guidance used by hydropower system managers to provide protection for pre-emergent chum salmon fry has been to limit TDG to 105% after allowing for depth compensation. A previous literature review completed in early 2006 shows that TDG levels as low as 103% have been documented to cause mortality in sac fry. Our study measured TDG in the incubation environment to evaluate whether these levels were exceeded during spring spill operations. Total dissolved gas levels were measured within chum salmon spawning areas near Ives Island and Multnomah Falls on the Columbia River. Water quality sensors screened at egg pocket depth and to the river were installed at both sites. At each location, we also measured dissolved oxygen, temperature, specific conductance, and water depth to assist with the interpretation of TDG results. Total dissolved gas was depth-compensated to determine when levels were high enough to potentially affect sac fry. This report provides detailed descriptions of the two study sites downstream of Bonneville Dam, as well as the equipment and procedures employed to monitor the TDG levels at the study sites. ...
Date: January 30, 2007
Creator: Arntzen, Evan V.; Geist, David R.; Panther, Jennifer L. & Dawley, Earl
Partner: UNT Libraries Government Documents Department

Lake Roosevelt Fisheries Evaluation Program, Part C; Lake Roosevelt Pelagic Fish Study: Washington Department of Fish and Wildlife, 1998 Annual Report.

Description: Pelagic fishes, such as kokanee and rainbow trout, provide an important fishery in Lake Roosevelt; however, spawner returns and creel results have been below management goals in recent years. Our objective was to identify factors that potentially limit pelagic fish production in Lake Roosevelt including entrainment, food limitation, piscivory, and other abiotic factors. We estimated the ratio of total fish entrained through Grand Coulee Dam to the pelagic fish abundance for September and October, 1998. If the majority of these fish were pelagic species, then entrainment averaged 10-13% of pelagic fish abundance each month. This rate of entrainment could impose considerable losses to pelagic fish populations on an annual basis. Therefore, estimates of species composition of entrained fish will be important in upcoming years to estimate the proportion of stocked pelagic fish lost through the dam. Food was not limiting for kokanee or rainbow trout populations since growth rates were high and large zooplankton were present in the reservoir. Estimates of survival for kokanee were low (< 0.01 annual) and unknown for rainbow trout. We estimated that the 1997 standing stock biomass of large (>1.1 mm) Daphnia could have supported 0.08 annual survival by kokanee and rainbow trout before fish consumption would have exceeded available biomass during late winter and early spring. Therefore, if recruitment goals are met in the future there may be a bottleneck in food supply for pelagic planktivores. Walleye and northern pikeminnow were the primary piscivores of salmonids in 1996 and 1997. Predation on salmonid prey was rare for rainbow trout and not detected for burbot or smallmouth bass. Northern pikeminnow had the greatest individual potential as a salmonid predator due to their high consumptive demand; however, their overall impact was limited because of their low relative abundance. We modeled the predation impact of 273,524 walleye ...
Date: November 1, 2002
Creator: Baldwin, Casey; Polacek, Matt & Bonar, Scott
Partner: UNT Libraries Government Documents Department

Elements of a decision support system for real-time management ofdissolved oxygen in the San Joaquin River deep water ship channel

Description: A decision support system (DSS) has been designed and will be implemented over the next three years to assist in the control and management of episodes of low dissolved oxygen (DO) in a Deep Water Ship Channel (DWSC), located near Stockton, California. The DSS integrates three information technology functions. The first part is the collection and management of data on flow, pollution loads and water quality. The second part is the simulation model which can forecast the dissolved oxygen sag in the DWSC and determine management actions necessary to improve dissolved oxygen concentrations. The third part is the graphical user interface, which facilitates the computer simulations and posting of the forecasted dissolved oxygen and remedial measures to a stakeholder group for implementations.
Date: July 15, 2004
Creator: Quinn, N.W.T.; Jacobs, Karl; Chen, Carl W. & Stringfellow, WilliamT.
Partner: UNT Libraries Government Documents Department

Water Quality Trends in the Entiat River Subbasin: Final 2008 Annual Report.

Description: The ISEMP program monitors the status and trend of water quality elements that may affect restoration project effectiveness in the Entiat subbasin. As part of this effort, the PNW Research Station (PNW) measures, analyzes and interprets temporal trends in natural stream water pH, dissolved oxygen, specific conductivity and temperature. The Entiat River is currently on the Clean Water Act 303(d) list for pH exceedence, and there is insufficient information to determine the spatial and temporal extent or potential causes of this exceedence. In the spring 2008, PNW redeployed data-logging, multiparameter probes at four locations in the Entiat subbasin to measure water quality parameters, focusing on pH. This resumed previous data collection that was interrupted by river ice in early December 2007. Instruments were again removed from the river in early December 2008. This annual report covers the period from December 2007 through December 2008. The highest pH values occurred during the low-flow period from midsummer through the following midspring then dropped sharply during the annual snowmelt runoff period from late spring through early summer. Water temperature began rapidly increasing during the receding limb of the annual snowmelt hydrograph. Highest mean monthly temperatures occurred in July and August, while instantaneous maxima occurred during the period July-September. Dissolved oxygen reached its lowest levels during the period of highest water temperature in July-September. Specific conductivity remained very low at all sites throughout the year.
Date: March 30, 2009
Creator: Woodsmith, Richard & Bookter, Andy
Partner: UNT Libraries Government Documents Department

Uranium Mobility During In Situ Redox Manipulation of the 100 Areas of the Hanford Site

Description: A series of laboratory experiments and computer simulations was conducted to assess the extent of uranium remobilization that is likely to occur at the end of the life cycle of an in situ sediment reduction process. The process is being tested for subsurface remediation of chromate and chlorinated solvent-contaminated sediments at the Hanford Site in southeastern Washington. Uranium species that occur naturally in the +6 valence state [U(VI)] at 10 ppb in groundwater at Hanford will accumulate as U(IV) through the reduction and subsequent precipitation conditions of the permeable barrier created by in situ redox manipulation. The precipitated uranium will be remobilized when the reductive capacity of the barrier is exhausted and the sediment is oxidized by the groundwater containing dissolved oxygen and other oxidants such as chromate. Although U(IV) accumulates from years or decades of reduction/precipitation within the reduced zone, U(VI) concentrations in solution are only somewhat elevated during aquifer oxidation because oxidation and dissolution reactions that release U(IV) precipitate to solution are slow. The release rate of uranium into solution was found to be controlled mainly by the oxidation/dissolution rate of the U(IV) precipitate (half-life 200 hours) and partially by the fast oxidation of adsorbed Fe(II) (halflife 5 hours) and the slow oxidation of Fe(II)CO3 (half-life 120 hours) in the reduced sediment. Simulations of uranium transport that incorporated these and other reactions under site-relevant conditions indicated that 35 ppb U(VI) is the maximum concentration likely to result from mobilization of the precipitated U(IV) species. Experiments also indicated that increasing the contact time between the U(IV) precipitates and the reduced sediment, which is likely to occur in the field, results in a slower U(IV) oxidation rate, which, in turn, would lower the maximum concentration of mobilized U(VI)...
Date: December 3, 1998
Creator: Szecsody, James E.; Krupka, Kenneth M.; Williams, Mark D.; Cantrell, Kirk J.; Resch, Charles T. & Fruchter, Jonathan S.
Partner: UNT Libraries Government Documents Department

Evaluation of Hydrogen Generation from Radiolysis from Breached Spent Fuel

Description: Ionizing radiation from spent nuclear fuel (SNF) can cause radiolytic decomposition of water and generation of hydrogen. Factors affecting hydrogen production include the type of radiation (alpha, gamma, and neutron), the radiation (alpha, gamma, and neutron), the linear energy transfer (LET) rates from the radiation, the water chemistry and dissolved gases, and physical conditions such as temperature and pressure. A review of the mechanisms for the radiolytic generation of hydrogen applicable to breached SNF has been performed. A qualitative evaluation of the potential for generation of hydrogen in the pure water used in water-filled shipping casks at the Savannah River Site (SRS) is made.
Date: September 17, 2002
Creator: Vinson, D.W.
Partner: UNT Libraries Government Documents Department