68 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Dissolution"  
Results: 1 - 24 next
open access

Corrosion Testing of a Plutonium-Loaded Lanthanide Borosilicate Glass Made With Frit B.A.

Description: Laboratory tests were conducted with a lanthanide borosilicate (LaBS) glass made with Frit B and added PuO2 (the glass is referred to herein as Pu LaBS-B glass) to measure the dependence of the glass dissolution rate on pH and temperature. These results are compared with the dependencies used in the Defense HLW Glass Degradation Model that was developed to account for HLW glasses in total system performance assessment (TSPA) calculations for the Yucca Mountain repository to determine if that mo… more
Date: September 30, 2006
Creator: Ebert, W. L. & Engineering, Chemical
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Modeling the Cathodic Region in Crevice Corrosion Under a Thin Electrolyte Film Including Particulates

Description: Crevice corrosion may be limited by the capacity of the external cathodic region to support anodic dissolution currents within the crevice. The analysis here focuses on behavior of metal surfaces covered by a thin ({approx}microns) layer of the electrolyte film including particulates. The particulates can affect the cathode current capacity (I{sub total}) by increasing the solution resistance (''volume effect'') and by decreasing the electrode area (''surface effect''). In addition, there can b… more
Date: March 14, 2006
Creator: Agarwal, A. S.; Landau, U.; Shan, X. & Payer, J. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Interlaboratory Study of the Reproducibility of the Single-Pass Flow-Through Test Method : Measuring the Dissolution Rate of Lrm Glass at 70 {Sup {Degree}}C and PH 10.

Description: An international interlaboratory study (ILS) was conducted to evaluate the precision with which single-pass flow-through (SPFT) tests can be conducted by following a method to be standardized by the American Society for Testing and Materials - International. Tests for the ILS were conducted with the low-activity reference material (LRM) glass developed previously for use as a glass test standard. Tests were conducted at 70 {+-} 2 C using a LiCl/LiOH solution as the leachant to impose an initial… more
Date: February 28, 2006
Creator: Ebert, W. L. & Engineering, Chemical
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Chemical Effects Head-Loss Research in Support of Generic Safety Issue 191.

Description: This summary report describes studies conducted at Argonne National Laboratory on the potential for chemical effects on head loss across sump screens. Three different buffering solutions were used for these tests: trisodium phosphate (TSP), sodium hydroxide, and sodium tetraborate. These pH control agents used following a LOCA at a nuclear power plant show various degrees of interaction with the insulating materials Cal-Sil and NUKON. Results for Cal-Sil dissolution tests in TSP solutions, sett… more
Date: October 31, 2006
Creator: Park, J. H.; Kasza, K.; Fisher, B.; Oras, J.; Natesan, K.; Shack, W. J. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Microbial Transformations of Radionuclides Released From Nuclear Fuel Reprocessing Plants.

Description: Microorganisms can affect the stability and mobility of the actinides U, Pu, Cm, Am, Np, and the fission products Tc, I, Cs, Sr, released from nuclear fuel reprocessing plants. Under appropriate conditions, microorganisms can alter the chemical speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution and the bioavailability. Dissolution or immobilization of radionuclides is brought about by direct enzymatic action or indi… more
Date: October 18, 2006
Creator: Francis, A. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Decontamination of Zircaloy Spent Fuel Cladding Hulls

Description: The reprocessing of commercial spent nuclear fuel (SNF) generates a Zircaloy cladding hull waste which requires disposal as a high level waste in the geologic repository. The hulls are primarily contaminated with fission products and actinides from the fuel. During fuel irradiation, these contaminants are deposited in a thin layer of zirconium oxide (ZrO{sub 2}) which forms on the cladding surface at the elevated temperatures present in a nuclear reactor. Therefore, if the hulls are treated to … more
Date: September 27, 2006
Creator: Rudisill, T. & John Mickalonis, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Chapter 9: Model Systems for Formation and Dissolution of Calcium Phosphate Minerals

Description: Calcium phosphates are the mineral component of bones and teeth. As such there is great interest in understanding the physical mechanisms that underlie their growth, dissolution, and phase stability. Control is often achieved at the cellular level by the manipulation of solution states and the use of crystal growth modulators such as peptides or other organic molecules. This chapter begins with a discussion of solution speciation in body fluids and relates this to important crystal growth param… more
Date: July 29, 2006
Creator: Orme, C. A. & Giocondi, J. L.
Item Type: Refine your search to only Book
Partner: UNT Libraries Government Documents Department
open access

Predicting dissolution patterns in variable aperture fractures: 1. Development and evaluation of an enhanced depth-averaged computational model

Description: Water-rock interactions within variable-aperture fractures can lead to dissolution of fracture surfaces and local alteration of fracture apertures, potentially transforming the transport properties of the fracture over time. Because fractures often provide dominant pathways for subsurface flow and transport, developing models that effectively quantify the role of dissolution on changing transport properties over a range of scales is critical to understanding potential impacts of natural and ant… more
Date: April 21, 2006
Creator: Detwiler, R L & Rajaram, H
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Development of a CO2 Sequestration Module by Integrating Mineral Activation and Aqueous Carbonation

Description: Mineral carbonation is a promising concept for permanent CO{sub 2} sequestration due to the vast natural abundance of the raw materials and the permanent storage of CO{sub 2} in solid form as carbonates. The sequestration of CO{sub 2} through the employment of magnesium silicates--olivine and serpentine--is beyond the proof of concept stage. For the work done in this project, serpentine was chosen as the feedstock mineral due to its abundance and availability. Although the reactivity of olivine… more
Date: August 14, 2006
Creator: Alexander, George; Aksoy, Parvana; Andresen, John; Maroto-Valer, Mercedes & Schobert, Harold
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Direct Observations of Sigma Phase Formation in Duplex Stainless Steels using In Situ Synchrotron X-Ray Diffraction

Description: The formation and growth of sigma phase in 2205 duplex stainless steel was observed and measured in real time using synchrotron radiation during 10 hr isothermal heat treatments at temperatures between 700 C and 850 C. Sigma formed in near-equilibrium quantities during the isothermal holds, starting from a microstructure which contained a balanced mixture of metastable ferrite and austenite. In situ synchrotron diffraction continuously monitored the transformation, and these results were compar… more
Date: July 3, 2006
Creator: Elmer, J W; Palmer, T A & Specht, E D
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Yucca Mountain Project: FY 2006 Annual Report for Waste Form Testing Activities.

Description: This report describes the experimental work performed at Argonne National Laboratory (Argonne) during fiscal year (FY 2006) under the Bechtel SAIC Company, LLC (BSC) Memorandum Purchase Order (MPO) contract number B004210CM3X. Because this experimental work is focused on the dissolution and precipitation behavior of neptunium, the report also includes, or incorporates by reference, earlier results that are relevant to presenting a more complete understanding of the likely behavior of neptunium … more
Date: November 1, 2006
Creator: Ebert, W. L.; Fortner, J. A.; Guelis, A. V. & Cunnane, J. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Microscopic Controls on the Desorption/Dissolution of Sorbed U(VI) and Their Influence on Reactive Transport

Description: A sizable groundwater U plume exists in Hanford's 300 A resulting from the disposal of fuel rod dissolution wastes containing Al, Cu, and U to the vadose zone. This project is studying U-contaminated samples collected along a flow path from the waste source to the Columbia River. Three primary objectives are being pursued: (1) To develop microscopic models for U desorption/adsorption in sediments along the flow path including both geochemical reaction and diffusive mass transport processes. (2)… more
Date: June 1, 2006
Creator: Zachara, John M.; Brown, Gordon E.; Davis, James A.; Lichtner, Peter C. & Steefel, C.I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mechanical and Thermal Properties of Ultra-High Carbon Steel Containing Aluminum

Description: The properties of ultrahigh carbon steels (UHCS) are strongly influenced by aluminum additions. Hardness studies of quenched UHCS-Al alloys reveal that the temperature for the start of transformation increases with increases in aluminum content. It is shown that this change is a function of the atomic percent of solute and of the valence state when comparisons are made with UHCSs containing silicon and tin as solutes. The thermal expansion of UHCSs with dilute aluminum additions shows no discon… more
Date: January 31, 2006
Creator: Syn, C K; Lesuer, D R; Goldberg, A; Tsai, H & Sherby, O D
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Potential COntrol Under Thin Aqueous Layers Using a Kelvin Probe

Description: Kelvin Probes can be modified to control as well as monitor potential. The design and operation of two different Kelvin Probe Potentiostats (KPPs) are described in this paper. One approach uses a permanent magnet and double coil to oscillate the needle at a fixed frequency, an AC backing potential, and software analysis and control schemes. This technique can also control the distance between the tip and sample, thereby tracking the topography of the sample. Both KPPs were used to make measurem… more
Date: August 17, 2006
Creator: Frankel, G. S.; Maier, B.; Stratman, M.; Rohwerder, M.; Michalik, A.; Dora, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Experimental and analytic studies to model kinetics and mass transport of carbon dioxide sequstration in depleted carbonate reservoirs

Description: There is undeniable evidence that concentration of carbon dioxide in the atmosphere is rising at an increasingly rapid rate primarily as the result of burning fossil fuels. Although the debate continues, most of the scientific community believes that higher levels of atmospheric CO2 will lead to a significant warming of the Earth’s climate and that there is already evidence that this is occurring. There are two ways to ameliorate this problem. One is to significantly reduce production of CO2, w… more
Date: October 31, 2006
Creator: Morse, John W & Mamora, Daulat
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Dosimetry Modeling for Predicting Radiolytic Production at the Spent Fuel - Water Interface

Description: Modeling of the alpha, beta, and gamma dose from spent fuel as a function of particle size and fuel to water ratio was examined. These doses will be combined with modeling of G values and interactions to determine the concentration of various species formed at the fuel water interface and their affect on dissolution rates.
Date: April 30, 2006
Creator: Miller, William H.; Kline, Amanda J. & Hanson, Brady D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Testing to evaluate the suitability of waste forms developed for electrometallurgically treated spent sodium-bonded nuclear fuel for disposal in the Yucca Mountain reporsitory.

Description: The results of laboratory testing and modeling activities conducted to support the development of waste forms to immobilize wastes generated during the electrometallurgical treatment of spent sodium-bonded nuclear fuel and their qualification for disposal in the federal high-level radioactive waste repository are summarized in this report. Tests and analyses were conducted to address issues related to the chemical, physical, and radiological properties of the waste forms relevant to qualificati… more
Date: January 31, 2006
Creator: Ebert, W. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of Petroluem Residua Solubility Measurement Methodology: Final Report

Description: In the present study an existing spectrophotometry system was upgraded to provide high-resolution ultraviolet (UV), visible (Vis), and near infrared (NIR) analyses of test solutions to measure the relative solubilities of petroleum residua dissolved in eighteen test solvents. Test solutions were prepared by dissolving ten percent petroleum residue in a given test solvent, agitating the mixture, followed by filtration and/or centrifugation to remove insoluble materials. These solutions were fina… more
Date: March 1, 2006
Creator: Redelius, Per
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

FLUID FLOW, SOLUTE MIXING AND PRECIPITATION IN POROUS MEDIA

Description: Reactions that lead to the formation of mineral precipitates, colloids or growth of biofilms in porous media often depend on the molecular-level diffusive mixing. For example, for the formation of mineral phases, exceeding the saturation index for a mineral is a minimum requirement for precipitation to proceed. Solute mixing frequently occurs at the interface between two solutions each containing one or more soluble reactants, particularly in engineered systems where contaminant degradation or … more
Date: September 1, 2006
Creator: Redden, George D; Fang, Y.; Scheibe, T.D.; Tartakovsky, A.M.; Fox, Don T; Fujita, Yoshiko et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

DEVELOPMENT OF A CO2 SEQUESTRATION MODULE BY INTEGRATING MINERAL ACTIVATION AND AQUEOUS CARBONATION

Description: Mineral carbonation provides a potential option for the long-term storage of carbon dioxide. Serpentine has been chosen as the feedstock mineral, due to its abundance and availability. However, the relatively low reactivity of serpentine has warranted research into physical and chemical treatments that have been shown to greatly increase its reactivity. The use of sulfuric acid as an accelerating medium for the removal of magnesium from serpentine has recently been investigated. In addition to … more
Date: March 25, 2006
Creator: Alexander, George; Maroto-Valer, M. Mercedes; Aksoy, Parvana & Schobert, Harold
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Microbial Transformations of Radionuclides and Environmental Restoration Through Bioremediation.

Description: Treatment of waste streams containing radionuclides, the remediation of contaminated materials, soils, and water, and the safe and economical disposal of radionuclides and toxic metals containing wastes is a major concern. Radionuclides may exist in various oxidation states and may be present as oxide, coprecipitates, inorganic, and organic complexes depending on the process and waste stream. Unlike organic contaminants, the metals cannot be destroyed, but must either be converted to a stable f… more
Date: September 29, 2006
Creator: Francis, A. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

In situ Microbial Community Control of the Stability of Bio-Reduced Uranium

Description: In aerobic aquifers typical of many Department of Energy (DOE) legacy waste sites, uranium is present in the oxidized U(VI) form which is soluble and thus mobile compared to U(IV). Previous work at the Old Rifle Uranium Mill Tailings Remedial Action (UMTRA) site demonstrated that biostimulation by acetate injection promoted growth of Geobacteraceae and stimulated the microbial reduction of U(VI) to less soluble U(IV) (1, 4). Despite the potential for oxidative dissolution of bio-reduced U(IV), … more
Date: June 1, 2006
Creator: Long, Phillip E.; McKinley, James P. & White, David C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Science-Based Approach to Understanding Waste Form Durability in Open and Closed Nuclear Fuel Cycles

Description: There are two compelling reasons for understanding source term and near-field processes in a radioactive waste geologic repository. First, almost all of the radioactivity is initially in the waste form, mainly in the spent nuclear fuel (SNF) or nuclear waste glass. Second, over long periods, after the engineered barriers are degraded, the waste form is a primary control on the release of radioactivity. Thus, it is essential to know the physical and chemical state of the waste form after hundred… more
Date: June 22, 2006
Creator: Peters, M. T. & Ewing, R. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

URANIUM-SERIES CONSTRAINTS ON RADIONUCLIDE TRANSPORT AND GROUNDWATER FLOW AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, MEXICO

Description: Uranium-series data for groundwater samples from the vicinity of the Nopal I uranium ore deposit are used to place constraints on radionuclide transport and hydrologic processes at this site, and also, by analogy, at Yucca Mountain. Decreasing uranium concentrations for wells drilled in 2003 suggest that groundwater flow rates are low (< 10 m/yr). Field tests, well productivity, and uranium isotopic constraints also suggest that groundwater flow and mixing is limited at this site. The uraniu… more
Date: April 1, 2006
Creator: S. J. Goldstein, S. Luo, T. L. Ku, and M. T. Murrell
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen