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Initial Assessment of the Consolidation of Chalcogels into a Viable Waste Form

Description: This report provides some preliminary data for the consolidation of chalcogen-based aerogels. The chalcogels tested to date at PNNL show great promise as iodine sorbents and preliminary consolidation research shows that they can be melted into a phase-pure glass at moderate temperatures. The preliminary consolidation experiments show that these materials might attack fused quartz so an alternative crucible material will likely need to be used to prevent this. The next steps will be to • Consider melting other chalcogel chemistries, e.g., Sn-Sb-S, Ge-Sn-S chalcogels • Consider melting chalcogels with adsorbed iodine to monitor iodine loss during melting • Optimize the consolidation temperatures to minimize the iodine loss and volatilization
Date: August 31, 2012
Creator: Riley, Brian J. & Lepry, William C.
Partner: UNT Libraries Government Documents Department

Radionuclide Retention in Concrete Wasteforms - FY13

Description: Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.
Date: October 15, 2013
Creator: Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C. et al.
Partner: UNT Libraries Government Documents Department

Halogen Collector Test Program

Description: Report documenting the Halogen Collector Test program, which was undertaken to provide "methods of removing trace quantities of radioactive iodine from an air stream" (p. 1). The report includes designs of the program and the test facility, test results, analysis of these results, and encountered problems. Appendices begin on page 38.
Date: March 1, 1960
Creator: Arthur D. Little, Inc.
Partner: UNT Libraries Government Documents Department

Analysis of vegetation for I¹³¹

Description: Report detailing an analysis of the deposition of I-131 on vegetation. Analysis was necessary to determine the potential hazards of the gases from the dissolution of the metal on vegetation.
Date: January 27, 1950
Creator: Leboeuf, M. B.
Partner: UNT Libraries Government Documents Department

Iodine Exchange Reaction

Description: This report discusses an analysis on the exchange reaction between iodine and unipositive iodine with pyridine.
Date: August 25, 1948
Creator: Kleinberg, Jacob & Sattizahn, James
Partner: UNT Libraries Government Documents Department

Membranes for the Sulfur-Iodine Integrated Laboratory Scale Demonstration

Description: INL has developed polymeric membrane-based chemical separations to enable the thermochemical production of hydrogen. Major activities included studies of sulfuric acid concentration membranes, hydriodic acid concentration membranes, SO2/O2 separation membranes, potential applications of a catalyst reactor system for the decomposition of HI, and evaluation of the chemical separation needs for alternate thermochemical cycles. Membranes for the concentration of sulfuric acid were studied using pervaporation. The goal of this task was to offer the sulfur-iodine (S-I) and the hybrid sulfur (HyS) cycles a method to concentrate the sulfuric acid containing effluent from the decomposer without boiling. In this work, sulfuric acid decomposer effluent needs to be concentrated from ~50 % acid to 80 %. This task continued FY 2006 efforts to characterize water selective membranes for use in sulfuric acid concentration. In FY 2007, experiments were conducted to provide specific information, including transmembrane fluxes, separation factors, and membrane durability, necessary for proper decision making on the potential inclusion of this process into the S-I or HyS Integrated Laboratory Scale demonstration.
Date: August 1, 2007
Creator: Stewart, Frederick F.
Partner: UNT Libraries Government Documents Department

Precise measurements of hyperfine components in the spectrum of molecular iodine

Description: Absolute wave numbers with a typical uncertainty of 1 MHz (95% confidence) were measured for 102 hyperfine-structure components of {sup 127}I{sub 2}. The data cover the range 560-656 nm, with no gaps over 50 cm{sup -1}. The spectra were observed using Doppler-free frequency modulation spectroscopy with tunable cw laser. The laser was locked to selected iodine components and its wave number measured with a high precision Fabry-Perot wavemeter. Accuracy is confirmed by good agreement of 9 of the lines with previous results from other laboratories. These measurements provide a well-distributed set of precise reference lines for this spectral region.
Date: May 1, 1996
Creator: Sansonetti, C.J.
Partner: UNT Libraries Government Documents Department

Passivation effects of surface iodine layer on tantalum for the electroless copper deposition.

Description: The ability to passivate metallic surfaces under non-UHV conditions is not only of fundamental interests, but also of growing practical importance in catalysis and microelectronics. In this work, the passivation effect of a surface iodine layer on air-exposed Ta for the copper electroless deposition was investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Although the passivation effect was seriously weakened by the prolonged air exposure, iodine passivates the Ta substrate under brief air exposure conditions so that enhanced copper wetting and adhesion are observed on I-passivated Ta relative to the untreated surface.
Access: This item is restricted to the UNT Community Members at a UNT Libraries Location.
Date: May 2004
Creator: Liu, Jian
Partner: UNT Libraries

Evaluation and Characterization of Membranes for HI/H2O/I2 Water Separation for the S-I Cycle

Description: In the Sulfur-Iodine (S-I) thermochemical cycle, iodine is added to the product of the Bunsen reaction to facilitate the separation of sulfuric acid (H2SO4) from hydriodic acid (HI). The amount of iodine can be as high as 83% of the overall mass load of the Bunsen product stream, which potentially introduces a large burden on the cycle’s efficiency. Removal of water from the HI and I2 mixture would substantially reduce the amount of required additional iodine. In this work, Nafion® membranes have been studied for their use as de-watering membranes. Specifically, two thicknesses of Nafion membranes have been found to be effective in this application. The thicker membrane, Nafion-117®, produces moderate fluxes of water with very high separation factors. On the other hand, the thinner membrane, Nafion-112®, yielded very large fluxes of water, however with smaller separation factors. All membranes were found to be durable and did not degrade in contact with the feed stream over periods of time up to three months.
Date: September 1, 2005
Creator: Stewart, Frederick F.
Partner: UNT Libraries Government Documents Department

NUCLEAR SPIN AND HYPERFINE-STRUCTURE MEASUREMENTS ON THE RADIOACTIVE-IODINE AND ASTATINE ISOTOPES (thesis)

Description: Atomic-beam magnetic resonance techniques were used to measure the nuclear spins of I/sup 123/, I/sup 124/, I/sup 126/, I/sup 130/, I/sup 132/, I/ sup 133/, I/sup 135/, and At/sup 211/. Also, measurements of the magnetic-dipole interaction constant, and the electroquadrupole interaction constant, and the electroquadrupole interaction constant for I/sup 131/ and I/sup 132/ are reported. The design of the atomic-beam apparatus is described. Experimental methods and sample preparation are discussed and results are interpreted in the light of the single particle shell-model theory of nuclear structure. (J.R.D.)
Date: August 1, 1959
Creator: Garvin, H L
Partner: UNT Libraries Government Documents Department

A STUDY OF THE CHEMICAL EFFECTS OF $beta$-DECAY FROM $sup 132$Te TO $sup 132$I USING PAPER ELECTROPHORESIS

Description: The present investigation utilizes high voltage electrophoresis for the determination of iodine oxidation states resulting from the beta decay of {sup 132}Te as both tellurite and tellurate in aqueous solution. The yield of periodate from basic Te(IV) growth solutions was shown to be negligible and that from basic Te(VI) growth solutions was shown to be significantly smaller than previously reported. The results are discussed in terms of the molecular species of tellurium likely to be present in the growth solutions. (auth)
Date: January 1, 1967
Creator: Gordon, B.M.
Partner: UNT Libraries Government Documents Department

Cu Electrodeposition on Ru with a Chemisorbed Iodine Surface Layer.

Description: An iodine surface layer has been prepared on Ru(poly) and Ru(0001) electrodes by exposure to iodine vapor in UHV and polarizing in a 0.1 M HClO4/0.005 M KI solution, respectively. A saturation coverage of I on a Ru(poly) electrode passivates the Ru surface against significant hydroxide, chemisorbed oxygen or oxide formation during exposure to water vapor over an electrochemical cell in a UHV-electrochemistry transfer system. Immersion of I-Ru(poly) results in greater hydroxide and chemisorbed oxygen formation than water vapor exposure, but an inhibition of surface oxide formation relative that of the unmodified Ru(poly) surface is still observed. Studies with combined electrochemical and XPS techniques show that the iodine surface adlayer remained on top of the surface after cycles of overpotential electrodeposition/dissolution of copper on both Ru(poly) and Ru(0001) electrodes. These results indicate the potential bifunctionality of iodine layer to both passivate the Ru surface in the microelectronic processing and to act as a surfactant for copper electrodeposition. The electrodeposition of Cu on Ru(0001) or polycrystalline Ru was studied using XPS with combined ultrahigh vacuum/electrochemistry methodology (UHV-EC) in 0.1 M HClO4 with Cu(ClO4)2 concentrations ranging from 0.005 M to 0.0005 M, and on polycrystalline Ru in a 0.05M H2SO4/0.005 M CuSO4/0.001 M NaCl solution. The electrochemical data show well-defined cyclic voltammograms (CV) with a Cu underpotential deposition (UPD) peak and overpotential deposition (OPD) peak. XPS spectra of Ru electrodes emersed from perchloric acid solution at cathodic potentials indicate that ClO4- anions dissociate to yield specifically adsorbed Cl and ClOx species. Subsequent Cu deposition results in the formation of a thin, insoluble Cu(II) film with Cu(I) underneath. In contrast, similar deposition on polycrystalline Ru in the sulfuric acid/Cu sulfate solution with NaCl added yields only Cu(0), indicating that the formation of Cu(II) and Cu(I) involves both Cl and perchlorate interactions with the ...
Access: This item is restricted to the UNT Community Members at a UNT Libraries Location.
Date: August 2005
Creator: Lei, Jipu
Partner: UNT Libraries

Independent and Relative Yields of I¹³¹, I¹³², I¹³³, I¹³⁴, and I¹³⁵ Formed in Fission of U²³⁵ by 14-Mev and Thermal Neutrons

Description: Abstract: "The following results were derived from experiments in which iodine was quickly separated from irradiated uranium metal at a known time after irradiation. The fractional chain yields are based on the cumulative chain yields at iodine."
Date: 1954
Creator: Wahl, Arthur C.
Partner: UNT Libraries Government Documents Department