REDUCTION AND SEQUESTRATION OF PERTECHNETATE TO TECHNETIUM DIOXIDE AND PROTECTION FROM RE-OXIDATION (open access)

REDUCTION AND SEQUESTRATION OF PERTECHNETATE TO TECHNETIUM DIOXIDE AND PROTECTION FROM RE-OXIDATION

This effort is part of the technetium management initiative and provides data for the handling and disposition of technetium. To that end, the objective of this effort was to challenge tin(II)apatite (Sn(II)apatite) against double-shell tank 241-AN-I0S simulant spiked with pertechnetate (TcO{sub 4}{sup -}). The Sn(II)apatite used in this effort was synthesized on site using a recipe developed at and provided by Sandia National Laboratories; the synthesis provides a high quality product while requiring minimal laboratory effort. The Sn(II)apatite reduces pertechnetate from the mobile +7 oxidation state to the non-mobile +4 oxidation state. It also sequesters the technetium and does not allow for re-oxidization to the mobile +7 state under acidic or oxygenated conditions within the tested period of time (6 weeks). Previous work indicated that the Sn(II)apatite can achieve an ANSI leachability index in Cast Stone of 12.8. The technetium distribution coefficient for Sn(II)apatite exhibits a direct correlation with the pH of the contaminated media. Table 1 shows Sn(II)apatite distribution coefficients as a function of pH. The asterisked numbers indicate that the lower detection limit of the analytical instrument was used to calculate the distribution coefficient as the concentration of technetium left in solution was less than the detection limit.
Date: July 11, 2012
Creator: JB, DUNCAN; JM, JOHNSON; WP, MOORE; KJ, HAGERTY; RN, RHODES & RC, MOORE
Object Type: Article
System: The UNT Digital Library
The Connection between Galaxies and Dark Matter Structures in the Local Universe (open access)

The Connection between Galaxies and Dark Matter Structures in the Local Universe

We provide new constraints on the connection between galaxies in the local Universe, identified by the Sloan Digital Sky Survey (SDSS), and dark matter halos and their constituent substructures in the {Lambda}CDM model using WMAP7 cosmological parameters. Predictions for the abundance and clustering properties of dark matter halos, and the relationship between dark matter hosts and substructures, are based on a high-resolution cosmological simulation, the Bolshoi simulation. We associate galaxies with dark matter halos and subhalos using subhalo abundance matching, and perform a comprehensive analysis which investigates the underlying assumptions of this technique including (a) which halo property is most closely associated with galaxy stellar masses and luminosities, (b) how much scatter is in this relationship, and (c) how much subhalos can be stripped before their galaxies are destroyed. The models are jointly constrained by new measurements of the projected two-point galaxy clustering and the observed conditional stellar mass function of galaxies in groups. We find that an abundance matching model that associates galaxies with the peak circular velocity of their halos is in good agreement with the data, when scatter of 0.20 {+-} 0.03 dex in stellar mass at a given peak velocity is included. This confirms the theoretical …
Date: July 11, 2012
Creator: Reddick, Rachel M.; Wechsler, Risa H.; Tinker, Jeremy L. & Behroozi, Peter S.
Object Type: Article
System: The UNT Digital Library
Full Toroidal Imaging of Non-axisymmetric Plasma Material Interaction in the National Spherical Torus eXperiment (open access)

Full Toroidal Imaging of Non-axisymmetric Plasma Material Interaction in the National Spherical Torus eXperiment

A pair of two dimensional fast cameras with a wide angle view (allowing a full radial and toroidal coverage of the lower divertor) was installed in the National Spherical Torus Experiment in order to monitor non-axisymmetric effects. A custom polar remapping procedure and an absolute photometric calibration enabled the easier visualization and quantitative analysis of non-axisymmetric plasma material interaction (e.g., strike point splitting due to application of 3D fields and effects of toroidally asymmetric plasma facing components).
Date: July 11, 2012
Creator: Filippo Scotti, A.L. Roquemore, and V. A. Soukhanovskii
Object Type: Article
System: The UNT Digital Library
Comparison of LHC and ILC Capabilities for Higgs Boson Coupling Measurements (open access)

Comparison of LHC and ILC Capabilities for Higgs Boson Coupling Measurements

I estimate the accuracies on Higgs boson coupling constants that experiments at the Large Hadron Collider and the International Linear Collider are capable of reaching over the long term.
Date: July 11, 2012
Creator: Peskin, Michael E.
Object Type: Article
System: The UNT Digital Library
APPLICATION FO FLOW FORMING FOR USE IN RADIOACTIVE MATERIAL PACKAGING DESIGNS (open access)

APPLICATION FO FLOW FORMING FOR USE IN RADIOACTIVE MATERIAL PACKAGING DESIGNS

This paper reports on the development and testing performed to demonstrate the use of flow forming as an alternate method of manufacturing containment vessels for use in radioactive material shipping packaging designs. Additionally, ASME Boiler and Pressure Vessel Code, Section III, Subsection NB compliance along with the benefits compared to typical welding of containment vessels will be discussed. SRNL has completed fabrication development and the testing on flow formed containment vessels to demonstrate the use of flow forming as an alternate method of manufacturing a welded 6-inch diameter containment vessel currently used in the 9975 and 9977 radioactive material shipping packaging. Material testing and nondestructive evaluation of the flow formed parts demonstrate compliance to the minimum material requirements specified in applicable parts of ASME Boiler and Pressure Vessel Code, Section II. Destructive burst testing shows comparable results to that of a welded design. The benefits of flow forming as compared to typical welding of containment vessels are significant: dimensional control is improved due to no weld distortion; less final machining; weld fit-up issues associated with pipes and pipe caps are eliminated; post-weld non-destructive testing (i.e., radiography and die penetrant tests) is not necessary; and less fabrication steps are required. Results …
Date: July 11, 2012
Creator: Blanton, P.; Eberl, K. & Abramczyk, G.
Object Type: Article
System: The UNT Digital Library
Stochastic Orbit Loss of Neutral Beam Ions From NSTX Due to Toroidal Alfven Eigenmode Avalanches (open access)

Stochastic Orbit Loss of Neutral Beam Ions From NSTX Due to Toroidal Alfven Eigenmode Avalanches

Short toroidal Alfven eigenmode (TAE) avalanche bursts in the National Spherical Torus Experiment (NSTX) cause a drop in the neutron rate and sometimes a loss of neutral beam ions at or near the full injection energy over an extended range of pitch angles. The simultaneous loss of wide ranges of pitch angle suggests stochastic transport of the beam ions occurs. When beam ion orbits are followed with a guiding center code that incorporates plasma's magnetic equilibrium plus the measured modes, the predicted ranges of lost pitch angle are similar to those seen in the experiment, with distinct populations of trapped and passing orbits lost. These correspond to domains where the stochasticity extends in the orbit phase space from the region of beam ion deposition to the loss boundary.
Date: July 11, 2012
Creator: Darrow, D. S.; Fredrickson, E. D.; Gorelenkov, N. N.; Gorelenkova, M.; Kubota, S.; Medley, S. S. et al.
Object Type: Report
System: The UNT Digital Library
Fast-ion Energy Loss During TAE Avalanches in the National Spherical Torus Experiment (open access)

Fast-ion Energy Loss During TAE Avalanches in the National Spherical Torus Experiment

Strong TAE avalanches on NSTX, the National Spherical Torus Experiment [M. Ono, et al., Nucl. Fusion 40 (2000) 557] are typically correlated with drops in the neutron rate in the range of 5% - 15%. In previous studies of avalanches in L-mode plasmas, these neutron drops were found to be consistent with modeled losses of fast ions. Here we expand the study to TAE avalanches in NSTX H-mode plasmas with improved analysis techniques. At the measured TAE mode amplitudes, simulations with the ORBIT code predict that fast ion losses are negligible. However, the simulations predict that the TAE scatter the fast ions in energy, resulting in a small (≈ 6%) drop in fast ion β. The net decrease in energy of the fast ions is sufficient to account for the bulk of the drop in neutron rate, even in the absence of fast ion losses. This loss of energy from the fast ion population is comparable to the estimated energy lost by damping from the Alfven wave during the burst. The previously studied TAE avalanches in L-mode are re-evaluated using an improved calculation of the potential fluctuations in the ORBIT code.
Date: July 11, 2012
Creator: Fredrickson, E D; Darrow, D S; Gorelenkov, N N; Kramer, G J; Kubota, S; Podesta, M et al.
Object Type: Report
System: The UNT Digital Library
Shubnikov-de Haas Oscillations in the Bulk Rashba Semiconductor BiTeI (open access)

Shubnikov-de Haas Oscillations in the Bulk Rashba Semiconductor BiTeI

Bulk magnetoresistance quantum oscillations are observed in high quality single crystal samples of BiTeI. This compound shows an extremely large internal spin-orbit coupling, associated with the polarity of the alternating Bi, Te, and I layers perpendicular to the c-axis. The corresponding areas of the inner and outer Fermi surfaces around the A-point show good agreement with theoretical calculations, demonstrating that the intrinsic bulk Rashba-type splitting is nearly 360 meV, comparable to the largest spin-orbit coupling generated in heterostructures and at surfaces.
Date: July 11, 2012
Creator: Bell, C.; Bahramy, M.S.; Murakawa, H.; Checkelsky, J.G.; Arita, R.; Kaneko, Y. et al.
Object Type: Article
System: The UNT Digital Library
Operation Tomodachi: Answers, Data Products,and Lessons Learned from the U.S. Department of Energy's Consequence Management Response Team (CMRT) to the Fukushima-Daiichi Reactor Accident (open access)

Operation Tomodachi: Answers, Data Products,and Lessons Learned from the U.S. Department of Energy's Consequence Management Response Team (CMRT) to the Fukushima-Daiichi Reactor Accident

This slide-show presents the DOE response to the Fukushima Diaiichi disaster, including aerial and ground monitoring, issues for which the team had not trained or planned for, and questions from decision makers.
Date: July 11, 2012
Creator: Hopkins, R.
Object Type: Article
System: The UNT Digital Library
Properties of hydrogen doped ZnO films prepared by radio frequency magnetron sputtering (open access)

Properties of hydrogen doped ZnO films prepared by radio frequency magnetron sputtering

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Date: July 11, 2012
Creator: Kronenberger, A; Polity, A; Hofmann, D M; Meyer, B K; Schleife, A & Bechstedt, F
Object Type: Article
System: The UNT Digital Library