INSTALLATION OF BUBBLERS IN THE SAVANNAH RIVER SITED DEFENSE WASTE PROCESSING FACILITY MELTER (open access)

INSTALLATION OF BUBBLERS IN THE SAVANNAH RIVER SITED DEFENSE WASTE PROCESSING FACILITY MELTER

Savannah River Remediation (SRR) LLC assumed the liquid waste contract at the Savannah River Site (SRS) in the summer of 2009. The main contractual agreement was to close 22 High Level Waste (HLW) tanks in eight years. To achieve this aggressive commitment, faster waste processing throughout the SRS liquid waste facilities will be required. Part of the approach to achieve faster waste processing is to increase the canister production rate of the Defense Waste Processing Facility (DWPF) from approximately 200 canisters filled with radioactive waste glass per year to 400 canisters per year. To reach this rate for melter throughput, four bubblers were installed in the DWPF Melter in the late summer of 2010. This effort required collaboration between SRR, SRR critical subcontractor EnergySolutions, and Savannah River Nuclear Solutions, including the Savannah River National Laboratory (SRNL). The tasks included design and fabrication of the bubblers and related equipment, testing of the bubblers for various technical issues, the actual installation of the bubblers and related equipment, and the initial successful operation of the bubblers in the DWPF Melter.
Date: December 8, 2010
Creator: Smith, M. & Iverson, D.
System: The UNT Digital Library
AFFECTS OF MECHANICAL MILLING AND METAL OXIDE ADDITIVES ON SORPTION KINETICS OF 1:1 LiNH2/MgH2 MIXTURE (open access)

AFFECTS OF MECHANICAL MILLING AND METAL OXIDE ADDITIVES ON SORPTION KINETICS OF 1:1 LiNH2/MgH2 MIXTURE

The destabilized complex hydride system composed of LiNH{sub 2}:MgH{sub 2} (1:1 molar ratio) is one of the leading candidates of hydrogen storage with a reversible hydrogen storage capacity of 8.1 wt%. A low sorption enthalpy of {approx}32 kJ/mole H{sub 2} was first predicted by Alapati et al. utilizing first principle density function theory (DFT) calculations and has been subsequently confirmed empirically by Lu et al. through differential thermal analysis (DTA). This enthalpy suggests that favorable sorption kinetics should be obtainable at temperatures in the range of 160 C to 200 C. Preliminary experiments reported in the literature indicate that sorption kinetics are substantially lower than expected in this temperature range despite favorable thermodynamics. Systematic isothermal and isobaric sorption experiments were performed using a Sievert's apparatus to form a baseline data set by which to compare kinetic results over the pressure and temperature range anticipated for use of this material as a hydrogen storage media. Various material preparation methods and compositional modifications were performed in attempts to increase the kinetics while lowering the sorption temperatures. This paper outlines the results of these systematic tests and describes a number of beneficial additions which influence kinetics as well as NH{sub 3} formation.
Date: December 8, 2010
Creator: Erdy, C.; Anton, D. & Gray, J.
System: The UNT Digital Library
Comparing Vacuum and Extreme Ultraviolet Radiation for Postionization of Laser Desorbed Neutrals from Bacterial Biofilms and Organic Fullerene (open access)

Comparing Vacuum and Extreme Ultraviolet Radiation for Postionization of Laser Desorbed Neutrals from Bacterial Biofilms and Organic Fullerene

Vacuum and extreme ultraviolet radiation from 8 - 24 eV generated at a synchrotron was used to postionize laser desorbed neutrals of antibiotic-treated biofilms and a modified fullerene using laser desorption postionization mass spectrometry (LDPI-MS). Results show detection of the parent ion, various fragments, and extracellular material from biofilms using LDPI-MS with both vacuum and extreme ultraviolet photons. Parent ions were observed for both cases, but extreme ultraviolet photons (16-24 eV) induced more fragmentation than vacuum ultraviolet (8-14 eV) photons.
Date: December 8, 2010
Creator: Gaspera, Gerald L.; Takahashi, Lynelle K.; Zhou, Jia; Ahmed, Musahid; Moored, Jerry F. & Hanley, Luke
System: The UNT Digital Library
Recent Advances in Automatic Alignment System for the National Iginition Facility (open access)

Recent Advances in Automatic Alignment System for the National Iginition Facility

The automatic alignment system for the National Ignition Facility (NIF) is a large-scale parallel system that directs all 192 laser beams along the 300-m optical path to a 50-micron focus at target chamber in less than 50 minutes. The system automatically commands 9,000 stepping motors to adjust mirrors and other optics based upon images acquired from high-resolution digital cameras viewing beams at various locations. Forty-five control loops per beamline request image processing services running on a LINUX cluster to analyze these images of the beams and references, and automaticallys teer the beams toward the target. This paper discusses the upgrades to the NIF automatic alignment system to handle new alignment needs and evolving requirements as related to various types of experiments performed. As NIF becomes a continuously-operated system and more experiments are performed, performance monitoring is increasingly important for maintenance and commissioning work. Data, collected during operations, is analyzed for tuning of the laser and targeting maintenance work. handling evolving alignment and maintenance needs is expected for the planned 30-year operational life of NIF.
Date: December 8, 2010
Creator: Wilhelmsen, K.; Awwal, A.; Kalantar, D.; Leach, R.; Lowe-Webb, R.; McGuigan, D. et al.
System: The UNT Digital Library