PRELIMINARY STUDY OF CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES (open access)

PRELIMINARY STUDY OF CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES

The Savannah River National Laboratory (SRNL) developed a series of ceramic waste forms for the immobilization of Cesium/Lanthanide (CS/LN) and Cesium/Lanthanide/Transition Metal (CS/LN/TM) waste streams anticipated to result from nuclear fuel reprocessing. Simple raw materials, including Al{sub 2}O{sub 3}, CaO, and TiO{sub 2} were combined with simulated waste components to produce multiphase ceramics containing hollandite-type phases, perovskites (particularly BaTiO{sub 3}), pyrochlores, zirconolite, and other minor metal titanate phases. Identification of excess Al{sub 2}O{sub 3} via X-ray Diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) in the first series of compositions led to a Phase II study, with significantly reduced Al{sub 2}O{sub 3} concentrations and increased waste loadings. Three fabrication methodologies were used, including melting and crystallizing, pressing and sintering, and Spark Plasma Sintering (SPS), with the intent of studying phase evolution under various sintering conditions. XRD and SEM/EDS results showed that the partitioning of the waste elements in the sintered materials was very similar, despite varying stoichiometry of the phases formed. The Phase II compositions generally contained a reduced amount of unreacted Al{sub 2}O{sub 3} as identified by XRD, and had phase assemblages that were closer to the initial targets. Chemical composition measurements showed no significant issues …
Date: September 22, 2010
Creator: Fox, K.; Billings, A.; Brinkman, K. & Marra, J.
Object Type: Report
System: The UNT Digital Library

Overview of the PV Module Model in PVWatts

Overview of the PV module model. PVWatts module power estimates were compared with those using the Sandia model for three modules and data sets.
Date: September 22, 2010
Creator: Marion, B.
Object Type: Presentation
System: The UNT Digital Library
The Disruption of Vessel-Spanning Bubbles with Sloped Fins in Flat-Bottom and 2:1 Elliptical-Bottom Vessels (open access)

The Disruption of Vessel-Spanning Bubbles with Sloped Fins in Flat-Bottom and 2:1 Elliptical-Bottom Vessels

Radioactive sludge was generated in the K-East Basin and K-West Basin fuel storage pools at the Hanford Site while irradiated uranium metal fuel elements from the N Reactor were being stored and packaged. The fuel has been removed from the K Basins, and currently, the sludge resides in the KW Basin in large underwater Engineered Containers. The first phase to the Sludge Treatment Project being led by CH2MHILL Plateau Remediation Company (CHPRC) is to retrieve and load the sludge into sludge transport and storage containers (STSCs) and transport the sludge to T Plant for interim storage. The STSCs will be stored inside T Plant cells that are equipped with secondary containment and leak-detection systems. The sludge is composed of a variety of particulate materials and water, including a fraction of reactive uranium metal particles that are a source of hydrogen gas. If a situation occurs where the reactive uranium metal particles settle out at the bottom of a container, previous studies have shown that a vessel-spanning gas layer above the uranium metal particles can develop and can push the overlying layer of sludge upward. The major concern, in addition to the general concern associated with the retention and release of …
Date: September 22, 2010
Creator: Gauglitz, Phillip A.; Buchmiller, William C.; Jenks, Jeromy WJ; Chun, Jaehun; Russell, Renee L.; Schmidt, Andrew J. et al.
Object Type: Report
System: The UNT Digital Library
NSTX Disruption Simulations of Detailed Divertor and Passive Plate Models by Vector Potential Transfer from OPERA Global Analysis Results (open access)

NSTX Disruption Simulations of Detailed Divertor and Passive Plate Models by Vector Potential Transfer from OPERA Global Analysis Results

The National Spherical Torus Experiment (NSTX) project is planning upgrades to the toroidal field, plasma current and pulse length. This involves the replacement of the center-stack, including the inner legs of the TF, OH, and inner PF coils. A second neutral beam will also be added. The increased performance of the upgrade requires qualification of the remaining components including the vessel, passive plates, and divertor for higher disruption loads. The hardware needing qualification is more complex than is typically accessible by large scale electromagnetic (EM) simulations of the plasma disruptions. The usual method is to include simplified representations of components in the large EM models and attempt to extract forces to apply to more detailed models. This paper describes a more efficient approach of combining comprehensive modeling of the plasma and tokamak conducting structures, using the 2D OPERA code, with much more detailed treatment of individual components using ANSYS electromagnetic (EM) and mechanical analysis. This capture local eddy currents and resulting loads in complex details, and allows efficient non-linear, and dynamic structural analyses.
Date: September 22, 2010
Creator: Titus, P. H.; Avasaralla, S.; Brooks, A. & Hatcher, R.
Object Type: Report
System: The UNT Digital Library
Progress on the NSTX Center Stack Upgrade (open access)

Progress on the NSTX Center Stack Upgrade

The National Spherical Torus Experiment (NSTX) will be upgraded to provide increased toroidal field, plasma current and pulse length. This involves the replacement of the so-called center stack, including the inner legs of the Toroidal Field (TF) coil, the Ohmic Heating (OH) coil, and the inner Poloidal Field (PF) coils. In addition the increased performance of the upgrade requires qualification of remaining existing components for higher loads. Initial conceptual design efforts were based on worst-case combinations of possible currents that the power supplies could deliver. This proved to be an onerous requirement and caused many of the outer coils support structures to require costly heavy reinforcement. This has led to the planned implementation of a Digital Coil Protection System (DCPS) to reduce design-basis loads to levels that are more realistic and manageable. As a minimum, all components must be qualified for the increase in normal operating loads with headroom. Design features and analysis efforts needed to meet the upgrade loading are discussed. Mission and features of the DCPS are presented.
Date: September 22, 2010
Creator: Dudek, L.; Chrzanowski, J.; Heitzenroeder, P.; Mangra, D.; Neumeyer, C.; Smith, M. et al.
Object Type: Article
System: The UNT Digital Library
Microscopic Motion of Liquid Metal Plasma Facing Components In A Diverted Plasma (open access)

Microscopic Motion of Liquid Metal Plasma Facing Components In A Diverted Plasma

Liquid metal plasma facing components (PFCs) have been identified as an alternative material for fusion plasma experiments. The use of a liquid conductor where significant magnetic fields are present is considered risky, with the possibility of macroscopic fluid motion and possible ejection into the plasma core. Analysis is carried out on thermoelectric magnetohydrodynamic (TEMHD) forces caused by temperature gradients in the liquid-container system itself in addition to scrape-off-layer currents interacting with the PFC from a diverted plasma. Capillary effects at the liquid-container interface will be examined which govern droplet ejection criteria. Stability of the interface is determined using linear stability methods. In addition to application to liquidmetal PFCs, thin film liquidmetal effects have application to current and future devices where off-normal events may liquefy portions of the first wall and other plasma facing components.
Date: September 22, 2010
Creator: Jaworski, M. A.; Morley, N. B.; Abrams, T; Kaita, R; Kallman, J; Kugel, H et al.
Object Type: Report
System: The UNT Digital Library
Biasing, Acquisition and Interpretation of a Dense Langmuir Probe Array in NSTX (open access)

Biasing, Acquisition and Interpretation of a Dense Langmuir Probe Array in NSTX

A dense array of 99 Langmuir probes has been installed in the lower divertor region of the National Spherical Torus Experiments (NSTX). This array is instrumented with a system of elec- tronics that allows flexibility in the choice of probes to bias as well as the type of measurement (including standard swept, single probe, triple probe and operation as passive floating potential and scrape-off-layer (SOL) current monitors). The use of flush-mounted probes requires careful inter- pretation. The time dependent nature of the SOL makes swept-probe traces difficult to interpret. To overcome these challenges, the single- and triple-Langmuir probe signals are used in comple- mentary fashion to determine the temperature and density at the probe location. A comparison to mid-plane measurements is made. Work is supported by DOE contracts DE-AC02-09CHI1466 and DE-PS02-07ER07-29.
Date: September 22, 2010
Creator: Jaworski, M. A.; Kallman, J.; Kaita, R.; Kugel, H.; LeBlanc, B.; Marsala, R. et al.
Object Type: Report
System: The UNT Digital Library
Chemical Species in the Vapor Phase of Hanford Double-Shell Tanks: Potential Impacts on Waste Tank Corrosion Processes (open access)

Chemical Species in the Vapor Phase of Hanford Double-Shell Tanks: Potential Impacts on Waste Tank Corrosion Processes

The presence of corrosive and inhibiting chemicals on the tank walls in the vapor space, arising from the waste supernatant, dictate the type and degree of corrosion that occurs there. An understanding of how waste chemicals are transported to the walls and the affect on vapor species from changing supernatant chemistry (e.g., pH, etc.), are basic to the evaluation of risks and impacts of waste changes on vapor space corrosion (VSC). In order to address these issues the expert panel workshop on double-shell tank (DST) vapor space corrosion testing (RPP-RPT-31129) participants made several recommendations on the future data and modeling needs in the area of DST corrosion. In particular, the drying of vapor phase condensates or supernatants can form salt or other deposits at the carbon steel interface resulting in a chemical composition at the near surface substantially different from that observed directly in the condensates or the supernatants. As a result, over the past three years chemical modeling and experimental studies have been performed on DST supernatants and condensates to predict the changes in chemical composition that might occur as condensates or supernatants equilibrate with the vapor space species and dry at the carbon steel surface. The experimental studies …
Date: September 22, 2010
Creator: Felmy, Andrew R.; Qafoku, Odeta; Arey, Bruce W. & Boomer, Kayle D.
Object Type: Report
System: The UNT Digital Library
Removing Phosphate from Hanford High-Phosphate Tank Wastes: FY 2010 Results (open access)

Removing Phosphate from Hanford High-Phosphate Tank Wastes: FY 2010 Results

The U.S. Department of Energy (DOE) is responsible for environmental remediation at the Hanford Site in Washington State, a former nuclear weapons production site. Retrieving, processing, immobilizing, and disposing of the 2.2 × 105 m3 of radioactive wastes stored in the Hanford underground storage tanks dominates the overall environmental remediation effort at Hanford. The cornerstone of the tank waste remediation effort is the Hanford Tank Waste Treatment and Immobilization Plant (WTP). As currently designed, the capability of the WTP to treat and immobilize the Hanford tank wastes in the expected lifetime of the plant is questionable. For this reason, DOE has been pursuing supplemental treatment options for selected wastes. If implemented, these supplemental treatments will route certain waste components to processing and disposition pathways outside of WTP and thus will accelerate the overall Hanford tank waste remediation mission.
Date: September 22, 2010
Creator: Lumetta, Gregg J.; Braley, Jenifer C.; Edwards, Matthew K.; Qafoku, Odeta; Felmy, Andrew R.; Carter, Jennifer C. et al.
Object Type: Report
System: The UNT Digital Library
DWPF DECON FRIT SUPERNATE ANALYSIS (open access)

DWPF DECON FRIT SUPERNATE ANALYSIS

The Savannah River National Laboratory (SRNL) has been requested to perform analyses on samples of the Defense Waste Processing Facility (DWPF) decon frit slurry (i.e., supernate samples and sump solid samples). Four 1-L liquid slurry samples were provided to SRNL by Savannah River Remediation (SRR) from the 'front-end' decon activities. Additionally, two 1-L sump solids samples were provided to SRNL for compositional and physical analysis. This report contains the results of the supernate analyses, while the solids (sump and slurry) results will be reported in a supplemental report. The analytical data from the decon frit supernate indicate that all of the radionuclide, organic, and inorganic concentrations met the limits in Revision 4 of the Effluent Treatment Plant (ETP) Waste Acceptance Criteria (WAC) with the exception of boron. The ETP WAC limit for boron is 15.0 mg/L while the average measured concentration (based on quadruplicate analysis) was 15.5 mg/L. The measured concentrations of Li, Na, and Si were also relatively high in the supernate analysis. These results are consistent with the relatively high measured value of B given the compositional make-up of Frit 418. Given these results, it was speculated that either (a) Frit 418 was dissolving into the supernate or …
Date: September 22, 2010
Creator: Peeler, D. & Crawford, C.
Object Type: Report
System: The UNT Digital Library
Next-Generation Flywheel Energy Storage: Development of a 100 kWh/100 kW Flywheel Energy Storage Module (open access)

Next-Generation Flywheel Energy Storage: Development of a 100 kWh/100 kW Flywheel Energy Storage Module

GRIDS Project: Beacon Power is developing a flywheel energy storage system that costs substantially less than existing flywheel technologies. Flywheels store the energy created by turning an internal rotor at high speeds—slowing the rotor releases the energy back to the grid when needed. Beacon Power is redesigning the heart of the flywheel, eliminating the cumbersome hub and shaft typically found at its center. The improved design resembles a flying ring that relies on new magnetic bearings to levitate, freeing it to rotate faster and deliver 400% as much energy as today’s flywheels. Beacon Power’s flywheels can be linked together to provide storage capacity for balancing the approximately 10% of U.S. electricity that comes from renewable sources each year.
Date: September 22, 2010
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Seasonal and inter-annual variability in 13C composition of ecosystem carbon fluxes in the U.S. Southern Great Plains (open access)

Seasonal and inter-annual variability in 13C composition of ecosystem carbon fluxes in the U.S. Southern Great Plains

The {delta}{sup 13}C signature of terrestrial carbon fluxes ({delta}{sub bio}) provides an important constraint for inverse models of CO{sub 2} sources and sinks, insight into vegetation physiology, C{sub 3} and C{sub 4} vegetation productivity, and ecosystem carbon residence times. From 2002-2009, we measured atmospheric CO{sub 2} concentration and {delta}{sup 13}C-CO{sub 2} at four heights (2 to 60 m) in the U.S. Southern Great Plains (SGP) and computed {delta}{sub bio} weekly. This region has a fine-scale mix of crops (primarily C{sub 3} winter wheat) and C{sub 4} pasture grasses. {delta}{sub bio} had a large and consistent seasonal cycle of 6-8{per_thousand}. Ensemble monthly mean {delta}{sub bio} ranged from -25.8 {+-} 0.4{per_thousand} ({+-}SE) in March to -20.1 {+-} 0.4{per_thousand} in July. Thus, C{sub 3} vegetation contributed about 80% of ecosystem fluxes in winter-spring and 50% in summer-fall. In contrast, prairie-soil {delta}{sub 13}C values were about -15{per_thousand}, indicating that historically the region was dominated by C{sub 4} vegetation and had more positive {delta}{sub bio} values. Based on a land-surface model, isofluxes ({delta}{sub bio} x NEE) in this region have large seasonal amplitude because {delta}{sub bio} and net ecosystem exchange (NEE) covary. Interannual variability in isoflux was driven by variability in NEE. The large seasonal …
Date: September 22, 2010
Creator: Torn, M. S.; Biraud, S.; Still, C. J.; Riley, W. J. & Berry, J. A.
Object Type: Article
System: The UNT Digital Library