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Recent Progress on the Standardized DOE Spent Nuclear Fuel Canister

Description: The Department of Energy (DOE) has developed a set of containers for the handling, interim storage, transportation, and disposal in the national repository of DOE spent nuclear fuel (SNF). This container design, referred to as the standardized DOE SNF canister or standardized canister, was developed by the Department's National Spent Nuclear Fuel Storage Program (NSNFP) working in conjunction with the Office of Civilian Radioactive Waste Management (OCRWM) and the DOE spent fuel sites. This canister had to have a standardized design yet be capable of accepting virtually all of the DOE SNF, be placed in a variety of storage and transportation systems, and still be acceptable to the repository. Since specific design details regarding the storage, transportation, and repository disposal of DOE SNF were not finalized, the NSNFP recognized the necessity to specify a complete DOE SNF canister design. This allowed other evaluations of canister performance and design to proceed as well as providing standardized canister users adequate information to proceed with their work. This paper is an update of a paper presented to the 1999 American Nuclear Society of Mechanical Engineers (ASME) Pressure Vessels and Piping (PVP) Conference. It discusses recent progress achieved in various areas to enhance acceptance of this canister not only by the DOE complex but also fabricators and regulatory agencies.
Date: May 7, 2002
Creator: Morton, D.K.; Snow, S.D.; Rahl, T.E.; Hill, T.J. (INEEL) & Morissette, R.P. (Beckman and Associates, Inc.)
Partner: UNT Libraries Government Documents Department

Proposal for Qualification of Gas-Generating Radioactive Payloads for Transportation within a Type B Package

Description: Characterization data describing radioactive materials (RAM) in storage are likely those associated with the processes that produced the materials or with the mission for which they were produced. Along with impurity data, often absent or unknown as a result of post-processing storage environment is moisture content. Radiolysis of moisture may lead to a hydrogen flammability hazard within a closed volume such as a storage can or a transportation package. This paper offers a practical means of qualifying payloads of unknown moisture content for shipment within Type B packaging, while supporting the DOE program to maintain radworker dose as low as reasonable achievable (ALARA). Specifically, the paper discusses part of a qualification program carried out at the Savannah River Site for onsite shipment of legacy RAM within the DDF-1 package. The DDF-1 is an onsite-only prototype of the currently certified 9975 package. Measurement of storage-can lid bulge can provide an upper bound for pressure within a storage can. Subsequent belljar testing can measure the rate of gas leakage from a storage can. These actions are shown sufficient to ensure that the performance of the 9975 containment vessels can accommodate the deflagration energy from flammable gas mixtures within Normal Conditions of Transport, and, and the consequences of a detonation shock wave within Hypothetical Accident Conditions.
Date: June 7, 2002
Creator: Houghtaling, T.K.
Partner: UNT Libraries Government Documents Department

Pressure dependence of the bandgap energy and the conduction-band mass for an n-type InGaAs/GaAs strained single-quantum-well

Description: We report the measurement of the pressure dependence for the bandgap energy E{sub g} and conduction-band mass m{sub c} for an 80{angstrom}-wide n-type In{sub 0.20}Ga{sub 0.80}As/GaAs single strained quantum well at 4.2K for pressures between 0 and 35 kbar and fields up to 30 tesla.
Date: July 7, 1997
Creator: Jones, E.D.; Tozer, S.T. & Schmiedel, T.
Partner: UNT Libraries Government Documents Department

Excess Thermodynamic Properties of Concentrated Aqueous Solutions at High Temperatures

Description: Measurements of the vapor pressure of the solvent in wide ranges of concentration and temperature provide information on solute solvation and ion pairing--the two phenomena most often invoked for description of dilute solutions. Even in moderately concentrated solutions, as interionic distances become comparable to ionic diameters, these simple concepts gradually lose their meaning and solutions behave like molten salts. The usefulness of experimental vapor pressure results increases rapidly with their accuracy, since derived properties, such as solution enthalpies and heat capacities, can be calculated. Very accurate results can be obtained by the isopiestic method, but primary vapor pressure data for standard solutions are needed. In order to obtain vapor pressures at conditions where accurate isopiestic standards are not available and to establish more accurate standards, the ORNL isopiestic apparatus was modified for simultaneous direct vapor pressure measurements and isopiestic comparisons. There are no comprehensive solution theories derived from molecular level models and able to predict thermodynamic properties of various electrolytes as the composition changes from dilute solutions to molten salts in a wide range of temperatures. Empirical and semi-empirical models are useful for representation of experimental results, interpretation of measurements of other properties such as conductance., solubility or liquid-vapor partitioning of solutes, and for verification of theoretical predictions. Vapor pressures for aqueous CaCl{sub 2}, CaBr{sub 2}, LiCl, LiBr, LiI, NaI were measured at temperatures between 380 and 523 K in the concentration range extended to water activities below 0.2 (over 30 mol/kg for LiCl). General equations based on the modified Pitzer ion-interaction model were used to obtain enthalpy and heat capacity surfaces, which are compared with direct calorimetric measurements.
Date: June 7, 2001
Creator: Guszkiewicz, M.S.
Partner: UNT Libraries Government Documents Department

Dense ceramic membranes for hydrogen separation.

Description: We have developed cermet membranes that nongalvanically separate hydrogen from gas mixtures. The highest measured hydrogen flux was 20.0 cm{sup 3} (STP)/min-cm{sup 2} for an ANL-3a membrane at 900 C. For ANL-3 membranes with thickness of 40-500 {micro}m, hydrogen permeation is limited by the bulk diffusion of hydrogen through the metal phase. The effect of hydrogen partial pressure on permeation rate confirmed this conclusion, suggesting that higher permeation rates may be obtained by decreasing the membrane thickness. Permeation rate in a syngas atmosphere for times up to 190 h showed no degradation in performance, which indicates that ANL-3 membranes may be suitable for long-term, practical hydrogen separation.
Date: May 7, 2002
Creator: Balachandran, U.; Lee, T. H.; Wang, S.; Zhang, G. & Dorris, S. E.
Partner: UNT Libraries Government Documents Department

Cryogenic Adsorption of Hydrogen Isotopes Over Nano-Structured Materials

Description: Porous materials such as zeolites, activated carbon, silica gels, alumina and a number of industrial catalysts are compared and ranked for hydrogen and deuterium adsorption at liquid nitrogen temperature. All samples show higher D{sub 2} adsorption than that of H{sub 2}, in which a HY sample has the greatest isotopic effect while 13X has the highest hydrogen uptake capacity. Material's moisture content has significant impact to its hydrogen uptake. A material without adequate drying could result in complete loss of its adsorption capacity. Even though some materials present higher H{sub 2} adsorption capacity at full pressure, their adsorption at low vapor pressure may not be as good as others. Adsorption capacity in a dynamic system is much less than in a static system. A sharp desorption is also expected in case of temperature upset.
Date: October 7, 2010
Creator: Xiao, S. & Heung, L.
Partner: UNT Libraries Government Documents Department

Cleanroom Energy Efficiency: Metrics and Benchmarks

Description: Cleanrooms are among the most energy-intensive types of facilities. This is primarily due to the cleanliness requirements that result in high airflow rates and system static pressures, as well as process requirements that result in high cooling loads. Various studies have shown that there is a wide range of cleanroom energy efficiencies and that facility managers may not be aware of how energy efficient their cleanroom facility can be relative to other cleanroom facilities with the same cleanliness requirements. Metrics and benchmarks are an effective way to compare one facility to another and to track the performance of a given facility over time. This article presents the key metrics and benchmarks that facility managers can use to assess, track, and manage their cleanroom energy efficiency or to set energy efficiency targets for new construction. These include system-level metrics such as air change rates, air handling W/cfm, and filter pressure drops. Operational data are presented from over 20 different cleanrooms that were benchmarked with these metrics and that are part of the cleanroom benchmark dataset maintained by Lawrence Berkeley National Laboratory (LBNL). Overall production efficiency metrics for cleanrooms in 28 semiconductor manufacturing facilities in the United States and recorded in the Fabs21 database are also presented.
Date: July 7, 2010
Creator: Initiative, International SEMATECH Manufacturing; Mathew, Paul A.; Tschudi, William; Sartor, Dale & Beasley, James
Partner: UNT Libraries Government Documents Department

Materials Performance in USC Steam

Description: Materials Performance in USC Steam: (1) pressure effects on steam oxidation - unique capability coming on-line; (2) hydrogen evolution - hydrogen permeability apparatus to determine where hydrogen goes during steam oxidation; and (3) NETL materials development - steam oxidation resource for NETL developed materials.
Date: September 7, 2011
Creator: Holcomb, G. R.; Tylczak, J.; Meier, G. H. & Yanar, N. M.
Partner: UNT Libraries Government Documents Department

A Survey of Pressure Vessel Code Compliance for Superconducting RF Cryomodules

Description: Superconducting radio frequency (SRF) cavities made from niobium and cooled with liquid helium are becoming key components of many particle accelerators. The helium vessels surrounding the RF cavities, portions of the niobium cavities themselves, and also possibly the vacuum vessels containing these assemblies, generally fall under the scope of local and national pressure vessel codes. In the U.S., Department of Energy rules require national laboratories to follow national consensus pressure vessel standards or to show ''a level of safety greater than or equal to'' that of the applicable standard. Thus, while used for its superconducting properties, niobium ends up being treated as a low-temperature pressure vessel material. Niobium material is not a code listed material and therefore requires the designer to understand the mechanical properties for material used in each pressure vessel fabrication; compliance with pressure vessel codes therefore becomes a problem. This report summarizes the approaches that various institutions have taken in order to bring superconducting RF cryomodules into compliance with pressure vessel codes. In Japan, Germany, and the U.S., institutions building superconducting RF cavities integrated in helium vessels or procuring them from vendors have had to deal with pressure vessel requirements being applied to SRF vessels, including the niobium and niobium-titanium components of the vessels. While niobium is not an approved pressure vessel material, data from tests of material samples provide information to set allowable stresses. By means of procedures which include adherence to code welding procedures, maintaining material and fabrication records, and detailed analyses of peak stresses in the vessels, or treatment of the vacuum vessel as the pressure boundary, research laboratories around the world have found methods to demonstrate and document a level of safety equivalent to the applicable pressure vessel codes.
Date: June 7, 2011
Creator: Peterson, Thomas; Klebaner, Arkadiy; Nicol, Tom; Theilacker, Jay; /Fermilab; Hayano, Hitoshi et al.
Partner: UNT Libraries Government Documents Department

The Application of Global Kinetic Models to HMX Beta-Delta Transition and Cookoff Processes

Description: The reduction of the number of reactions in kinetic models for both the HMX beta-delta phase transition and thermal cookoff provides an attractive alternative to traditional multi-stage kinetic models due to reduced calibration effort requirements. In this study, we use the LLNL code ALE3D to provide calibrated kinetic parameters for a two-reaction bidirectional beta-delta HMX phase transition model based on Sandia Instrumented Thermal Ignition (SITI) and Scaled Thermal Explosion (STEX) temperature history curves, and a Prout-Tompkins cookoff model based on One-Dimensional Time to Explosion (ODTX) data. Results show that the two-reaction bidirectional beta-delta transition model presented here agrees as well with STEX and SITI temperature history curves as a reversible four-reaction Arrhenius model, yet requires an order of magnitude less computational effort. In addition, a single-reaction Prout-Tompkins model calibrated to ODTX data provides better agreement with ODTX data than a traditional multi-step Arrhenius model, and can contain up to 90% less chemistry-limited time steps for low-temperature ODTX simulations. Manual calibration methods for the Prout-Tompkins kinetics provide much better agreement with ODTX experimental data than parameters derived from Differential Scanning Calorimetry (DSC) measurements at atmospheric pressure. The predicted surface temperature at explosion for STEX cookoff simulations is a weak function of the cookoff model used, and a reduction of up to 15% of chemistry-limited time steps can be achieved by neglecting the beta-delta transition for this type of simulation. Finally, the inclusion of the beta-delta transition model in the overall kinetics model can affect the predicted time to explosion by 1% for the traditional multi-step Arrhenius approach, while up to 11% using a Prout-Tompkins cookoff model.
Date: December 7, 2006
Creator: Wemhoff, A P; Burnham, A K & Nichols III, A L
Partner: UNT Libraries Government Documents Department

Edge-Plasma Properties in Liquid-Wall Environments

Description: Flowing liquid walls have been proposed as the first wall and/or divertor plates for magnetic fusion energy devices because they may solve a number of technological problems for fusion power plants. A key question for their successful use is the edge-plasma shielding of wall-vapor impurities from the core plasma. A self-consistent analysis of the combined hydrogen/impurity edge plasmas for distributed wall impurity sources is performed using the two-dimension fluid transport code UEDGE for tokamak parameters. Three regimes of edge-plasma response are identified. Comparisons are made between previous results for lithium (from Li or SnLi walls) and fluorine (from the molten salt Flibe walls), and new results for Sn (from Sn walls). Owing to its lower vapor pressure, Sn is found to have the lowest impact on the edge and core plasma. For the Sn wall, the effects of toroidal versus slab geometries are studied, as well as the influence of spatial variations in evaporation fluxes.
Date: September 7, 2001
Creator: Rognlien, T D; Resink, M E & Brooks, J N
Partner: UNT Libraries Government Documents Department

Role of the radiation pressure gradient in giant and supergiant star evolution

Description: Since some of the earliest evolutionary calculations it has been found that post main sequence stars become red giants (e.g. Sandage and Schwarzschild, 1952). However the exact physical processes that lead to and determine the rate of redward evolution are not completely understood. We hypothesized that the redward evolution might be due to an increase in radiation pressure somewhere in the star that causes the layers above it to be pushed outward, resulting in an expanded envelope and a cooler surface temperature. If the radiative luminosity somewhere in the star approached the Eddington limit, the outer layers would obviously expand. However, due to the presence of gas pressure, the critical value for expansion would be somewhat less than the Eddington limit.
Date: October 7, 1983
Creator: Brunish, W.M.; Cox, A.N.; Becker, S.A. & Despain, K.H.
Partner: UNT Libraries Government Documents Department