Lightweight pressure vessels and unitized regenerative fuel cells (open access)

Lightweight pressure vessels and unitized regenerative fuel cells

Energy storage systems have been designed using lightweight pressure vessels with unitized regenerative fuel cells (URFCs). The vessels provide a means of storing reactant gases required for URFCs; they use lightweight bladder liners that act as inflatable mandrels for composite overwrap and provide a permeation barrier. URFC systems have been designed for zero emission vehicles (ZEVs); they are cost competitive with primary FC powered vehicles that operate on H/air with capacitors or batteries for power peaking and regenerative braking. URFCs are capable of regenerative braking via electrolysis and power peaking using low volume/low pressure accumulated oxygen for supercharging the power stack. URFC ZEVs can be safely and rapidly (<5 min.) refueled using home electrolysis units. Reversible operation of cell membrane catalyst is feasible without significant degradation. Such systems would have a rechargeable specific energy > 400 Wh/kg.
Date: September 6, 1996
Creator: Mitlitsky, F.; Myers, B. & Weisberg, A.H.
System: The UNT Digital Library
Comprehensive supernate treatment (open access)

Comprehensive supernate treatment

This task involves the recovery of the liquid (supernatant or supernate) portions of Oak Ridge National Laboratory (ORNL) Melton Valley Storage Tank waste in a hot cell and treatment of the supernate to separate and remove the radionuclides. The supernate is utilized in testing various sorbent materials for removing cesium, strontium, and technetium from the highly alkaline, saline solutions. Batch tests are used to evaluate and select the most promising materials for supernate treatment to reduce the amount of waste for final disposal. Once the sorbents have been selected based on the results from the batch tests, small column tests are made to verify the batch data. Additional data from these tests can be used for process design. The sorption tests emphasize evaluation of newly developed sorbents and engineered forms of sorbents. Methods are also evaluated for recovering the radionuclides from the sorbents, including evaluating conditions for eluting ion exchange resins. A final report will summarize the results and compare the results with those of other investigators, along with recommendations for separating and concentrating radionuclides from DOE storage tank supernates at Oak Ridge and other sites. Documentation of the data and the significance of the findings will be compared, and …
Date: December 6, 1996
Creator: Egan, B. Z.; Collins, J. L.; Davidson, D. J.; Anderson, K. K. & Chase, C. W.
System: The UNT Digital Library
Spin physics at RHIC (open access)

Spin physics at RHIC

Operation of RHIC with two beams of highly polarized protons (70%, either longitudinal or transverse) at high luminosity L = 2 x 10{sup 32} cm{sup -2} sec{sup -1} for two months/year will allow the STAR and PHENIX detectors to perform high statististics studies of polarization phenomena in the perturbative region of hard scattering where both QCD and ElectroWeak theory make detailed predictions for polarization effects. The collision c.m. energy, {radical}s = 200 - 500 GeV, represents a new domain for the study of spin. Direct photon production will be used to measure the gluon polarization in the polarized proton. A new twist comes from W-boson production which is expected to be 100% parity violating and will thus allow measurements of flavor separated Quark and antiquark (u, {bar u}, d, {bar d}) polarization distributions. Searches for parity violation in strong interaction processes such as jet and leading particle production will be a sensitive way to look for new physics beyond the standard model, one possibility being quark substructure.
Date: September 6, 1996
Creator: Tannenbaum, Michael J.
System: The UNT Digital Library
Spray cooling heat-transfer with subcooled trichlorotrifluoroethane (Freon-113) for vertical constant heat flux surfaces (open access)

Spray cooling heat-transfer with subcooled trichlorotrifluoroethane (Freon-113) for vertical constant heat flux surfaces

Experiments were done using subcooled Freon-113 sprayed vertically downward. Local and average heat transfers were investigated fro Freon-113 sprays with 40 C subcooling, droplet sizes 200-1250{mu}m, and droplet breakup velocities 5-29 m/s. Full-cone type nozzles were used to generate the spray. Test assemblies consisted of 1 to 6 7.62 cm vertical constant heat flux surfaces parallel with each other and aligned horizontally. Distance between heated surfaces was varied from 6.35 to 76.2 mm. Steady state heat fluxes as high as 13 W/cm{sup 2} were achieved. Dependence on the surface distance from axial centerline of the spray was found. For surfaces sufficiently removed from centerline, local and average heat transfers were identical and correlated by a power relation of the form seen for normal-impact sprays which involves the Weber number, a nondimensionalized temperature difference, and a mass flux parameter. For surfaces closer to centerline, the local heat transfer depended on vertical location on the surface while the average heat transfer was described by a semi-log correlation involving the same parameters. The heat transfer was independent of the distance (gap) between the heated surfaces for the gaps investigated.
Date: June 6, 1996
Creator: Kendall, C. M. & Holman, J. P.
System: The UNT Digital Library
Hanford`s spent nuclear fuel retrieval: an agressive agenda (open access)

Hanford`s spent nuclear fuel retrieval: an agressive agenda

Starting December 1997, spent nuclear fuel that has been stored in the K Reactor Fuel Storage Basins will be retrieved over a two year period and repackaged for long term dry storage. The aging and sometimes corroding fuel elements will be recovered and processed using log handled tools and teleoperated manipulator technology. The U.S. Department of Energy (DOE) is committed to this urgent schedule because of the environmental threats to the groundwater and nearby the Columbia River.
Date: December 6, 1996
Creator: Shen, E.J., Westinghouse Hanford
System: The UNT Digital Library
X-ray backlit imaging measurement of in-flight pusher density for an indirect drive capsule implosion (open access)

X-ray backlit imaging measurement of in-flight pusher density for an indirect drive capsule implosion

Both the efficiency of an implosion and the growth rate of hydrodynamic instability increase with the aspect ratio of an implosion. In order to study the physics of implosions with high Rayleigh-Taylor growth factors, we use doped ablators which should minimize x-ray preheat and shell decompression, and hence increase in-flight aspect ratio. We use x-ray backlighting techniques to image the indirectly-driven capsules. We record backlit 4.7 keV images of the full capsule throughout the implosion phase with 55 ps and 15 {mu}m resolution. We use these images to measure the in-flight aspect ratios for doped ablators, and we inferred the radial density profile as a function of time by Abel inverting the x-ray transmission profiles.
Date: May 6, 1996
Creator: Kalantar, D. H.; Haan, S. W. & Hammel, B. A.
System: The UNT Digital Library
Point projection radiography with the FXI (open access)

Point projection radiography with the FXI

Radiography techniques utilizing large area x-ray sources (typically {<=} 7 keV) and pinhole-imaging gated x-ray diagnostics have long been used at the Nova laser facility. However, for targets requiring higher energy x-ray backlighters (> 9 keV), low conversion efficiencies and pinhole losses combine to make this scheme unworkable. The technique of point projection radiography has been improved upon to make imaging at high x-ray energies feasible. In this scheme a {open_quotes}point{close_quotes} source of x-rays, usually a small diameter ({<=}25 {mu}m) fiber, is illuminated with a single, 100 ps pulse from the Nova laser. A gated x-ray imager with a 500 ps electronic gate width is used to record the projected image. The experimental challenges this technique presents and experimental results will be discussed.
Date: May 6, 1996
Creator: Budil, K.; Perry, T.S. & Alvarez, S.A.
System: The UNT Digital Library
Physics design and scaling of recirculating induction accelerators: from benchtop prototypes to drivers (open access)

Physics design and scaling of recirculating induction accelerators: from benchtop prototypes to drivers

Recirculating induction accelerators (recirculators) have been investigated as possible drivers for inertial fusion energy production because of their potential cost advantage over linear induction accelerators. Point designs were obtained and many of the critical physics and technology issues that would need to be addressed were detailed. A collaboration involving Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory researchers is now developing a small prototype recirculator in order to demonstrate an understanding of nearly all of the critical beam dynamics issues that have been raised. We review the design equations for recirculators and demonstrate how, by keeping crucial dimensionless quantities constant, a small prototype recirculator was designed which will simulate the essential beam physics of a driver. We further show how important physical quantities such as the sensitivity to errors of optical elements (in both field strength and placement), insertion/extraction, vacuum requirements, and emittance growth, scale from small-prototype to driver-size accelerator.
Date: February 6, 1996
Creator: Barnard, J. J.; Cable, M. D. & Callahan, D. A.
System: The UNT Digital Library
Single stage to orbit mass budgets derived from propellant density and specific impulse (open access)

Single stage to orbit mass budgets derived from propellant density and specific impulse

The trade between specific impulse (Isp) and density is examined in view of Single Stage To Orbit (SSTO) requirements. Mass allocations for vehicle hardware are derived from these two properties, for several propellant combinations and a dual-fuel case. This comparative analysis, based on flight-proven hardware, indicates that the higher density of several alternative propellants compensates for reduced Isp, when compared with cryogenic oxygen and hydrogen. Approximately half the orbiting mass of a rocket- propelled SSTO vehicle must be allocated to propulsion hardware and residuals. Using hydrogen as the only fuel requires a slightly greater fraction of orbiting mass for propulsion, because hydrogen engines and tanks are heavier than those for denser fuels. The advantage of burning both a dense fuel and hydrogen in succession depends strongly on tripropellant engine weight. The implications of the calculations for SSTO vehicle design are discussed, especially with regard to the necessity to minimize non-tankage structure.
Date: June 6, 1996
Creator: Whitehead, J. C.
System: The UNT Digital Library
Use of strain-annealing to evolve the grain boundary character distribution in polycrystalline copper (open access)

Use of strain-annealing to evolve the grain boundary character distribution in polycrystalline copper

We have used a two-step (low and high temperature) strain-annealing process to evolve the grain boundary character distribution (GBCD) in fully recrystallized oxygen-free electronic (OFE) Cu bar that was forged and rolled. Orientation imaging microscopy has been used to characterize the GBCD after each step in the processing. The fraction of special grain boundaries was {similar_to}70% in the starting recrystallized material. Three different processing conditions were employed: high, moderate, and low temperature. The high-temperature process resulted in a reduction in the fraction of special GBs while both the lower temperature processes resulted in an increase in special fraction up to 85%. Further, the lower temperature processes resulted in average deviation angles from exact misorientation, for special boundaries, that were significantly smaller than observed from the high temperature process. Results indicate the importance of the low temperature part of the two-step strain-annealing process in preparing the microstructure for the higher temperature anneal and commensurate increase in the special fraction.
Date: November 6, 1996
Creator: King, W.E. & Schwartz, A.J.
System: The UNT Digital Library
Meteorological monitoring at the Savannah River Site in 1995 (open access)

Meteorological monitoring at the Savannah River Site in 1995

The meteorological monitoring program at the Savannah River Site (SRS) has traditionally provided weather information for a variety of needs such as input for calculating the transport and diffusion of an accidental release of an atmospheric contaminant or applications which require a longer term data base representative of the local climatology. These applications include dosimetric and air quality calculations, engineering analyses, environmental characterizations, and risk assessments. In today`s shrinking budgetary climate, new initiatives for the SRS meteorological monitoring program are developing. These new initiatives and an overview of the meteorological monitoring program at the SRS are presented.
Date: March 6, 1996
Creator: Parker, M. J. & Addis, R. P.
System: The UNT Digital Library
Calculating the shrapnel generation and subsequent damage to first wall and optics components for the National Ignition Facility (open access)

Calculating the shrapnel generation and subsequent damage to first wall and optics components for the National Ignition Facility

The purpose of this work is to computationally assess the threat from shrapnel generation on the National Ignition Facility (NIF) first wall, final optics, and ultimately other target chamber components. Shrapnel is defined as material.that is in a solid, liquid, or clustered-vapor phase with sufficient velocity to become a threat to exposed surfaces as a consequence of its impact. Typical NIF experiments will be of two types, low neutron yield shots in which the capsule is not cryogenically cooled, and high yield shots for which cryogenic cooling of the capsule is required. For non-cryogenic shots, shrapnel would be produced by spaIIing, melting and vaporizing of ``shine shields`` by absorption and shock wave loading following 1-{omega} and 2-{omega} laser radiation. For cryogenic shots, shrapnel would be generated through shock wave splitting, spalling, and droplet formation of the cryogenic tubes following neutron energy deposition. Motion of the shrapnel is determined not only by particle velocities resulting from the neutron deposition, but also by both x-ray and debris loading arising from explosion of the hohlraum. Material responses of different target area components are computed from one- dimensional and two-dimensional stress wave propagation codes. Well developed rate-dependent spall computational models are used for stainless …
Date: August 6, 1996
Creator: Tokheim, R. E.; Seaman, L.; Cooper, T.; Lew, B.; Curran, D. R.; Sanchez, J. et al.
System: The UNT Digital Library
First results of a polychromatic artificial sodium star for the correction of tilt (open access)

First results of a polychromatic artificial sodium star for the correction of tilt

This paper presents the first results of a joint experiment carried out at Lawrence Livermore National Laboratory during January, 1996. Laser and optical systems were tested to provide a polychromatic artificial sodium star for the correction of tilt. This paper presents the results of that experiment.
Date: March 6, 1996
Creator: Friedman, H.; Foy, R..; Tallon, M. & Migus, A.
System: The UNT Digital Library
Heavy ion fusion experiments at LLNL (open access)

Heavy ion fusion experiments at LLNL

We review the status of the experimental campaign being carried out at Lawrence Livermore National Laboratory, involving scaled investigations of the acceleration and transport of space-charge dominated heavy ion beams. The ultimate goal of these experiments is to help lay the groundwork for a larger scale ion driven inertial fusion reactor, the purpose of which is to produce inexpensive and clean electric power.
Date: February 6, 1996
Creator: Barnard, J. J.; Cable, M. D. & Callahan, D. A.
System: The UNT Digital Library
XUV probing of laser imprint in a thin foil using an x-ray laser backlighter (open access)

XUV probing of laser imprint in a thin foil using an x-ray laser backlighter

For direct drive ICF, a capsule is imploded by directly illuminating the surface with laser light. Beam smoothing and uniformity of illumination affect the seeding of instabilities at the ablation front. We have developed a technique for studying the imprint of a laser beam on a thin foil using an x-ray laser as an XUV backlighter. We use multilayer XUV optics to relay the x-ray laser onto the directly driven foil, and then to image the foil modulation onto a CCD camera. This technique allows us to measure small fractional variations in the foil thickness. We have measured the modulation due to imprint from a low intensity 0.35 pm drive beam incident on a 3 {mu}m Si foil using an yttrium x-ray laser on Nova. We present results from a similar technique to measure the imprinted modulation due to a low intensity 0.53 {mu}m drive beam incident on a 2 {mu}m Al foil using a germanium x-ray laser at the Vulcan facility.
Date: May 6, 1996
Creator: Kalantar, D.H.; DaSilva, L.B. & Demir, A.
System: The UNT Digital Library