Containment and recovery system for fuel-reprocessing plants (open access)

Containment and recovery system for fuel-reprocessing plants

Tritium containment and removal problems in a fuel-reprocessing plant are identified and conceptual process designs for reducing emissions to the environment to below 1 Ci/day are studied. The conceptual design recommended would allow an air atmosphere in the reprocessing-plant hall and would use a continuous-catalytic-oxidizer/molecular-sieve-adsorber cleanup system to maintain a 40-..mu..Ci/m/sup 3/ tritium level (5 ..mu..Ci/m/sup 3/ HTO) against 180 Ci/day leakage from components and process piping.
Date: August 25, 1976
Creator: Galloway, T. R.
System: The UNT Digital Library
Tritium control in a mirror-fusion central power station (open access)

Tritium control in a mirror-fusion central power station

Tritium-containment systems for the blanket and power systems of a mirror-fusion reactor are described. These systems are designed to reduce emissions to below 1 Ci/d. The overall conceptual design uses air as the reactor-hall atmosphere. A continuous catalytic oxidizer-molecular sieve adsorber cleanup system would be used to control a 180-Ci/d leakage from reactor components, energy recovery systems, and process piping. Such a system would maintain a 40 ..mu..Ci/m/sup 3/ tritium level (5 ..mu..Ci/m/sup 3/ HTO) in the hall. The blanket considered contains submodules with Li/sub 2/Be/sub 2/O/sub 3/-Be for tritium breeding. This canned breeding material is scavenged with a lithium-vapor-doped helium gas stream. The container consists of molybdenum alloy (TZM) tubes and tube sheets with the breeding material packed and sintered in the shell surrounding the tubes. Potassium vapor coolant (also lithium-doped) passes through these tubes to recover the heat at 950/sup 0/C. Leakage following an intermediate TZM exchanger would result in a loss of 0.7 Ci/d into the steam through the Haynes-25 alloy boiler (potassium boiling). A moving getter bed is used to recover the tritium from the LiT and Li/sub 2/T scavengers in both the helium blanket scavenging flow and the potassium vapor coolant.
Date: August 25, 1976
Creator: Galloway, T. R.
System: The UNT Digital Library
Radiation blistering in metals and alloys (open access)

Radiation blistering in metals and alloys

Radiation blistering in solids has been identified as a process leading to damage and erosion of irradiated surfaces. Some of the major parameters governing the blistering process in metals and some metallic alloys are the type of projectile and its energy, total dose, dose rate, target temperature, channeling condition of the projectile, orientation of the irradiated surface plane, and target material and its microstructure. Experimental results and models proposed for blister formation and rupture are reviewed. The blistering phenomenon is important as an erosion process in applications such as fusion reactor technology (plasma-wall interactions) and accelerator technology (erosion of components and targets). A description of methods for the reduction of surface erosion caused by blistering is included.
Date: August 25, 1975
Creator: Das, S. K. & Kaminsky, M.
System: The UNT Digital Library
Material dynamics at extreme pressures and strain rates (open access)

Material dynamics at extreme pressures and strain rates

Solid state experiments at extreme pressures (10-100 GPa) and strain rates ({approx}10{sup 6}-10{sup 8}s{sup -1}) are being developed on high-energy laser facilities, and offer the possibility for exploring new regimes of materials science. [Re 2004] These extreme solid-state conditions can be accessed with either shock loading or with quasi-isentropic ramped pressure pulses being developed on the Omega laser. [Ed 2004] Velocity interferometer measurements establish the high strain rates. Constitutive models for solid-state strength under these conditions are tested by comparing 2D continuum simulations with experiments measuring perturbation growth due to the Rayleigh-Taylor instability in solid-state samples. Lattice compression, phase, and temperature are deduced from extended x-ray absorption fine structure (EXAFS) measurements, from which the shock-induced a-w phase transition in Ti is inferred to occur on sub-nanosecond time scales. [Ya 2004] Time resolved lattice response and phase can be inferred from dynamic x-ray diffraction measurements, where the elastic-plastic (1D-3D) lattice relaxation in shocked Cu is shown to occur promptly (< 1 ns). [Lo 2003] Subsequent large-scale MD simulations have elucidated the microscopic dynamics that underlie the 3D lattice relaxation. Deformation mechanisms are identified by examining the residual microstructure in recovered samples. [Re 2004] For example, the slip-twinning threshold in single-crystal Cu …
Date: August 25, 2004
Creator: Remington, Bruce A.; Cavallo, Rob M.; Edwards, Michael J.; Ho, David D.; Lasinski, Barbara F.; Lorenz, Karl T. et al.
System: The UNT Digital Library
Confinement and neutral beam injection studies on ORMAK (Draft) (open access)

Confinement and neutral beam injection studies on ORMAK (Draft)

Plasma confinement and neutral beam injection heating were investigated on the Oak Ridge Tokamak (ORMAK) plasma with improved plasma parameters due to higher injection power (to 360 kW), discharge current (to 220 kA) and toroidal field (to 26 kG). With increasing injection power up to 360 kW with otherwise constant operational parameters, the central ion temperature increased roughly linearly from 0.7 keV to 1.8 keV. The scaling of ion temperature with injection power and plasma density reasonably agrees with theoretical predictions based on neoclassical ion heat conduction and classical beam energy transport.
Date: August 25, 1976
Creator: unknown
System: The UNT Digital Library
Fabrication of a Carbon Nanotube-Embedded Silicon Nitride Membrane for Studies of Nanometer-Scale Mass Transport (open access)

Fabrication of a Carbon Nanotube-Embedded Silicon Nitride Membrane for Studies of Nanometer-Scale Mass Transport

A membrane consisting of multiwall carbon nanotubes embedded in a silicon nitride matrix was fabricated for fluid mechanics studies on the nanometer scale. Characterization by tracer diffusion and scanning electron microscopy suggests that the membrane is free of large voids. An upper limit to the diffusive flux of D{sub 2}O of 2.4x10-{sup 8} mole/m{sup 2}-s was determined, indicating extremely slow transport. By contrast, hydrodynamic calculations of water flow across a nanotube membrane of similar specifications predict a much higher molar flux of 1.91 mole/m{sup 2}-s, suggesting that the nanotubes produced possess a 'bamboo' morphology. The carbon nanotube membranes were used to make nanoporous silicon nitride membranes, fabricated by sacrificial removal of the carbon. Nitrogen flow measurements on these structures give a membrane permeance of 4.7x10{sup -4} mole/m{sup 2}-s-Pa at a pore density of 4x10{sup 10} cm{sup -2}. Using a Knudsen diffusion model, the average pore size of this membrane is estimated to be 66 nm, which agrees well with TEM observations of the multiwall carbon nanotube outer diameter. These membranes are a robust platform for the study of confined molecular transport, with applications inseparations and chemical sensing.
Date: August 25, 2004
Creator: Holt, J K; Noy, A; Huser, T; Eaglesham, D & Bakajin, O
System: The UNT Digital Library
IN SITU PRECISE ANGLE MONITORING ON SYNCHROTRON RADIATION MONOCHROMATOR BY USE OF PENCIL BEAM INTERFEROMETER. (open access)

IN SITU PRECISE ANGLE MONITORING ON SYNCHROTRON RADIATION MONOCHROMATOR BY USE OF PENCIL BEAM INTERFEROMETER.

Monochromator is a very important and precise instrument used in beam lines at synchrotron radiation facilities. We need to know if there is actual thermal distortion on gratings resulting in the degradation of the monochromator resolution. We need to know the characteristics of the grating rotation. It is possible to make a simple but precise in-situ distortion monitoring and rotation angle test of the grating by use of a precise pencil beam angle monitor. We have made preliminary measurements on a monochrometer grating of an undulator beam line X1B at Brookhaven National Laboratory. We monitored a small amount of angle variation on the grating. We detected 1.7 {micro}rad backlash (P-V) of the grating controlling system.
Date: August 25, 2003
Creator: QIAN,S. TAKACS,P. DONG,Q. HULBERT,S.
System: The UNT Digital Library
Bounds and Estimates for Elastic Constants of Random Polycrystals of Laminates (open access)

Bounds and Estimates for Elastic Constants of Random Polycrystals of Laminates

In order to obtain formulas providing estimates for elastic constants of random polycrystals of laminates, some known rigorous bounds of Peselnick, Meister, and Watt are first simplified. Then, some new self-consistent estimates are formulated based on the resulting analytical structure of these bounds. A numerical study is made, assuming first that the internal structure (i.e., the laminated grain structure) is not known, and then that it is known. The purpose of this aspect of the study is to attempt to quantify the differences in the predictions of properties of the same system being modeled when such internal structure of the composite medium and spatial correlation information is and is not available.
Date: August 25, 2004
Creator: Berger, E. L.
System: The UNT Digital Library
Thermal expansion of metals over the entire liquid range (open access)

Thermal expansion of metals over the entire liquid range

This paper reviews the current state of the art for measuring liquid metal densities. Conventional high precision techniques for use below 2000K as well as new techniques for more extreme temperatures are addressed. Pertinent data, which have appeared since the last critical reviews, for elemental metals are discussed.
Date: August 25, 1977
Creator: Shaner, J. W.
System: The UNT Digital Library
Large-Actuator-Number Horizontal Path Correction of Atmospheric Turbulence utilizing an Interferometric Phase Conjugate Engine (open access)

Large-Actuator-Number Horizontal Path Correction of Atmospheric Turbulence utilizing an Interferometric Phase Conjugate Engine

An adaptive optical system used to correct horizontal beam propagation paths has been demonstrated. This system utilizes an interferometric wave-front sensor and a large-actuator-number MEMS-based spatial light modulator to correct the aberrations incurred by the beam after propagation along the path. Horizontal path correction presents a severe challenge to adaptive optics systems due to the short atmospheric transverse coherence length and the high degree of scintillation incurred by laser propagation along these paths. Unlike wave-front sensors that detect phase gradients, however, the interferometric wave-front sensor measures the wrapped phase directly. Because the system operates with nearly monochromatic light and uses a segmented spatial light modulator, it does not require that the phase be unwrapped to provide a correction and it also does not require a global reconstruction of the wave-front to determine the phase as required by gradient detecting wave-front sensors. As a result, issues with branch points are eliminated. Because the atmospheric probe beam is mixed with a large amplitude reference beam, it can be made to operate in a photon noise limited regime making its performance relatively unaffected by scintillation. The MEMS-based spatial light modulator in the system contains 1024 pixels and is controlled to speeds in excess …
Date: August 25, 2004
Creator: Baker, K. L.; Stappaerts, E. A.; Gavel, D.; Tucker, J.; Silva, D. A.; Wilks, S. C. et al.
System: The UNT Digital Library
Laser-Driven Hydrodynamic Experiments in the Turbulent Plasma Regime: from OMEGA to NIF (open access)

Laser-Driven Hydrodynamic Experiments in the Turbulent Plasma Regime: from OMEGA to NIF

There is a great deal of interest in studying the evolution of hydrodynamic phenomena in high energy density plasmas that have transitioned beyond the initial phases of instability into a fully developed turbulent state. Motivation for this study arises both in fusion plasmas as well as in numerous astrophysical applications where the understanding of turbulent mixing is essential. Double-shell ignition targets, for example, are subject to large growth of short wavelength perturbations on both surfaces of the high-Z inner shell. These perturbations, initiated by Richtmyer-Meshkov and Rayleigh-Taylor instabilities, can transition to a turbulent state and will lead to deleterious mixing of the cooler shell material with the hot burning fuel. In astrophysical plasmas, due to the extremely large scale, turbulent hydrodynamic mixing is also of widespread interest. The radial mixing that occurs in the explosion phase of core-collapse supernovae is an example that has received much attention in recent years and yet remains only poorly understood. In all of these cases, numerical simulation of the flow field is very difficult due to the large Reynolds number and corresponding wide range of spatial scales characterizing the plasma. Laboratory experiments on high energy density facilities that can access this regime are therefore …
Date: August 25, 2003
Creator: Robey, H. F.; Miles, A. R.; Hansen, J. F.; Blue, B. E. & Drake, R. P.
System: The UNT Digital Library
The Effect of a Short Wavelength Mode on the Nonlinear Evolution of a Long-Wavelength Perturbation Driven by a Strong Blast Wave (open access)

The Effect of a Short Wavelength Mode on the Nonlinear Evolution of a Long-Wavelength Perturbation Driven by a Strong Blast Wave

We present a computational study of the formation of jets at strongly driven hydrodynamically unstable interfaces, and the interaction of these jets with one another and with developing spikes and bubbles. This provides a nonlinear spike-spike and spike-bubble interaction mechanism that can have a significant impact on the large-scale characteristics of the mixing layer. These interactions result in sensitivity to the initial perturbation spectrum, including the relative phases of the various modes, that persists long into the nonlinear phase of instability evolution.
Date: August 25, 2003
Creator: Miles, A; Edwards, J & Robey, H F
System: The UNT Digital Library
Excitation Cross Section Measurement for n=3 to n=2 Line Emission in Fe{sup 20+} to Fe{sup 23+} (open access)

Excitation Cross Section Measurement for n=3 to n=2 Line Emission in Fe{sup 20+} to Fe{sup 23+}

Electron impact excitation cross sections have been measured for iron L-shell 3 {yields} 2 lines of FeXXI to FeXXIV at the EBIT-II electron beam ion trap using a crystal spectrometer and a 6 x 6-element array microcalorimeter. The cross sections were determined by direct normalization to the well established cross section of radiative electron capture and a summary of calculated energy dependent radiative recombination cross sections for electron capture into the ground state fine structure levels of Fe{sup 16+} to Fe{sup 23+} ions is given. The measurement results for 17 lines and their comparison with model calculations are presented. While agreement of the model calculations with experiment is good for most measured lines, significant discrepancies were found for a few lines, including the strongest line in Fe XXI.
Date: August 25, 2004
Creator: Chen, H; Beiersdorfer, P; Scofield, J; Brown, G; Boyce, K; Kelley, R L et al.
System: The UNT Digital Library
Neutron Scintillators for Downscattered Neutron Imaging (open access)

Neutron Scintillators for Downscattered Neutron Imaging

Images of neutron emission from Inertial Confinement Fusion (ICF) (D,T) targets reveal the internal structure of the target during the fusion burn. 14-MeV neutrons provide images which show the size and shape of the region where (D,T) fusion is most intense. Images based on ''downscattered'' neutrons with energies from 5 to 10 MeV emphasize the distribution of deuterium and tritium fuel within the compressed target. The downscattered images are difficult to record because the lower energy neutrons are detected with less efficiency than the much more intense pulse of 14-MeV neutrons which precedes them at the detector. The success of downscattered neutron imaging will depend on the scintillation decay times and the sensitivities to lower-energy neutrons of the scintillator materials that are used in the detectors. A time-correlated photon counting system measured the decay of neutron-induced scintillation for times as long as several hundred ns. Accelerators at the University of California, Berkeley, and the Lawrence Livermore National Laboratory provided stable 14-MeV neutron sources for the measurements. Measurements of scintillator decay characteristics indicate that some commercially available scintillators should be suitable for recording both 14-MeV and downscattered neutron images of compressed ICF targets.
Date: August 25, 2003
Creator: Moran, M. J.; Koch, J.; Barrera, C. A. & Morse, E. C.
System: The UNT Digital Library
Near earth object fuels (neo-fuels): Discovery, prospecting and use (open access)

Near earth object fuels (neo-fuels): Discovery, prospecting and use

The 1992 discovery of a water-ice, near-Earth object (NEO) in the space near Earth is evaluated as a source of rocket fuel and life support materials for Earth orbit use. Nuclear thermal rockets using steam propellant are evaluated and suggested. The space geological formation containing such water-rich NEO`s is described. An architecture couples near-Earth object fuels (neo-fuel) extraction with use in Earth orbits. Preliminary mass payback analyses show that space tanker systems fueled from space can return in excess of 100 times their launched mass from the NEO, per trip. Preliminary cost estimates indicate neo-fuel costs at Earth orbit can be 3 orders of magnitude below today`s cost. A suggested resource verification plan is presented.
Date: August 25, 1992
Creator: Zuppero, A. C. & Jacox, M. G.
System: The UNT Digital Library
The Effect of Prior Out-of-Plane Damage on the in-Plane Behavior of Unreinforced Masonry Infilled Frames (open access)

The Effect of Prior Out-of-Plane Damage on the in-Plane Behavior of Unreinforced Masonry Infilled Frames

In order to address the effect of prior out-of-plane damage on the in-plane behavior of unreinforced masonry infills, two full-scale (24 feet tall by 28 feet long) structural clay tile infills and one frame-only (no infilling) were constructed and tested. The infilled frame, consisting of two wide flange columns surrounded by masonry plasters and an eccentric wide flange purlin, was identical to many of the infills located at the Oak Ridge Y-12 Plant. The masonry infill was approximately 12.5 inches thick and was composed of individual four- and eight-inch hollow clay tile (HCT) units. One of the infill panels was tested out-of-plane by four quasi-static actuators -- two on each column. The test structure was deflected out-of-plane equally at all four actuator locations in order to simulate the computed deflection path of the top and bottom chords of a roof truss framing into the columns at these locations. Prior to the infill testing, a bare frame was loaded similarly in order to determine the behavior and stiffness contribution of the frame only. Following the out-of-plane test of the infilled panel, the structure was loaded in-plane to failure in order to ascertain residual strength. A second, identical infilled frame was then …
Date: August 25, 1993
Creator: Henderson, R. C.; Jones, W. D.; Burdette, E. G. & Porter, M. L.
System: The UNT Digital Library
Speckle imaging using the principle value decomposition method (open access)

Speckle imaging using the principle value decomposition method

Obtaining diffraction-limited images in the presence of atmospheric turbulence is a topic of current interest. Two types of approaches have evolved: real-time correction and speckle imaging. A speckle imaging reconstruction method was developed by use of an ''optimal'' filtering approach. This method is based on a nonlinear integral equation which is solved by principle value decomposition. The method was implemented on a CDC 7600 for study. The restoration algorithm is discussed and its performance is illustrated. 7 figures.
Date: August 25, 1978
Creator: Sherman, J.W.
System: The UNT Digital Library
Measurements of Neutrons in Enclosures and Outside of Shielding at the Tevatron (open access)

Measurements of Neutrons in Enclosures and Outside of Shielding at the Tevatron

The characteristics of the spectra of neutrons produced by the losses of accelerated proton beams both within accelerator enclosures and outside of shielding has been determined from measurements at various locations around the Fermilab Tevatron and its associated experimental areas. The measurements were performed with a multisphere spectrometer consisting of either /sup 6/LiI scintillators or /sup 6,7/LiF TLD's placed at the centers of moderating polyethylene spheres with diameters ranging from 5.08 to 45.7 cm. The fluence and dose equivalent energy distributions and average quality factors obtained from spectrum unfolding calculations are summarized for this accelerator environment. 22 refs., 8 figs., 3 tabs.
Date: August 25, 1988
Creator: Cossairt, J. D.; Elwyn, A. J.; Freeman, W. S.; Salsbury, W. C. & Yurista, P. M.
System: The UNT Digital Library
Near earth object fuels (neo-fuels): Discovery, prospecting and use (open access)

Near earth object fuels (neo-fuels): Discovery, prospecting and use

The 1992 discovery of a water-ice, near-Earth object (NEO) in the space near Earth is evaluated as a source of rocket fuel and life support materials for Earth orbit use. Nuclear thermal rockets using steam propellant are evaluated and suggested. The space geological formation containing such water-rich NEO's is described. An architecture couples near-Earth object fuels (neo-fuel) extraction with use in Earth orbits. Preliminary mass payback analyses show that space tanker systems fueled from space can return in excess of 100 times their launched mass from the NEO, per trip. Preliminary cost estimates indicate neo-fuel costs at Earth orbit can be 3 orders of magnitude below today's cost. A suggested resource verification plan is presented.
Date: August 25, 1992
Creator: Zuppero, A. C. & Jacox, M. G.
System: The UNT Digital Library
Ion chamber gamma burst detector (open access)

Ion chamber gamma burst detector

A gamma ray burst detector of x-ray photons 2 to 10 keV is designed to maximize area, 100 m/sup 2/, and sensitivity, 10/sup -10/ ergs cm/sup -2/ s/sup 1/2/ modest directionality, 2 x 10/sup -4/ sr, and minimize thickness, 3 mg cm/sup -2/, as a plastic space balloon ion chamber. If the log N - log S curve for gamma bursts extends as the -3/2 power, the sensitivity is limited by gamma-burst peak overlap in time so that the question of the size spectrum and isotropy is maximally tested. Supernova type I prompt x-ray bursts of congruent to 3-ms duration should be detected at a rate of several per day from supernova at a distance greater than 100 Mpc.
Date: August 25, 1981
Creator: Colgate, S. A.
System: The UNT Digital Library
Mirror theory applied to toroidal systems (open access)

Mirror theory applied to toroidal systems

Central features of a mirror plasma are strong departures from Maxwellian distribution functions, ambipolar potentials and densities which vary along a field line, end losses, and the mirror field itself. To examine these features, mirror theorists have developed analytical and numerical techniques to solve the Fokker-Planck equation, evaluate the potentials consistent with the resulting distribution functions, and assess the microstability of these distributions. Various combinations of mirror-plasma features are present and important in toroidal plasmas as well, particularly in the edge region and in plasmas with strong rf heating. In this paper we survey problems in toroidal plasmas where mirror theory and computational techniques are applicable, and discuss in more detail three specific examples: calculation of the toroidal generalization of the Spitzer-Haerm distribution function (from which trapped-particle effects on current drive can be calculated), evaluation of the nonuniform potential and density set up by pulsed electron-cyclotron heating, and calculation of steady-state distribution functions in the presence of strong rf heating and collisions. 37 refs.
Date: August 25, 1987
Creator: Cohen, R.H.
System: The UNT Digital Library
Build-up of tritium in a liquid-lithium breeding blanket for an inertial-confinement-fusion chamber (open access)

Build-up of tritium in a liquid-lithium breeding blanket for an inertial-confinement-fusion chamber

The build-up of tritium in a liquid lithium breeding blanket for an ICF chamber has been examined. The break-even time is found to decrease both the increasing tritium breeding ratio and increasing values of ..cap alpha.., the fraction of unburned tritium absorbed in lithium. The break-even inventory also decreased with increasing breeding ratio but increases with increasing values ..cap alpha... For a molten-salt extraction process, the steady-state tritium inventory in lithium is inversely proportional to lithium flow rate through the extraction system. The lithium flow rate through the tritium extraction system required to maintain a given tritium concentration increases with increasing values of ..cap alpha...
Date: August 25, 1981
Creator: Meier, W. R.
System: The UNT Digital Library
Viewgraph notes: geologic aspects of terminal storage of radioactive wastes (open access)

Viewgraph notes: geologic aspects of terminal storage of radioactive wastes

This document contains copies of viewgraphs discussed in a presentation made at the Fifth Annual Power Conference, August 29 to September 2, 1977. No text. 19 figures, 11 references.
Date: August 25, 1977
Creator: Lomenick, T.F.
System: The UNT Digital Library
Supernovae, compact stars and nuclear physics (open access)

Supernovae, compact stars and nuclear physics

We briefly review the current understanding of supernova. We investigate the implications of rapid rotation corresponding to the frequency of the new pulsar reported in the supernovae remnant SN1987A. It places very stringent conditions on the equation of state if the star is assumed to be bound by gravity alone. We find that the central energy density of the star must be greater than 12 times that of nuclear density to be stable against the most optimistic estimate of general relativistic instabilities. This is too high for the matter to plausibly consist of individual hadrons. We conclude that the newly discovered pulsar, if its half-millisecond signals are attributable to rotation, cannot be a neutron star. We show that it can be a strange quark star, and that the entire family of strange stars can sustain high rotation under appropriate conditions. We discuss the conversion of a neutron star to strange star, the possible existence of a crust of heavy ions held in suspension by centrifugal and electric forces, the cooling and other features. 39 refs., 8 figs., 2 tabs.
Date: August 25, 1989
Creator: Glendenning, N.K.
System: The UNT Digital Library