Waste management strategy for nuclear fusion power systems from a regulatory perspective (open access)

Waste management strategy for nuclear fusion power systems from a regulatory perspective

A waste management strategy for future nuclear fusion power systems is developed using existing regulatory methodology. The first step is the development of a reference fuel cycle. Next, the waste streams from such a facility are identified. Then a waste management system is defined to safely handle and dispose of these wastes. The future regulator must identify the decisions necessary to establish waste management performance criteria. The data base and methodologies necessary to make these decisions must then be developed. Safe management of nuclear fusion wastes is not only a technological challenge, but encompasses significant social, political, and ethical questions as well.
Date: December 6, 1977
Creator: Heckman, R.A.
System: The UNT Digital Library
Physics at the Planck scale (open access)

Physics at the Planck scale

Effective supergravity theories suggested by superstrings can be explored to determine their potential for successfully describing both observed physics at zero temperature and an inflationary cosmology. An important ingredient in this study is the dynamics of gaugino condensation, which has been the subject of recent activity. 33 refs., 2 figs.
Date: December 6, 1990
Creator: Gaillard, M.K. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Physics)
System: The UNT Digital Library
Damage history of Argus, a 4TW Nd-glass system (open access)

Damage history of Argus, a 4TW Nd-glass system

Argus is a twin beam, 20 cm output aperture, Nd:glass laser system that has delivered 4TW to a laser fusion target. This performance is based on the concepts that multiple spatial filtering can prevent beam fill factors. Damage to optics due to self focusing and filamentation does not occur on Argus. The only form of damage is induced by broadband radiation from xenon flashlamps interacting with contaminants on or in the Nd:glass. The severity of damage is measured by the fraction of the beam obscured by the damage sites. This averages 0.1% per surface or 0.75% per arm. The amount of damage does not appear to be strongly related to the number of amplifier firings and generally occurs during the first few firings.
Date: December 6, 1977
Creator: Stowers, I.F. & Patton, H.G.
System: The UNT Digital Library
Visualization of Scalar Adaptive Mesh Refinement Data (open access)

Visualization of Scalar Adaptive Mesh Refinement Data

Adaptive Mesh Refinement (AMR) is a highly effective computation method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations, which must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR grids as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR scalar data visualization research.
Date: December 6, 2007
Creator: VACET; Weber, Gunther; Weber, Gunther H.; Beckner, Vince E.; Childs, Hank; Ligocki, Terry J. et al.
System: The UNT Digital Library
A Temperature-Profile Method for Estimating Flow Processes inGeologic Heat Pipes (open access)

A Temperature-Profile Method for Estimating Flow Processes inGeologic Heat Pipes

Above-boiling temperature conditions, as encountered, forexample, in geothermal reservoirs and in geologic repositories for thestorage of heat-producing nuclear wastes, may give rise to stronglyaltered liquid and gas flow processes in porous subsurface environments.The magnitude of such flow perturbation is extremely hard to measure inthe field. We therefore propose a simple temperature-profile method thatuses high-resolution temperature data for deriving such information. Theenergy that is transmitted with the vapor and water flow creates a nearlyisothermal zone maintained at about the boiling temperature, referred toas a heat pipe. Characteristic features of measured temperature profiles,such as the differences in the gradients inside and outside of the heatpipe regions, are used to derive the approximate magnitude of the liquidand gas fluxes in the subsurface, for both steady-state and transientconditions.
Date: December 6, 2004
Creator: Birkholzer, Jens T.
System: The UNT Digital Library
Modeling An atmospheric Release As An Area Source In Support Of Waste Disposal At The Savannah River Site (open access)

Modeling An atmospheric Release As An Area Source In Support Of Waste Disposal At The Savannah River Site

None
Date: December 6, 2005
Creator: SIMPKINS, ALI
System: The UNT Digital Library
Application of exterior complex scaling to positron-hydrogencollisions including rearrangement (open access)

Application of exterior complex scaling to positron-hydrogencollisions including rearrangement

The first application of an exterior complex scaling method to an atomic scattering problem with distinct rearrangement channels is reported. Calculations are performed for positron-hydrogen collisions in an s-wave model employing an electron-positron potential of V{sub 12} = -(8+(r{sub 1}-r{sub 2}){sup 2}){sup 1/2}, using the time-independent propagating exterior complex scaling (PECS) method. This potential has the correct long-range Coulomb tail of the full problem and the results demonstrate that ECS-based methods can accurately calculate scattering, ionization and positronium formation cross sections in this three-body rearrangement collision.
Date: December 6, 2007
Creator: Bartlett, Philip L.; Stelbovics, Andris T.; Rescigno, Thomas N. & McCurdy, C. William
System: The UNT Digital Library
IEC International Standards Under Development For Radiation-Generating Devices (open access)

IEC International Standards Under Development For Radiation-Generating Devices

The International Electrotechnical Commission (IEC) is the leading and oldest global organization with over 100 years history of developing and publishing international standards for all electrical, electronic and related technologies, including radiation detection instrumentation. Subcommittee 45B 'Radiation Protection Instrumentation' of the IEC has recently started the development of two standards on radiation-generating devices. IEC 62463 'Radiation protection instrumentation--X-ray Systems for the Screening of Persons for Security and the Carrying of Illicit Items' is applicable to X-ray systems designed for screening people to detect if they are carrying objects such as weapons, explosives, chemical and biological agents and other concealed items that could be used for criminal purposes, e.g. terrorist use, drug smuggling, etc. IEC 62523 'Radiation protection instrumentation--Cargo/Vehicle radiographic inspection systems' applies to cargo/vehicle imaging inspection systems using accelerator produced X-ray or gamma radiation to obtain images of the screened objects (e.g. cargo containers, transport and passenger vehicles and railroad cars). The objective of both standards is to specify standard requirements and general characteristics and test procedures, as well as, radiation, electrical, environmental, mechanical, and safety requirements and to provide examples of acceptable methods to test these requirements. In particular the standards address the design requirements as they relate to …
Date: December 6, 2007
Creator: Voytchev, M; Radev, R; Chiaro, P; Thomson, I; Dray, C & Li, J
System: The UNT Digital Library
Temperature dependent evolution of the electronic and local atomic structure in the cubic colossal magnetoresistive manganite La1-xSrxMnO3 (open access)

Temperature dependent evolution of the electronic and local atomic structure in the cubic colossal magnetoresistive manganite La1-xSrxMnO3

We have studied the temperature-dependent evolution of the electronic and local atomic structure in the cubic colossal magnetoresistive manganite La{sub 1-x}Sr{sub x}MnO{sub 3} (x= 0.3-0.4) with core and valence level photoemission (PE), x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES), resonant inelastic x-ray scattering (RIXS), extended x-ray absorption fine structure (EXAFS) spectroscopy and magnetometry. As the temperature is varied across the Curie temperature T{sub c}, our PE experiments reveal a dramatic change of the electronic structure involving an increase in the Mn spin moment from {approx} 3 {micro}B to {approx} 4 {micro}B, and a modification of the local chemical environment of the other constituent atoms indicative of electron localization on the Mn atom. These effects are reversible and exhibit a slow-timescale {approx}200 K-wide hysteresis centered at T{sub c}. Based upon the probing depths accessed in our PE measurements, these effects seem to survive for at least 35-50 {angstrom} inward from the surface, while other consistent signatures for this modification of the electronic structure are revealed by more bulk sensitive spectroscopies like XAS and XES/RIXS. We interpret these effects as spectroscopic fingerprints for polaron formation, consistent with the presence of local Jahn-Teller distortions of the MnO{sub 6} octahedra around the Mn …
Date: December 6, 2007
Creator: Arenholz, Elke; Mannella, N.; Booth, C. H.; Rosenhahn, A.; Sell, B. C.; Nambu, A. et al.
System: The UNT Digital Library
The entropy in supernova explosions (open access)

The entropy in supernova explosions

The explosion of a supernova forms because of the collapse to a neutron star. In addition an explosion requires that a region of relatively high entropy be in contact with the neutron star and persisting for a relatively protracted period of time. The high entropy region ensures that the maximum temperature in contact with the neutron star and in hydrostatic equilibrium is less than some maximum. This temperature must be low enough such that neutrino emission cooling is small, otherwise the equilibrium atmosphere will collapse adding a large accretion mass to the neutron star. A so-called normal explosion shock that must reverse the accretion flow corresponding to a typical stellar collapse must have sufficient strength or pressure to reverse this flow and eject the matter with 10{sup 51} ergs for a typical type II supernova. Surprisingly the matter behind such a shock wave has a relatively low entropy low enough such that neutrino cooling would be orders of magnitude faster than the expansion rate. The resulting accretion low would be inside the Bondi radius and result in free-fall accretion inside the expanding rarefaction wave. The accreted mass or reimplosion mass unless stopped by a high entropy bubble could than exceed …
Date: December 6, 1990
Creator: Colgate, S. A.
System: The UNT Digital Library
Ultrasonic off-normal imaging techniques for under sodium viewing. [LMFBR] (open access)

Ultrasonic off-normal imaging techniques for under sodium viewing. [LMFBR]

Advanced imaging methods have been evaluated for the purpose of constructing images of objects from ultrasonic data. Feasibility of imaging surfaces which are off-normal to the sound beam has been established. Laboratory results are presented which show a complete image of a typical core component. Using the previous system developed for under sodium viewing (USV), only normal surfaces of this object could be imaged. Using advanced methods, surfaces up to 60 degrees off-normal have been imaged. Details of equipment and procedures used for this image construction are described. Additional work on high temperature transducers, electronics, and signal analysis is required in order to adapt the off-normal viewing process described here to an eventual USV application.
Date: December 6, 1979
Creator: Michaels, T.E. & Horn, J.E.
System: The UNT Digital Library
Alternating gradient synchrotron (open access)

Alternating gradient synchrotron

With the start of a research and development effort directed towards the Superconducting Super Collider (SSC), it is essential that US industry become involved as soon as possible. For that reason, I describe what a conventional accelerator complex is like and therefore what the first stages of the SSC would entail.
Date: December 6, 1984
Creator: Lowenstein, D.I.
System: The UNT Digital Library
Diffusive transport enhancement by isolated resonances and distribution tails growth in hadronic beams (open access)

Diffusive transport enhancement by isolated resonances and distribution tails growth in hadronic beams

The escape rates and evolution of a distribution of particles are considered for a 2-D model of transverse motion of particles in hadronic storage rings, when nonlinear resonances and external diffusion are present. Dynamic enhancement of diffusion inside separatrices can develop under a certain geometry of resonance oscillations and relatively wide resonances, leading to the fast growth of distribution tails and escape rates. The phenomenon is absent in 1-D. 10 refs., 4 figs.
Date: December 6, 1990
Creator: Gerasimov, A.
System: The UNT Digital Library
Fuel adjacency effects on fast reactor cladding mechanical properties. [LMFBR] (open access)

Fuel adjacency effects on fast reactor cladding mechanical properties. [LMFBR]

Simulated transient tests were conducted on 234 cladding specimens from EBR-II irradiated mixed oxide fuel pins; approximately 75% of the specimens were from the fuel column region, with the remainder from the plenum and below the fuel column. The cladding specimens were taken from the N-E, N-F,, PNL-9, PNL-10, PNL-11, P-23A, P-23B, P-23C, and WSA-3 fuel pins irradiated at 15.2 to 37 KW/cm to burnup levels from 11 to 110 MWd/Kg. All the fuel pins used 20% cold worked Type 316 stainless steel cladding. Irradiation temperatures ranged from 370 to 725/sup 0/C with a peak fluence of 10/sup 23/ n/cm/sup 2/ (E > 0.1 MeV).
Date: December 6, 1978
Creator: Hunter, C. W. & Johnson, G. D.
System: The UNT Digital Library
Positive ion systems: state of the art and ultimate potential (open access)

Positive ion systems: state of the art and ultimate potential

The PLT or ISX-B ion source has been operated at 40-keV, 60-A, and 0.3-sec pulses with H(D) neutral injected power of 750 kW (approximately 1000 kW) on the PLT device. This report gives a brief description of this system and some future plans. (MOW)
Date: December 6, 1977
Creator: Haselton, H.H.
System: The UNT Digital Library
Quantifying the Contribution of Lubrication Oil to Particulate Emissions from a Diesel Engine (open access)

Quantifying the Contribution of Lubrication Oil to Particulate Emissions from a Diesel Engine

The contribution of lubrication oil to particulate matter (PM) emissions from a Cummins B5.9 Diesel engine was measured using accelerator mass spectrometry to trace carbon isotope concentrations. The engine operated at fixed medium load (285 N-m (210 ft.lbs.) 1600 m) used 100% biodiesel fuel (B100) with a contemporary carbon-14 ({sup 14}C) concentration of 103 amol {sup 14}C/ mg C. The C concentration of the exhaust C02 and PM were 102 and 99 amol {sup 14}C/mg C, respectively. The decrease in I4C content in the PM is due to the consumption of lubrication oil which is {sup 14}C-free. Approximately 4% of the carbon in PM came from lubrication oil under these operating conditions. The slight depression in CO{sub 2} isotope content could be attributed to ambient CO{sub 2} levels and measurement uncertainty.
Date: December 6, 2002
Creator: Cheng, A. S.; Rich, D.; Dibble, R. W. & Buchholz, B. A.
System: The UNT Digital Library
Low-Temperature Growth of DKDP for Improving Laser-Induced Damage resistance at 350nm (open access)

Low-Temperature Growth of DKDP for Improving Laser-Induced Damage resistance at 350nm

A set of twenty-three 20-L crystallizer runs exploring the importance of several engineering variables found that growth temperature is the most important variable controlling damage resistance of DKDP over the conditions investigated. Boules grown between 45 C and room temperature have a 50% probability of 3{omega} bulk damage that is 1.5 to 2 times higher than boules grown between 65 and 45 C. This raises their damage resistance above the NIF tripler specification for 8 J/cm{sup 2} operation by a comfortable margin. Solution impurity levels do not correlate with damage resistance for iron less than 200 ppb and aluminum less than 2000 ppb. The possibility that low growth temperatures could increase damage resistance in NIF-scale boules was tested by growing a large boule in a 1000-L crystallizer with a supplemental growth solution tank. Four samples representing early and late pyramid and prism growth are very close to the specification as best it is understood at the present. Implications of low temperature growth for meeting absorbance, homogeneity, and other material specifications are discussed.
Date: December 6, 2000
Creator: Burnham, A K; Runkel, M; Hawley-Fedder, R A; Carman, M L; Torres, R A & Whitman, P K
System: The UNT Digital Library
Full Wave Analysis of RF Signal Attenuation in a Lossy Cave using a High Order Time Domain Vector Finite Element Method (open access)

Full Wave Analysis of RF Signal Attenuation in a Lossy Cave using a High Order Time Domain Vector Finite Element Method

We present a computational study of signal propagation and attenuation of a 200 MHz dipole antenna in a cave environment. The cave is modeled as a straight and lossy random rough wall. To simulate a broad frequency band, the full wave Maxwell equations are solved directly in the time domain via a high order vector finite element discretization using the massively parallel CEM code EMSolve. The simulation is performed for a series of random meshes in order to generate statistical data for the propagation and attenuation properties of the cave environment. Results for the power spectral density and phase of the electric field vector components are presented and discussed.
Date: December 6, 2004
Creator: Pingenot, J; Rieben, R & White, D
System: The UNT Digital Library
ALPHA SPECTROMETRIC EVALUATION OF SRM-995 AS A POTENTIAL URANIUM/THORIUM DOUBLE TRACER SYSTEM FOR AGE-DATING URANIUM MATERIALS (open access)

ALPHA SPECTROMETRIC EVALUATION OF SRM-995 AS A POTENTIAL URANIUM/THORIUM DOUBLE TRACER SYSTEM FOR AGE-DATING URANIUM MATERIALS

Uranium-233 (t{sub 1/2} {approx} 1.59E5 years) is an artificial, fissile isotope of uranium that has significant importance in nuclear forensics. The isotope provides a unique signature in determining the origin and provenance of uranium-bearing materials and is valuable as a mass spectrometric tracer. Alpha spectrometry was employed in the critical evaluation of a {sup 233}U standard reference material (SRM-995) as a dual tracer system based on the in-growth of {sup 229}Th (t{sub 1/2} {approx} 7.34E3 years) for {approx}35 years following radiochemical purification. Preliminary investigations focused on the isotopic analysis of standards and unmodified fractions of SRM-995; all samples were separated and purified using a multi-column anion-exchange scheme. The {sup 229}Th/{sup 233}U atom ratio for SRM-995 was found to be 1.598E-4 ({+-} 4.50%) using recovery-corrected radiochemical methods. Using the Bateman equations and relevant half-lives, this ratio reflects a material that was purified {approx} 36.8 years prior to this analysis. The calculated age is discussed in contrast with both the date of certification and the recorded date of last purification.
Date: December 6, 2011
Creator: Beals, D.
System: The UNT Digital Library
Deriving Daytime Variables From the AmeriFlux Standard Eddy Covariance Data Set (open access)

Deriving Daytime Variables From the AmeriFlux Standard Eddy Covariance Data Set

A gap-filled, quality assessed eddy covariance dataset has recently become available for the AmeriFluxnetwork. This dataset uses standard processing and produces commonly used science variables. This shared dataset enables robust comparisons across different analyses. Of course, there are many remaining questions. One of those is how to define 'during the day' which is an important concept for many analyses. Some studies have used local time ?for example 9am to 5pm; others have used thresholds on photosynthetic active radiation (PAR). A related question is how to derive quantities such as the Bowen ratio. Most studies compute the ratio of the averages of the latent heat (LE) and sensible heat (H). In this study, we use different methods of defining 'during the day' for GPP, LE, and H. We evaluate the differences between methods in two ways. First, we look at a number of statistics of GPP. Second, we look at differences in the derived Bowen ratio. Our goal is not science per se, but rather informatics in support of the science.
Date: December 6, 2008
Creator: Ingen, Catharine van; Agarwal, Deborah A.; Humphrey, Marty & Li, Jie
System: The UNT Digital Library
Inclusive hadron distributions in p+p collisions from saturation models of HERA DIS data. (open access)

Inclusive hadron distributions in p+p collisions from saturation models of HERA DIS data.

Dipole models based on various saturation scenarios provide reasonable fits to small-x DIS inclusive, diffractive and exclusive data from HERA. Proton un-integrated gluon distributions extracted from such fits are employed in a k{sub {perpendicular}}-factorization framework to calculate inclusive gluon distributions at various energies. The n-particle multiplicity distribution predicted in the Glasma flux tube approach shows good agreement with data over a wide range of energies. Hadron inclusive transverse momentum distributions expressed in terms of the saturation scale demonstrate universal behavior over a wider kinematic range systematically with increasing center of mass energies.
Date: December 6, 2010
Creator: Tribedy, P. & Venugopalan, R.
System: The UNT Digital Library
National Waste Terminal Storage Program information meeting, December 7-8, 1976. [Slides only, no text] (open access)

National Waste Terminal Storage Program information meeting, December 7-8, 1976. [Slides only, no text]

Volume II of the report comprises copies of the slides from the talks presented at the second session of the National Waste Terminal Storage Program information meeting. This session was devoted to geologic studies. (LK)
Date: December 6, 1976
Creator: unknown
System: The UNT Digital Library
Spin and diffractive physics with A Fixed-Target ExpeRiment at the LHC (AFTER@LHC) (open access)

Spin and diffractive physics with A Fixed-Target ExpeRiment at the LHC (AFTER@LHC)

None
Date: December 6, 2012
Creator: Lorce, C.; Anselmino, M.; Arnaldi, R.; Brodsky, S.J.; Chambert, V.; Didelez, J.P. et al.
System: The UNT Digital Library
High-Z Radiation Shields for X-ray Free Electron Laser Detectors (open access)

High-Z Radiation Shields for X-ray Free Electron Laser Detectors

None
Date: December 6, 2012
Creator: Tomada, Astrid; Boutet, S.; Duda, B.; Hart, P.; Kenney, C.; Manger, L. et al.
System: The UNT Digital Library