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SRE CONTROL ROD SHIELDING REQUIREMENTS (open access)

SRE CONTROL ROD SHIELDING REQUIREMENTS

Data taken on radiation traverse of the Mark 1 control rod were analyzed. Future radiation levels for all SRE control and safety rods were predicted from this. The shielding necessary to ship a complete rod and that necessary to protect a person doing maintenance work on these rods were calculated. The unshielded gamma dose rate 1 cm from the surface of the most highly activated portion of the control rod was calculated to be 5.0 x 10/sup 4/ r/hr 14 days after shutdown following an extended power run of 90 days duration. (M.C.G.)
Date: October 22, 1957
Creator: Whittum, H.O.
Object Type: Report
System: The UNT Digital Library
Development of a high-density energy-storage capacitor for Nova (open access)

Development of a high-density energy-storage capacitor for Nova

This paper covers Maxwell's approach to developing energy storage capacitors. Based on previous capacitor designs of 3 KJ, 5 KJ and 10 KJ, the final Nova 12.5 KJ capacitor evolved. At the outset of the Nova capacitor development program, a relatively new dielectric system, polypropylene-paper-DOP, seemed to show superiority in volumetric efficiency, life, and more importantly cost. However, as a result of studies performed at Maxwell, a high-density, energy-storage capacitor was developed utilizing new high-quality, high-density paper and caster oil as the dielectric. Test data have demonstrated that the Maxwell 12.5 KJ capacitor exceeds all LLNL's qualification requirements.
Date: October 22, 1981
Creator: Haskell, D. K.; Cooper, R. A.; Sevigny, J. A.; Merritt, B. T.; Carder, B. M. & Whitham, K.
Object Type: Article
System: The UNT Digital Library
Diamond-turning tool setting by interferogram analysis (open access)

Diamond-turning tool setting by interferogram analysis

A method was developed to establish a numerically controlled tool path with respect to the work spindle centerline. Particularly adapted to the diamond turning of optics, this method is based upon interferogram analysis and is applicable to the establishment of the work spindle centerline relative to the tool path for any center-turned optic having a well-defined vertex radius of curvature. The application reported is for an f/2 concave spherical mirror.
Date: October 22, 1980
Creator: Rasnick, W.H. & Yoder, R.C.
Object Type: Report
System: The UNT Digital Library
The public response to Monitored Retrievable Storage: An interim report (open access)

The public response to Monitored Retrievable Storage: An interim report

This report describes public opinion concerning the proposed monitored retrievable storage facility to be located in the vicinity of Oak Ridge, Tennessee. The majority of individuals who did express an opinion opposed the facility due to transport/safety concerns and environmental/health concerns. (CBS)
Date: October 22, 1985
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Collection of CASIM calculations (open access)

Collection of CASIM calculations

Monte Carlo calculations of hadronic cascades at Fermilab have usually been done using the code CASIM written by A. Van Ginneken. These calculations are often performed to determine the quantity of shielding required for radiation protection purposes. A number of examples of such calculations have been presented previously. Several years of practical experience have led the author to develop the collection of additional cases included in the present report. These results along with those given earlier will serve as a useful reference. No attempt was made here to consider all possibilities; rather, the purpose was to develop a useful set of examples. Exceptionally intricate cases should, of course, receive individualized attention as appropriate.
Date: October 22, 1982
Creator: Cossairt, J.D.
Object Type: Report
System: The UNT Digital Library
Characterizing the nano and micro structure of concrete to improve its durability (open access)

Characterizing the nano and micro structure of concrete to improve its durability

New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images on ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools will be shown on this paper.
Date: October 22, 2008
Creator: Monteiro, P. J. M.; Kirchheim, A. P.; Chae, S.; Fischer, P.; MacDowell, A. A.; Schaible, E. et al.
Object Type: Article
System: The UNT Digital Library
Recent Searches for Exotic Physics at the BaBar/PEP-II B-factory (open access)

Recent Searches for Exotic Physics at the BaBar/PEP-II B-factory

I present three recent results from searches for exotic physics at the BABAR/PEP-II B-factory. These results span many of the samples produced at the B-factory, including B mesons, {tau} leptons, and {Upsilon}(3S) mesons. We have searched for CPT-violation in B{sup 0} mixing and find no significant deviation from the no-violation hypothesis. We have also searched for lepton-flavor-violating decays of the {tau} using {tau}{sup -} {yields} {omega}{ell}{sup -} and {tau}{sup -} {yields} {ell}{sup -}{ell}{sup +}{ell}{sup -} and their charge conjugates. We find no evidence for these processes and set upper limits on their branching fractions. Finally, we have searched for a low-mass Higgs boson in the decay {Upsilon}(3S) {yields} {gamma}A{sup 0}, where the Higgs decays invisibly. We find no evidence for such a decay and set upper limits across a range of possible Higgs masses.
Date: October 22, 2008
Creator: Sekula, Stephen Jacob
Object Type: Article
System: The UNT Digital Library
The National Ignition Facility: The world's largest optical system (open access)

The National Ignition Facility: The world's largest optical system

None
Date: October 22, 2007
Creator: Stolz, C J
Object Type: Article
System: The UNT Digital Library
Potential of Photovoltaics (open access)

Potential of Photovoltaics

Presented at the Association of Industrial Metallizers, Coaters and Laminators (AIMCAL) Fall Technical Conference 2008 and 22nd International Vacuum Web Coating Conference held October 19-22, 2008 in Myrtle Beach, South Carolina. This presentation discusses PV in the world energy portfolio, PV basics, PV technologies, and vacuum web-coating applications in PV.
Date: October 22, 2008
Creator: Nelson, B. P.
Object Type: Article
System: The UNT Digital Library
Scientific Needs for Future X-Ray Sources in the U.S.: A White Paper (open access)

Scientific Needs for Future X-Ray Sources in the U.S.: A White Paper

Many of the important challenges facing humanity, including developing alternative sources of energy and improving health, are being addressed by advances that demand the improved understanding and control of matter. While the visualization, exploration, and manipulation of macroscopic matter have long been technological goals, scientific developments in the twentieth century have focused attention on understanding matter on the atomic scale through the underlying framework of quantum mechanics. Of special interest is matter that consists of natural or artificial nanoscale building blocks defined either by atomic structural arrangements or by electron or spin formations created by collective correlation effects (Figure 1.1). The essence of the challenge to the scientific community has been expressed in five grand challenges for directing matter and energy recently formulated by the Basic Energy Sciences Advisory Committee. These challenges focus on increasing our understanding of, and ultimately control of, matter at the level of atoms, electrons, and spins, as illustrated in Figure 1.1. Meeting these challenges will require new tools that extend our reach into regions of higher spatial, temporal, and energy resolution. Since the fundamental interaction that holds matter together is of electromagnetic origin, it is intuitively clear that electromagnetic radiation is the critical tool in …
Date: October 22, 2008
Creator: Falcone , Roger; Stohr, Joachim; Bergmann, Uwe; Corlett, John; Galayda, John; Hastings, Jerry et al.
Object Type: Report
System: The UNT Digital Library
On The Reproducibility of Seasonal Land-surface Climate (open access)

On The Reproducibility of Seasonal Land-surface Climate

The sensitivity of the continental seasonal climate to initial conditions is estimated from an ensemble of decadal simulations of an atmospheric general circulation model with the same specifications of radiative forcings and monthly ocean boundary conditions, but with different initial states of atmosphere and land. As measures of the ''reproducibility'' of continental climate for different initial conditions, spatio-temporal correlations are computed across paired realizations of eleven model land-surface variables in which the seasonal cycle is either included or excluded--the former case being pertinent to climate simulation, and the latter to seasonal anomaly prediction. It is found that the land-surface variables which include the seasonal cycle are impacted only marginally by changes in initial conditions; moreover, their seasonal climatologies exhibit high spatial reproducibility. In contrast, the reproducibility of a seasonal land-surface anomaly is generally low, although it is substantially higher in the Tropics; its spatial reproducibility also markedly fluctuates in tandem with warm and cold phases of the El Nino/Southern Oscillation. However, the overall degree of reproducibility depends strongly on the particular land-surface anomaly considered. It is also shown that the predictability of a land-surface anomaly implied by its reproducibility statistics is consistent with what is inferred from more conventional predictability …
Date: October 22, 2004
Creator: Phillips, T J
Object Type: Article
System: The UNT Digital Library
U.S. and Russian Collaboration in the Area of Nuclear Forensics (open access)

U.S. and Russian Collaboration in the Area of Nuclear Forensics

Nuclear forensics has become increasingly important in the fight against illicit trafficking in nuclear and other radioactive materials. The illicit trafficking of nuclear materials is, of course, an international problem; nuclear materials may be mined and milled in one country, manufactured in a second country, diverted at a third location, and detected at a fourth. There have been a number of articles in public policy journals in the past year that call for greater interaction between the U. S. and the rest of the world on the topic of nuclear forensics. Some believe that such international cooperation would help provide a more certain capability to identify the source of the nuclear material used in a terrorist event. An improved international nuclear forensics capability would also be important as part of the IAEA verification toolkit, particularly linked to increased access provided by the additional protocol. A recent study has found that, although international progress has been made in securing weapons-usable HEU and Pu, the effort is still insufficient. They found that nuclear material, located in 40 countries, could be obtained by terrorists and criminals and used for a crude nuclear weapon. Through 2006, the IAEA Illicit Trafficking Database had recorded a …
Date: October 22, 2007
Creator: Kristo, M J
Object Type: Article
System: The UNT Digital Library
Diffusion of a Highly-Charged Supramolecular Assembly: Direct Observation of Ion-Association in Water (open access)

Diffusion of a Highly-Charged Supramolecular Assembly: Direct Observation of Ion-Association in Water

Understanding the solution behavior of supramolecular assemblies is essential for a full understanding of the formation and chemistry of synthetic host-guest systems. While the interaction between host and guest molecules is generally the focus of mechanistic studies of host-guest complexes, the interaction of the host-guest complex with other species in solution remains largely unknown, although in principle accessible by diffusion studies. Several NMR techniques are available to monitor diffusion and have recently been reviewed. Pulsed gradient spin-echo (PGSE) NMR methods have attracted increasing interest, since they allow diffusion coefficients to be measured with high accuracy; they have been successfully used with observation of {sup 7}Li and {sup 31}P nuclei as well as with {sup 1}H NMR. We report here the direct measurement of diffusion coefficients to observe ion-association interactions by counter cations with a highly-charged supramolecular assembly. Raymond and coworkers have described the design and chemistry of a class of metal-ligand supramolecular assemblies over the past decade. The [Ga{sub 4}L{sub 6}]{sup 12-} (L = 1,5-bis(2,3-dihydroxybenzamido)naphthalene) (1) (Figure 1) assembly has garnered the most attention, with the exploration of the dynamics and mechanism of guest exchange as well as the ability of 1 to achieve either stoichiometric or catalytic reactions inside …
Date: October 22, 2007
Creator: University of California, Berkeley; Laboratory, Lawrence Berkeley National; Raymond, Kenneth; Pluth, Michael D.; Tiedemann, Bryan E.F.; van Halbeek, Herman et al.
Object Type: Article
System: The UNT Digital Library
Final Report: Radiation-magnetohydrodynamic evolution and instability of conductors driven by megagauss magnetic fields (open access)

Final Report: Radiation-magnetohydrodynamic evolution and instability of conductors driven by megagauss magnetic fields

We are pleased to report important progress in experimentally characterizing and numerically modeling the transformation into plasma of walls subjected to pulsed megagauss magnetic fields. Understanding this is important to Magnetized Target Fusion (MTF) because an important limitation to the metal liner approach to MTF comes from the strong eddy current heating on the surface of the metal liner. This has intriguing non-linear aspects when the magnetic field is in the megagauss regime as needed for MTF, and may limit the magnetic field in an MTF implosion. Many faculty, students, and staff have contributed to this work, and, implicitly or explicitly, to this report. Contributors include, in addition to the PIs, Andrey Esaulov, Stephan Fuelling, Irvin Lindemuth, Volodymyr Makhin, Ioana Paraschiv, Milena Angelova, Tom Awe, Tasha Goodrich, Arunkumar Prasadam, Andrew Oxner, Bruno Le Galloudec, Radu Presura, and Vladimir Ivanov. Highlights of the progress made during the grant include: • 12 articles published, and 44 conference and workshop presentations made, on a broad range of issues related to this project; • An ongoing experiment that uses the 1 MA, 100-ns Zebra z-pinch at UNR to apply 2 5 megagauss to a variety of metal surfaces, examining plasma formation and evolution; • …
Date: October 22, 2008
Creator: Bauer, Bruno, S. & Siemon, Richard, E.
Object Type: Report
System: The UNT Digital Library
Monte Carlo Modeling and Analyses of Yalina- Booster Subcritical Assembly Part II : Pulsed Neutron Source. (open access)

Monte Carlo Modeling and Analyses of Yalina- Booster Subcritical Assembly Part II : Pulsed Neutron Source.

One of the most reliable experimental methods for measuring the kinetic parameters of a subcritical assembly is the Sjoestrand method applied to the reaction rate generated from a pulsed neutron source. This study developed a new analytical methodology for characterizing the kinetic parameters of a subcritical assembly using the Sjoestrand method, which allows comparing the analytical and experimental time dependent reaction rates and the reactivity measurements. In this methodology, the reaction rate, detector response, is calculated due to a single neutron pulse using MCNP/MCNPX computer code or any other neutron transport code that explicitly simulates the fission delayed neutrons. The calculation simulates a single neutron pulse over a long time period until the delayed neutron contribution to the reaction is vanished. The obtained reaction rate is superimposed to itself, with respect to the time, to simulate the repeated pulse operation until the asymptotic level of the reaction rate, set by the delayed neutrons, is achieved. The superimposition of the pulse to itself was calculated by a simple C computer program. A parallel version of the C program is used due to the large amount of data being processed, e.g. by the Message Passing Interface (MPI). The new calculation methodology has …
Date: October 22, 2008
Creator: Talamo, A.; Gohar, M. Y. A. & Rabiti, C.
Object Type: Report
System: The UNT Digital Library
Biosecurity Techbase FY07 Final Report (open access)

Biosecurity Techbase FY07 Final Report

This tech base award has close links with the Viral Identification Characterization Initiative (VICI) ER LDRD. The tech base extends developed code to enable a capability for biodefense, biosurveillance, and clinical diagnostics. The code enables the design of signatures to detect and discover viruses, without relying on prior assumptions as to the species of virus present. This approach for primer and signature design contrasts with more traditional PCR approaches, in which a major weakness is the unlikelihood of viral discovery or detection of unanticipated species. There were three crucial areas of the project that were not research and development, so could not be funded under the ER LDRD, but were a reduction to practice of the existing VICI algorithm that were necessary for the success of overall computational project goals. These areas, funded by the 2007 Tech Base award, were: (1) improvement of the code developed under the VICI LDRD by incorporating T{sub m} and free energy predictions using Unafold; (2) porting of code developed on the kpath Sun Solaris cluster to the Yana and Zeus LC machines; and (3) application of that code to perform large numbers of simulations to determine parameter effects.
Date: October 22, 2007
Creator: Gardner, S N & Williams, P L
Object Type: Report
System: The UNT Digital Library
Leveraging Structure to Improve Classification Performance in Sparsely Labeled Networks (open access)

Leveraging Structure to Improve Classification Performance in Sparsely Labeled Networks

We address the problem of classification in a partially labeled network (a.k.a. within-network classification), with an emphasis on tasks in which we have very few labeled instances to start with. Recent work has demonstrated the utility of collective classification (i.e., simultaneous inferences over class labels of related instances) in this general problem setting. However, the performance of collective classification algorithms can be adversely affected by the sparseness of labels in real-world networks. We show that on several real-world data sets, collective classification appears to offer little advantage in general and hurts performance in the worst cases. In this paper, we explore a complimentary approach to within-network classification that takes advantage of network structure. Our approach is motivated by the observation that real-world networks often provide a great deal more structural information than attribute information (e.g., class labels). Through experiments on supervised and semi-supervised classifiers of network data, we demonstrate that a small number of structural features can lead to consistent and sometimes dramatic improvements in classification performance. We also examine the relative utility of individual structural features and show that, in many cases, it is a combination of both local and global network structure that is most informative.
Date: October 22, 2007
Creator: Gallagher, B. & Eliassi-Rad, T.
Object Type: Report
System: The UNT Digital Library
Measured and projected performance of plasma direct converters (open access)

Measured and projected performance of plasma direct converters

Test results from two plasma direct converters and their predicted cost and performance on tandem mirror fusion reactors are present. The tests were done at high power density (approx. 70 W/cm/sup 2/) in steady state to simulate the predicted conditions in a reactor. A single stage unit and a two-stage unit of the Venetian blind type were tested at up to 100 kV and 6 kW for a total time of about 80 hours. Measured efficiencies, when projected to a reactor, are typically about 50% for a single stage unit and 60 to 70% for a two-stage unit, depending on the energy distribution of the ions, the degree of subdivision of the collectors, and on the gas pressure. The high ambipolar potential in tandem mirror devices makes this good efficiency possible. When radiatively cooled grids are used, the incident power density is limited to about 100 W/cm/sup 2/ by the thermionic emission of electrons.
Date: October 22, 1981
Creator: Barr, W.L. & Moir, R.W.
Object Type: Article
System: The UNT Digital Library
Engineering problems of the fusion breeder (open access)

Engineering problems of the fusion breeder

A study of fission suppressed blankets for the tandem mirror not only showed such blankets to be feasible but also to be safer than fissioning blankets. Such hybrids could produce enough fissile material to support up to 17 light water reactors of the same nuclear power rating. Beryllium was compared to /sup 7/Li for neutron multiplication; both were considered feasible but the blanket with Li produced 20% less fissile fuel per unit of nuclear power in the reactor. The beryllium resource, while possibly being too small for extensive pure fusion application, would be adequate (with carefully planned industrial expansion) for the hybrid because of the large support ratio, and hence few hybrids required. Radiation damage and coatings for beryllium remain issues to be resolved by further study and experimentation. Molten salt reprocessing was compared to aqueous solution reprocessing (thorex). The molten salt reprocessing cost is $3.4/g fissile, whereas aqueous reprocessing cost $24 or $43/g for the thorium metal or oxide fuel form.
Date: October 22, 1981
Creator: Moir, R. W.; Lee, J. D. & Barr, W. L.
Object Type: Article
System: The UNT Digital Library
Results of the metallographic examination of the Ta crucible used in the M. S. E. runs (open access)

Results of the metallographic examination of the Ta crucible used in the M. S. E. runs

A cross section from a Ta crucible used in numerous Molten Salt Extraction (MSE) runs was submitted to metallography to determine the soundness of the crucible wall, type of Pu attack, depth of wall penetration by the Pu and general microstructure. The crucible contained molten Pu and Am, with CaCl{sub 2}, KCl and PuCl{sub 3} salts ran at temperatures of 750{degree}C to 900{degree}C for approximately 10 to 12 hours. This report documents the findings of this study.
Date: October 22, 1990
Creator: Furr, J.S.
Object Type: Report
System: The UNT Digital Library
The role of purine degradation in methane biosynthesis and energy production in Methanococcus vannielii (open access)

The role of purine degradation in methane biosynthesis and energy production in Methanococcus vannielii

Research continues on the role of purine degradation in methane biosynthesis and energy production in Methanococcus vannielii. This report summarizes current progress of the research. Topics include: A survey of other methanogens for the purine degradation pathway; isolate and characterize the enzyme and products of formiminoglycine cleavage; ascertain the fate of glycine from the formiminoglycine cleavage; elucidate the route of incorporation of the formyl moiety of formiminoglycine into methane biosynthesis; determine the percent methane and amino acid synthesis from purine degradation; and related studies on xanthine dehydrogenase and pyrimidine degradation of M. Vannielii. (SM)
Date: October 22, 1990
Creator: DeMoll, E.
Object Type: Report
System: The UNT Digital Library
MFTF-B electron-cyclotron-resonance heating system (open access)

MFTF-B electron-cyclotron-resonance heating system

The MFTF-B ECRH system will provide 1.6-MW of microwave power for heating of electrons within the thermal barrier and potential maximum regions of the plasma end-plugs. Absorption of this radiation increases the resonant electron energy which locally alters the electrostatic confining potential within the plasma. The result is a thermal barrier which will isolate end-plug electrons from those in the solenoid thus increasing the plasma confinement time. Microwave energy will be generated by eight 200 kW gyrotrons located outside the vacuum vessel at strategic positions near each end-plug. High voltage dc power will be obtained from a -90 kV, 90 A power supply. A compensation network will condition the dc power and channel it to eight independent pulse power regulatory/isolation networks. Each of these networks will, on command, provide -80 kV, 8 A of dc power to its attendant gyrotron cabinet positioned within the vault. Each gyrotron will interface to a quasi-optical waveguide which will transport microwave power to an antenna system located inside the vacuum vessel. The antenna systems will direct the microwave radiation into the resonant heating zones of the plasma. A local control and monitoring system will interface to the MFTF-B Supervisory Control and Diagnostics System. This …
Date: October 22, 1981
Creator: Krause, K. H.; Pollock, G. G. & Yugo, J. J.
Object Type: Article
System: The UNT Digital Library
Engineering problems of tandem-mirror reactors (open access)

Engineering problems of tandem-mirror reactors

We have completed a comparative evaluation of several end plug configurations for tandem mirror fusion reactors with thermal barriers. The axi-cell configuration has been selected for further study and will be the basis for a detailed conceptual design study to be carried out over the next two years. The axi-cell end plug has a simple mirror cell produced by two circular coils followed by a transition coil and a yin-yang pair, which provides for MHD stability. This paper discusses some of the many engineering problems facing the designer. We estimated the direct cost to be 2$/W/sub e/. Assuming total (direct and indirect) costs to be twice this number, we need to reduce total costs by factors between 1.7 and 2.3 to compete with future LWRs levelized cost of electricity. These reductions may be possible by designing magnets producing over 20T made possible by use of combinations of superconducting and normal conducting coils as well as improvements in performance and cost of neutral beam and microwave power systems. Scientific and technological understanding and innovation are needed in the area of thermal barrier pumping - a process by which unwanted particles are removed (pumped) from certain regions of velocity and real space …
Date: October 22, 1981
Creator: Moir, R.W.; Barr, W.L. & Boghosian, B.M.
Object Type: Article
System: The UNT Digital Library
Dispersion calculations for non-radiological hazardous chemical emissions from the Defense Waste Processing Facility and related activities (open access)

Dispersion calculations for non-radiological hazardous chemical emissions from the Defense Waste Processing Facility and related activities

The Environmental Protection Agency's (EPA) Industrial Source Complex -- Short Term (ISCST) air dispersion model was used to examine potential atmospheric impacts of routine benzene and mercury emissions from the Defense Waste Processing Facility (DWPF), In-Tank Precipitation (ITP) facilities, and the Saltstone Facility. The highest model estimated 8-hour average ground-level benzene concentrations were found to occur in the immediate vicinity of the ITP filter/stripper building (241-96H). Subsequent model calculations were used to determine minimum stack release heights that would be necessary to achieve compliance with this workplace exposure standard for currently anticipated emission levels. The highest 24-hour average site boundary concentrations of benzene and mercury generally occurred to the north of S and H areas. Concentrations were well below the ambient concentration standards that have been identified for these substances in an air toxics policy proposed by the State of South Carolina. Estimates of annual average benzene concentrations for offsite locations were used to estimate the excess lifetime cancer risk. Assuming continuous 70-year exposure to the estimated annual benzene concentrations, the excess cancer risk to the maximum exposed individual was estimated to be 3 {times} 10{sup {minus}7}. Similar lifetime exposure summed over the surrounding population resulted in an estimated average …
Date: October 22, 1990
Creator: Hunter, C.H.
Object Type: Report
System: The UNT Digital Library