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Assessment of Preferred Depleted Uranium Disposal Forms

Description: The Department of Energy (DOE) is in the process of converting about 700,000 metric tons (MT) of depleted uranium hexafluoride (DUF6) containing 475,000 MT of depleted uranium (DU) to a stable form more suitable for long-term storage or disposal. Potential conversion forms include the tetrafluoride (DUF4), oxide (DUO2 or DU3O8), or metal. If worthwhile beneficial uses cannot be found for the DU product form, it will be sent to an appropriate site for disposal. The DU products are considered to be low-level waste (LLW) under both DOE orders and Nuclear Regulatory Commission (NRC) regulations. The objective of this study was to assess the acceptability of the potential DU conversion products at potential LLW disposal sites to provide a basis for DOE decisions on the preferred DU product form and a path forward that will ensure reliable and efficient disposal.
Date: June 1, 2000
Creator: Croff, A.G.; Hightower, J.R.; Lee, D.W.; Michaels, G.E.; Ranek, N.L. & Trabalka, J.R.
Partner: UNT Libraries Government Documents Department

Assessment of the roles of the Advanced Neutron Source Operators

Description: The Advanced Neutron Source (ANS) is unique in the extent to which human factors engineering (HFE) principles are being applied at the conceptual design stage. initial HFE accomplishments include the development of an ANS HFE program plan, operating philosophy, and functional analysis. In FY 1994, HFE activities focused on the role of the ANS control room reactor operator (RO). An operator-centered control room model was used in conjunction with information gathered from existing ANS system design descriptions and other literature to define a list of RO responsibilities. From this list, a survey instrument was developed and administered to ANS design engineers, operations management personnel at Oak Ridge National Laboratory`s High Flux Isotope Reactor (HFIR), and HFIR ROs to detail the nature of the RO position. Initial results indicated that the RO will function as a high-level system supervisor with considerable monitoring, verification, and communication responsibilities. The relatively high level of control automation has resulted in a reshaping of the RO`s traditional safety and investment protection roles.
Date: March 1, 1995
Creator: Hill, W.E.; Houser, M.M.; Knee, H.E. & Spelt, P.F.
Partner: UNT Libraries Government Documents Department

Beta testing the Intel Paragon MP

Description: This report summarizes the third phase of a Cooperative Research and Development Agreement between Oak Ridge National Laboratory and Intel in evaluating a 28-node Intel Paragon MP system. An MP node consists of three 50-MHz i860XP`s sharing a common bus to memory and to the mesh communications interface. The performance of the shared-memory MP node is measured and compared with other shared-memory multiprocessors. Bus contention is measured between processors and with message passing. Recent improvements in message passing and I/O are also reported.
Date: June 1, 1995
Creator: Dunigan, T.H.
Partner: UNT Libraries Government Documents Department

Bias in calculated k{sub eff} from subcritical measurements by the {sup 252}Cf-source-driven noise analysis method

Description: The development of MCNP-DSP, which allows direct calculation of the measured time and frequency analysis parameters from subcritical measurements using the {sup 252}Cf-source-driven noise analysis method, permits the validation of calculational methods for criticality safety with in-plant subcritical measurements. In addition, a method of obtaining the bias in the calculations, which is essential to the criticality safety specialist, is illustrated using the results of measurements with 17.771-cm-diam, enriched (93.15), unreflected, and unmoderated uranium metal cylinders. For these uranium metal cylinders the bias obtained using MCNP-DSP and ENDF/B-V cross-section data increased with subcriticality. For a critical experiment [height (h) = 12.629 cm], it was {minus}0.0061 {+-} 0.0003. For a 10.16-cm-high cylinder (k {approx} 0.93), it was 0.0060 {+-} 0.0016, and for a subcritical cylinder (h = 8.13 cm, k {approx} 0.85), the bias was {minus}0.0137 {+-} 0.0037, more than a factor of 2 larger in magnitude. This method allows the nuclear criticality safety specialist to establish the bias in calculational methods for criticality safety from in-plant subcritical measurements by the {sup 252}Cf-source-driven noise analysis method.
Date: July 1, 1995
Creator: Mihalczo, J.T. & Valentine, T.E.
Partner: UNT Libraries Government Documents Department

Bibliography of documents and related materials collected for the Hawaii Geothermal Project Environmental Impact Statement

Description: This report has been prepared to make available and archive information developed during preparation of the Environmental Impact Statement for Phases 3 and 4 of the Hawaii Geothermal Project as defined by the state of Hawaii in its April 1989 proposal to Congress. On May 17, 1994, the USDOE published a notice in the Federal Register withdrawing its Notice of Intent of February 14, 1992, to prepare the HGP EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. This report provides a bibliography of documents, published papers, and other reference materials that were obtained or used. The report provides citations for approximately 642 documents, published papers, and other reference materials that were gathered to describe the potentially affected environment on the islands of Hawaii, Maui, and Oahu. The listing also does not include all the reference materials developed by support subcontractors and cooperating agencies who participated in the project. This listing does not include correspondence or other types of personal communications. The documents listed in this report can be obtained from original sources or libraries.
Date: March 1, 1995
Creator: Glenn, F.M.; Boston, C.R.; Burns, J.C.; Hagan, C.W. Jr.; Saulsbury, J.W. & Wolfe, A.K.
Partner: UNT Libraries Government Documents Department

Biochemical basis of drought tolerance in hybrid Populus grown under field production conditions. CRADA final report

Description: The purpose of this cooperative effort was to assess the use of osmotically active compounds as molecular selection criteria for drought tolerance in Populus in a large-scale field trial. It is known that some plant species, and individuals within a plant species, can tolerate increasing stress associated with reduced moisture availability by accumulating solutes. The biochemical matrix of such metabolites varies among species and among individuals. The ability of Populus clones to tolerate drought has equal value to other fiber producers, i.e., the wood products industry, where irrigation is used in combination with other cultural treatments to obtain high dry weight yields. The research initially involved an assessment of drought stress under field conditions and characterization of changes in osmotic constitution among the seven clones across the six moisture levels. The near-term goal was to provide a mechanistic basis for clonal differences in productivity under various irrigation treatments over time.
Date: April 1, 1997
Creator: Tschaplinski, T.J.; Tuskan, G.A. & Wierman, C.
Partner: UNT Libraries Government Documents Department

Assurances associated with Monte Carlo code results

Description: All Monte Carlo computer codes have an uncertainty associated with the final result. This uncertainty (or standard deviation) is due to the sampling method inherent within the Monte Carlo technique. The basic assumptions required for the final result and uncertainty to be valid are (1) the random numbers used are truly random, (2) there is no correlation between histories, (3) the number of histories used is sufficient to represent the problem, and (4) the entire problem is adequately sampled. The first two assumptions are an integral are strongly dependent on how a problem is set up and the number of histories processed. These are items the user has direct control over. This paper examines six aspects of the KENO Monte Carlo code that affect the above-mentioned four assumptions.
Date: June 1, 1995
Creator: Hollenbach, D.F. & Petrie, L.M.
Partner: UNT Libraries Government Documents Department

Atmospheric CO{sub 2} concentrations -- Mauna Loa Observatory, Hawaii 1958--1986

Description: Since 1958, CO{sub 2} concentrations at Mauna Loa Observatory have been obtained using a nondispersive, dual detector, infrared gas analyzer. Air samples are obtained from air intakes at the top of four 7m towers and one 27m tower. Those involved in the monitoring project have attempted to improving sampling techniques, reduce possible contamination sources, and adjust data to represent uncontaminated, true conditions throughout the twenty-eight year sampling period. The gas analyzer is calibrated by standardized CO{sub 2}-in-nitrogen reference gases twice daily. Flask samples are taken twice a month for comparison to the data recorded using the infrared gas analyzer. Data are scrutinized daily for possible contamination and archived on magnetic tape for further scrutiny and adjustment. Daily, monthly, and annual averages are computed for the Mauna Loa data after deletion of contaminated samples and readjustment of the data. These averages have shown a steady rise in annual average concentration from 316 parts per million by volume (ppmv) in 1959 to 346 ppmv in 1986.
Date: September 1, 1986
Creator: Boden, T.A.
Partner: UNT Libraries Government Documents Department

Atmospheric CO{sub 2} concentrations the CSIRO (Australia) monitoring program from aircraft 1972 - 1981

Description: Atmospheric CO{sub 2} concentrations were measured in the troposphere and lower stratosphere over the Australia-New Zealand region and as far south as Antarctica for the period 1972-1981. The samples were collected from aircraft over a large range of latitudes and altitudes. The sampling program has been based on the cooperation of the Australia Department of Transport, Quantas Airways, Trans Australia Airlines, the United States, New Zealand and Australian Air Forces and occasional chartering of light aircraft for special purposes.
Date: September 1, 1984
Creator: Beardsmore, D.J. & Pearman, G.I.
Partner: UNT Libraries Government Documents Department

Atom probe field ion microscopy of high resistivity materials

Description: Over the last 30 years the atom probe has proved to be a powerful tool for studying nanometer-sized compositional fluctuations in a wide range of metallic alloys but has had only limited applications to semiconductors and ceramics. One of the primary reasons for this difference is the higher resistivity of semiconducting and ceramic specimens. Because of this high resistivity, the high voltage field evaporation pulse is attenuated before it reaches the apex of the specimen thereby making the pulse ineffective for field evaporation. Experiments have demonstrated that both variants of the voltage-pulsed atom probe (i.e., those instruments in which the field evaporation pulse is applied directly to the specimen and those in which the negative pulse is applied to a counter electrode in front of the specimen) are equally affected. In this overview, the limits of applicability of the voltage-pulsed atom probe to high resistivity materials are examined. In this study, a wide range of materials have been examined to determine whether field ion microscopy and voltage-pulsed field evaporation can be achieved and the results are summarized in the report. Field ion microscopy including dc field evaporation was possible for all materials except bulk ceramic insulators and glasses. Field ion microscopy requires some conductivity both to achieve a high electric field at the apex of the specimen, and also to support the field ion current. In contrast, voltage-pulsed field evaporation requires transmission of the pulse to the apex of the specimen. All metallic alloys including high resistance alloys and metallic glasses were successfully field evaporated with a voltage pulse. Specimens that were produced from bulk material of several conducting ceramics including MoSi, TiB and TiC were also successfully field evaporated with a voltage pulse.
Date: February 1, 1998
Creator: Sibrandij, S. J.; Larson, D. J. & Miller, M. K.
Partner: UNT Libraries Government Documents Department

Atom probe field ion microscopy of model Ni-Al-Be superalloys

Description: Nickel-based superalloys used in jet engines consist of a face-centered cubic Ni matrix, gamma, containing a high density of Ll{sub 2} ordered Ni{sub 3}Al precipitates. At high temperatures, the strength of the alloy depends on the strength of the precipitate phase. This paper reports on the strengthening of Ni-Al superalloys containing Be. Beryllium is expected to be a potent strengthener.
Date: April 1, 1997
Creator: Thomson, R.C.; Russell, K.F. & Miller, M.K.
Partner: UNT Libraries Government Documents Department

Atomic and molecular physics and data activities for astrophysics at Oak Ridge National Laboratory

Description: The atomic astrophysics group at ORNL produces, collects, evaluates, and disseminates atomic and molecular data relevant to astrophysics and actively models various astrophysical environments utilizing this information. With the advent of the World Wide Web, these data are also being placed on-line to facilitate their use by end-users. In this brief report, the group`s recent activities in data production and in modeling are highlighted. For example, the authors describe recent calculations of elastic and transport cross sections relevant to ionospheric and heliospheric studies, charge transfer between metal ions and metal atoms and novel supernova nebular spectra modeling, ion-molecule collision data relevant to planetary atmospheres and comets, and data for early universe modeling.
Date: April 1, 1998
Creator: Jeffery, D.J.; Kristic, P.S.; Liu, W.; Schultz, D.R. & Stancil, P.C.
Partner: UNT Libraries Government Documents Department

Bench- and pilot-scale demonstration of thermal desorption for removal of mercury from the Lower East Fork Poplar Creek floodplain soils

Description: Thermal desorption is an innovative technology that has seen significant growth in applications to organically contaminated soils and sludges for the remediation of hazardous, radioactive and mixed waste sites. This paper will present the results of a bench and pilot-scale demonstration of this technology for the removal of mercury from the Lower East Fork Poplar Creek floodplain soil. Results demonstrate that the mercury in this soil can be successfully removed to the target treatment levels of 10 milligrams per kilogram (mg/kg) and that all process residuals could be rendered RCRA-nonhazardous as defined by the Resource Conservation and Recovery Act. Sampling and analyses of the desorber off-gas before and after the air pollution control system demonstrated effective collection of mercury and organic constituents. Pilot-scale testing was also conducted to verify requirements for material handling of soil into and out of the process. This paper will also present a conceptual design and preliminary costs of a full-scale system, including feed preparation, thermal treatment, and residuals handling for the soil.
Date: April 1, 1995
Creator: Morris, M.I.; Sams, R.J.; Gillis, G.; Helsel, R.W.; Alperin, E.S.; Geisler, T.J. et al.
Partner: UNT Libraries Government Documents Department

Benchmark of SCALE (SAS2H) isotopic predictions of depletion analyses for San Onofre PWR MOX fuel

Description: The isotopic composition of mixed-oxide (MOX) fuel, fabricated with both uranium and plutonium, after discharge from reactors is of significant interest to the Fissile Materials Disposition Program. The validation of the SCALE (SAS2H) depletion code for use in the prediction of isotopic compositions of MOX fuel, similar to previous validation studies on uranium-only fueled reactors, has corresponding significance. The EEI-Westinghouse Plutonium Recycle Demonstration Program examined the use of MOX fuel in the San Onofre PWR, Unit 1, during cycles 2 and 3. Isotopic analyses of the MOX spent fuel were conducted on 13 actinides and {sup 148}Nd by either mass or alpha spectrometry. Six fuel pellet samples were taken from four different fuel pins of an irradiated MOX assembly. The measured actinide inventories from those samples has been used to benchmark SAS2H for MOX fuel applications. The average percentage differences in the code results compared with the measurement were {minus}0.9% for {sup 235}U and 5.2% for {sup 239}Pu. The differences for most of the isotopes were significantly larger than in the cases for uranium-only fueled reactors. In general, comparisons of code results with alpha spectrometer data had extreme differences, although the differences in the calculations compared with mass spectrometer analyses were not extremely larger than that of uranium-only fueled reactors. This benchmark study should be useful in estimating uncertainties of inventory, criticality and dose calculations of MOX spent fuel.
Date: February 1, 2000
Creator: Hermann, O.W.
Partner: UNT Libraries Government Documents Department

Benchmark testing of {sup 233}U evaluations

Description: In this paper we investigate the adequacy of available {sup 233}U cross-section data (ENDF/B-VI and JENDL-3) for calculation of critical experiments. An ad hoc revised {sup 233}U evaluation is also tested and appears to give results which are improved relative to those obtained with either ENDF/B-VI or JENDL-3 cross sections. Calculations of k{sub eff} were performed for ten fast benchmarks and six thermal benchmarks using the three cross-section sets. Central reaction-rate-ratio calculations were also performed.
Date: July 1, 1997
Creator: Wright, R.Q. & Leal, L.C.
Partner: UNT Libraries Government Documents Department

Benchmarking a computational fluid dynamics model of separated flow in a thin rectangular channel for use in predictive design analysis

Description: The Advanced Neutron Source (ANS) reactor is being designed to provide a research tool with capabilities beyond those of any existing reactors. One portion of its state-of-the-art design requires high speed fluid flow through narrow channels between the fuel plates in the core. Experience with previous reactors has shown that fuel plate damage can occur when debris becomes lodged at the entrance to these channels. Such debris can disrupt the fluid flow to the plate surfaces and prevent adequate cooling of the fuel. Preliminary ANS designs addressed this issue by providing an unheated entrance length for each fuel plate. In theory, any flow disruption would recover within this unheated length, thus providing adequate heat removal from the downstream heated portions of the fuel plates.
Date: April 1, 1995
Creator: Stovall, T.K.; Crabtree, A. & Felde, D.
Partner: UNT Libraries Government Documents Department

Batch-Equilibrium Hot-Cell Tests of Caustic-Side Solvent Extraction (CSSX) with SRS Simulant Waste and Internal 137Cs Irradiation

Description: The solvent was loaded with {sup 137}Cs and subsamples were stored on a shaker table while in contact with the extract, scrub, or strip aqueous phases. Evidence of solvent degradation was evaluated at exposure times of 0, 20, 54, and 83 days. This resulted in estimated solvent doses ranging up to 1.24 Mrad, equivalent to the dose expected to be received during 16.5 years of operation at the plant proposed for the Savannah River Site. The break times and distribution of cesium of the batch samples remained constant within experimental error; in addition, no third-phase formation was observed. The solvent concentrations of calix[4]arene-bis-(tert-octylbenzo-crown-6) and 1-(2,2,3,3-tetra-fluoroproproxy)-3-(4-sec-butylphenoxy)-2-propanol remained constant within experimental error. Solvent degradation with irradiation was evidenced by a decrease in the trioctylamine (TOA) concentration in the solvent and an increase in the solvent concentration of the degradation product 4-sec-butylphenol. No decline in extraction or scrubbing performance of the irradiated solvents was observed. The stripping performance of the solvent was seriously impaired with irradiation; however, a mild caustic wash and replenishment of the TOA concentration restored the ability to strip the irradiated solvent.
Date: September 17, 2001
Creator: Spence, R. D.
Partner: UNT Libraries Government Documents Department

Batch test equilibration studies examining the removal of Cs, Sr, and Tc from supernatants from ORNL underground storage tanks by selected ion exchangers

Description: Bench-scale batch equilibration tests have been conducted with supernatants from two underground tanks at the Melton Valley Storage Tank (MVST) Facility at Oak Ridge National Laboratory (ORNL) to determine the effectiveness of selected ion exchangers in removing cesium, strontium, and technetium. Seven sorbents were evaluated for cesium removal, nine for strontium removal, and four for technetium removal. The results indicate that granular potassium cobalt hexacyanoferrate was the most effective of the exchangers evaluated for removing cesium from the supernatants. The powdered forms of sodium titanate (NaTiO) and cystalline silicotitanate (CST) were superior in removing the strontium; however, for the sorbents of suitable particle size for column use, titanium monohydrogen phosphate (TiHP {phi}), sodium titanate/polyacrylonitrile (NaTiO-PAN), and titanium monohydrogen phosphate/polyacrylonitrile (TiP-PAN) gave the best results and were about equally effective. Reillex{trademark} 402 was the most effective exchanger in removing the technetium; however, it was only slightly more satisfactory than Reillex{trademark} HPQ.
Date: June 1, 1995
Creator: Collins, J.L.; Egan, B.Z.; Anderson, K.K.; Chase, C.W. & Bell, J.T.
Partner: UNT Libraries Government Documents Department

Bayesian Separation of Lamb Wave Signatures

Description: A persistent problem in the analysis of Lamb wave signatures in experimental data is the fact that several different modes appear simultaneously in the signal. The modes overlap in both the frequency and time domains. Attempts to separate the overlapping Lamb wave signatures by conventional signal processing methods have been unsatisfactory. This paper reports an exciting alternative to conventional methods. Severely overlapping Lamb waves are found to be readily separable by Bayesian parameter estimation. The authors have used linear-chirped Gaussian-windowed sinusoids as models of each Lamb wave mode. The separation algorithm allows each mode to be examined individually.
Date: July 19, 2001
Creator: Kercel, SW
Partner: UNT Libraries Government Documents Department

Prospects and status of low-aspect-ratio tokamaks

Description: The prospects for the low-aspect-ratio (A) tokamak to fulfill the requirements of viable fusion power plants are considered relative to the present status in data and modeling. Desirable physics and design features for an attractive Blanket Test Facility and power reactors are estimated for low-A tokamaks based on calculations improved with the latest data from small pioneering experiments. While these experiments have confirmed some of the recent predictions for low-A, they also identify the remaining issues that require verification before reliable projections can be made for these deuterium-tritium applications. The results show that the low-A regime of small size, modest field, and high current offers a path complementary to the standard and high A tokamaks in developing the full potential of fusion power.
Date: December 1994
Creator: Peng, Y. K. M.
Partner: UNT Libraries Government Documents Department

Cementitious Stabilization of Mixed Wastes with High Salt Loadings

Description: Salt loadings approaching 50 wt % were tolerated in cementitious waste forms that still met leach and strength criteria, addressing a Technology Deficiency of low salt loadings previously identified by the Mixed Waste Focus Area. A statistical design quantified the effect of different stabilizing ingredients and salt loading on performance at lower loadings, allowing selection of the more effective ingredients for studying the higher salt loadings. In general, the final waste form needed to consist of 25 wt % of the dry stabilizing ingredients to meet the criteria used and 25 wt % water to form a workable paste, leaving 50 wt % for waste solids. The salt loading depends on the salt content of the waste solids but could be as high as 50 wt % if all the waste solids are salt.
Date: April 1999
Creator: Spence, R. D.; Burgess, M. W.; Fedorov, V. V. & Downing, D. J.
Partner: UNT Libraries Government Documents Department

CensusPlus: A sampling and prediction approach for the 2000 census of the United States

Description: For a general audience, this paper offers details of a simple proposal for estimation of the population and housing in the year 2000 for the United States. Under CensusPlus, two surveys (mass enumeration and plus sample enumeration) are made of a universe with M blocks. The mass enumeration results in an initial preliminary count for each and every block in the country. The plus sample blocks undergo a second extra high quality count which when compared with the initial count leads to observed resolved counts for the sample blocks. Under a simple model, resolved counts are predicted for the nonsample blocks. Hence an optimal estimator of N, the universe size. is obtained by adding these observed (in sample) and predicted (not in sample) resolved block counts. In fact, this sum turns out to be the classical ratio estimator. This one number census collection is additive and consistent for all levels of geography. In addition, this paper presents sample sizes for the number of blocks required by the plus sample enumeration to support reliable state level estimates of population produced by CensusPlus. In particular and using data from the 1990 Census Files and the 1990 PES Block Data File, it is shown that a nationwide deeply stratified probability sample of 22,120 blocks is needed to ensure that the housing unit population of a given state is estimated with a standard error of 40,000 persons. The 1990 PES Block Data File also provides some early empirical evidence that the model is very likely to hold.
Date: July 1, 1995
Creator: Wright, T.
Partner: UNT Libraries Government Documents Department