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Stress-corrosion cracking studies in coal-liquefaction systems

Description: Coal liquefaction plants with 6000 ton/d capacity are currently being planned by DOE as a step toward commercial production of synthetic fossil fuels. These plants will demonstrate the large-scale viability of the Solvent Refined Coal (SRC) process, which has been used since 1974 in two operating pilot plants: a 50-ton/d unit at Fort Lewis, Washington, and a 6-ton/d plant in Wilsonville, Alabama. Experience in these plants has shown that austenitic stainless steels are susceptible to stress corrosion cracking associated with residual stresses from cold working or welding. The corrodants responsible for the cracking have not yet been positively identified but are suspected to include polythionic acids and chlorides. To screen candidate materials of construction for resistance to stress corrosion cracking, racks of stressed U-bend specimens in welded and as-wrought conditions have been exposed at the Wilsonville and Fort Lewis SRC pilot plants. These studies have identified alloys that are suitable for critical plant applications.
Date: January 1, 1981
Creator: Baylor, V.B. & Keiser, J.R.
Partner: UNT Libraries Government Documents Department

Nuclear Structure References (NSR) file. [Mostly information for input]

Description: The use of the Nuclear Structure References file by the Nuclear Data Project at ORNL is described. Much of the report concerns format information of interest only to those preparing input to the system or otherwise needing detailed knowledge of its internal structure. 17 figures. (RWR)
Date: August 1, 1978
Creator: Ewbank, W.B.
Partner: UNT Libraries Government Documents Department

Chemical thermodynamic representation of <UO/sub 2+-x/>

Description: The entire <UO/sub 2+-x/> data base for the dependence of the nonstoichiometry, x, on temperature and chemical potential of oxygen (oxygen potential) was retrieved from the literature and represented. This data base was interpreted by least-squares analysis using equations derived from the classical thermodynamic theory for the solid solution of a solute in a solvent. For hyperstoichiometric oxide at oxygen potentials more positive than -266700 + 16.5T kJ/mol, the data were best represented by a (UO/sub 2/)-(U/sub 3/O/sub 7/) solution. For O/U ratios above 2 and oxygen potentials below this boundary, a (UO/sub 2/)-(U/sub 2/O/sub 4/./sub 5/) solution represented the data. The <UO/sub 2-x/> data were represented by a (UO/sub 2/)-(U/sub 1///sub 3/) solution. The resulting equations represent the experimental ln(PO/sub 2/) - ln(x) behavior and can be used in thermodynamic calculations to predict phase boundary compositions consistent with the literature. Collectively, the present analysis permits a mathematical representation of the behavior of the total data base.
Date: January 1, 1984
Creator: Lindemer, T.B. & Besmann, T.M.
Partner: UNT Libraries Government Documents Department

Overview of material control and accountability considerations for a waste isolation repository

Description: The material control and accountability needs of a waste isolation repository are examined. Three levels of control are discussed: (1) item identification and control, (2) tamper indication, and (3) quantitative material assay. A summary of waste characteristics is presented and, based on these, plus a consideration of the accessibility of the various types of waste, material control by item identification and accountability (where the individual waste container is the basic unit) is recommended. Tamper indicating procedures are also recommended for the intermediate and low level waste categories. 6 tables.
Date: January 1, 1978
Creator: Blakeman, E.D.; Jenkins, J.D. & Allen, E.J.
Partner: UNT Libraries Government Documents Department

Large break loss of coolant severe accident sequences at the HFIR (High Flux Isotope Reactor)

Description: An assessment of many potential HFIR severe accident phenomena was conducted during the HFIR design effort, and many severe accident mitigating features were designed into the plant. These evaluation typically incorporated a bounding'' or highly conservative analysis approach and employed tools and techniques representative of the state of knowledge in the mid-1960s. Recently, programs to address severe accident issues were initiated at the Oak Ridge National Laboratory (ORNL) to support the HFIR probabilistic risk assessment (PRA) and equipment qualification and accident management studies. This paper presents the results of environment condition calculations conducted to evaluate a response of HFIR's heat exchanger cell environment to a double-ended rupture of a 0.25 m diameter coolant loop downstream of the circulating pump and check valve. The confinement calculations were performed using an atmospheric fission product source for the heat exchanger cell consistent with, but more conservative than that stipulated in Regulatory Guide 1.89. The results of the calculations indicate that the heat exchanger cell atmospheric temperature peaks at 377 K 225 seconds into the transient and then begins decreasing at approximately 1.7 K per minute. 8 refs., 5 figs.
Date: January 1, 1990
Creator: Simpson, D.B. & Greene, S.R.
Partner: UNT Libraries Government Documents Department

Studies of pulsed laser melting and rapid solidification using amorphous silicon

Description: Pulsed-laser melting of ion implantation-amorphized silicon layers, and subsequent solidification were studied. Measurements of the onset of melting of amorphous silicon layers and of the duration of melting, and modified melting model calculations demonstrated that the thermal conductivity, K/sub a/, of amorphous silicon is very low (K/sub a/ approx. = 0.02 W/cm-K). K/sub a/ is also the dominant parameter determining the dynamical response of amorphous silicon to pulsed laser radiation. TEM indicates that bulk (volume) nucleation occurs directly from the highly undercooled liquid silicon that can be prepared by pulsed laser melting of amorphous silicon layers at low laser energy densities. A modified thermal melting model is presented. The model calculations demonstrate that the release of latent heat by bulk nucleation occurring during the melt-in process is essential to obtaining agreement with observed depths of melting. These calculations also show that this release of latent heat accompanying bulk nucleation can result in the existence of buried molten layers of silicon in the interior of the sample after the surface has solidified. The bulk nucleation implies that the liquid-to-amorphous phase transition (produced using picosecond or uv nanosecond laser pulses) cannot be explained using purely thermodynamic considerations.
Date: June 1, 1984
Creator: Lowndes, D.H. & Wood, R.F.
Partner: UNT Libraries Government Documents Department


Description: Progress is reported for the applications of /sup 11/C, /sup 195m/Pt, /sup 75/Se, and /sup 123m/Te. Additional human clinical trials with /sup 11/C-DL-tryptophan and /sup 11/C-l-aminocyclobutane carboxylic acid have been completed. The modified Buecherer-Strecker amino acid synthesis has been used to prepare /sup 11/C-DL-phenylglycine and /sup 11/C-DL-phenylalanine. These two new /sup 11/C-labeled amino acids will be studied as potential tumor localizing agents. Preliminary studies concerning the comparative organ and subcellular distribution of /sup 195m/Pt-labeled cis- and trans- dichlorodiamineplatinum(II) have been completed. The results of in vivo studies have shown the cis isomer to bind to nuclear DNA to a significantly greater extent than the trans isomer. A series of /sup 123m/Te-labeled long-chain fatty acid analogs have been prepared as isosteres of unsaturated fatty acids. Several of these compounds show pronounced heart uptake in rats and may represent a new class of potential myocardial imaging agents. Studies on the preparation and tissue distribution of /sup 75/Se-..beta..-aminoethyl selenosulfate continue.
Date: December 1, 1978
Creator: Knapp, Jr., F. F.
Partner: UNT Libraries Government Documents Department

Seventeenth nuclear accident dosimetry intercomparison study: August 11-15, 1980

Description: The Seventeenth Nuclear Accident Dosimetry Intercomparison Study was conducted August 11-15, 1980, at the Oak Ridge National Laboratory. Nuclear criticality accidents with three different neutron and gamma ray energy spectra were simulated by operating the Health Physics Research Reactor in the pulse mode. Participants from 13 organizations exposed dosimeters set up as area monitors and mounted on phantoms for personnel monitoring. Analysis of experimental results reported by participants showed that less than 60% of the neutron dose measurements using foil activation, thermoluminescent, or sodium activation methods and less than 20% of the gamma dose measurements using thermoluminescent dosimeters met nuclear criticality accident dosimetry guidelines which suggest accuracies of +-25% for neutron dose and +-20% for gamma dose. This indicates that continued development and evaluation of criticality accident dosimetry systems for area and personnel monitoring are required to improve measurement accuracy so that existing standards can be met.
Date: April 1, 1981
Creator: Swaja, R.E. & Greene, R.T.
Partner: UNT Libraries Government Documents Department

Advanced Neutron Source: The designer's perspective

Description: The Advanced Neutron Source (ANS) is a research facility based on a 350 MW beam reactor, to be brought into service at the Oak Ridge National Laboratory at the end of the century. The primary objective is to provide high-flux neutron beams and guides, with cold, thermal, hot, and ultra-cold neutrons, for research in many fields of science. Secondary objectives include isotopes production, materials irradiation and activation analysis. The design of the ANS is strongly influenced by the historical development of research and power reactor concepts, and of the regulatory infrastructure of the Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC). Current trends in reactor safety also impact the climate for the design of such a reactor.
Date: January 1, 1990
Creator: Peretz, F.J.
Partner: UNT Libraries Government Documents Department

Practical application of passive safety features for the advanced neutron source cooling system

Description: This paper presents the results of a conceptual design study leading to the definition of a reference design for the Advanced Neutron Source (ANS) heavy water cooling system. The objective of this study was to define a cooling system that not only met the ANS goals for operating parameters, reliability, availability, and maintainability, but also utilized inherent, passive, and diverse features and characteristics to satisfy the ANS internal events core melt goal of <10{sup {minus}5}/year.
Date: January 1, 1990
Creator: Maxon, B.S.; McNutt, G.R. (Oak Ridge National Lab., TN (USA)) & Miller, R. (Australian Nuclear Science and Technology Organisation, Lucas Heights (Australia))
Partner: UNT Libraries Government Documents Department

Use of phosphite and hypophosphite to fix ruthenium from high-activity wastes in solid media

Description: Fission product Ru, normally volatile to the extent of 20 to 60% in evaporation and calcination of simulated high level radioactive wastes at 500 to 1000/sup 0/C, can be 99.9% retained in the solid product by addition of 2 moles of phosphite or hypophosphite per liter of waste. As little as 0.1 mole per liter lowered the Ru volatility during distillation approaching equilibrium by factors which varied from 38 for Darex to 225 for TBP-25 (aluminum) waste solutions. The final products with Purex, TBP-25, and Darex (stainless steel) wastes were insoluble glassy solids with densities of 2.4 to 3.8 g/ml and represented volume reductions of 2.9 to 8. These volume reductions are essentially the same as those obtained when the waste is calcined without additives.
Date: June 19, 1962
Creator: Godbee, H.W. & Clark, W.E.
Partner: UNT Libraries Government Documents Department

Atomic data for fusion

Description: This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research.
Date: July 1, 1990
Creator: Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A. (eds.) & Barnett, C.F.
Partner: UNT Libraries Government Documents Department

Radiation dosimetry in experimental animals exposed to tritiated water under different conditions. [Comparison between single injection and protracted low-level exposures in mice]

Description: The radiation dose to the germ cells of male mice, which sired the offspring scored in a specific-locus mutation test of injected tritiated water, was calculated. The weighted mean dose for germ cells which received all of the radiation at postspermatogonial stages was 430 rads, while that for germ cells irradiated almost entirely as spermatogonia was 615 rads. Most of the animals received a single intraperitoneal injection of HTO of 0.50 mCi/g body weight, but a few of them received 00.75 mCi/g. These weighted mean doses reflect the contribution of both groups. The percentage of the total dose delivered from /sup 3/H incorporated into macromolecules is small - less than 0.5%. The percentage of the total radioactivity in dry material from the testis on day 1 postinjection is 0.6%, on day 7 it is 3.2%, and on day 605 it is 95%. Tritium is incorporated into testicular DNA from tritiated water, and peak levels of radioactivity in this macromolecule are reached from 3 to 9 days following injection. The stable incorporation of tritium into trichloracetic acid insoluble materials is about 75% in protein and 25% in nucleic acids at all time periods following injection. Doses from single injections of tritiated water are inherently more variable than for protracted low-level exposures. This is because small differences in water balance near the time of injection can make a very large difference in total radiation dose.
Date: January 1, 1978
Creator: Cumming, R.B.; Sega, G.A. & Walton, M.F.
Partner: UNT Libraries Government Documents Department

Growth and transport properties of Y-Ba-Cu-O/Pr-Ba-Cu-O superlattices

Description: The pulsed-laser deposition method has been used to fabricate epitaxial, nonsymmetric M(Y) {times} N(Pr) superlattices in which YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) layers either M = 1,2,3,4,8, or 16 c-axis unit cells thick are separated by insulating PrBa{sub 2}Cu{sub 3}O{sub 7-x} (PBCO) layers N unit cells thick (N = 1 to {approximately}32). The zero-resistance superconducting transition temperature, T{sub c0}, initially decreases rapidly with increasing PBCO layer thickness, but then saturates at T{sub c0} {approximately} 19 K, 54 K, 71 K, or 80 K, or structures containing 1-,2-,3-, or 4-cell-thick YBCO layers, respectively. Critical current density measurements carried out on structures with 16- or 32-cell thick YBCO layers show that the magnitude of J{sub c}(H = 0) {approximately} 1-2 MA/cm{sup 2}, as well as the magnetic field dependence and the anisotropy of J{sub c}(H) all are in good agreement with corresponding measurements on thicker, single-layer YBCO films. Thus, there is no evidence of an enhanced J{sub c}(H) due to the multi-layered structure, for the layer thickness investigated to date. The systematic variation of T{sub c0}, as a function of the YBCO and PBCO layer thickness, is discussed in light of other recent experiments and theoretical model calculations. The superlattices' structural and compositional order are characterized using x-ray diffraction, transmission electron microscopy, and scanning tunneling microscopy, and details of the pulsed-laser deposition process are reported. 42 refs., 7 figs.
Date: January 1, 1990
Creator: Lowndes, D.H.; Norton, D.P.; Budai, J.D.; Christen, D.K.; Klabunde, C.E.; Warmack, R.J. et al.
Partner: UNT Libraries Government Documents Department

Simulation of low-power, low-flow sodium boiling with a transparent, atmospheric pressure water loop

Description: Experiments have been performed in a transparent, single-tube boiling loop, using water as the working fluid, to simulate sodium boiling behavior in a similar geometry. Testing has been performed over a wide range of flows, powers, and temperatures to examine the onset of boiling, flow regimes, oscillatory flow behavior, and dryout. Analysis of experimental data has been aided by the use of high-speed motion pictures. Instrument data from selected tests are presented and discussed, as well as results from computer simulations of the experiments. The computer model is presented, and scaling laws for the comparison of water and sodium oscillatory boiling are discussed. Comparison of the data from this loop with sodium boiling data has shown that an atmospheric pressure, two-phase water system is a good simulant for boiling liquid sodium. 11 refs., 91 figs., 2 tabs.
Date: March 1, 1984
Creator: Levin, A.E.; Montgomery, B.H.; Carbajo, J.J. & Wantland, J.L.
Partner: UNT Libraries Government Documents Department

Radioluminescent (RL) airfield lighting system program

Description: In 1980, the US Air Force Engineering and Services Center (AFESC) at Tyndall Air Force Base, Florida, requested that the Radioisotope Technology Group of Oak Ridge National Laboratory (ORNL) develop large-scale, tritium-powered, radioluminescent (RL) airfield lighting systems. The RL lighting systems possess the advantages of being portable, requiring no electrical power source, having a long shelf life, and being unaffected by environmental extremes. These characteristics make the RL system well-suited for harsh environments where the cost of electrical power production is high and traditional incandescent airfield lighting systems are difficult to maintain. RL lighting is typically a large-surface-area, low-intensity light source that operates 100% of the time. The RL light sources gradually decrease in brightness over time, so periodic replacement (every 6 to 8 years) is necessary. RL lighting functions best in low ambient light, which provides the high contrast ratios necessary for successful use of these devices. 12 figs., 8 tabs.
Date: September 1, 1990
Creator: Tompkins, J.A. (Westinghouse Electric Corp., Las Vegas, NV (USA)); Haff, K.W. & Schultz, F.J. (Oak Ridge National Lab., TN (USA))
Partner: UNT Libraries Government Documents Department

Recent results obtained by use of accelerators on plasma-edge properties in controlled-fusion devices and on properties of high-power neutral beams

Description: The study of plasma-wall interactions is of primary importance in present fusion devices. Measurements of incident fuel and impurity fluxes, retention and release of fuel atoms, and erosion of internal components are of particular interest. Accelerators in the megaelectronvolt range are being used both to measure the depth profile of fuel atoms implanted in samples placed in the plasma edge by use of nuclear reactions and to measure impurities and film thicknesses by use of elastic scattering reactions. Secondary ion mass spectrometry (SIMS) is used to determine flux and energy distributions of fuel atoms and to measure species composition and impurities in the beams of high power neutral beam injectors. Recent results obtained with these techniques are presented and areas of future study are discussed.
Date: January 1, 1982
Creator: Langley, R.A.
Partner: UNT Libraries Government Documents Department

Differential charge state fractions of He following ionization by fast H/sup /minus// projectiles

Description: The differential charge state fractions of He ions produced in ionization by fast H/sup /minus// projectiles have been measured at projectile scattering angles between 0.25 and 1.59 mrad and an impact energy of 1.0 MeV. These charge state fractions have been measured for each of the possible final charge states of the H/sup /minus// projectile (H/sup /minus//, H, and p/sup +/). Combined with earlier measurements of simple ionization (no change in projectile charge state) by protons and of capture and ionization by protons, some systematics cam be noted. The fraction of doubly charged He ions exhibits a distinct peak between 0.9 and 1.1 mrad for simple ionization. A similar peak is seen at approx.0.55 mrad for ionization accompanied by either capture by protons or by single stripping of H/sup /minus//. The data for proton impact suggest that all the peaks are related to double ionization of the target. The double ionization mechanisms will be discussed in terms of their possible contribution to the observed structures. 13 refs., 3 figs.
Date: January 1, 1988
Creator: Giese, J.P. & Horsdal, E.
Partner: UNT Libraries Government Documents Department

Calculational assessment of critical experiments with mixed oxide fuel pin arrays moderated by organic solution

Description: Critical experiments have been conducted with organic-moderated mixed oxide (MOX) fuel pin assemblies at the Pacific Northwest Laboratory (PNL) Critical Mass Laboratory (CML). These experiments are part of a joint exchange program between the United States Department of Energy (USDOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan in the area of criticality data development. The purpose of these experiments is to benchmark computer codes and cross-section libraries and to assess the reactivity difference between systems moderated by water and those moderated by an organic solution. Past studies have indicated that some organic mixtures may be better moderators than water. This topic is of particular importance to the criticality safety of fuel processing plants where fissile material is dissolved in organic solutions during the solvent extraction process. In the past, it has been assumed that the codes and libraries benchmarked with water-moderated experiments were adequate when performing design and licensing studies of organic-moderated systems. Calculations presented in this paper indicated that the SCALE code system and the 27-energy-group cross-section accurately compute k-effectives for organic moderated MOX fuel-pin assemblies. Furthermore, the reactivity of an organic solution with a 32-vol-% TBP/68-vol-% NPH mixture in a heterogeneous configuration is the same, for practical purposes, as water. 5 refs.
Date: January 1, 1987
Creator: Smolen, G.R.
Partner: UNT Libraries Government Documents Department

Application of ion implantation to electrochemical studies

Description: The application of ion implantation to electrochemical studies is illustrated with a study of electrocatalysis of the chlorine evolution reaction at RuO{sub 2}, IrO{sub 2}, TiO{sub 2} mixed oxide anodes in chloride solutions. Electrode/solution interfaces of well defined catalyst composition are generated in a reproducible manner by implantation of Ru (or Ir) into Ti followed by in situ oxidation of the near surface titanium alloys. Ion implantation enables the tailoring on an atomic scale of an electrochemical interface. Analysis by Rutherford backscattering adds the ability of quantitative mechanistic study in terms of actual ion concentration at the interface. In addition, ion implantation, as a processing technique, creates new materials with improved properties which may have future practical use in catalytic materials.
Date: January 1, 1990
Creator: Vallet, C.E. & White, C.W.
Partner: UNT Libraries Government Documents Department

Matrix-assisted laser desorption fourier transform mass spectrometry for biological compounds

Description: The recent development of matrix-assisted UV laser desorption (LD) mass spectrometry has made possible the ionization and detection of extremely large molecules (with molecular weights exceeding 100,000 Daltons). This technique has generated enormous interest in the biological community for the direct examination of large peptides and oligonucleotides. Although this matrix-assisted ionization method has been developed and used almost exclusively with time-of-flight (TOF) mass spectrometers, research is currently in progress to demonstrate this technique with trapped ion mass spectrometers, such as Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The potential capabilities of FTMS for wide mass range, high resolution measurement, and ion trapping experiments suggest that this instrumental technique should be useful for the detailed structural characterization of large ions generated by the matrix-assisted technique. We have recently demonstrated that matrix-assisted ultraviolet laser desorption can be successfully used with FTMS for the ionization of small peptides. The objective of this report is to summarize the application and current limitations of matrix-assisted laser desorption FTMS for the characterization of peptides and oligonucleotides at the isomeric level. 4 refs., 3 figs., 2 tabs.
Date: January 1, 1990
Creator: Hettich, R. & Buchanan, M.
Partner: UNT Libraries Government Documents Department

Relative potency as a means of evaluating ELF (Extremely Low Frequency) health risks

Description: In the 1970's, a variety of developments took place to heightened public and scientific interest in electromagnetic fields. During this time, biological studies of nonionizing electromagnetic fields were taking place, but no clear evidence of risks to public health was identified. Then came the surprising epidemiological finding suggesting that 60 Hz magnetic fields may be related to some childhood leukemias. Our particular interest at ORNL was how to interpret the available data with respect to human exposures to the nearly ubiquitous fields. A review of the available data showed that consistent biological effects were difficult to identify. Classical toxicological tests used in chemical risk assessment had not been performed with Extremely Low Frequency (ELF) fields but rather a wide range of mechanistic studies had been pursued. To evaluate the level of anticipated hazard or risk there was neither a mechanistic understanding nor a consistent phenomenological outcome. A risk evaluation normally requires one or the other of these two types of information. Two quite different approaches were pursued: meta-analysis and relative potency. The first of these is a method to combine data from similar experiments to enhance the relative statistical power of a collection of small sample size studies, and will not be discussed further. The second, relative potency, will be the focus of this paper. 20 refs., 2 figs.
Date: September 1, 1990
Creator: Easterly, C.E. & Glass, L.R.
Partner: UNT Libraries Government Documents Department

Proceedings of the fourth annual conference on fossil energy materials

Description: The Fourth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on may 15--17, 1990. The meeting was sponsored by the US Department of Energy's Office of Fossil Energy through the Advanced Research and Technology Development (AR TD) Materials Program, and ASM International. The objective of the AR TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The work is divided into the following categories: (1) Ceramics, (2) New Alloys, (3) Corrosion and Erosion, and (4) Technology Assessment and Technology Transfer. Individual projects are processed separately for the data bases.
Date: August 1, 1990
Creator: Judkins, R.R. & Braski, D.N. (comps.)
Partner: UNT Libraries Government Documents Department