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Murakami density limit in tokamaks and reversed-field pinches (open access)

Murakami density limit in tokamaks and reversed-field pinches

A theoretical upper limit for the density in an ohmically heated tokamak discharge follows from the requirement that the ohmic heating power deposited in the central current-carrying channel exceed the impurity radiative cooling in this critical region. A compact summary of our results gives this limit n/sub M/ for the central density as n/sub M/ = (Z/sub e//(Z/sub e/-1)/sup 1/2/n/sub eo/ (B/sub T//1T)(1m/R) where n/sub eo/ depends strongly on the impurity species and is remarkably independent of the central electron temperature T/sub e/(0). For T/sub e/(0) approx. 1 keV, we have n/sub eo/ = 1.5 x 10/sup 14/ cm/sup -3/ for beryllium, n/sub eo/ = 5 x 10/sup 13/ cm/sup -3/ for oxygen, n/sub eo/ = 1.0 x 10/sup 13/ cm/sup -3/ for iron, and n/sub eo/ = 0.5 x 10/sup 13/ cm/sup -3/ for tungsten. The results agree quantitatively with Murakami's original observations. A similar density limit, known as the I/N limit, exists for reversed-field pinch devices and this limit has also been evaluated for a variety of impurity species.
Date: March 1, 1984
Creator: Perkins, F.W. & Hulse, R.A.
Object Type: Report
System: The UNT Digital Library
Microscopic and semi-classical treatments of octupole deformation in the light actinides (open access)

Microscopic and semi-classical treatments of octupole deformation in the light actinides

Microscopic and semi-classical descriptions of octupole deformation are compared. New semi-classical results, obtained with the use of a Woods-Saxon potential are presented. Comparisons with experiment are made. 21 references.
Date: January 1, 1984
Creator: Chasman, R.R.
Object Type: Article
System: The UNT Digital Library
Technician support for operation and maintenance of large fusion experiments: the tandem mirror experiment upgrade (TMX-U) approach (open access)

Technician support for operation and maintenance of large fusion experiments: the tandem mirror experiment upgrade (TMX-U) approach

As experiments continue to grow in size and complexity, a few technicians will no longer be able to maintain and operate the complete experiment. Specialization is becoming the norm. Subsystems are becoming very large and complex, requiring a great deal of experience and training for technicians to become qualified maintenance/operation personnel. Formal in-house and off-site programs supplement on-the-job training to fulfill the qualification criteria. This paper presents the Tandem Mirror Experiment-Upgrade (TMX-U) approach to manpower staffing, some problems encountered, possible improvements, and safety considerations for the successful operation of a large experimental facility.
Date: December 1, 1983
Creator: Mattson, G.E.
Object Type: Article
System: The UNT Digital Library
Decontamination of Savannah River Plant H-Area hot-canyon crane (open access)

Decontamination of Savannah River Plant H-Area hot-canyon crane

Decontamination techniques applicable to the remotely operated bridge cranes in canyon buildings at the Savannah River Plant (SRP) were identified and were evaluated in laboratory-scale tests. High pressure Freon blasting was found to be the most attractive process available for this application. Strippable coatings were selected as an alternative technique in selected applications. The ability of high pressure Freon blasting plus two strippable coatings (Quadcoat 100 and Alara 1146) to remove the type of contamination expected on SRP cranes was demonstrated in laboratory-scale tests. Quadrex HPS was given a contract to decontaminate the H-Area hot canyon crane. Decontamination operations were successfully carried out within the specified time-frame window. The radiation level goals specified by SRP were met and decontamination was accomplished with 85% less personnel exposure than estimated by SRP before the job started. This reduction is attributed to the increased efficiency of the new decontamination techniques used. 6 refs., 1 tab.
Date: January 1, 1985
Creator: Rankin, W N & Sims, J R
Object Type: Article
System: The UNT Digital Library
Nuclear power in the Soviet Bloc (open access)

Nuclear power in the Soviet Bloc

The growth of Soviet Bloc nuclear power generation to the end of the century is evaluated on the basis of policy statements of objectives, past and current nuclear power plant construction, and trends in the potential for future construction. Central to this study is a detailed examination of individual reactor construction and site development that provides specific performance data not given elsewhere. A major commitment to nuclear power is abundantly clear and an expansion of ten times in nuclear electric generation is estimated between 1980 and 2000. This rate of growth is likely to have significant impact upon the total energy economy of the Soviet Bloc including lessening demands for use of coal, oil, and gas for electricity generation.
Date: March 1, 1982
Creator: Davey, W.G.
Object Type: Report
System: The UNT Digital Library
SPXCPL: two-dimensional modeling program of self-potential effects from cross-coupled fluid and heat flow (User's Guide and documentation for Version 1. 0) (open access)

SPXCPL: two-dimensional modeling program of self-potential effects from cross-coupled fluid and heat flow (User's Guide and documentation for Version 1. 0)

The program is applicable to the calculation of self-potential effects due to fluid flow (electrokinetic effects) and heat flow (thermoelectric effects). The geological structure is two dimensional but the sources can be either finite line sources or point sources. The accuracy of the calculated potentials depends on the model discretization and the distance from the source(s). For the default mesh, the accuracy is usually a few percent at a distance of about one unit from the source. Surface boundary conditions for the primary problem require careful consideration as the form of the flow near the air-earth interface can have a profound effect on the resultant electric potentials. For temperature problems the appropriate boundary condition is a constant temperature, which is taken as zero. With this boundary condition there is a normal flux of heat at the surface and there will be induced electrical sources here, if the surface medium has a nonzero coupling coefficient. In the models, zero temperature at the surface is produced by giving the air a very large thermal conductivity.
Date: March 1, 1982
Creator: Sill, W. R. & Killpack, T. J.
Object Type: Report
System: The UNT Digital Library
Di-leptons at the Bevalac (open access)

Di-leptons at the Bevalac

Recent results on the production of di-leptons measured by the Di-Lepton-Spectrometer (DLS) collaboration are discussed. Results are reported from observations made on p /plus/ Be collisions with proton beams from 1.0 to 4.9 GeV and on Ca collisions with calcium beams of 1.0 to 2.0 GeV/A. The shape of the distributions are similar to that at higher energies. The low mass cross section appears to be explained by ..pi..-..pi.. annihilation, but detailed calculations are needed to substantiate that hypothesis. (LEN)
Date: March 1, 1988
Creator: Matis, H.S.
Object Type: Article
System: The UNT Digital Library
Analysis of the results of the Midland PRA (open access)

Analysis of the results of the Midland PRA

This paper presents the results of a limited review of the Midland PRA (MPRA), aimed at facilitating regulatory analyses and at providing insights into safety related plant failures. In particular, stress was laid on the root causes of accident sequences, particularly their failure modes, viz., hardware, human, maintenance, test, and repair. Because this information was difficult to extract in this detailed and sophisticated PRA (and in certain others) a special algorithm was developed to display the leading sequences contributing to core damage and/or to public risk in terms of the above generic failure modes. This was done in a hierarchical fashion to allow tracing the important accident sequences to the systems failures. The weighted core damage frequency (CDF) values of the sequences considered then provided a (quantitative) ranked importance listing of these failure modes, led by hardware failures (in 78%) and human factors (in 37%), etc. Multiple maintenance situations (reflecting on test and maintenance specifications) were also evaluated, but played only a small role (less than or equal to3%). Similar tabulations were also made of the (weighted) importance of the support systems (such as the electric power system, the component cooling water systems, etc.) and of the role of the …
Date: January 1, 1986
Creator: Bozoki, G. & Teichmann, T.
Object Type: Article
System: The UNT Digital Library
Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements (open access)

Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements

A computer controlled, scanning monochromator system specifically designed for the rapid, sequential determination of the elements is described. The monochromator is combined with an inductively coupled plasma excitation source so that elements at major, minor, trace, and ultratrace levels may be determined, in sequence, without changing experimental parameters other than the spectral line observed. A number of distinctive features not found in previously described versions are incorporated into the system here described. Performance characteristics of the entire system and several analytical applications are discussed.
Date: March 1, 1980
Creator: Floyd, M. A.
Object Type: Report
System: The UNT Digital Library
Relation between finite element methods and nodal methods in transport theory (open access)

Relation between finite element methods and nodal methods in transport theory

This paper examines the relationship between nodal methods and finite-element methods for solving the discrete-ordinates form of the transport equation in x-y geometry. Specifically, we will examine the relation of three finite-element schemes to the linear-linear (LL) and linear-nodal (LN) nodal schemes. The three finite-element schemes are the linear-continuous-diamond-difference (DD) scheme, the linear-discontinuous (LD) scheme, and the quadratic-discontinuous (QD) scheme. A brief derivation of the (LL) and (LN) nodal schemes is given in the third section of this paper. The approximations that cause the LL scheme to reduce to the DD, LD, and QD schemes are then indicated. An extremely simple method of deriving the finite-element schemes is then introduced.
Date: January 1, 1985
Creator: Walters, W. F.
Object Type: Article
System: The UNT Digital Library
Kaon-nucleus interactions (open access)

Kaon-nucleus interactions

The recent progress in hypernuclear physics, in particular the studies of ..lambda.. and ..sigma.. states via the strangeness-exchange (K/sup -/,..pi../sup -/) reaction, are reviewed. Prospects for future investigations with (proposed) intense kaon beams are also evaluated, for instance the production of high spin hypernuclei via the (..pi../sup +/,K/sup +/) reaction, and the formation of strangeness S = -2 hypernuclei (..lambda lambda.. or Xi/sup -/) by means of the (K/sup -/,K/sup +/) process. A very brief resume of elastic, inelastic and charge exchange reactions induced by the interaction of K/sup +/ mesons with nuclei is given.
Date: January 1, 1980
Creator: Dover, C B
Object Type: Article
System: The UNT Digital Library
Second Nuclear Era (open access)

Second Nuclear Era

The Institute for Energy Analysis with support from The Andrew W. Mellon Foundation has studied the decline of the present nuclear era in the United States and the characteristics of a Second Nuclear Era which might be instrumental in restoring nuclear power to an appropriate place in the energy options of our country. The study has determined that reactors operating today are much safer than they were at the time of the TMI accident. A number of concepts for a supersafe reactor were reviewed and at least two were found that show considerable promise, the PIUS, a Swedish pressurized water design, and a gas-cooled modular design of German and US origin. Although new, safer, incrementally improved, conventional reactors are under study by the nuclear industry, the complete lack of new orders in the United States will slow their introduction and they are likely to be more expensive than present designs. The study recommends that supersafe reactors be taken seriously and that federal and private funds both be used to design and, if feasible, to build a prototype reactor of substantial size. 146 references, 8 figures, 2 tables.
Date: March 1, 1984
Creator: Weinberg, Alvin M.; Spiewak, Irving; Barkenbus, Jack N.; Livingston, Robert S. & Phung, Doan L.
Object Type: Report
System: The UNT Digital Library
Use of principal components analysis and three-dimensional atmospheric-transport models for reactor-consequence evaluation (open access)

Use of principal components analysis and three-dimensional atmospheric-transport models for reactor-consequence evaluation

This work explores the use of principal components analysis coupled to three-dimensional atmospheric transport and dispersion models for evaluating the environmental consequences of reactor accidents. This permits the inclusion of meteorological data from multiple sites and the effects of topography in the consequence evaluation; features not normally included in such analyses. The technique identifies prevailing regional wind patterns and their frequencies for use in the transport and dispersion calculations. Analysis of a hypothetical accident scenario involving a release of radioactivity from a reactor situated in a river valley indicated the technique is quite useful whenever recurring wind patterns exist, as is often the case in complex terrain situations. Considerable differences were revealed in a comparison with results obtained from a more conventional Gaussian plume model using only the reactor site meteorology and no topographic effects.
Date: January 1, 1982
Creator: Gudiksen, P. H.; Walton, J. J.; Alpert, D. J. & Johnson, J. D.
Object Type: Article
System: The UNT Digital Library
Fueling of tandem mirror reactors (open access)

Fueling of tandem mirror reactors

This paper summarizes the fueling requirements for experimental and demonstration tandem mirror reactors (TMRs), reviews the status of conventional pellet injectors, and identifies some candidate accelerators that may be needed for fueling tandem mirror reactors. Characteristics and limitations of three types of accelerators are described; neutral beam injectors, electromagnetic rail guns, and laser beam drivers. Based on these characteristics and limitations, a computer module was developed for the Tandem Mirror Reactor Systems Code (TMRSC) to select the pellet injector/accelerator combination which most nearly satisfies the fueling requirements for a given machine design.
Date: January 1, 1985
Creator: Gorker, G. E. & Logan, B. G.
Object Type: Article
System: The UNT Digital Library
Development of a mathematical model of a packed column for benzene removal from salt solutions (open access)

Development of a mathematical model of a packed column for benzene removal from salt solutions

A mathematical model of a packed column was developed to describe the removal of benzene from radioactive salt solutions at the Savannah River Site. The model was developed from existing, generalized mass transfer correlations for randomly dumped packing, and the correlations were adapted for structured packing. Thermophysical data specific to the solutions of interest were incorporated into the model. Verification of the code was completed using operating data from stripping columns at other locations.
Date: January 1, 1989
Creator: Georgeton, G.K.
Object Type: Article
System: The UNT Digital Library
Testing program for determining the mechanical properties of concrete to temperatures of 621/sup 0/C (open access)

Testing program for determining the mechanical properties of concrete to temperatures of 621/sup 0/C

Concrete temperatures in a Liquid Metal Fast Breeder Reactor (LMFBR) in excess of normal code limits can result from postulated large sodium spills in equipment cells. Elevated temperature concrete property data which may have application for providing a basis for the design and evaluation of such postulated accident conditions is limited. Data thus needed to be developed commensurate with LMFBR plant applications for critical physical and mechanical concrete properties under prototypic thermal accident conditions. A test program was conducted to define the variations in physical and mechanical properties of a limestone aggregate concrete and a lightweight insulating concrete exposed to elevated temperatures. Five test series were conducted: unconfined compression, shear, rebar bond, sustained loading (creep), and thermal properties. Testing procedures for determining the mechanical properties of concrete from ambient to 621/sup 0/C (1150/sup 0/F) are described. Ther thermal properties tests are discussed in a separate paper which is also being presented at this conference.
Date: January 1, 1980
Creator: Oland, C.B.; Naus, D.J. & Robinson, G.C.
Object Type: Article
System: The UNT Digital Library
Survey of helium in soil gases of Long Valley, Califorina (open access)

Survey of helium in soil gases of Long Valley, Califorina

Soil and water samples in and around the Long Valley geothermal area, Mono County, California, were collected and analyzed for helium by means of a modified mass spectrometer leak detector to see what relationship helium concentrations might have to geothermal features of the area, and to previously studied mercury anomalies in the area. Anomalously high concentrations of helium occurred over part of a major Sierra Nevada frontal fault and over other faults outside of the caldera. Anomalously low concentrations of helium occurred in several areas of high mercury concentrations, which were also areas of hydrothermal alteration. Quantities of helium exsolved from water samples did not fit any pattern.
Date: January 1, 1980
Creator: Hinkle, M. E. & Kilburn, J. E.
Object Type: Report
System: The UNT Digital Library
Boundary element formulation for planar time-dependent inelastic deformation of plates with cutouts (open access)

Boundary element formulation for planar time-dependent inelastic deformation of plates with cutouts

A boundary element formulation for planar, time-dependent, inelastic deformation problems for bodies with cutouts is presented in this paper. A stress function description for these nonlinear problems leads to a nonhomogeneous biharmonic equation for the stress function rate. An integral representation of the solution uses modified kernels which guarantee that the cutout boundary is traction free for all time. This incorporation of the effect of the cutout on the stress field into the kernels leads to an accurate determination of stresses in the near field of the cutout. Illustrative analytical examples for circular plates with circular cutouts are presented in this paper. In a companion paper, numerical solutions are presented for problems of finite plates with very narrow elliptic cutouts. These problems are of considerable importance in inelastic fracture.
Date: February 1, 1980
Creator: Mukherjee, S. & Morjaria, M.
Object Type: Report
System: The UNT Digital Library
Neutron environment in d + Li facilities (open access)

Neutron environment in d + Li facilities

A microscopic d + Li neutron yield model has been developed based upon classical models and experimental data. Using equations suggested by the Serber and evaporation models, a generalized least squares adjustment procedure generated angular yields for E/sub d/ to 40 MeV using the available experimental data. The HEDL-UCD experiment at E/sub d/ = 35 was used to adjust parameters describing the neutron spectra. The model is used to predict yields, spectra, and damage responses in the FMIT Test Cell.
Date: January 1, 1980
Creator: Mann, F. M.; Schmittroth, F. & Carter, L. L.
Object Type: Article
System: The UNT Digital Library
Comprehensive energy-management program. Hybrid photovoltaic/thermal absorber. Annual report, September 1, 1980-December 31, 1981 (open access)

Comprehensive energy-management program. Hybrid photovoltaic/thermal absorber. Annual report, September 1, 1980-December 31, 1981

Research work was done during the reporting period on the two-part research program: (A) to improve energy conservation through increased unit and system efficiencies, energy management, and system optimization, and (B) to develop a novel, low-cost hybrid photovoltaic/thermal absorber. Performance tests were conducted on all the boilers and chillers on campus. Several corrective measures were indicated and implemented. A detailed survey of energy use by functions and consumption/demand study has been in progress. A preliminary computer simulation model of the entire campus has been developed and made operational. It has been demonstrated both analytically and experimentally that the reradiation losses from the absorber can be reduced significantly by utilizing a light-pipe absorber. Two paraboloidal dishes, one of 6 ft diameter and the other of 20 ft diameter have been utilized. Collector efficiencies have been measured at coolant outlet temperatures up to 282/sup 0/C with a square light-pipe absorber and with 6 ft diameter concentrator. Laser ray testing was conducted on both the 6 ft and 20 ft diameter concentrators. Design of the total energy absorber has been completed.
Date: December 1, 1981
Creator: Kumar, G. N.; Sellers, J. P. & Dybczak, Z. W.
Object Type: Report
System: The UNT Digital Library
Establishment of viscometer capability for geopressured fluids. Project 61024 final report, November 19, 1978-December 31, 1979 (open access)

Establishment of viscometer capability for geopressured fluids. Project 61024 final report, November 19, 1978-December 31, 1979

The feasibility of modifying the IGT capillary viscometer for the measurement of methane-saturated brines at 10,000 psi and 200/sup 0/C was evaluated. The viscometer was cleaned, modified, reassembled and pressure treated. The density cells were calibrated to a precision of approximately 7%. The viscosity of pure value was measured and the best value obtained was 6% below values reported in the literature. The operation of the viscometer was time-consuming and required meticulous cleaning between experiments. Some corrosion at the mercury surface interfered with the efficient operation of the timing device. Other problems were encountered due to gas bubbles trapped in the capillary flow path. Consequently, data on methane-saturated brine could not be obtained within the funding limitations of this program. It is concluded that further work on the existing viscometer would not be cost-effective.
Date: October 1, 1980
Creator: Rockar, E. & Randolph, P.
Object Type: Report
System: The UNT Digital Library
Organic components of nuclear wastes and their potential for altering radionuclide distribution when released to soil (open access)

Organic components of nuclear wastes and their potential for altering radionuclide distribution when released to soil

Normal waste processing at the Hanford operations requires the use of many organic materials, chiefly in the form of complexing agents and diluents. These organic materials and their chemical and radiolytic degradation products, have potential for complexing fission products and transuranium elements, both in the waste streams and upon infiltration into soil, perhaps influencing future sorption or migration of the nuclides. Particular complexation characteristics of various nuclides which constitute the major fission products, long-lived isotopes, and the most mobile in radioactive wastes are discussed briefly with regards to their anticipated sorption or mobility in soils. Included in the discussion are Am, Sb, Ce, Cs, Co, Cm, Eu, I, Np, Pm, Pu, Ra, Ru, Sr, Tc, U, and Zr. 107 references.
Date: August 1, 1980
Creator: McFadden, K.M.
Object Type: Report
System: The UNT Digital Library
Characterization of solids in the Three Mile Island Unit 2 Reactor defueling water: Addendum (open access)

Characterization of solids in the Three Mile Island Unit 2 Reactor defueling water: Addendum

Shortly after ORNL/TM-10362 was issued, it was discovered that a series of 31 figures had been inadvertently omitted. These figures, which consist of scanning electron microscope (SEM) photographs and energy-dispersive X-ray fluorescence scans, provide significant information about the results obtained in the tests performed with water sample W3. This Addendum includes these figures. Details of and comments on the SEM photographs may be found in ORNL/TM-10362.
Date: March 1, 1988
Creator: Campbell, D.O.
Object Type: Report
System: The UNT Digital Library
Development and process evaluation of improved Fischer-Tropsch slurry catalysts (open access)

Development and process evaluation of improved Fischer-Tropsch slurry catalysts

The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.
Date: January 1, 1987
Creator: Withers, H.P. (Air Products and Chemicals, Inc., Allentown, PA (United States)); Bukur, D.B. & Rosynek, M.P. (Texas A and M Univ., College Station, TX (United States))
Object Type: Report
System: The UNT Digital Library