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Design and fuel management of PWR cores to optimize the once-through fuel cycle

Description: The once-through fuel cycle has been analyzed to see if there are substantial prospects for improved uranium ore utilization in current light water reactors, with a specific focus on pressurized water reactors. The types of changes which have been examined are: (1) re-optimization of fuel pin diameter and lattice pitch, (2) axial power shaping by enrichment gradation in fresh fuel, (3) use of 6-batch cores with semi-annual refueling, (4) use of 6-batch cores with annual refueling, hence greater extended (approximately doubled) burnup, (5) use of radial reflector assemblies, (6) use of internally heterogeneous cores (simple seed/blanket configurations), (7) use of power/temperature coastdown at the end of life to extend burnup, (8) use of metal or diluted oxide fuel, (9) use of thorium, and (10) use of isotopically separated low sigma/sub a/ cladding material. State-of-the-art LWR computational methods, LEOPARD/PDQ-7/FLARE-G, were used to investigate these modifications.
Date: August 1, 1978
Creator: Fujita, E.K.; Driscoll, M.J. & Lanning, D.D.
Partner: UNT Libraries Government Documents Department

Development of a model to predict flow oscillations in low-flow sodium boiling. [Loss-of-Piping Integrity accidents]

Description: Tests performed in a small scale water loop showed that voiding oscillations, similar to those observed in sodium, were present in water, as well. An analytical model, appropriate for either sodium or water, was developed and used to describe the water flow behavior. The experimental results indicate that water can be successfully employed as a sodium simulant, and further, that the condensation heat transfer coefficient varies significantly during the growth and collapse of vapor slugs during oscillations. It is this variation, combined with the temperature profile of the unheated zone above the heat source, which determines the oscillatory behavior of the system. The analytical program has produced a model which qualitatively does a good job in predicting the flow behavior in the wake experiment. The amplitude discrepancies are attributable to experimental uncertainties and model inadequacies. Several parameters (heat transfer coefficient, unheated zone temperature profile, mixing between hot and cold fluids during oscillations) are set by the user. Criteria for the comparison of water and sodium experiments have been developed.
Date: April 1, 1980
Creator: Levin, A.E. & Griffith, P.
Partner: UNT Libraries Government Documents Department

Advanced wet-dry cooling tower concept cross-flow tests

Description: The design, operation, instrumentation, and performance testing of a crossflow evaporative cooling tower are discussed, and computer predictions for performance are compared with test data. Experimental results for 14 runs agreed with heat and mass transfer coefficient calculations within 5% for 11 runs and within 8% for the remaining 3 runs. It was concluded that the computer model is valid for use in future design studies, that the wet-dry packing is effective in reducing cooling water consumption, and that the crossflow air-water arrangement shows much promise for future development. (LCL)
Date: January 1, 1977
Creator: Snyder, T.; Bentley, J.; Giebler, M.; Glicksman, L.R. & Rohsenow, W.M.
Partner: UNT Libraries Government Documents Department

Two dimensional, two fluid model for sodium boiling in LMFBR fuel assemblies

Description: A two dimensional numerical model for the simulation of sodium boiling transient was developed using the two fluid set of conservation equations. A semiimplicit numerical differencing scheme capable of handling the problems associated with the ill-posedness implied by the complex characteristic roots of the two fluid problems was used, which took advantage of the dumping effect of the exchange terms. Of particular interest in the development of the model was the identification of the numerical problems caused by the strong disparity between the axial and radial dimensions of fuel assemblies. A solution to this problem was found which uses the particular geometry of fuel assemblies to accelerate the convergence of the iterative technique used in the model. Three sodium boiling experiments were simulated with the model, with good agreement between the experimental results and the model predictions.
Date: May 1, 1980
Creator: Granziera, M.R. & Kazimi, M.S.
Partner: UNT Libraries Government Documents Department

Investigation of the physical and numerical foundations of two-fluid representation of sodium boiling with applications to LMFBR experiments

Description: This work involves the development of physical models for the constitutive relations of a two-fluid, three-dimensional sodium boiling code, THERMIT-6S. The code is equipped with a fluid conduction model, a fuel pin model, and a subassembly wall model suitable for stimulating LMFBR transient events. Mathematically rigorous derivations of time-volume averaged conservation equations are used to establish the differential equations of THERMIT-6S. These equations are then discretized in a manner identical to the original THERMIT code. A virtual mass term is incorporated in THERMIT-6S to solve the ill-posed problem. Based on a simplified flow regime, namely cocurrent annular flow, constitutive relations for two-phase flow of sodium are derived. The wall heat transfer coefficient is based on momentum-heat transfer analogy and a logarithmic law for liquid film velocity distribution. A broad literature review is given for two-phase friction factors. It is concluded that entrainment can account for some of the discrepancies in the literature. Mass and energy exchanges are modelled by generalization of the turbulent flux concept. Interfacial drag coefficients are derived for annular flows with entrainment. Code assessment is performed by simulating three experiments for low flow-high power accidents and one experiment for low flow/low power accidents in the LMFBR. While the numerical results for pre-dryout are in good agreement with the data, those for post-dryout reveal the need for improvement of the physical models. The benefits of two-dimensional non-equilibrium representation of sodium boiling are studied.
Date: March 1, 1983
Creator: No, H.C. & Kazimi, M.S.
Partner: UNT Libraries Government Documents Department

Low-Cost Solar Array Project. Task I. Silicon material: investigation of the hydrogenation of SiCl/sub 4/. Seventh quarterly report

Description: Research and development work on the hydrochlorination of SiCl/sub 4/ and m.g. silicon metal to SiHCl/sub 3/ is reported. Activities include a series of experiments to study the life of the Si mass bed. The effect of prolonged reaction on the rate of the hydrochlorination reaction was studied, and a material balance on the reaction was made. A corrosion study was made on Incoloy 800 as the selected material of construction for the hydrochlorination reactor in the Union Carbide EPSDU. (WHK)
Date: January 12, 1981
Creator: Mui, J.Y.P
Partner: UNT Libraries Government Documents Department

Climatic fluctuations, volcanic aerosol and carbon dioxide changes. Annual progress report, 1 October 1979-30 September 1980

Description: Technical progress made for the contract period 1 October 1979-30 September 1980, and in fact since the last progress report was prepared on 18 June 1979, is summarized. The relationship between tropospheric air temperature, sea surface temperature patterns and volcanic aerosol has been derived by the application of generalized least squares analysis, which takes account of significant autocorrelation between the variables. Up to 50% of the variance of the tropical tropospheric air temperature can be explained in terms of preceding values of the variables. The technique is being applied to make a preliminary climatic forecast of the effect of the Mt. St. Helen's eruption of 18 May 1980 on zonal mean Northern Hemisphere temperature. A regression approach was used to forecast winter temperature over the continental US using parameters from our data base. Techniques for experimental climatic forecasting are being developed and studies of the background sea-air interaction processes are being made. We have shown that surface effects extend up to at least 500 mb in the atmosphere. Tropical rainfall has been found to vary with the Southern Oscillation Index; this rainfall provides the main energy supply to the atmosphere in the form of latent heat liberation.
Date: May 21, 1980
Creator: Newell, R.E.
Partner: UNT Libraries Government Documents Department

Method for evaluating the potential of geothermal energy in industrial process heat applications

Description: A method is presented for evaluating the technical and economic potential of geothermal energy for industrial process heat applications. The core of the method is a computer program which can be operated either as a design analysis tool to match energy supplies and demands, or as an economic analysis tool if a particular design for the facility has already been selected. Two examples are given to illustrate the functioning of the model and to demonstrate that results reached by use of the model closely parallel those that have been determined by more traditional techniques. Other features of interest in the model include: (1) use of decision analysis techniques as well as classical methods to deal with questions relating optimization; (2) a tax analysis of current regulations governing percentage depletion for geothermal deposits; and (3) development of simplified correlations for the thermodynamic properties of salt solutions in water.
Date: May 1, 1980
Creator: Packer, M.B.; Mikic, B.B. & Meal, H.C., Guillamon-Duch, H.
Partner: UNT Libraries Government Documents Department

Low temperature and neutron physics studies. Progress report, September 1976--August 1977. [MIT Research Reactor]

Description: Progress on the rebuilding and reinstallation of neutron spectrometers at the reconstructed MIT Research Reactor is reported. Some of these units have been operating on a regular basis since January 1977 and the research program has resumed. Fundamental studies on the operating characteristics of a neutron interferometer system are discussed. Preliminary work on specimen preparation leading to an extended study of the diamagnetic scattering of neutrons by bismuth is reported.
Date: August 1, 1977
Creator: Schull, C.G.
Partner: UNT Libraries Government Documents Department

Effect of virtual mass on the characteristics and the numerical stability in two-phase flows

Description: It is known that the typical six equation two-fluid model of the two-phase flow possesses complex characteristics, exhibits unbounded instabilities in the short-wavelength limit and constitutes an ill-posed initial value problem. Among the suggestions to overcome these difficulties, one model for the virtual mass force terms were studied here, because the virtual mass represents real physical effects to accomplish the dissipation for numerical stability. It was found that the virtual mass has a profound effect upon the mathematical characteristic and numerical stability. Here a quantitative bound on the coefficient of the virtual mass terms was suggested for mathematical hyperbolicity and numerical stability. It was concluded that the finite difference scheme with the virtual mass model is restricted only by the convective stability conditions with the above suggested value.
Date: April 1, 1981
Creator: No, H.C. & Kazimi, M.S.
Partner: UNT Libraries Government Documents Department

Graded index antireflective coatings for glass. Second annual report

Description: M.I.T. is conducting research which will lead to a process for forming broad band antireflective (AR) coatings on glass. Use of these coatings increases the extractable heat from flat-plate solar collectors by 30 to 50% compared with their performance under equivalent solar flux, surface temperature and ambient conditions without broad band AR coatings. Graded index surface films can virtually eliminate reflection losses if controlled properly. Graded index films on a borosilicate glass (Corning Glass Works No. 7740, Pyrex) has been demonstrated. While glass treated this way exhibited adequate optical properties, the glass itself, cannot be fabricated by the float glass process because of excessive working temperatures, and consequently is too expensive for solar applications. The objective of this work is to define glass compositions and processing steps which will result in graded index surface films (which exhibit broad band AR characteristics) on glasses which can be fabricated by the float glass process. The mechanism by which these graded index surface films are produced on glass surfaces consists of preferentially etching one phase from a phase separated glass. The film which remains consists of a porous structure in which the fraction of solid phase increases continuously from the free surface toward the bulk glass. Scattering effects are eliminated by limiting the size of the pore structure to dimensions which are substantially less than the wavelength of light. With this structure, the local index of refraction is proportional to the fraction of solid phase which is present. Characterizations are intended to define the microstructural and chemical nature of the surface film throughout its thickness. Progress is reported. (WHK)
Date: May 1, 1980
Creator: Haggerty, J.S.
Partner: UNT Libraries Government Documents Department

Key contributions in MHD power generation. Quarterly report, 1 June 1979-31 August 1979

Description: Activities during the third quarter of the contract period are reported in detail. The tasks reported on include: (1) investigation of electrical behavior in the vicinity of electrode and insulating walls; (2) studies of critical performance issues in the development of combustion disk generators; (3) development and testing of electrode modules, including studies of insulator properties; and (4) determination of coal combustion kinetics and ash behavior relevant to two-stage MHD combustors, and investigation of the mixing and flow aerodynamics of a high swirl geometry second stage.
Date: November 1, 1979
Creator: Louis, J F
Partner: UNT Libraries Government Documents Department

Low temperature and neutron physics studies. Progress report, May 1979-May 1980

Description: Experimental research work with the neutron diffraction spectrometers at the MIT Research Reactor has concentrated during the past year on (a) dynamical diffraction effects in perfect crystals, (b) exploitation of a neutron interferometer system in studying various fundamental physics problems and (c) studies of the Fresnel diffraction patterns produced by simple slit systems. It has been found that neutrons in the process of being diffracted in an extended crystal travel with an anomalous drift velocity smaller than the normal group velocity. Moreover the transmission of these drift neutrons through the crystal has been established as being anomalously high analogously to the anomalous Borrman transmission of x-rays. A two-crystal interferometer system has been used to search for the existence of a Shimony phase effect that would arise from the presence of additional nonlinear energy terms in the Schrodinger equation. No phase effects were found and an upper limit of 3 x 10-/sup 13/ eV has been set for the magnitude of such terms. The interferometer has also been used to search for a possible coupling of the neutron magnetic structure with a vector magnetic potential and again no phase effect was measurable. Preliminary experiments on the effect of interferometer rotation while the neutrons are in transit have shown that the normal effects caused by terrestrial rotation can be modified or suppressed. Additional research has been carried out at Institut Laue-Langevin (Grenoble) in which single (and multiple) slit Fresnel diffraction patterns are being studied in a search for nonlinear optical effects.
Date: May 1, 1980
Partner: UNT Libraries Government Documents Department

Future development and acceptance of light water reactors in the U. S

Description: The objectives of the project include: (i) analysis of institutional and regulatory issues influencing the development and deployment of nuclear power in the United States, (ii) identification and evaluation of technical initiatives to improve the productivity of nuclear plants, and (iii) economic analysis of the impact of regulatory, institutional, and technical initiatives upon the capacity and generation mix decisions of utilities, consumption of scarce fuels such as oil and gas, electricity demand, and the discounted aggregate cost of energy delivered to consumers. A summary of the analysis and findings is presented.
Date: September 1, 1978
Partner: UNT Libraries Government Documents Department

Thermodynamic properties of pure and saline (geothermal) water

Description: In order to evaluate the performance of proposed processes utilizing geothermal energy, it is essential to determine the thermodynamic properties of fluid streams at various points in the system. The method described ascertains the values of these properties for either pure water or salt solution, correlating temperature, pressure, enthalpy, and entropy in the liquid, two-phase, and vapor regions. The corresponding FORTRAN computer formulation is coded in one subroutine and twenty-six function subprograms, sixteen of which represent correlations of the properties of pure water. The subroutine chooses the appropriate correlations, validates input data, and embodies a large fraction of the salt solution algorithms. Including nonexecutable comment lines, the entire formulation requires less than 910 lines of code. (MHR)
Date: January 1, 1980
Creator: Packer, M.B.; Mikic, B.B.; Meal, H.C. & Guillamon-Duch, H.
Partner: UNT Libraries Government Documents Department

Methodology for assessing alternative water-acquisition-and-use strategies for energy facilities in the American West

Description: A method for assessing alternative strategies for acquiring and using water at western energy plants was developed. The method was tested in a case study of cooling-water use for a hypothetical steam-electric power plant on the Crazy Woman Creek, an unregulated stream in Wyoming. The results from the case study suggest a careful analysis of reservoir design and water-right purchase strategies can reduce the cost of acquiring and using water at an energy facility. The method uses simulation models to assess the capital and operating costs and expected monthly water-consumption rates for different cooling-system designs. The method also uses reservoir operating algorithms to select, for a fixed cooling-system design, the optimal tradeoff between building a make-up water reservoir and purchasing water rights. These tradeoffs can be used to derive the firm's true demand curve for different sources of water. The analysis also reveals the implicit cost of selecting strategies that minimize conflicts with other water users. Results indicate that: (1) cooling ponds are as good as or preferred to wet towers because their costs already include provisions for storing water for use during the normally dry summer months and during occasional drought years; (2) the energy firm's demand for overall water consumption in the cooling system was found to be inversely proportional to both the cost of installing make-up water reservoirs, and the size of the energy facility; and (3) the firm's willingness to pay for existing rights is proportional to both the cost of installing reservoirs, and the size of the energy facility.
Date: December 1, 1981
Creator: Shaw, J.J.; Adams, E.E.; Harleman, D.R.F. & Marks, D.H.
Partner: UNT Libraries Government Documents Department

Recommendations concerning energy information model documentation, public access, and evaluation

Description: A review is presented of the Energy Information Administration (EIA) response to Congressional and management concerns, relating specifically to energy information system documentation, public access to EIA systems, and scientific/peer evaluation. The relevant organizational and policy responses of EIA are discussed. An analysis of the model development process and approaches to, and organization of, model evaluation is presented. Included is a survey of model evaluation studies. A more detailed analysis of the origins of the legislated documentation and public access requirements is presented in Appendix A, and the results of an informal survey of other agency approaches to public access and evaluation is presented in Appendix B. Appendix C provides a survey of non-EIA activities relating to model documentation and evaluation. Twelve recommendations to improve EIA's procedures for energy information system documentation, evaluation activities, and public access are determined. These are discussed in detail. (MCW)
Date: October 1, 1979
Creator: Wood, D.O. & Mason, M.J.
Partner: UNT Libraries Government Documents Department

Low temperature and neutron physics studies. Progress report, August 1, 1972--August 31, 1973

Description: Results are summarized briefly for studies of the diamagnetic scattering of neutrons by Bi, nuclear polarization of /sup 7/Li, the lowtemperature transformation in ZrV/sub 2/, dynamic diffraction in perfect Cu crystals, and neutron flight-time transmission in pyrolytic graphite. These results either are preliminary or have already been published. (7 references) (DLC)
Date: August 31, 1973
Partner: UNT Libraries Government Documents Department

Low temperature and neutron physics studies. Progress report, September 1974--August 1975

Description: Progress on and completion of various studies in solid state and neutron physics through use of neutron spectrometers is outlined. Topics discussed include: (a) characterization of the low temperature magnetization in the Cu(Fe) Kondo alloy, (b) study of the charge-density-wave phase transition in the superconductors NbSe$sub 2$ and TaSe$sub 2$, (c) neutron scattering by nuclearly polarized $sup 7$Li, (d) extraneous scattering effects in the passage of polarized neutrons through high-field magnets, (e) preparation of neutron interferometer systems, and (f) revision of spectrometer facilities. (auth)
Date: August 19, 1975
Partner: UNT Libraries Government Documents Department