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Kinetics for the reaction of hydrogen with uranium powder

Description: The reaction of hydrogen with uranium powder was investigated at 13.3 and 26.6 kPa between 50 and 250/sup 0/C. The reaction order was independent of temperature but varied from 2/3-order at 13.3 kPa to 1st-order at 26.6 kPa. Increasing temperatures resulted in decreasing reaction rates over the temperature range studied. A reaction mechanism with adsorption as the rate controlling step is proposed to explain the temperature behavior. Decomposition of the hydride was found to follow a zero-order rate process.
Date: January 1, 1979
Creator: Stakebake, J.L.
Partner: UNT Libraries Government Documents Department

Heat transfer and pressure drop in gas-cooled fluidized-bed combustors for gas turbine systems: analysis and application to design

Description: Information is presented concerning the effects of design parameters for fluidized bed air heaters for gas turbines on the cost-related characteristics of the inbed heat exchanger. An analysis of the pressure drop/heat transfer relations is described and the results and implications for design are presented. According to these results, the cost of the heater for a pressurized, closed-cycle turbine system is likely to exceed that of an open-cycle system in which the compressor discharge pressure is lower. Higher air pressure and higher allowable pressure drop are shown to be effective in lowering the operating temperature of the heat exchanger tubes.
Date: January 1, 1979
Creator: Graves, R L
Partner: UNT Libraries Government Documents Department

Modulated molecular beam mass spectrometric studies of the high temperature pyrolysis of hydrocarbons

Description: The pyrolysis products of benzene and toluene were studied as functions of temperature (up to 2000/sup 0/C) and pressure. Above 1400/sup 0/C, most of the larger species are unstable; above 1700/sup 0/C, no species heavier than C/sub 6/H/sub 6/ are observed at any pressure. Above 1500/sup 0/C and at higher pressures, the products are dominated by species containing even numbers of carbon atoms (C/sub 2/ to C/sub 12/). While polyacetylenes up to C/sub 8/H/sub 2/ were observed, they are present in low abundances, with the max concentrations occurring at 1350/sup 0/C. Polycyclic aromatic hydrocarbons are formed readily. 6 figures. (DLC)
Date: July 1, 1979
Creator: Smith, R.D.
Partner: UNT Libraries Government Documents Department

Acoustic emission monitoring of steel and concrete structural elements with particular reference to primary nuclear containment structures

Description: Primary containments for nuclear reactors are either thick-walled steel pressure vessels (pressurized water reactors) or massive prestressed concrete structures (gas-cooled reactors). The ability to detect and analyze flaws in these structures is important for ensuring structural integrity throughout their 30 to 40 year design life. Relatively recent advancements in nondestructive testing utilizing acoustic emission (AE) have made it a potentially viable technique for in-service monitoring of the structural integrity of primary containment structures. To provide background for an assessment of the capability of AE to monitor the structural integrity of primary nuclear containments, intermediate pressure vessels tested under the Heavy-Section Steel Technology (HSST) Program and relatively simple concrete structures have been monitored by AE while under test. The results of this monitoring program are discussed.
Date: January 1, 1979
Creator: Naus, D.J.
Partner: UNT Libraries Government Documents Department

Behavior of deep flaws in a thick-wall cylinder under thermal shock loading

Description: Behavior of inner-surface flaws in thick-walled vessels was studied in a 991-mm OD x 152 mm wall x 1220 mm length cylinder with toughness properties similar to those for HSST Plate. The initial temperature of 93/sup 0/C and a thermal shock medium of liquid nitrogen (-197/sup 0/C) were employed. The initial flaw selected was a sharp, 16 mm deep, long (1220 mm) axial crack. Crack arrest methodology was shown to be valid for deep flaws under severe thermal shock. (FS)
Date: January 1, 1979
Creator: Cheverton, R.D.
Partner: UNT Libraries Government Documents Department

PCRV design verifiction and support at Oak Ridge National Laboratory

Description: For more than a decade, a comprehensive program of analytical and experimental studies of prestressed concrete reactor vessels (PCRVs) and related technology has been conducted at Oak Ridge National Laboratory (ORNL) under the auspices of the Department of Energy and its predecessors. The program has been directed primarily toward gas-cooled reactors since they are the only reactor concepts utilizing PCRVs. The goals of the program are to provide technical support for ongoing PCRV design activities, contribute to the technological data base, and provide independent review and evaluation of the relevant technology. The tasks selected for implementation are identified through direct communication with the PCRV designers, through participation in ACI-ASME design code activities and based on the findings of literature reviews and communications with researchers in other countries. Current areas of study encompass analysis methods, materials properties, instrumentation, and structural models. Although the major portion of the overall effort is supported by the HTGR Base Technology Program, the task areas are generic in nature and are therefore relevant to the GCFR as well.
Date: January 1, 1979
Creator: Callahan, J.P.
Partner: UNT Libraries Government Documents Department

Test of thick vessel with a flaw in residual stress field

Description: Intermediate test vessel V-8, a 152-mm-thick vessel fabricated of SA533, grade B, class 1 steel, was pressurized to failure at -23/sup 0/C. The vessel contained a fatigue-sharpened notch adjacent to a half-bead weld repair that had not been stress relieved. Residual stresses and fracture toughnesses were determined before the pressure test by measurements on a prototypical weld, and fracture predictions were made by linear elastic fracture analysis. Predictions agreed well with test results, demonstrating the important influence of high residual stresses on fracture behavior.
Date: January 1, 1979
Creator: Bryan, R.H.; Iskander, S.K.; Holz, P.P.; Merkle, J.G. & Whitman, G.D.
Partner: UNT Libraries Government Documents Department

Fractographic study of a thick wall pressure vessel failure

Description: The pressure vessel described in this paper is identified as Intermediate Test Vessel 1 (ITV-1) and was fabricated of SA508, Class 2 Steel. It was tested to failure at 54/sup 0/C (130/sup 0/F). The gross failure appeared to be a brittle fracture although accompanied by a measured strain of 0.9%. Seven regions of the fracture were examined in detail and the observed surfaces were compared to Charpy V-notch (C/sub v/) specimens of SA508, Class 2 steel broken at temperatures above and below the ductile to brittle transition temperature. Three samples from the vessel were taken in the region around the fatigue notch and four from areas well removed from the notch. All these were carefully examined both optically and by scanning electron microscopy (SEM). It was established that early crack extension was by ductile mode until a large flaw approximately 500 mm long 83 mm wide was developed. At this point the vessel could no longer contain the internal pressure and final rupture was by brittle fracture.
Date: January 1, 1979
Creator: Canonico, D.A.; Crouse, R.S. & Henson, T.J.
Partner: UNT Libraries Government Documents Department

FUETAP (formed under elevated temperatures and pressures) concretes as hosts for radioactive wastes

Description: Cementitious solids formed at less than or equal to 250/sup 0/C and less than or equal to 1000 psi offer excellent possibilities as hosts for radioactive wastes. Preliminary results are presented on the effect of mix composition, temperatre, and pressure on the physical properties of the resulting solids. Initial leach results are encouraging in the assessment of the ability of these FUETAP concretes to isolate radionuclides from the environment.
Date: January 1, 1979
Creator: Moore, J.G.; Rogers, G.C.; Paehler, J.H. & Devaney, H.E.
Partner: UNT Libraries Government Documents Department

Effect of heat treatment on fracture of Type 304L stainless steel in a hydrogen environment

Description: Thermal treatments have a significant effect on the mechanical behavior of Type 304L stainless steel tested in a high-pressure (69 MPa) hydrogen environment. A grain size increase from 10 to 350 ..mu..m increased susceptibility to hydrogen damage and accentuated changes in fracture morphology. The Hall-Petch relation for yield strength was the same for tests in both hydrogen and helium environments. Sensitization increased ductility loss in hydrogen but did not change the fracture mode of smooth bar tensile specimens. Variation in quench rate from 0.25 to 50/sup 0/K/sec had only a minor influence on susceptibility to hydrogen embrittlement. The absence of an abrupt load drop at fracture and change in fracture morphology for tests in high-pressure hydrogen indicate that fracture initiated at or near the surface and rapidly propagated inward.
Date: January 1, 1979
Creator: Caskey, G.R. Jr. & Donovan, J.A.
Partner: UNT Libraries Government Documents Department

Response of a double tube sheet structure to hydraulic pressure transients

Description: A general procedure was developed to analyze complex tube-sheet structures under dynamic loading conditions. The top shield of a Savannah River Plant production reactor is a stainless steel box structure perforated by tubular conduits. It supports the hanging fuel assemblies and the weight of the reactor superstructure. During normal reactor operation the top shield and the fuel assemblies are submerged in water coolant. For a postualted transient induced by a loss-of-coolant, a loading profile was constructed that considered (1) reduction of bouyancy, (2) rapid pressure changes due to generation and condensation of steam, and (3) vacuum force on one side following condensation. Dynamic responses to such a loading are analytically represented by linear combinations of natural modes that satisfy a fourth-order equation of motion. Localized stress magnification in the tube-sheets of the structure is determined according to the theory of perforated plates.
Date: January 1, 1979
Creator: Yau, W.F. & Harris, S.D.
Partner: UNT Libraries Government Documents Department

Notch and hydrogen effects on sensitized 21-6-9 stainless steel

Description: Type 21-6-9 stainless steel alloy is slightly notch sensitive in the solution annealed condition, a behavior that is aggravated by sensitization anneal at 920/sup 0/K. The lower toughness of the sensitized alloy is a measure of microstructural embrittlement associated with carbide precipitation in grain boundaries. The tendency toward grain boundary fracture in the sensitized alloy is accentuated by stress concentration at the notch. Also, there is an increase in notch sensitivity when the alloy is tested in a high pressure (69 MPa) hydrogen environment, due to susceptibility of the grain boundaries to hydrogen embrittlement.
Date: January 1, 1979
Creator: Caskey, C.R. Jr.
Partner: UNT Libraries Government Documents Department

WRAP-PWR-EM system development and applications

Description: The WRAP-EM system is a complete computational system for analysis of loss-of-coolant accidents (LOCAs) in light-water power reactors. The system has been developed for use by the Nuclear Regulatory Commission in evaluating and interpreting reactor vendor model methods and results. WRAP-PWR-EM is the integrated system of codes used for the analysis of pressurized water reactors (PWRs) GAPCON-THERMAL-2 is used to initialize fuel parameters as a function of reactor operating time. Both the blowdown and reflood phases of an accident are analyzed by RELAP4/MOD5. The refill calculation is based on a simple accumulator flow model (FLOW4) developed at NRC, and the hot-pin analysis is performed by FRAP-T4-LACE. The automated transfer of relevant data from one code to another is accomplished through interface routines developed at SRL (except RELAP4/MOD5-FLOOD to FRAP).
Date: January 1, 1979
Creator: Beranek, F.
Partner: UNT Libraries Government Documents Department

On the spurious pressures generated by certain GFEM solutions of the incompressible Navier-Stokes equations

Description: The spurious pressures and acceptable velocities generated when using certain combinations of velocity and pressure approximations in a Galerkin finite element discretization of the primitive variable form of the incompressible Navier-Stokes equations are analyzed both theoretically and numerically for grids composed of quadrilateral finite elements. Schemes for obtaining usable pressure fields from the spurious numerical results are presented for certain cases.
Date: October 15, 1979
Creator: Sani, R.L.; Gresho, P.M. & Lee, R.L.
Partner: UNT Libraries Government Documents Department

Permeability of generic repository rocks at simulated in situ conditions. [Comparison of Westerly granite and White Lake genissic granite]

Description: New laboratory data are reported on the effect of confining (lithostatic) pressure, pore-water pressure, and principal stress difference on permeability of Westerly granite and White Lake gneissic granite. Permeabilities as low as 10/sup -19/ cm/sup 2/ (10/sup -11/ D) have been measured successfully, using a transient technique. Principal strains, electrical conductivity, and compressional velocity are determined simultaneously. Applied loads on the 15-cm diameter by 28-cm long test sample are controlled automatically and all data are taken by a microcomputer. Results on the gneissic granite indicate permeabilities of 10/sup -18/ to 10/sup -19/ cm/sup 2/ that appear to be unaffected either by effective pressure or by stress. The granite yields permeabilities of 4x10/sup -16/ cm/sup 2/ that decrease by a factor of two with pressure and vary by a factor of two with stress. When compared to the initial value, compressional velocities increase by 4% and conductivity decreases by 50% as pressure is increased to 50 MPa in the gneissic granite. In granite, these become 3% and 58%, respectively. At pressure, loading of the granite of 0.5 of failure stress increases conductivity by about 20%.
Date: April 23, 1979
Creator: Heard, H.C.; Trimmer, D.; Duba, A. & Bonner, B.
Partner: UNT Libraries Government Documents Department

Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop. [LMFBR]

Description: A comparison is made between computed results and experimental data for single-phase natural convection in an experimental sodium loop. The tests were conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) Facility, an engineering-scale high temperature sodium facility at the Oak Ridge National Laboratory used for thermal-hydraulic testing of simulated LMFBR subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during these tests was typical of decay heat levels. Tests were conducted both with zero initial forced flow and with a small initial forced flow. The bypass line was closed in most tests, but open in one. The computer code used to analyze these tests (LONAC (LOw flow and NAtural Convection)) is an ORNL-developed, fast running, one-dimensional, single-phase finite difference model for simulating forced and free convection transients in the THORS loop.
Date: January 1, 1979
Creator: Ribando, R J
Partner: UNT Libraries Government Documents Department

Results of the PBF/LOFT Lead Rod Test Series

Description: The PBF/LOFT Lead Rod (PBF/LLR) Test Series consisted of four sequential, nuclear blowdown experiments (Test LLR-3, LLR-5, LLR-4, and LLR-4A). The primary objective of the test series was to evaluate the extent of mechanical deformation that would be expected to occur to low pressure (0.1 MPa) light water reactor design fuel rods subjected to a series of nuclear blowdown tests, and to determine if subjecting deformed fuel rods to subsequent testing would result in rod failure. The extent of mechanical deformation (buckling, collapse, or waisting of the cladding) was evaluated by comparison of cladding temperatue versus system pressure response with out-of-pile experimental data and by posttest visual examinations and cladding diametral measurements.
Date: January 1, 1979
Creator: Varacalle, Jr, D J; Garner, R W & Hobbins, R R
Partner: UNT Libraries Government Documents Department

Fiber-optic coupled pressure transducer

Description: A fiber-optic coupled pressure transducer was developed for measurement of pressure transients produced by fast electrical discharges in laser cavities. A detailed description of the design and performance will be given. Shock tube performance and measurements in direct electrical discharge regions will be presented.
Date: January 1, 1979
Creator: Tallman, C.R.; Wingate, F.P. & Ballard, E.O.
Partner: UNT Libraries Government Documents Department

Acoustic emission: who needs it - and why

Description: Acoustic emission (AE) is an emerging NDT method that offers attractive capabilities for monitoring structural integrity and characterizing materials behavior. Although its limitations are such that it should not be regarded as a panacea, AE is proving to be a viable complement to the other NDT methods. The paper examines the extent and reasons for the growing industrial interest in AE. Some of the inherent limitations of conventional NDT methods are discussed, and several surveys of defects found during the manufacture and operation of pressure boundary components are reviewed. Although welds and weld-affected areas are the most likely locations for significant defects, very little experience is available to date to describe the AE response during impending pressure vessel failures due to weld associated defects. Acoustic emission offers potential for providing increased assurance of both initial, and continued, structural integrity. Furthermore, if AE is properly applied in conjunction with recently proposed fitness-for-purpose criteria, it may be possible to reduce present manufacturing costs without compromising actual structural adequacy. This technology is exhibiting definite signs of increasing industrial maturity, as evidenced by the recent availability of industrial standards, and the activities of various AE related technical groups throughout the world.
Date: May 1, 1979
Creator: Spanner, J. C.
Partner: UNT Libraries Government Documents Department

Contributions of shock-wave physics to high-pressure standards

Description: Obtaining a primary pressure standard by dynamic means is discussed. The evolution and current state of the copper Hugoniot curve and its reduction to an isotherm is given. Similar, but less complete, considerations are given for tantalum.
Date: January 1, 1979
Creator: Fritz, J.N.
Partner: UNT Libraries Government Documents Department

Measurement and analysis of drag in multiphase flow systems. [LMFBR]

Description: A combined experimental and analytical program undertaken to evaluate an interfield momentum coupling model used in the computer code SIMMER is described. The behavior of a slugging, vapor-particle flow system was observed and recorded using gamma densitometry, differential pressure measurement, and motion pictures. The primary parameter observed was slug period. When the system was modeled using SIMMER, the calculated behavior of the flow was qualitatively similar to that observed experimentally, but both the period and maximum slug height were underestimated, indicating too weak coupling between the vapor and particle fields. The SIMMER drag correlation was modified, resulting in much better agreement. Final discrepancies between experiment and analysis are discussed.
Date: January 1, 1979
Creator: Rexroth, P.E. & Starkovich, V.S.
Partner: UNT Libraries Government Documents Department

Aqueous solutions database to high temperatures and pressures: NaCl solutions

Description: A survey is made of available experimental data on sodium chloride solutions which are used in geothermal energy exploration and development for electrical power production and direct use. The data are classified as thermodynamic, transport and physical; they are useful in the design and development of a geothermal area from brine production through utilization, to brine disposal. An ideal data system for geothermal energy is described.
Date: August 1, 1979
Creator: Phillips, S.L.; Otto, R.J.; Ozbek, H. & Tavana, M.
Partner: UNT Libraries Government Documents Department

Evaluation of the effects of detonation in a spherical bomb. [PWR; BWR]

Description: An analysis is presented of the time-dependent pressure forces and impulse loadings on the walls of the hemispherical dome of a nuclear reactor pressure vessel arising from a centrally ignited hydrogen-oxygen detonation. Investigated in this context are the effects of richness of the detonable gas mixture as well as those due to the inclusion of water vapor. In the analysis the gas mixture was treated as a perfect gas, and the partial differential equations governing the gasdynamic flow were integrated using the CLOUD CODE - a finite-difference technique set in Lagrangian coordinates and incorporating the smoothing action of artificial viscosity. The most interesting results pertain to the ringing of pressure pulses at the walls. Their frequency is quite uniform, and their pressure peaks, at levels significantly higher than that of combustion at constant volume, decay at a negligible rate.
Date: November 1, 1979
Creator: Kurylo, J. & Oppenheim, A.K.
Partner: UNT Libraries Government Documents Department

Downhole pressure changes measured with a fluid filled capillary tube

Description: An analysis was done on the transmission of a pressure signal through a small diameter (approx. = 0.14 cm) fluid transmission line. The effects of the viscosity and compressibility of the fluid, of the tubing size, and of the temperature changes with time were investigated. Both an oil and a nitrogen filled tube were considered. For a small disturbance, say 1% of the bulk modulus, the propagation of the pressure signal was characterized by a diffusion equation with a source term. For large disturbances, compressibility effects become significant and the signal propagation must be described by a wave equation with damping. A comparison was done between the theoretical model and experimental results with excellent agreement. An oil filled tubing could be described by the small disturbance equation. The pressure response of a nitrogen filled tubing was modelled with the large disturbance equation. It is also shown that for the former case, the wellhead data can be inverted to give the actual downhole pressure using a minimization technique.
Date: July 1, 1979
Creator: Miller, C.W. & Zerzan, J.M.
Partner: UNT Libraries Government Documents Department