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CALCULATION OF THE REQUIREMENTS FOR OPERATION OF REFRACTORY-METAL COMPONENTS AT HIGH TEMPERATURE IN VACUUM

Description: Equations based on kinetic theory relate the contamination of refractory metals in vacuum to the appropriate variables. Several examples are given for which the allowable system pressures are calculated. The examples illustrate the effect of varying several parameters. The importance of the sticking factor for active gases on hot refractory metals and its effect on the system design are discussed. The data for estimating the sticking factor for O/sub 2/ on Nb are given, along with some estimate… more
Date: September 18, 1962
Creator: Clausing, R.E.
Partner: UNT Libraries Government Documents Department
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Multigroup Calculations of Effective Delayed-Neutron Fractions, Prompt- Neutron Lifetime, and Related Kinetics Parameters. IBM-704 Program 1188/RE

Description: In the course of a recent study of kinetics parameters, it was found that RE-185, because of its limitations, was inadequate to handle the problems involved with the reactors considered. Program ll88/RE was written entirely independent of and is intended to make RE-185 obsolete. The multigroup calculations of primary interest performed by the code are as follows: the total effective delayed-neutron fraction and its distribution into six ' families'' which are characterized by their periods; the… more
Date: March 1962
Creator: Kvitek, L. C.
Partner: UNT Libraries Government Documents Department
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Arc Melting in the Tungsten Electrode Furnace

Description: An arc furnace is described which employs a nonconsumable tungsten electrode and a water-cooled copper hearth. It is used successfully for melting refractory metals and alloys. The furnace is equipped with a vacuum system, an inert gas supply, and an 800-ampere directcurrent power supply. (auth)
Date: November 1, 1961
Creator: Williams, D. E. & Levingston, H. L.
Partner: UNT Libraries Government Documents Department
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DESIGN AND OPERATION OF 1800 F PUMPED BOILING RUBIDIUM LOOP SYSTEM AND DETERMINATION OF DENSITY AND VAPOR PRESSURE RUBIDIUM BETWEEN 174 AND 1800 F. Space Power Systems Technology Studies: Rubidium, Corrosion and Physical Properties Evaluation Program. Final Report (Report No. 16), February 1, 1960 through May 31, 1961

Description: A pumped boiling rubidium loop was designed, operated, and analyzed. The loop simulated some of the characteristics of a boiling rubidium space power conversion system. Such a system would involve either a reactor or heat exchanger as the power source, and a turbine and radiator as the power conversion and vapor condensing equipment. This loop was used to study instrumentation and control problems and effects of rubidium corrosion on containment materials, and to gain some rough physical proper… more
Date: October 31, 1962
Partner: UNT Libraries Government Documents Department
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CATASTROPHIC OXIDATION OF HIGH-TEMPERATURE ALLOYS

Description: The growth of nonprotective, crust-like oxide films was encountered in high-temperature alloy systems that contain molybdenum, vanadium, or tungsten as strengthening additions. The cause of accelerated oxidation in such alloys appears to be associated with the characteristically low melting temperatures of oxides of these refractory elements. The factors that contribute to a breakdown of oxidation protection in these systems are outlined and remedial methods which may be used to avoid catastrop… more
Date: November 10, 1961
Creator: DeVan, J. H.
Partner: UNT Libraries Government Documents Department
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NASA-AEC LIQUID METALS CORROSION MEETING HELD DECEMBER 14-15, 1961, BROKHAVEN NATIONAL LABORATORY, UPTON, LONG ISLAND, NEW YORK

Description: Twenty-two papers are included. Separate abstracts were prepared for fifteen of these. The presentations not abstracted concern liquid metal research, evaluation of materials in gaseous and liquid Hg, liquid metal corrosion, of loop materials, effects of K vapor on refrsctory alloys, research program on Na components, Na loop studies, and determination of O in Na. (J.R.D.)
Date: October 31, 1962
Partner: UNT Libraries Government Documents Department
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Extraction of Niobium-95 From Nitric Acid Solutions With Tri-N-Butyl Phosphate

Description: The distribution coefficient (DC o/a) of Nb/sup 95/ between aqueous nitric acid and 30% Tri-n-butyl phosphate (TBP) in n-dodecane increased from ~0.004 to O.1 N acid deficient solution to 0.05 in 4 M HNO/sub 3/ for the extractable portion of the niobium. Greater than 70% of the niobium was unextractable. The presence of 3% chemically degraded TBP, 7% chemically degraded Amsco, or both decreased the amount of unextractable niobium to <20% and degraded TBP increased the distribution of the extrac… more
Date: July 1, 1962
Creator: Moore, J. G. & Rainey, R. H.
Partner: UNT Libraries Government Documents Department
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Diffusion in polycrystalline Y/sub 2/O/sub 3/ and Er/sub 2/O/sub 3/

Description: A tracer sectioning technique was employed to measure cation self-diffusion coefficients in fully dense polycrystalline materials under oxidizing conditions. Results are D = 1.65x10/sup -2/ exp(-69,200/RT) cm/sup 2//s for Y/sub 2/O/sub 3/ (1400 to 1670/sup 0/C), and D = 1.48 exp(-102,200/RT) cm/sup 2//s for Er/sub 2/O/sub 3/ (1400 to 1700/sup 0/C). The greater activation energy for erbium diffusion in erbia is attributed to a mass effect. Oxygen diffusion coefficients were extracted from observ… more
Date: May 1, 1968
Creator: Berard, M.F.
Partner: UNT Libraries Government Documents Department
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710 reactor program. Progress report No. 17

Description: This report is the seventeenth in a series of progress reports of the advanced high-temperature gas reactor - 710 program. This report describes the work performed and progress made from September 1 to October 31, 1965 on the following current tasks in the 710 program: Development of Refractory-Metal Fuel Elements; Critical Experiments of Fast-Spectrum, Refractory-Metal Reactors; Experimental Reactor Preliminary Design and Development; Test Facilities Design and Evaluation; and Investigations o… more
Date: December 1, 1965
Partner: UNT Libraries Government Documents Department
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Fabrication, characterization, and thermal-property measurements of ThO/sub 2/--UO/sub 2/ fuel materials (LWBR Development Program)

Description: Thermophysical-property specimens of ThO/sub 2/, ThO/sub 2/-10 wt % UO/sub 2/, and ThO/sub 2/-20 wt % UO/sub 2/ were fabricated and characterized. Each material composition was represented by specimens with nominal densities of 95, 85, and 75 percent of theoretical. Thermal-diffusivity, linear-thermal-expansion, and specific-heat measurements were made at 300 to 1900/sup 0/C and used to determine thermal conductivity. Results of linear-thermal-expansion and specific-heat measurements were appro… more
Date: October 1, 1967
Creator: Springer, J. R.; Eldridge, E. A.; Goodyear, M. U.; Wright, T. R. & Lagedrost, J. F.
Partner: UNT Libraries Government Documents Department
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Theoretical density of lithium aluminate updated

Description: The ''handbook'' density for LiAlO/sub 2/ is 2.55 g/cc. Recent data show that it should be revised to 2.62 g/cc. In the future densities reported as percent of theoretical should be based on 2.62 g/cc as being 100 percent. Values quoted on this basis will be more realistic. In order to avoid confusion it will be necessary to state which number percent of theoretical density are based upon--that is, ''2.62 g/cc = 100 percent,'' or ''2.55 g/cc = 100 percent.'' For the convenience of those working… more
Date: January 12, 1966
Creator: Gurwell, W. E.
Partner: UNT Libraries Government Documents Department
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Thermodynamics of Certain Refractory Compounds. Part II. Continued Theoretical and Experimental Studies on an Extended List. Second Quarterly Progress Report, September 1 to November 30, 1963

Description: The thermodynamic properties of refractory borides, carbides, nitrides, and oxides of some 31 elements are compiled. Several tables for elements and compounds not previously reported are presented, and the experimental spectroscopic studies of the vapor of boron oxide and hydroxide are discussed. (R.J.S.)
Date: December 15, 1962
Creator: Schick, H. L.; Anthrop, D. F.; Dreikorn, R. E.; Feber, R. C.; Hanst, P. L.; Panish, M. B. et al.
Partner: UNT Libraries Government Documents Department
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Ceramic-to-Metal Seals for High-Temperature Thermionic Converters. Quarterly Technical Report No. 2

Description: Seals capable of long life at 1500 c- C in cesium and vacuum environments are developed. Improved methods of sealing both metallized and unmetallized ceramic members to refractory metals are developed. Associated work on ceramics, refractory metal alloys, and ceramic-metal composites is made. (auth)
Date: April 15, 1963
Partner: UNT Libraries Government Documents Department
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Corrosion Mechanisms in Refractory Metal-Alkali Metal Systems

Description: The use of liquid metals introduces solid-liquid metal interactions which are not primarily electrochemical, as found in systems involving aqueous raedia. The corrosion of solid metals by these coolants occurs as the system attempts to attain chemical equilibrium. The mechanisms by which this can occur are (a) dissolutioning, which results from the solubility relationships between the solid and liquid metals, and (b) impurity reactions, resulting from the presence of interstitial impurities, su… more
Date: September 16, 1963
Creator: DiStefano, J.R. & Hoffman, E.E.
Partner: UNT Libraries Government Documents Department
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Summary Technical Report for the Period January 1, 1963 to March 31, 1963

Description: A semicontinuous ion exchange column was used for the pilot-scaie production of purified uranyl chloride solutions from scrap leach liquor. Continuous box mixer-settler tests demonstrated that an Aliquot-336--Solvesso 100 system will satisfactorily extract uranium from scrap leach liquor. An airless shot blaster is being used to clean slag from debries using uranium shot as the blasting medium. Plasma-spraying equipment was installed for coating graphite crucibles and molds with refractory mate… more
Date: May 10, 1963
Partner: UNT Libraries Government Documents Department
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