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Description: The flux of hydrogen gas through Hastelloy B, hot forged to 20% reduction was determined as a function of membrane thickness, pressure differential, and temperature. The experimental data were fitted to the equation J = (1810 P/sup 1/2//X exp (-8422/T) where J is the flux (cc at STP/ (cm/sup 2/- hr)); P is the pressure (atmospheres); X is the membrane thickness (mm); and T is the temperature ( deg K). (auth)
Date: February 15, 1961
Creator: Rudd, D. W.; Vose, D. W. & Vetrano, J. B.
Partner: UNT Libraries Government Documents Department

Radioisotopic heat sources. Revision 1

Description: For the radioisotopes with half-lives over a year, only eight appear to be obtainable in the foreseeable future. The fission products, strontium-90, cesium-137, and promethium-147, exist in wastes from reactor processing, diluted with enormous volumes of other elements and salts. Among those isotopes producible by irradiation of special target materials (cobalt-60, uranium-232, plutonium-238, and curium-244) cobalt-60, though easy to produce, requires a special design for the heat source generator because much of its emitted energy is penetrating gamma radiation. Cobalt-60 appears, therefore, to be rather limited in its prospects for use. Plutonium-238 is favored as a heat source because of its long half-line and no need for special shielding. However, its projected high cost, scarcity, and biological hazard encourages the search for a competitive material. When plutonium assumes a significant place as a recycled fuel in thermal reactors for power production, curium-244 can then become available at costs below that for plutonium-238. Curiunm-244 has five times the specific power of plutonium-238 and appears to be just as easy to handle. Promethium-147, although probably on the ''short end'' of the half-life scale, can be considered for some uses as a substitute for plutonium-238. Although the factors of availability, gamma activity, and biological characteristics are unfavorable, the strongly points for uranium-232 (and thorium-228) are extremely high power densities, relatively low expected costs, and unusually long-life nearly constant heat output. The short life of thorium-228 (1.9 years) is a disadvantage. This study indicates that aged promethium-147 should be receiving more serious attention as a heat source.
Date: October 15, 1963
Creator: Rohrmann, C.A.
Partner: UNT Libraries Government Documents Department

Protection of Graphite by Impregnation. Quarterly Progress Report No. 3 for September 1-November 30, 1960. Vitro Job 2195

Description: The hypothesis that sample resistivity is the controlling factor in electrokinetic impregnation was substantiated. Experiments show that dense clay- bonded silicon carbide can be impregnated beneath the surface pores whereas only surface pore impregnation is achieved with both dense and porous graphite. The resistivity of the materials differ by a factor of about 1O/sup 10/. Although deep penetration of the substrate by the particles of the coating system is not achieved during deposition, there is evidence of considerable diffusion of the binder-carbide solid solution into the pores of the graphite after sintering. A number of sintered, crack-free, and adherent TaC coatings on ATJ graphite panels were prepared which showed evidence of surface pore penetration. The attainment of satisfactory reproducibility was difficult because of preferential deposition of the binder metal and contamination from erosion of the chrome-manganese steel ball mill. Efforts to prevent contamination by lining the mill with rubber were unsatisfactory. A silicon carbide liner for the mill was ordered and will be received in December. To prevent preferential deposition, precoating of the tantalum carbide particles with nickel by chemical precipitation and electroless nickel plating was investigated. Nickel coatings were obtained by both techniques; however, the chemically precipitated nickel was not adherent when the coated particles were placed in the electrophoretic bath. Good adherence was obtained by electroless plating; but this material, when sintered, cracked during the cooling cycle. Further investigation established that both iron and nickel are required as binders to obtain well-sintered Tar. Work was begun on the preparation of coated rocket nozzle liners for testing at NOL. Graphite nozzles were machined to the WM-D-800-2 configuration, and a cell was designed for obtaiining a uniform electrophoretic deposit. Test coatings were within the required thickness tolerance of plus or minus 0.002 in. The coatings, thus far, have cracked at ...
Date: December 15, 1960
Creator: Ortner, M. H. & Klach, S. J.
Partner: UNT Libraries Government Documents Department

Emission Characteristics of Tantalum, Tungsten, Rhenium, and Iridium in Plasma Diodes

Description: Experimental determinations of the ionic and electronic emission characteristics of Ta, W, Re, and lr cathodes in vapor thermionic converters are compared. It is shown that Ta provides superior thermal ionization qualities at high pressure compared with W, Re, and Lr. High electronic current densities may be obtained from Cs on Re and Cs on Ir at much lower Cs vapor pressures than from Ta or W. An over-all efficiency of 19% was achieved with a Re cathode at 2440 deg K. (auth)
Date: March 15, 1962
Creator: Gust, W. H.
Partner: UNT Libraries Government Documents Department

A Mass-Spectrometric Investigation of Sulfur Vapor as a Function of Temperature

Description: A mass-spectrometric investigation was performed on sulfur vapor in equilibrium with the condensed phase at 120 to 210 gas-cooled C. It was found that, in this temperature range, equilibrium sulfur vapor contains appreciable quantities of S/sub 8/, S/sub 7/, S/sub 6/, and S/sub 5/ only. The sulfur vapor emanated as a small well-collimated molecular beam from a specially constructed source into an ionization chamber which was designed to exclude from analysis any sulfur vapor that had impinged on the walls or the hot electron filament. Essential identical ionization potentials were determined for S/sub 8/ , S/sub 7/, S/sub 6/, and S/sub 5/ of 9.8 0.4 ev. The heat of vaporizati on of S/sub 7/ was calculated to be approximately 2.5 kcal greater than that of S/ sub 8/. Upper limits for S/sub 8/ and S/sub 7/ composition in S vapor at 120 gas- cooled C were determined to be 86% and 14%, respectively. It is proposed thst S/sub 8/ is the vaporizing species, that S/sub 7/, S/sub 6/, and S/sub 5/ result from dissociation of S/sub 8/. and that all four molecules have a ring configuration. (auth)
Date: June 15, 1960
Creator: Zietz, M. C.
Partner: UNT Libraries Government Documents Department

Antiproton-Proton Cross Sections at 1.0, 1.25, and 2.0 BeV

Description: The antiproton--proton interaction was studied at three energies, 2.0, 1.25, and 0.98 Bev. Antiprotons produced internally in the Revatron and channeled externally by a system of bending magnets and quadrupoles were selected from background particles by using a gas Cherenkov counter and scintillation counters. At the two lower energies, an electrostatic-magnetic velocity spectrometer was used to reject background particles. A liquidhydrogen target was completely surrounded by scintillation counters so that all charged secondaries from the antiproton--proion interactions could be detected. With the information obtained from these counters, the --p-bar--p total, elastic, inelastic, and charge-exchange cross sections and the angular distribution of the elastic scatterings were obtained at each energy. The total cross section was found to be 80, 89, and 100 mb at 2.0 1.25. and 0.98 Bev. respeclively. The inelastic cross section was about twothirds of ihe total cross section at each energy. It was found that each of the partial cross sections was dropping off slowly with energy. The results were fitted by an optic al-model c alculation. (auth)
Date: March 15, 1960
Creator: Coombes, C. A.
Partner: UNT Libraries Government Documents Department

THE DEVELOPMENT OF URANIUM CARBIDE AS A NUCLEAR FUEL. Third Annual Report, September 1, 1961 to October 31, 1962

Description: = 9 6 < ? < 0 t and fabrication method on irradiation stability, thermal conductivity, and hot hardness of uranium carbide were determined. Hypostoichiometric and stoichiometric uranium carbides prepared by both powder metallurgy and skull casting and hyperstoichiometric cast carbide were tested. The preparation of 12% enriched uranium carbide specimens for irradiation testing was completed. Sintered specimens were 98% of theoretical density for hypostoichiometric uranium carbide and 92 to 93% of theoretical for stoichiometric uranium carbide. All cast specimens were above 98.7% of theoretical density. Five different specimens, 4.4 and 4.8 450 deg C in a 0.1 wt% carbon, cast material and sintered material, and 5.2 450 deg C in a 0.1 wt% carbon, cast uranium carbide, were canned separately in niobium-1 wt% Zr and inserted into each of three capsules. The fuel specimens in capsule UNC-1-2 were contained in a sodium bond. This capsule was removed after 15,000 MW-d/ton U burnup in the MTR. The specimens in capsule UNC-1-3 were canned using an interference fit between cladding and fuel. This capsule was removed from the MTR after 14,440 MW-d/ton U burnup. Fuel surface temperatures ran in the range of 650 to 870 un. Concent 85% C and center-line temperatures were calculated at about 1050 to 1100 un. Concent 85% C. Specimens were prepared for thermal expansion, thermal conductivity, and hot hardness measurements. These properties are being determined from room temperature to 1000 un. Concent 85% C for multiple specimens of each test condition. Thermal expansion of uranium carbide from room temperature to 1000 un. Concent 85% C was found to be 12.4 x 10/sup -6/ per un. Concent 85% C for 4.4 wt% carbon sintered material, and 11.5 x 10/sup - 6/ per un. Concent 85% C for 4.7 wt% carbon cast material, Additional data on thermal expansion ...
Date: January 15, 1963
Creator: Crane, J.; Kalish, H.S. & Litton, F.B.
Partner: UNT Libraries Government Documents Department


Description: An experimental program to evaluate the performance of FCR and EFCR fuel during transient operation is outlined, and the initial series of tests are described in some detail. Test results from five experiments in the TREAT reactor, using 1-in. OD SS-clad UO/sub 2/ fuel specimens, are compared with regard to fuel temperatures, mechanical integrity, and post-irradiation appearance. Incipient fuel pin failure limits for transients are identified with maximum fuel temperatures in the range of 7000 deg F. Multiple transient damage to the cladding is likely for transients above the melting point of the fuel. (auth)
Date: November 15, 1962
Creator: Field, J.H.
Partner: UNT Libraries Government Documents Department


Description: The objectives of the SNAP-7D program were to design, manufacture, test and deliver a thirty-watt electric generating system for a modified U. S. Navy NOMAD-class weather buoy to be stationed in the Gulf of Mexico. The sixty-watt Sr/sup 90/ thermoelectric generator, the relay panel, the batteries, and the installation of the system in a boattype buoy are described. In addition to delivering the power supply, many tests were required for the SNAP-7D system to demonstrate its conformance to the contract statement of work. The electrical tests of the generator and of the system, the shock and vibration tests, and the tests at the environmental temperature extremes are discussed. (auth) Quantitative studies were made of the angular distribution of elastic and inelastic scattering of 25-kev electrons on noble gases, and the results were compared with scattering theory in the Born approximation. Results are presented in tables and graphs. (M.C.G.)
Date: March 15, 1963
Creator: Young, C.N.
Partner: UNT Libraries Government Documents Department


Description: Work done on the EGCR graphite combustion problem that may follow from the maximum credible accident, that is the rapid loss of pressure from the primaryreactor coolant system is summarized. The solution to date is to protect the fuel support sleeves with a siliconized siliconcarbide coating and to allow the moderator surfaces to oxidize. The moderator surfaces have available only 6.5% of the total core flow which places an upper limit on the rate of oxidation. The rate of heat removal through the sleeve to the main coolant flow is sufficient to cause a decrease in temperature throughout the reactor and subsequent quenching of the oxidation. This method depends only on continued coolant flow from one blower. Problems attendant with this and other schemes of controlling the fire are discussed. (auth)
Date: June 15, 1961
Creator: Fontana, M.H.
Partner: UNT Libraries Government Documents Department

PATHFINDER ATOMIC POWER PLANT. Technical Progress Report, January-March 1963

Description: Progress made in the development of the Sioux Falls Power Reactor is reported. Information is presented on stainless steel corrosion in oxygenated steam, development of low-enrichment superheater fuel elements, nuclear analysis of first-core boron-stainless steel poison shims and transient simulator, and testing and stability of oscillator rod assembly and in-core ion chambers. (N.W.R.)
Date: June 15, 1963
Partner: UNT Libraries Government Documents Department


Description: A review is presented of various types of solutions of metals in molten salts, especially in their own molten halides. With relatively little reference to the older literature, the progress made in the last 20 years is discussed. Roughly, the solutions are classified into two groups: The metal may retain, to some degree, its metallic properties in the solution, or it may lose them through strong interaction with the salt solvent. The alkali-metal systems are typical examples of the former type, while solutions of cadmium or bismuth represent the second. Equilibrium phase diagram data are presented in detail for many metal- salt systems. These include critical solution temperatures, that is, temperatures above which metal and salt are miscible in all proportions. Electrical conductivity is singled out as a most significant physical property from which conclusions on the state of the electron in the solution may be drawn. In the electronically conducting solutions, notably of the alkali metals, the electrons may be thought to resemble F centers in color-center colored crystals. In solutions where electronic conductance is absent, monomeric, dimeric, and even more highly poly, merized species of the solute metal in a low valence state must be assumed to occur. (auth)
Date: August 15, 1963
Creator: Bredig, M. A.
Partner: UNT Libraries Government Documents Department

Post-operation evaluation of fuel elements from the SNAP 10 Flight System 3 Reactor

Description: Declassifled 28 Nov 1973. The S10FS-3 Reactor was disassembled and examined. The core was removed from the core vessel and all 37 fuel elements were subjected to a nondestructive screening examination followed by a detailed examination of selected elements. The screening examination consisted of visual inspection, dimensional measurement, eddy current scanning for hydrogen distribution, and gamma scanning. The subsequent detaiIed examination of selected elements included fission gas measurement, determination of hydrogen permeation rate, inspection of disassembled fuel elements, dimensional measurement of fuel, fuel density determination, hydrogen analysis, and fuel and cladding metallography. No defects or unexpected results were observed, and the examination firmly supported the conclusion that all the fuel elements completed the reactor operation in good condition. (auth)
Date: September 15, 1967
Creator: Golding, T. A.
Partner: UNT Libraries Government Documents Department

Hydraulic Characteristics of HNPF 8-Rod Fuel Element

Description: Pressure drop and vibration characteristics were determined for an 8-rod fuel element model of the design intended for use with uranium carbide (UC) in the Hallam Nuclear Power Facility (HNPF). Measurements with water as the test fluid were converted to equivalent values for sodium, the HNPF coolant, using the principles of dimensional similitude. Initially UC elements will be concluded in an HNPF core loading comprised primarily of 19-rod U-Mo fuel elements. In this core loading, the UC fuel element requires 17.5 lb/sec of sodium coolant at a core pressure drop of 11 psi. The measured fuel element pressure drop ranged from 0.27 to 5.8 psi over the sodium flow range from 3.5 to 17.4 lb/sec. The existing HNPF variable orifice can adjust flow for this fuel element over the range from 5.7 to 21 lb/sec at a core pressure drop of 11 psi. No significant vibration of the fuel rods was induced by the flow of water. (auth)
Date: August 15, 1963
Creator: Begley, R. J.
Partner: UNT Libraries Government Documents Department