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Production of Uranium Metal

Description: Experiments were carried out for the purpose of increasing production, efficiency, and purity of uranium metal. The electrolytic method as described by Driggs and Lilliendahl for the preparation of uranium metal was followed with but little deviation. The yield of metal at the very best was only 50%. The metal powder produced, at times, was very pyrophoric. Methods were found whereby the metal, at least in part, can be made from the oxides with an average yield of about 90%. The small amounts of sludge and slag accumulated in this modified process can readily be re-used in the electrolysis pot and, therefore, an overall yield of 96% can be obtained. Information accumulated from these experiments has been compiled in such a manner as to be readily available for factory use, for patent purposes and for future publication.
Date: February 17, 1943
Creator: Nagy, R.
Partner: UNT Libraries Government Documents Department


Description: The design of the thermionic converter to be evaluated was completed. The converter incorporates a tantalum-10% tungsten alloy liquid metal containment tube insulated by BeO from a tungsten-25% rhenium emitter. A nickel collector with an interelectrode space of 8 mils was selected. The predicted performance of this converter indicates a power output of 4.7 w/cm/sup 2/ with an efficiency of 12% when the emitter temperature is 1500 deg C. A bifilar tungsten filament was selected for use as a heater in this program based on a study contained in this report. (auth)
Date: October 31, 1964
Creator: Harter, F.C.
Partner: UNT Libraries Government Documents Department


Description: At the end of June 1960, 36% of the construction and 94% of the firm design of the Heavy Water Components Test Reactor (HWCTR) were complete. Revised calculations of transients in the liquid-D/sub 2/O-cooled loop of the HWCTR showed that the safety of the loop was not impaired by recent changes in the location and design of the loop heat exchanger. Preliminary operation of a full- scale mock-up of the bayonet for the boiling-D/sub 2/O-cooled loop of the HWCTR indicated that flow-induced vibrations probably will not be a serious problem in this loop. Irradiation specimens were prepared of Zircaloy-clad tubes of uranium oxide that had been vibratory-compacted and swaged to 91% of theoretical density. The National Research University irradiation of a Zircaloy-clad uranium metal fuel tube was terminated because of mechanical damage to the assembly during an attempted reinsertion into the reactor loop. Tandemextruded joints of Zircaloy to stainless steel were readied for long-term irradiation tests to determine the effects of exposure on the mechanical properties of the joints. (For preceding period see DP-505.) (auth)
Date: October 1, 1960
Creator: Hood, R.R. & Isakoff, L. comps.
Partner: UNT Libraries Government Documents Department


Description: 8 7 < 6 ; : : = 8 g developed for recovering fissionable and fertile materials from shortcooled reactor fuels. The second laboratory demonstration of the melt-refining process with highly irradiated EBR- IItype fuel pins was completed. A 392-g charge of U-5% fissium fuel pins irradiated to an estimated burnup of 0.4 total at.% and cooled 28 days was melt refined for three hours at 1400 deg C. Data were not obtained on the behavior of fission products. The effect of N concentration on the nitridation rates of unirradiated U-fissium alloys in Ar-N atmospheres was determined. Experiments on the storage of fuel pins at 350 deg C in Ar atmospheres showed that the presence of 5% N lowered product yields only slightly during subsequent melt-refining operations. Supplementary pouring techniques, such as the use of probes and mashers designed to break crusts over the melts, are moderately effective, but are a less desirable solution to the problem of maintaining high yields than the elimination of contaminants in the Ar atmosphere. A liquid metal process is under development for recovery of the fissionable material contained in melt refining crucible skulls produced in the EBR-II fuel cycle. Information obtained in separate studies of the individual process steps is listed. A systematic study is underway to ascertain the influence of atomic size, metallic valence, and electronic configuration on the coprecipitation of various metallic elements with the Cd-Ce intermetallic phase CeCd/sub 11/. Values for the coprecipitation coefficient lambda , defined by the equation log (tracer in solution/ total tracer) = lambda log (carrier in solution/total carrier), were determined for Na, Li, K, Y, Ba, lambda = 0; La, lambda = 1.49; Th, lambda = 1.08; Pr, lambda = 0.63; Ga, lambda = 0.23; Sm, lambda = 0.17; U, lambda = 0.13; Sr, lambda = ...
Date: October 31, 1961
Partner: UNT Libraries Government Documents Department


Description: Chemical-metallurgical processing studies were made of pyrometallurgical development snd research, and fuel processing facilities for EBR-II. Fuel-cycle applications of fluidization and volatility techniques included laboratory investigations of fluoride volatility processes, engineeringscale development, and conversion of UF/sub 6/ to UO/sub 2/. Reactor safety studies consisted of metal oxidation and ignition kinetics, and metal-water reactions. Reactor chemistry investigations were conducted to determine nuclear constants and suitable reactor decontamination methods. Routine operations are summarized for the high-level gammairradiation facillty and waste processing. (B.O.G.)
Date: March 1, 1961
Partner: UNT Libraries Government Documents Department


Description: Progress is reported on the following studies: the possible relationship between environmental Ra/sup 226/ and incidence of bone tumors in human populations; the incidence of tumors in mice exposed to chronic gamma irradiation; the effects of chronic gamma irradiation on histology of testes cells; the effects of periodic exposure to gamma radiation on the mortality of guinea pigs; determinations of the density of various mouse tissues; the synthesis of dimethyl formarmide (DMF) and uranyl nitrate-DMF; an investigation of the role of the small intestine in acute radiation death in mice following exposure to fast neutrons or gamma radiation; the effect of neutron dose on the incidence of mammary tumors and fertility of female rats and mice; measurements of Cs/sup 137/ in samples of tea and human milk made with a gamma spectrometer; the latency and growth of bone tumors induced by injected Sr/sup 90/ in two strains of mice; histopathologic changes in the skeleton of mice following injection of various doses of Ra/sup 226/ the development of mathematical models of cellular populations; reaction mechanisms in the response of chicks to radiation injuries; cell generation times in E. coli; the demonstration of infective organisms living in the cytoplasm of A. proteus; electron microscopic study of the fine structure of fat cells as related to structure; the effects of enzymes on induction of bacteriophage of E. coli; lipid metabolism and the isolation, fractionation, and analysis of cholesterol esters obtained during turnover studies; tracer studies on the role of urea in nitrogen metabolism using deuterium-labeled urea in which free energies of formation for deuterm-urea were determined; the participation of metal ions in transmethylation activity of enzymes in microorganisms; the effects of ultraviolet irradiation on yeast cells; the effects of thiol compounds on mitochondrial swelling; the effects of photoperiodism on flowering of xanthium; the ...
Date: December 1, 1960
Partner: UNT Libraries Government Documents Department


Description: Investigatiors were made of various materials for development of metal- canned and semi-homogeneous GCRE-II fuel element concepts. The materials were studied for application to development of fuels, grapanite, silicon-silicon carbide coatings, metal claddings, carburization barrier coatings, and graphite joining. A survey of the literature showad that uranium carbide fuels are superior to other types for the applications described and that refractory metal or metal carbide fuel coatings appear superior to other types for use with the types of graphite investigated. Experimental measurements were made of the thermal conductivity, tensile strength, stress-strain reiationships, and thermal expansion of graphite powdsr bonded with baked carbon at a final firing temperature of 760 deg C. Results showed that these materials were stronger and more isotropic at all test temperatures than a standard structure graphite such as ATJ. The thermal conductivity is somewhat lower and the thermal extansion slightly higher than the corresponding properties of ATJ. A silicon-silicon carbide coating was developed as an osidation-resistant coating for graphite. Preliminary air oxidation tests at 1000 deg C showed that the first samples survived 2000 hr with 10% failure. Subsequent experiments showed that it is reasonable to expect better performance in further tests. Tests for compatibility with graphite were conducted on zirconium, Zircaloy-2, "A" nickel, and K-Monel at 1750 and 1850 deg F for 1000 and 1500 hr. Chemical analyses, metallography, and tensile tests indicated that the K-Monel is the material most compatible with graphite; it possesses good strength and ductility with negligible carburization or carbon diffusion. Zircaloy-2 tubing showed a growth of from 3.4 to 3.8% when thermal cycled 100 times between 850 and 1850 deg F. Tests for compatibility with Hastelloy X were conducted on graphite samples coated with molybdenum, niobium carbide, and zirconium carbide at 1750 deg F and 300 psi for 1000 and ...
Date: December 30, 1960
Creator: Carpenter, R. & Del Grosso, A.
Partner: UNT Libraries Government Documents Department


Description: A study was made of approximately 132 reports on gascooled reactors and related subjects. Charts and tables containing the following information are included: all available reactor information, reactor flow diagrams of suggested concepts, possible core arrangement at core cross section, typical fuel and moderator cell. possible fuel types for unit fuel cell, the properties of materials for moderators and reflectors. the compatibility of gases and base fuel materials at maximum surface temperatures, maximun interfacs temperatures of fuel elements and core-jacket combinations, allowable operating temperatures and compatibility of gases and various metals. prefenences for gas coolants, cost and availability of gases plant thermal cycle efficiencies, thermal properties of gases, pumping power and reactor coolant inlet temperatures, obtainable heat fluxes, composition and physical properties of potential cladding materials. atomic and themal properties of cladding materials. fabrication characteristics and costs of cladding materials. possible process applications of gases at high temperature, and potential high-temperature materials. The various categories of gas-cooled reactors and examples of each type are discussed. A gas reactor program for high-temperature experimentation is proposed. (M.C.G.)
Date: November 1, 1960
Creator: Armstrong, R.H.
Partner: UNT Libraries Government Documents Department


Description: Reduction of small charges of uranium tetrafluoride with magnesium proved to be successful. By hand-tamping of UF/sub 4/-- Mg blend, tap densities ranglng between3.1 and 3.4 g/cc were obtained. The reduction yields for these densities ranged from 72.79 to 93.71%. In the case of machinecompacted UF4-- Mg blend having tap densities from 3.58 to 3.68 g/cc, reduction yields were higher, ranging between 91.45 and 97.2%. Machine-compacted blends gave much more uniform temperature distribution curves during the preheating period, as a result of higher tap densities. The best yields were obtained by firing a machine- compacted blend containing 5% Mg excess at a furnace temperature of 650 deg C, giving an average crude metal yield of 96.3%. However, the high carbon content of 174 ppm in the crude uranium biscuits obtained by compacts reduction, as a result of hydrocarbon binder presence, appeared to be a disadvantage. Attempts were also made to demonstrate the initiation of the reduction reaction at temperatures lower than 500 deg C by taking x-ray-diffraction patterns of the samples of the UF4-- Mg charges heated up to various temperatures. (auth)
Date: February 1, 1961
Creator: Milosavljevich, J. & Baird, J.
Partner: UNT Libraries Government Documents Department


Description: In the utilization of nuclear heat energy, liquid metal could be used in a vapor cycle to propel a column of liquid metal in a jet pump or injector where electrical energy could be extracted by means of a MHD arrangement. The recirculating system is being studied as a means of increasing the efficiency. Results are described briefly for a preliminary run made using steam and water; the efficiency of conversion of steam kinetic energy to liquid kinetic energy was approximates 20%. The possible causes of the low efficiency and some of the methods for decreasing hydraulic losses are outlined. (D.L.C.)
Date: October 31, 1963
Creator: Sowa, E.S.
Partner: UNT Libraries Government Documents Department


Description: Approximately 2000 supplemental rods were made for use in EBR-II Fuel Cycle Facility startup tests. They were made in the same manner as Core-I fuel rods but using partially depleted pins instead of fuel pins. A duplex'' or double melting operation was used for Core-I production. The alloys were first melted together and cast in and ingot mold. The ingot was then remelted and injection castto produce fuel pins. In order to simplify the operation, a single melt, or simplex'' operation, alloying and injecting casting in one step was tried. This operation was unsatisfactory because of uncontrollable gas evolution from the ingredients of the charge. The interior parts of the furnace became coated with condensed metal to an extent that threatened mechanical and electrical failure of the furnace. A thermocouple head was developed for use in the injection casting furnace. It had increased accuracy and reliability, and was more easily remotely replaced. The improvements were due to unit construction and improved cold-junction contacts. A statistical analysis was made of a sample of 412 rods. The analysis produced (1) and equation for predicting sodium levels through the selection of sodium loads, and (2) evidence that jacket-preassembly classification is necessary under existing specifications for sodium level. (auth)
Date: September 1, 1963
Creator: Carson, N.J. Jr.; Jelinek, H.F. & Shuck, A.B.
Partner: UNT Libraries Government Documents Department


Description: Calculations of critical size, reactivity coefficients, and delayed neutron fractions are described for mockups of a plutonium-fueled EBR-I (Mark IV) and five possible metal-fueled power reactors. The calculations for critical size were performed using the SNG transport-theory code. The reactivity coefficients were estimated by SNG calculations or by one-group perturbation- theory desk calculations. The delayed-neutron fractions were estimated by an approximate method, which starts with a calculation of beta for a bare core and then makes a correction for the small effect of the blanket. The reactivity effects studied were the effects of fuel-plate and whole-core expansion and control-rod worths. (auth)
Date: September 1, 1960
Creator: Baker, A.R.
Partner: UNT Libraries Government Documents Department

Luminescence process, refractory stabilities, and new and novel electronic states: scanning chemical reactions and novel products for laser induced isotope separation. Progress report, March 1, 1975--November 20, 1975

Description: The formulation and development of versatile oven systems for high temperature metal vaporation at temperatures greater than 2000$sup 0$C are discussed. The construction of an apparatus appropriate to the production and study of small metal aggregates M/sub n/ (2 less than or equal to n less than or equal to 6) is discussed at length. This includes a consideration of the construction and operation of an argon ion pumped dye laser system. The dye laser system will be used to induce fluorescence from the small metal aggregates, and thereby will lead to the study of their molecular electronic structure. The production of carbon vapor and the reaction of this vapor with metal atoms and metal dimers to form metal carbides is outlined. A thorough study of the luminescence process leading to a new understanding of those chemiluminescent phenomena occurring as a result of the ''single collision'' bimolecular reaction of metal atoms and metal dimers with select oxidants is outlined. Methods for the determination of upper bounds to the heats of sublimation and vaporization of those metals which can be strongly oxidized in a ''single collision'' bimolecular reaction are presented. Extremely simple methods by which one can infer the radiative lifetimes of metastable product chemiluminescing molecules are also discussed. Beginning efforts toward the formulation of new and novel catalytic surfaces via aggregate deposition are outlined. Current studies of the titanium oxide system are presented. These chemiluminescence studies allow the determination of a lower bound to the TiO dissociation energy and a determination of the heat of vaporization of titanium metal. (auth)
Date: November 1, 1975
Creator: Gole, J.L.
Partner: UNT Libraries Government Documents Department


Description: Modifications of EBWR are described, and data from analysis of control- rod operational crud deposit are tabulated. Development and construction progress on Borax V are summarized. Research for ZPR III is reported on a series of uranium oxide critical cores. Comparative data on composition, critical masses, and central fission ratios are tabulated for these assemblies. Developmental work on ZPR-VI, ZPR-IX, and Juggernaut is summarized, followed by a summary of EBR-I operation and development of EBR-II. Studies of reactor steam superheating concepts are reported from which conclusions are listed. In reactor safety studies, data were obtained on the extent of water reaction with various metal combinations for use in cores as function of energy input. In other work in-pile melt down studies were conducted. Operation and development of TREAT are described. Nuclear technological developments are summarized in sections on physics, fuel development, reactor components and materials, separations development, and advanced reactor development. (For preceding period see ANL- 6295.) (J.R.D.)
Date: February 15, 1961
Partner: UNT Libraries Government Documents Department