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- A Physical Property Summary for Fluoride Mixtures
- This report presents a summary of certain physical properties that have been determined experimentally on the fluoride mixture that have been formulated at ORNL (Rers. 1, 2). These properties include the density, enthalpy, heat capacity, heat of fusion, thermal conductivity, viscosity, Prandtl number, electrical conductivity and surface tension. In addition to the experimental data, values have been predicted for the heat capacity and density of the other mixtures from the correlations of these properties. Estimates of the viscosity have also been made for a number of the mixtures on which no experimental data were available.
- Fluorox Moving-Bed Process for Producing UO3, UF4, and UF6: Bibliography
- A partial bibliography of reports on the Fluorox moving-bed for producing UO3, UF4, and UF6 is given.
- Basic Gamma-Ray Data for ART Heat Deposition Calculations
- In order that fairly accurate thermal stress calculations can be made on the ART, it is necessary to have a reasonable picture of the temperature distribution in the reactor. To get the temperature distributions, and to determine cooling requirements in various parts of the reactor, one must know the heat deposition rates due to alpha particles, beta rays, gamma rays, and neutrons in all parts of the reactor. The present report contains only the basic physical data necessary to determine the heat deposition rates due to gamma rays. Neutron fluxes in the core and reflector regions of the ART are to be obtained from two-dimensional multigroup calculations (performed by the Curtiss-Wright Corporation). These fluxes, in conjunction with the neutron absorption cross sections, determine the neutron capture and inelastic scattering rates in the core and in the reflector. The data in this report permit the calculation of the number of gamma rays originating at various energies at every point in the core and reflector.
- Aircraft Nuclear Propulsion Project Quarterly Progress Report for Period Ending June 10, 1956 [Secret Version]
- Progress report of the Oak Ridge National Laboratory Aircraft Nuclear Propulsion Project providing updates on various projects, experiments, and other work. This report includes summaries of project activities in: aircraft reactor test design, ART physics, ART instruments and controls, component development and testing, procurement and construction, ART, ETU, and in-pile loop operations, phase equilibrium studies, chemical reactions in molten salts, physical properties of molten materials, production of fuels, compatibility of materials at high temperatures, chemistry, analytical chemistry, metallurgy, dynamic corrosion studies, general corrosion studies, fabrication research, welding and brazing investigations, mechanical properties studies, ceramic research, nondestructive testing studies, heat transfer and physical properties, radiation damage, fuel recovery and reprocessing, critical experiments.
- Aircraft Nuclear Propulsion Project Quarterly Progress Report for Period Ending June 10, 1956 [Declassified Version]
- Progress report of the Oak Ridge National Laboratory Aircraft Nuclear Propulsion Project providing updates on various projects, experiments, and other work. This report includes summaries of project activities in: aircraft reactor test design, ART physics, ART instruments and controls, component development and testing, procurement and construction, ART, ETU, and in-pile loop operations, phase equilibrium studies, chemical reactions in molten salts, physical properties of molten materials, production of fuels, compatibility of materials at high temperatures, chemistry, analytical chemistry, metallurgy, dynamic corrosion studies, general corrosion studies, fabrication research, welding and brazing investigations, mechanical properties studies, ceramic research, nondestructive testing studies, heat transfer and physical properties, radiation damage, fuel recovery and reprocessing, critical experiments.
- Analysis of Thorex Pilot Plant Radiation Exposures During 1955
- The Thorex Pilot Plant at Oak Ridge National Laboratory was operated during 1955, processing reactor-irradiated thorium slugs to recover U233 and thorium and 12 MTR fuel elements to recover U235 and Np237. The radiation exposure received by operating personnel during this period averaged 60 mrcp/man-week. Most radiation exposure was received in areas that were intended to be only slightly or nonradioactive. However, because insufficient decontamination of process solutions was achieved and equipment surfaces became contaminated from equipment failures, these areas became primary sources of personnel exposure. The installation of additional shielding where needed and the prompt removal of surface contamination successfully reduced the radiation levels and exposures in these areas. Remote control of processing equipment and sampling of very radioactive solutions from process equipment was successfully accomplished, and assisted in the reduction of exposure to operating personnel.
- HRT Reactor Hazards
- Several potential hazards that have been recognized and anticipated in the design and fabrication of the pressure vessel in the Homogeneous Reactor Test are discussed. These hazards results from the high operating pressure and temperature of the reactor, the exposure of the reactor vessel material to potential embrittlement and other affects of fast-neutron irradiation, and the need for containment of corrosive flowing liquids. The steps taken in recognition of these hazards are also discussed. The applicability of present codes to the reactor vessel fabrication is considered. Additional fields are suggested where recommended practices developed by code writing bodies could assist in development-type reactor design and fabrication.
- Metallurgy Division Semiannual Progress Report for Period Ending April 10, 1956
- Progress report of the Oak Ridge National Laboratory Metallurgy Division providing updates on various projects, experiments, and other work. This report includes a summary of scholarly output and summaries of general corrosion, dynamic corrosion, mechanical properties, nondestructive testing, welding and brazing, fabrication, physical chemistry of corrosion, HRP metallurgy, the package power reactor program, APPR absorber, metallurgical materials and processing, metallography, ceramics, fundamental physico-metallurgical research.
- Metallurgy Division Semiannual Progress Report for Period Ending October 10, 1955
- Progress report of the Oak Ridge National Laboratory Metallurgy Division providing updates on various projects, experiments, and other work. This report includes a summary of nondestructive testing, physical chemistry of corrosion, fundamental physico-metallurgical research, HRP metallurgy, process metallurgy, metallurgical materials and processing, metallography, and ceramics research.
- Operation of the ORNL Graphite Reactor and the Low-Intensity Test Reactor — 1955 LITR Flux Traverses
- The ORNL Graphite Reactor operated very well during 1955. The downtime was low, only 8.6%. The fuel in the bonded slugs did not perform as well in 1955 as in 1954. Much of the trouble was undoubtedly due to growth of slugs which were not beta-transformed. It is known that some slugs had grown over 1/2 in. The automatic central system installed in 1954 continued to operate satisfactorily. The cooling system gave minor trouble when one of the 900-hp fan meters had to be replaced because of shorts in the rotor. The high radiation in the canal was the largest source of trouble. Approximately 55 tons of slugs discharged from the reactor in 1952 was sent to the Metal Recovery Plant. Enough slugs had raptured, due to their long exposure in the canal and reactor, to badly contaminate of water. Most of the contamination was removed by the end of the year, but the radioactivity which had soaked into the canal wells was enough to give high radiation fields. A solution to this problem was being sought at the end of the year. A study is under way on the possibility of increasing the flux of the ORNL Graphite Reactor by reloading with enriched uranium fuel. Results of the study appear to be promising.
- Analytical Chemistry Division Semiannual Progress Report for Period Ending April 20, 1954
- Progress report of the Oak Ridge National Laboratory Analytical Chemistry Division providing updates on various projects, experiments, and other work in ionic analyses, analytical instrumentation, radiochemical analyses, activation analyses, spectrochemical analyses, inorganic preparations, optical and electron microscopy.
- The ANCO System for Boron Isotope Enrichment Progress Report for Period Ending September 20, 1955
- A new gas-liquid countercurrent system (the ANCO system from Anisole-Complex) for the enrichment of boron isotopes has been developed. It is believed that use of this systems will result in a considerably lower unit cost for enriched boron-10 than was previously possible. The system utilizes the exchange reaction between BF3 (gas) and BF3·anisole (liquid) to concentrate boron-10 in the liquid phase. The single stage isotopic separation factor for this system has been found to vary from 1.039 at 0°C to 1.029 at 30°C. The isotopic exchange reaction has been shown to be rapid. Vapor pressures of the complex as a function of temperature have been measured and the heat of formation of the complex determined. Laboratory experiments show that quantitative removal of the BF3 from the complex can be accomplished by heating. A complete miniature ANCO plant was constructed and operated in the laboratory to test the feasibility of the system. The system was found to operate efficiently with a minimum of attention, and to enrich the isotopes of boron as expected. Based upon the experience obtained with the laboratory ANCO unit, a pilot plant large enough to utilize a 6-inch diameter exchange column was designed. The design calculations of the major pieces of equipment are presented.
- High-Thermal-Conductivity Fin Material for Radiators
- This report is the result of a study to develop heat-resistant fin materials possessing a high thermal conductivity for air radiators. Since an economical and commercially feasible product was desired, the investigation was restricted primarily to a study of electroplated copper, clad copper, and copper alloys. Sheet material 0.008 to 0.010 in. thick was evaluated for fabricability and for metallurgical stability and thermal conductivity at 1500°F. From the results of the rests it was concluded that: (1) electroplates were unsatisfactory; (2) clad-copper fins possessing a thermal conductivity of 50% of that of copper are commercially feasible; (3) copper-aluminum alloys possessing a thermal conductivity approaching that of copper at 1500°F are possible. Service tests of clad copper and the copper-aluminum alloys indicate that the choice of materials will be dictated by the requirements of the radiator, since each presents some unique problems.
- Aircraft Nuclear Propulsion Project Quarterly Progress Report for Period Ending March 10, 1956
- This quarterly progress report of the Aircraft Nuclear Propulsion Project at ORNL records the technical progress of the research on circulating-fuel reactors and ether ANP research at the Laboratory under its Contract W-7405-eng-26. The report is divided into three major parts: I. Reactor Theory, Component Development, and Construction, II. Materials Research, and III. Shielding Research.
- Biology Division Semiannual Progress Report for Period Ending February 15, 1956
- Progress report of the Oak Ridge National Laboratory Biology Division providing updates on various projects, experiments, and other work. This report includes a summary of scholarly output from the division and departmental activities in cytology and genetics, mammalian genetics and development, microbial protection and recovery, mammalian recovery, pathology and physiology, general physiology, biochemistry, enzymology and photosynthesis, microbiology, plant biochemistry, and biophysics.
- Thorex Thorium Nitrate Product Specifications
- Activity and ionic impurity specifications are presented for Thorex thorium nitrate products. Two sets of specifications are given, one set for direct handling during refabrication of production reactor thorium metal slugs and the second for refabrication of future power reactor thorium metal elements by semi-remote technics. Consideration was given to the health hazard problems associated with each process step between the Thorex process and final refabricated source material in order to arrive at these specifications.
- Chemistry Division Semiannual Progress Report for Period Ending December 20, 1955
- Semiannual Progress report of the Oak Ridge National Laboratory Chemistry Division providing updates on various projects, experiments, and other work in inorganic and physical chemistry, nuclear chemistry, organic chemistry, chemical physics, chemistry of separation processes, radiation chemistry, and reactor chemistry.
- Determination of Trivalent Uranium in Fluoride Salt Mixtures by the Modified Hydrogen Evolution Method
- The hydrogen evolution method for the determination of uranium trifluoride which was developed by Manning, Miller and Rowan has been used for the determination of trivalent uranium in this laboratory for the past three years. The method has been applied to many different sample types supposedly pure UF3, mixtures of UF3 and UF4 and the large variety of mixtures of fluoride salts that have been investigated as possible nuclear fuels. These mixtures contained alkali metal, beryllium and zirconium fluorides. Several modifications have been made that have substantially improved the performance and ease of operation of the method. These improvements include the use of (1) an inexpensive, long-lasting source of pure carbon dioxide, (2) vacuum to assist in purging the system of gases that are insoluble in potassium hydroxide solution, (3) deaerated acid that has an extremely low quantity of non-absorbable gases, (4) slower flow rates of purging gas, (5) a sampling technique to minimize contamination, and (6) more dilute absorber solution to reduce film error. It is the purpose of this report to show the effect of these modifications and the applicability of the method various sample types that contain uranium trifluoride.
- HRP Radiation Corrosion Studies
- A fifth in-pile loop experiment, L-4-8, was completed. The loop operated in-pile for a total of 1637 hr, during which time the LITR energy output was 4377 Mwhr. The average fission power in the loop based o cesium analyses was 622 w when the LITR was at full power (3 Mw). Based on oxygen data, the generalized corrosion rate for the first 300 hr was 4.0 mpy; the rate for the remaining 1357 hr was 0.7 mpy. The nickel data gave parallel results. The corrosion of the type 347 stainless steel, Zircaloy-2, and Ti-55AX [unintelligible] exposed in the core and in in-line holders was generally consistent with that observed in previous in-pile loop experiments. Some differences with steel were attributed to the fact that this was the first loop containing steel specimens operated with 0.04 m H2SO4 present in the uranyl sulfate charge solution (0.17 m UO2SO4, 0.03 m CuSO4). Stress specimens, made from the alloys Zircaloy-2, type 17-4 PH stainless steel, and Ti-C-130-AM, were exposed in care, in-line, and pressurizer locations. Microscopic examination and average weight loss gave no indication of effects attributable to the stressed condition of the specimens.
- Bulk ThO2, a Reactor Material
- Thorium, a fertile material, is of interest to the Reactor Program in the production of U233. Thorium can be extracted and processed to a very pure bulk metal for fabrication into solid fertile elements. There are advantages, technical and economic, for using fabricated bulk thorium dioxide rather than the metal in some applications. It is the purpose of this paper to point out these advantages and to present briefly the technology related to fabrication, radiation damage and chemical processing of ThO2.
- Fission Product Activities in Irradiated Natural Uranium, Enriched Uranium, and Thorium
- Calculated data and graphs describing the effects of batch thermal-neutron irradiations on the buildup of fission products in natural uranium, enriched uranium, and thorium are presented together with empirical equations and plots correlating total fission product activities and/or decontamination factors. Fluxes of 1012-1015 are considered.
- A Combined Distillation-Electrochemical Method for Recovery of Hydrofluoric Acid
- Electrodialysis in an ion-exchange membrane cell was shown to be technically feasible for the concentration of an azeotropic mixture of HF and water. A flowsheet is presented for recovery of anhydrous HF by distillation and electrodialysis of the azeotropic residue. In the electrodialysis step, 2.6 kwhr of energy per pound of anhydrous product was consumed, with electricity at 1¢ per kilowatt-hour, the total operating cost of the electrodialysis equipment alone, including amortization, would be 6¢ per pound of HF.
- Bibliography of ORNL-BSF Reports Pertinent to Swimming Pool Type Reactor Design (Revised)
- Much of the shielding work carried out with the Bulk Shielding Reactor (BSR) has yielded data of particular interest for the design of swimming pool type reactors, However, it is often difficult for a reactor designer to locate such data since it may be recorded in a report primarily concerned with shielding problems. Therefore, this memorandum presents a bibliography of reports from the Bulk Shielding Facility arranged according to the application of data to the various aspects of reactor design.
- Electronuclear Research Division Semiannual Progress Report for Period Ending September 20, 1955
- The installations of the beam deflector in the ORL 86-inch Cyclotron is sufficiently complete to allow initial testing the system permits the optional use of high-current internal targets. A survey of [illegible] cross sections made with 14-Mev neutrons indicates qualitative agreement with statistical theory. An internal-conversion ion spectrograph and a fission-fragment spectrograph were built and put in operation. The [illegible] functions severed proton-induced reactions of possible use in isotope production were measured. A capsule-type target is being used for the irradiation of chemical compounds. Nuclear physics research with 26-Mev nitrogen lens from the ORNL 63-inch Cyclotron concerned the following: a theoretical interpretation of elastic nitrogen-nitrogen scattering a detailed investigation of some nitrogen-nitrogen nuclear reactions; the measurement of reactions across sections in boron and aluminum; and the identification and the energy spectre of protons and alpha particles resulting from nitrogen-induced reactions with light elements. A study is being made of the practicality of a fixed-frequency cyclotron to accelerate protons to about 1 [illegible] for application in [illegible] research. Phase compensation would be obtained with an unusual magnetic-field configuration which has eight [illegible] cycles with about 72 deg of spiral, Also, a proposal was made to convert the 44-in. proton cyclotron a new 48-in. magnet would permit the acceleration of heavy ions to energies up to 81 Mev.
- Development of a Cubic Oxide Protective Film on Zirconium
- Observations of the effects of neutron damage to zirconium oxides led to the conclusion that the cubic form of ZrO2 is more stable to such damage than the monoclinic form. It has been reported that zirconium corrodes more rapidly in certain liquids when exposure is made under radiation (neutrons and fission products). It is well known that on heating monoclinic ZrO2 a transformation, monoclinic to tetragonal (very similar to cubic), occurs at about 1500°C. The transformation involves sufficient atomic rearrangement that pieces of ZrO2 normally crack and crumble. It is suggested that the effects of neutrons on monoclinic ZrO2 may be similar so that a protective oxide film on the metal would be destroyed soon after its formation. It might be possible, therefore, that the protective oxide film on zirconium metal which is normally monoclinic might be less resistant to corrosion under radiation damage than a similar film which was cubic.
- Some Experiments Relating Ion Diffusion in a Plasma to the Neutral Gas Density in the Presence of a Magnetic Field
- In some recent experiments the ion density in a plasma was measured as a function of radial distance from a d-c arc source of ions for the magnetic field intensities from 2500 to 14000 oersted. The diffusion coefficient appeared to very inversely as the square of the magnetic field strength, D~1/H2. The absolute value of D was shown to be approximately that which would be predicted by the collision diffusion theory when account is taken of the shorting effect of the end walls. The purpose of this report is to continue the examination of ion diffusion in a plasma and field experimentally the relation between the diffusion coefficient and the neutral gas pressure for a constant magnetic field.
- Preliminary Results of APPR Critical Experiments, Part I.
- This memorandum is the first in a series reporting progress in the program of critical experiments in the ORNLArmy Package Power Reactor Project. The critical assembly, designated as CA-25, is analogous to the APPR design core and consists of 45 fuel boxes, in a 7 x 7 array with the corners removed, contaIned in a large water tank. Two sides of each box are slotted for the insertion and positioning of any desired loading of eighteen plates of fuel, structural material, and poison. The array is submerged in water to provide a moderated and reflector. Enriched uranium metal, in two-mil-thick foils 2.5 x 22 in, is encased in type 304 stainless steel sheets, 2.7 x 23 x 0.0105 in., to form fuel plates. Stainless steel plates, 2.7 x 23 x 0.025 in. are used to simulate additional steel in the APPR core. It is, therefore, possible to maintain an essentially constant metal to water ration in the assembly when the fuel content is varied. The fuel is distributed as uniformly as possible in all boxes and a symmetrical distribution of materials is maintained in the core at all times. Fuel plates containing half-width (1.25 in) uranium foils are provided for making small changes in loading
- Air Scattering of Co60 Gamma Rays: Theory Versus Experiment
- For Co60 source at 15 meters, the air-scattered gamma dose rate predicted by theory is excerpted from ORNL-1575, pp. 167-203. This is compared with experimental measurements for the same source and comparable geometry reported by Convair in CVAC-170T. After applying an appropriate correction for ground scattering as estimated in Mart-55-16T (Convair), the two results are found to be in substantial agreement.
- ORNL Mortal Recovery Plant: Processing of ORNL Graphite Reactor Fuel Elements During the Period July and August, 1955
- From July 7 to August 31, 1955, 20 tons of uranium and 1,200 g of plutonium were recovered in 47 days of plant operation at an average rate of 833 lb/day of uranium and at a cost of $2.60/lb of uranium. Uranium and plutonium recoveries were, respectively, 99.9 and 95.5 per cent.
- Methods of Analysis of Anisole-BF3 Solution
- The methods of analysis given in this report are those which were used in the Analytical Chemistry Division of the Oak Ridge National Laboratory for analyzing samples which were derived from the experimental work on the separation of the isotopes of boron by chemical exchange. The samples consisted principally of boron trifluoride solutions in anisole (methyl phenyl ether, CH30C6H5). The boron concentration ranged from a few parts per million to 5 or 6 per cent. Boron was determined on all samples. During the early stages of the project, iron and copper were occasionally determined, while a limited number of aqueous solutions and water extracts of anisole solutions of BF3 were analyzed for fluoboric and hydroxyfluoboric acids, boric acid, total boron, and total fluoride. Boron was determined by the use of either a spectrophotometric or volumetric method, depending on the amount available. Initially, if the amount of sample and boron concentration were such as to provide a total of at least 2 to 4 mg of boron, the volumetric method was utilized and found to be satisfactory. For smaller amount, the spectrophotometric method was used. Later, because of its greater speed and simplicity, the spectrophotometric method was used for samples in the intermediate range of 4 to 20 mg of boron in preference to the volumetric method. The latter method includes a step which requires four hours for hydrolyzing fluoboric acid completely to boric acid. This time-consuming step is avoided by the use of the spectrophotometric method. Iron and copper were determined by spectrophotometric methods. Orthophenanthroline was used as the chromogenic reagent in the determination of iron, whereas sodium diethylidithiocarbamate was used for determining copper. A special technique, developed by Wamser (1), was used, with some modifications, for the determination of fluboric and hydroxyfluboric acids, boric acid, and fluoride in a …
- Aircraft Nuclear Propulsion Project Quarterly Progress Report for Period Ending December 10, 1955
- This quarterly progress report of the Aircraft Nuclear Propulsion Project at ORNL records the technical progress of the research on circulating-fuel reactors and other ANP research at the Laboratory under its Contract W-7405-eng-26. The report is divided into three major parts: I. Reactor Theory, Component Development, and Construction, II. Materials Research, and III. Shielding Research. The ANP Project is comprised of about 530 technical and scientific personnel engaged in many phases of research directed forward the achievement of nuclear propulsion of aircraft. A considerable portion of this research is performed in support of the work of other organizations participating in the national ANP effort. However, the bulk of the ANP research at ORNL is directed toward the development of a circulating-fuel type of reactor. The design, construction, and operation of the Aircraft Reactor Test (ART), with the cooperation of the Pratt & Whitney Aircraft Division, are the specific objectives of the project. The ART is to be a power plant system that will include a 60-Mv circulating-fuel reflector-moderated reactor and adequate means for heat disposal. Operation of the system will be for the purpose of determining the feasibility, and the problems associated with the design, construction, and operation, of a high-power, circulating-fuel, reflector-moderated aircraft reactor system.
- The Technology of Uranium Dioxide a Reactor Material
- Consideration has been given to various forms of fissionable material for use in atomic reactors, including the pure metals, their alloys and compounds. Of particular interest is the dioxide of uranium which is refractory and corrosion resistant in some environments.The oxide is useful in both granular and bulk forms. Small grains of uranium oxide can be mixed with other materials to form matrix type elements where they serve either as a convenient or necessary form of fuel or fertile material. For other applications the oxide may be fabricated in bulk form such as pellets, rods, plates, or blocks.There is a need for knowledge of the properties of the properties of this oxide, particularly as it affects fabrication in the various forms required. This knowledge is also required by reactor designers and engineers. There is in addition a challenging field for basic studies of sintering rates, oxidation behavior and other phenomena. Fabrication techniques have been developed to produce uranium oxide in various forms with consideration given to the economy of production. The continued application of basic knowledge of these materials has led to simpler. more practical means of fabrication and has thus widened the scope of their use in atomic reactors.
- Chemical Separation of Isotopes Section Semiannual Progress Report for Period Ending June 30, 1955
- The countercurrent gas-liquid system BF3(g)—anisole·BF3(l) for the concentration of boron isotopes has been studied. The single-storage separation factor varies from 1.039 at 0°C to 1.029 at 30°C. Rate of exchange is rapid, and, with efficient contacting equipment, complete exchange may be obtained in less than 15 sec. A total separation of 1.525 has been realized in laboratory equipment. The critical-product reflux reaction is quite efficient. Only about 55 moles of BF3 remain in each million moles of effluent solvent under laboratory conditions. The vapor pressure of BF3 over the complex rises sharply as the temperature is increased. At 0°C the pressure is 150 mm Hg, and at 40°C the pressure has risen to 1800 mm Hg. From vapor-pressure measurements, an approximate upper limit of ΔH= -12kcal per mole of complex was calculated for the reaction [equation not transcribed]. Qualitative tests indicate good resistance of anisole to decomposition by BF3 under plant conditions. The uncatalyzed exchange of boron between BF3 and BCl3 was found to be too slow to be exploited in a countercurrent system. The single-stage, equilibrium separation factor for the Nitrox system is a function of acid concentration. At 26°C the factor ranges from 1.064 with 1 M acid to 1.020 with 15 M acid. A contractor is described for studies on gas-liquid equilibria. A product-end refluxer for the Nitrox system, NO(g) vs HNO3(aq), was designed and operated and was found to be satisfactory for use in this exchange system. The nitrogen-isotope separation factor for the system NO(g) vs FeNO++(aq) was found to be 1.009 at 16.5°C. The N13 concentrated in the liquid phase. The fractionation of nitrogen isotopes between aqueous ammonium hydroxide and metal-ammonia complexes adsorbed on Dowex 50 resin is being studied. The separation factors for complexes of Ni, Cu, and Zn have been measured; further experiments …
- Determination of Traces of Uranium Metal by Decomposition of the Hydride
- Two methods were developed for the determination of uranium metal in UF3 with other fluoride compounds. A simplified method of determination which has a relatively high degree of precision (coefficient of variation 2 per cent) is carried out by decomposing the hydride in an atmosphere of carbon dioxide and subsequently measuring the hydrogen over an aqueous solution of potassium hydroxide. The ignition of the hydride in an atmosphere of oxygen and volumetric measurement of the water at reduced pressures provide a more sensitive method of determination. The coefficient of variation of the latter procedure is 7 per cent. The yield of gas from the reaction of the hydride with ammonia and gaseous hydrogen chloride was found to be neither stoichiometric nor reproducible.
- Laboratory Development of the Thorex Process
- Changes made in the Thorex process flowsheet were a decrease in the extraction column acidity to decrease thorium losses and the addition of a second thorium solvent-extraction cycle to provide the increased decontamination required when thorium irradiated to 2000-4000 g of U233 per ton is processed. Bonded slugs could not be dissolved by the Thorex flowsheet procedure. Various laboratory scale studies on feed preparation, first-cycle variables, and radiation damage to the solvent are reported.
- Handling Techniques for Rubidium
- Experience in handling and purifying rubidium metal, prior to high-temperature corrosion testing, has been obtained. Some of the physical and chemical properties of this metal are listed. Distillation and filtration experiences are described, and the analysis of samples following such purification procedures are given. Stripping procedures following corrosion testing are discussed briefly. Results of preliminary corrosion experiments indicate that Inconel in a satisfactory container material for boiling rubidium at temperatures up to 1520°F.
- Determination of Trivalent Uranium with Methylene Blue
- A direct titrimetric method for the determination of trivalent uranium in uranium trifluoride and mixtures of fused fluoride salts was developed. The method is based on the stoichiometric oxidation of trivalent uranium to the tetravalent oxidation state with an acidic solution of methylene blue. The sample containing trivalent uranium is dissolved at room temperature in an excess of standard methylene blue solution in a carbon dioxide atmosphere; the excess oxidant is variation of the method is 1.5 per cent for 5 mg quantities of trivalent uranium. The method was applied to various mixtures of fluoride salts containing both trivalent and tetravalent uranium.
- Interim Evaluation of the Fluorox Process for UF4 and UF6 Manufacture
- The conversion of UNH to UF4 and UF6, utilizing moving-bed techniques, is being studied; sufficient progress has been made that an evaluation of the process is warranted. The procedures under study, the Fluorox Process, have three major advantages: (1) substitution of HF for high-cost fluorine, (2) considerable reduction in HF requirements, and (3) marked reduction in plant-size and mechanical complexity.
- Relative Biological Hazards of Radiations Expected in Homogeneous Reactors TBR and HPR
- An evaluation of the relative health hazards of radioisotopes produced in nuclear reactors is reported. The most important hazards were indicated to be I131, the Sr90 - Y90 chain, the Ce144 -Pr144 chain, Sr 89, the Ba140-La40 chain, Y91, the Zr95-Nb95 chain, Pr143, La140 , and Pa233. The most critical body organs affected by air-borne contamination are the thyroid gland, the bone marrow, the lungs, and the gastrointestinal tract. Where possible, continuous daily removal of gaseous and solid fission products from the reactor environment can be shown to permit very significant reductions in the total hazards. Homogeneous reactors, such as the Thermal Breeder Reactor and the Homogeneous Plutonium Producer Reactor, specifically studied in this report, are designed with daily removal cycles and may be considered potentially safer than heterogeneous reactors.
- Development of the Excer Process
- Two revised Excer process flowsheets are presented for the production of UF4 from urnayl nitrate solution. In both, the uranium is sorbed on a cation-exchange resin and eluted with aqueous HF. In one, the resulting UO2F2 in dilute HF is mixed with dilute sulfuric or hydrochloric acid and electrolytically reduced in a cation-exchange-membrane cell, and the precipitated UF4·0.75H2O is dried and dehydrated to anhydrous UF4. A cost of 20¢ per pound of reduced uranium is estimated. In the other, ammonium fluoride is also added to the uranyl fluoride solution before the electrolytic reduction step, and the precipitate is UF4·04NH4F. A flowsheet for preparing UF4 from raw ore is also shown. The uranium is sorbed on an anion-exchange resin from a sulfuric acid leach liquor and eluted with dilute HCl. Ammonium fluoride and HF are added to the UO2Cl2-HCl solution before the uranyl ion is electrolytically reduced to precipitate UF4·0.4NH4F. Decontamination factors as high as 45 and 9 for gross beta and gamma activities and of 10 to 5000 for light metal impurities were obtained in the electrolytic reduction step.
- Analytical Chemistry Division Semiannual Progress Report For Period Ending October 20, 1955
- The development of ionic methods for the determination of corrosive products in the highly radioactive Homogeneous Reactor (HR) fuels has been of major interest in the work of the Ionic Analyses Laboratory. Methods for the spectrophotometric determination of aluminum and for the polarographic determination of iron in HR fuels have been developed. The polarographic determination of molybdenum in uranyl sulfate solutions was studied. A polarographic method for the determination of zinc was developed. A fluorometric method for the determination of microgram amounts of fluoride was studied. Three organic reagents were investigated as precipitants for microgram quantities of zirconium in HR fuel. The automatic photometric titration technique was applied to the determination of thorium and of sulfate. A method was developed for the ion-exchange separation and potentiometric titration of cobalt. The ultraviolet absorption spectra of technetium and rhenium were studied.
- A Fluoride Fuel In-Pile Loop Experiment
- An inconel loop circulating fluoride fuel (62 1/2 make [unintelligible] NaF, 12 1/2 make [unintelligible] ZrF4, 25 make [unintelligible] UF4, 92 [unintelligible] enriched) was operated at 1485°F with a temperature difference of about 35°F in the Low Intensity Test Reactor for 645 hr. For 475 hr of this time the reactor was at full power, and fission power generation in the loop was 2.7 kw, with a max length power density of 0.4 kw/cc. The total volume of fuel was 1290 cc (5.o kg [unintelligible] and the the flow through the irradiated section was 8.6 fps (Reynolds number 5500). The loop has been disassembled and has been examined by chemical and metallographic analyses. Ne acceleration of corrosion of decomposition of fuel by irradiation was noted, although deposition of fission-product ruthenium was absorbed. Ne mass transfer of Inconel was formed, and the corrosive [unintelligible] was general and relatively light. The average corrosive generation, in the usual form of subsurface yields, was 0.5 [unintelligible], the maximum penetration was 2 to 3 miles.
- The Influence of End Mirrors, High Density and Long Tube Length on Radial Diffusion
- Diffusion in an arc plasma across a magnetic field is investigated. The geometry is similar to that reported in ORNL-1890 but with the addition of magnetic mirrors on the ends of the arc chamber. It is shown that mirrors do not eliminate the "short circuit" effect. Comparison of the e-folding length, rₒ, of the radial ion density with and without mirrors, affords a direct measurement of ℓ/λ where ℓ is the arc length and λ the mean-free-path. In addition rₒ is independent of gas pressure with mirrors and varies as √p without mirrors. The condition for the elimination of the "short circuit" effect is discussed, as well as the case in which the "short circuit" is still present but the ions diffuse (rather than stream) to the end walls. In this case rₒ is directly proportional to the gas pressure. These effects are compared to some experimental results of Neidigh
- Enthalpies and Heat Capacities of Solid and Molten Fluoride Mixtures
- The enthalpies and heat capacities of seventeen fluoride mixtures in the liquid state have been determined using Bunsen Ice Calorimeters and copper block calorimeters. The fluoride mixtures were composed of the fluorides of two or more of the following metals: lithium, sodium, potassium, beryllium, zirconium, and uranium. The enthalpies and heat capacities of most of these mixtures were studied in the solid state also. Estimates of the heat of fusion have been made. General empirical equations have been developed which represent the enthalpies and heat capacities of the fluoride mixtures in the liquid and in the solid state.
- Enthalpies and Heat Capacities of Solid and Molten Fluoride Mixtures
- The enthalpies and heat capacities of seventeen fluoride mixtures in the liquid state have been determined using Bunsen Ice Calorimeters and copper block calorimeters. The fluoride mixtures were composed of the fluorides of two or more of the following metals: lithium, sodium, potassium, beryllium, zirconium, and uranium. The enthalpies and heat capacities of most of these mixtures were studied in the solid state also. Estimates of the heat of fusion have been made. General empirical equations have been developed which represent the enthalpies and heat capacities of the fluoride mixtures in the liquid and in the solid state.
- Fabrication of Heat Exchangers and Radiators for High Temperature Reactor Applications
- Two 500-kw fused-fluoride-to-Nak heat exchangers, two 500-kw NaK-to-air radiators, and a 20-tube high-velocity heat exchanger were fabricated for a heat-exchanger development program. A construction procedure, utilizing both inert-arc-welding and high temperature dry-hydrogen brazing, was used successfully on all of the units. The tube-to-header joints were welded and back-brazed; the manifold joints were inert-arc-welded with full penetration; and the tube-to-fin joints were brazed. A detailed description of the fabrication of each type of component is discussed and a cost analysis of the 500-kw units is presented.
- Determination of Corrosion Products and Additives in Homogeneous Reactor Fuel III. Polarographic Determination of Iron(III)
- An ion-exchange -- polarographic method was developed for the determination of iron(III) in Homogeneous Reactor Fuels. Copper, which interferes, is removed from the fuel by plating it onto a cadmium coil. Iron is oxidized to iron(III) by potassium permanganate, and the iron(III) is separated from interfering metal ions by ion exchange on a Dowex 1 resin column that is in the sulfate form. The iron(III) in the effluent is determined polarographically in 0.5 M sodium citrate solution as supporting electrolyte. A fairly well defined polarographic wave is obtained for the iron(III) → iron(II) reduction at a half-wave potential of approximately -0.15 v. vs. the S.C.E. The relative standard deviation of the data for 2 µg of iron(III) per ml of solution in the polarographic cell was 6.5%; for 10 µg of iron(III) per ml it was 0.6%.
- Biology Progress Report for Period Ending August 15, 1955
- Progress report of the Oak Ridge National Laboratory Biology Division providing updates on various projects, experiments, and other work. This report includes a summary of scholarly output from the division and departmental activities in: cytology and genetics, microbial protection and recovery, mammalian recovery, mammalian genetics and development, pathology and physiology, microbiology, biochemistry, enzymology and photosynthesis, plant biochemistry, general physiology, and biophysics.
- Solid State Division Semiannual Progress Report for Period Ending August 31, 1955
- LITR Fluoride-Fuel Loop. — The inconel loop was dismantled for removal of the samples and for recovery of the uranium by using the remote cutting tools installed in a half cell of the Solid State Building. Disassembly proceeded without incident. An electric-arc cutting technique was developed for removal of the stainless steel enclosure around the pump bowl. Fission power and maximum flux were determined by irradiating a simulated loop, by heat-balance calculations, by radiochemical analyses for fission products in the fuel, by measuring the activation of cobalt foils attached to the loop, and by activation of the loop tubing itself. The determination of the power by these various methods gave 2.5 to 2.8 kw during operation of the loop, and the maximum power density was 0.4 kw/cc. Chemical analyses of the fuel were carried out to determine U, Zr, and the major constituents of inconel: Ni, Cr, and Fe.
- Homogeneous Reactor Project Quarterly Progress Report for Period Ending July 31, 1955
- Construction of the HRT reactor shield tank was completed, and the inside surfaces were painted. The roof structure for the tank is being assembled in preparation for an acceptance pressure test. Service piping and instrument lines are being installed in the central room area by ORNL craft forces. This work is approximately 50% complete. Fabrication of all temperature system components, except the blanket outer storage tanks, has been completed.