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.

Calculations are given for eighteen stainless steel clad helium bonded specimens of UO2-ThO2 containing normal U to be placed in 6 holes in a holder in a position of the ORR not to exceed a peak unperturbed flux of 4 x 10^14 n.cm^2/sec and irradiated to a peak nvt of 1.96 x 10^21 neutrons/cm^2

Continued work on the adsorbability of metal complexes from concentrated LiCl solutions and LiCl-HCl mixtures on a strong-base anion-exchange resin further demonstrated the much higher adsorbability of these complexes from LiCl solutions than from HCl solutions. The effect is believed to be due to the formation of less strongly adsorbed undissociated chloro-complex acids in the case of the HCl solutions.

Report issued by the Oak Ridge National Laboratory discussing the development of a closed-loop control system. As stated in the statement, "the purpose of this thesis was to design and build a closed-loop control system to be used as an indicator of the level of high temperature liquids contained in a tank" (p. 1). This report includes tables, illustrations, and photographs.

Several experiments have been performed at ORNL with light water solutions of uranyl nitrate (highly enriched in either U^233 or U^235) in an essentially bare sphere 27 inches in diameter. This report presents the results of several calculations with elementary bare reactor theory and a discussion of the observed discrepancies between the calculated and experimental results. If the observed critical concentration is used in the calculations, the calculated effective multiplication constant is less than unity' thus a higher critical concentration would be predicted than is actually observed.

The "absolute" containment of ions in the DCX magnetic mirror field resulting from the cylindrical symmetry of the field is discussed. The regions of confinement in space and momentum are plotted for 300 Kev deuterons.

Either system appears to be fairly satisfactory from a containment standpoint. Current results indicate probable over-all rates of about 0.2mils/mo for titanium vs. 1.5-3.0 mils/mo for Ni-o-nel. Tests are not 100% comparable due to changes made in flowsheet conditions, but have been of sufficient variation and length as to allow good predictions to be made. Both metals show some tendency toward local attack in Thorex solutions. These tendencies are increased by poor welding techniques.

In a discussion about design of cyclotron resonators, the suggestion has been made that a wide range variable-frequency system might be constructed with two coupled resonant circuits. It also would present the possibility of tuning without the switching of high-current contacts, a troublesome item now commonly used for cyclotrons. One of the circuits would be the dee and its stem which might, or might not, be tuned. The second circuit could be located out of the magnet gap in a region where more space is usually available. Tuning could be accomplished by variation of the coupling between the two circuits and/or by, say, variable capacitance of the tuned, or tunable, circuit.

From abstract: "The Darex process developed for the recovery of uranium from stainless steel-containing reactor fuels consists of three steps: (1) dissolution of the fuel material in dilute aqua regia, (2) removal of chloride from the solution to prevent corrosion of downstream stainless steel process equipment, and (3) adjustment of the nitrate solution to solvent extraction feed conditions."

The use of mercury as a solvent in the recovery of uranium from spent fuels is of the interest at Oak Ridge National Laboratory. The vapor pressure of mercury is lowered by increased concentration of uranium. By dew-point measurements, the vapor pressure at 175°C was found to very between 2 and 8mm of mercury, and at 375°C, between 300 and 1100 mm of mercury, depending upon composition as described below. Plots of the log of mercury vapor pressure vs. the reciprocal of absolute temperature gave a family of straight lines. Each line corresponded to one of the composition: UHg2, UHg3, UHg4, and a saturated solution of UHg4 in Hg. No Mutual solubility of the intermetallics was indicated.

A replica electron microscope study of as-polished and cathodically etched surfaces of pyrolytic carbon coating on fuel particles has been made in an attempt to characterize coatings that showed as much as a 30% difference in bult density. High and low density coating could be characterized by their polished surface textures; however, these features were not indicative of the true structure as seen by direct electron transmission. Microvoids detected by the transmission study of cleavage flakes exist on too fine a scale to be observed either optically or by electron microscope examination of replicas of the polished surface. Other features such as the effect of cathodic and chemical etching, coating delamination, and duplex coating interfaces have also been examined.

Report containing ongoing research and development taking place at the Oak Ridge National Laboratory's Electronuclear Division.

The ORNL 86-in. cyclotron is being modified to provide for deflection of the proton beam. It is expected that operation will be resumed late in the spring. Nuclear physics work was limited, for the most part, to interpretation of previously collected data and to making preparations for utilizing the deflected beam. It was found that for certain isotopes the production rates could be almost doubled by operating at a slightly reduced energy and a much larger current. With the use of the ORNL 63-in. cyclotron, the absolute values of the electron capture and loss cross sections for 26-Mev nitrogen ions were obtained. The angular distribution of the cross sections for elastic scattering of nitrogen by nitrogen was measured at energies from 13 to 22 Mev. A double-focusing 90-deg magnet is being planned for use in identifying stable reaction products from nitrogen-induced reactions. The major components of the revised 44-in. test cyclotron were assembled and are being tested. Consideration is being given to the use of these components, along with a new 20,000-oersted magnet and a shielded cyclotron room, and if the tests are satisfactory the Laboratory will have available a machine which will accelerate N5+ ions to 81 Mev.

Report documenting the problems, design, and operation of countercurrent liquid-foam columns.

The power and estimated reprocessing load are tabulated for existing and proposed United States and United States-built reactors of 10 Kw or greater thermal power.

Technical report covering the work done to explore heat transfer analytically and experimentally in liquid metals in turbulent flow within the thermal entrance region of circular tubes having uniform well temperature. Includes implications of this research. [From Summary]

By using a large central fuel and blanket reprocessing facility, slurry-fueled aqueous homogeneous reactors can attain an estimated minimum fuel cycle cost of 1.4-1.6 mills/kwh; with solution-fueled two-region reactors, a doubling time of 14 years may be obtained at a fuel cycle cost of 2.0 mills/kwh. On-site processing appears desirable only for large power stations made up of reactors designed for short doubling times. For instance, a solution-fueled two-region reactor can attain a 12-year doubling time at an estimated fuel cycle cost of 1.5 mills/kwh at a 2000 Mw electricity station with an on-site processing plant.

Report issued by the Oak Ridge National Laboratory discussing semiannual progress made by the Gas-Cooled Reactor Program. Descriptions of progress and studies conducted are presented. This report includes tables, illustrations, and photographs.

In a sense, the whole process of differentiation is one of directed functional mosaicism. It is, however, the accidental or random juxtaposition in the same organism of cells having actually or effectively different genotypes that is generally thought of as true mosaicism. The study of this condition constitutes a perfect meeting place for the fields of genetics and developmental biology, providing, as it does, interrelated information on mutability, cell lineage (including the special problems of cell lineage of the germ line), and the effect of genotype on part of the organism versus the whole. The discovery in recent years that most or all of one X chromosome of the normal mammalian female become randomly inactivated early in development, an event that leads to functional mosaicism, provides us with a great potential tool for the study of gene action. The present paper will attempt to bring together results of diverse observations and experiments (many of them as yet unpublished) bearing on both genetic and functional mosaicism in the mouse.

In conjunction with Gas-Cooled Reactor heat-transfer studies, local and mean heat-transfer factors are predicted from the heat transfer-mass transfer analogy using subliming naphthalene in air. Experimentation was conducted on 1-in.-dis septafoil rods in a 4-in. -dis flow channel with rod center-to center spacings of 1.10, 1.25, and 1.40 in. at a Reynolds modulus of approximately 60,000. Ratios of local mass transfer to mean mass transfer for a given rod vary as much as from 0.7 to 1.3 (outer rod, 1.10-in. spacings). Mean values of the mass-transfer factor are, in general, above that predicted by the correlation j-0.023 NRe^-0.2; as much as 46% got the outer rod t 1.25-in. spacing. The data indicate that for maximum mass transfer and minimum variation of the mass-transfer factor, an optimum rod spacing exists; the best observes is at 1.40-in.

Samples containing 5 to 10 mg of uranium were extracted with hexone (methyl isobutyl ketone) and titrated coulometrically in sulphate media. Relative standard deviations of 0.45% for samples containing 5 mg and 0.56% for 10 mg were determined by precision studies.

Report issued by the Oak Ridge National Laboratory discussing radiation corrosion studies. As stated in the introduction, "the purpose of this experiment was to compare the performance of a large number of materials under similar irradiation and exposure conditions" (p. 1). This report includes tables, illustrations, and photographs.

In-pile loop experiments L-2-15 and L-4-16 were two of a series designed to test the radiation corrosion of Zircaloy-2 and other possible reactor construction materials in UO2SO4 solutions under various conditions of radiation intensities, temperatures, solution compositions, and velocity flow past specimens.

Report issued by the Oak Ridge National Laboratory discussing annual progress made by the Instrumentation and Controls Division during 1966. Descriptions of progress and studies conducted are presented. This report includes tables, illustrations, and photographs.