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.

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.

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.

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.

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.

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.

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.

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.

From abstract: "The methods of applying results of bulk-shielding measurements to the design of reactor shields is outlined. Geometrical transformations for the more common shapes are derived, as are approximate means of calculating leakage of radiation. As an illustration of the methods, the ORNL Lid Tanks and Bulk Shielding Facility data are transformed to a standard geometry and compared. Two direct calculations of water attenuation, using cross sections described in the previous article, are finally compared with the experimental data."

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]

Technical report presenting a consideration of the characteristics of fused salt-ThF4 solutions suitable for use in homogeneous reactors. Presented in tandem with a brief survey of the literature pertaining to such solutions and a summary of the experimental work accomplished. [From Abstract]

Technical report covering the metallurgy of thorium and on fabrication techniques. Report investigates the stability and corrosion resistance of thorium exposed to eutectic NaK, extrusion as a means of fabrication of thorium tubes or rods, and corrosion of large single metal crystals by liquid metals. [From Summary]

This report describes a computer program--Oak Ridge Thermal Ellipsoid Plot program (OR TEP)--for drawing crystal structure illustrations with a mechanical plotter.

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."

From introduction: "This is the ninth of a series of quarterly reports which will cover the progress and results from the conceptual design, economic evaluations and research and development work performed by the General Electric Company as part of the Nuclear Superheat Project."

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 containing ongoing projects and experiments undertaken by the Oak Ridge National Laboratory's Molten-Salt Reactor Program.

From foreword: "This is a documentation of the experiments performed and the data accumulated during the early period of the Experimental Gas-Cooled Reactor (EGCR) fuel element design."

Report containing material from several Oak Ridge National Laboratory groups regarding nuclear safety.

Report containing experiments conducted at the Oak Ridge National Laboratory's Critical Experiments Facility. These experiments involved "determining the critical parameters of the assembly with varying amounts of neutron absorber in the D20 reflector, measuring the relative neutron flux distribution for various conditions of reflector poison and fissile solution concentration, determining the ratio of the absolute thermal-neutron flux in the center of the assembly to the power in the fissile solution , and determining the effect on reactivity of reducing the hydrogen density in the central region of the assembly" (p. 1).

Report containing ongoing research and development of the Oak Ridge National Laboratory's Physics Division.

Report concerning the relatively inexpensive fabrication of an aluminum-based fuel element for the Oak Ridge National Laboratory's 250-Mw Advanced Test Reactor.

Manual for the Oak Ridge National Laboratory's Isotopes Development Center. Includes procedures for the production, storage, and shipment of radioisotopes.

Report concerning the fixation and disposal of toxic waste derived from the Purex solvent extraction process.