Certain oralloy (Oy) lattices were immersed in infinite water for determining critical masses at various low-Oy densities. Three Oy unit sizes were used. In a broad sense the experiment shows safe and unsafe conditions for handling heterogeneous Oy-water mixtures.

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 …

Abstract: "Static measurements have been made of the currents produced by Co-60 gamma irradiation of solid dielectric RG 8/U cable. Sensitivity curves are presented as a function of the magnitude and polarity of the collection voltage to 90 volts. It is shown that the current is due to a polarity- and voltage-sensitive ionization component and to a polarity- and voltage-insensitive component attributed to the Compton process. The total cable sensitivity at -90 volts, with saturation not achieved, was (11 +/- 1) x 10-(-12) coulomb per roentgen-meter of cable, or 0.08 percent of what one would expect from ionization in an air dielectric cable of this volume."

The primary purpose of these researches was to clarify the various functions of organic substrates in bacterial photosynthesis. The following aspects were investigated; (1) metabolic pathways under photosynthetic and oxidative conditions, (2) energy transfers occurring during the metabolism in cell free extracts, and (3) the relationship between photosynthetic rate and light intensity for selected organic substrates. The results of these investigations were summarized in a paper entitled "The Application of Carbon-14 to Studies on Bacterial Photosynthesis" which was submitted to the United Nations as a contribution to the International Conference on the peaceful Uses of Atomic Energy, Geneva, Switzerland, August 8-10, 1955. A reproduction of this paper constitutes a major portion of this report.

This technical report describes a simple way to calculate numerical values of K and l shell photoelectric absorption coefficients (averaged over subshells) for highly ionized atoms.

A report about uranium alloys, fuel element development,, zirconium-uranium alloys, zirconium erosion, and the development of reactor materials.

Theoretical and experimental investigations of the use of soluble poisons (neutron absorbers) to supplement mechanical control rods are summarized. Experimental evaluation of poisons of interest includes in-pile and out-of-pile tests simulating anticipated reactor operating conditions. Other phases of the investigation included methods of poison injection, removal, and cleanup of poison-diluted reactor systems, as well as studies to evaluate possible application of soluble poison control in existing and proposed reactors.

The water plant for a high temperature reactor must be capable of providing several purities of water to the various components of the installation. The actual treatment methods will depend on the location and size of the reactor, the size and sources of the water and the ease of disposal of radioactive wastes. This document examines the needs for the various water purities. It also defines the area of future work to provide the information necessary for the design of water plants for high temperature reactors or for the conversion of existing reactors to recirculation cooling.

The following document describes suggestions on the application of the A-48 ion accelerator beam currents to the Sherwood Program.

In the reference document, a statistical method for analyzing run to rupture tests involving two metal types, a test material and a control standard, is presented. It often happens that more than two metal types are involved in a production test. In this document, the statistical procedure recommended for this situation is presented.

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.

From Abstract: "This paper deals with the vacuum design considerations of large systems involving the application of 8-inch through 32-inch mercury diffusion pumps. The selection, rating, and optimization of pumps are discussed along with the closely allied problem of baffling the pumps. The materials of construction and methods of fabrication to avoid subsequent system contamination are dealt with in detail. System interlocking and its associated instrumentation are illustrated by referral to the operation of a large particle-accelerator vacuum system."

From introduction: "Centrifugal casting appeared to be the only method by which the intricate shape could be produced in a cold mold. With this in mind, a program was initiated for the purpose of determining the feasibility of centrifugally casting plates of uranium-5 w.o chromium and uranium-2 w/o zirconium."

Report discussing the trajectories of blobs of plasma as it travels across a magnetic field. Various observations are made about the blobs, such as the fact that they are diamagnetic, and that they can be either elastically scattered from each other or form a compound entity with a possible toroidal structure. "It is believed that these blobs are actually stable configurations of plasma and magnetic field, having both diamagnetic moment and spin."

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.

From abstract: "Plamons (plasma-magnetic entities) are toroidal "packages" of plasma wrapped up in their own magnetic field. Experimental evidence for the existence of plasmons is adduced and theoretical considerations concerning their various types and their stability are discussed."

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.

The penetration rates of thorium metal by boiling nitric acid were measured as a function of the concentration of fluoride catalyst and of nitric acid. Dissolved thorium and aluminum were found to inhibit the reaction. Thoris exhibited penetration rates much lower than those of thorium metal. In addition to the specific rate measurements, pot type batch dissolvings were carried out to estimate plant time cycles. An empirical mathematical equation was devised which correlates the results of these batch dissolvings and facilitates application of the data to other types of dissolvers.

The possible hazards from the refining and processing of thorium are of wide interest in atomic energy work. A review of the data available was made at Hanford in the last year to support consultations on the hazards of radioisotopes with other plants which may handle thorium. Since a major discrepancy between the published values of air MPC's and the metabolic data was noted, a review of the calculations on thorium was made in order to obtain the best estimates available. This document tabulates the pertinent data and applies them to the calculation of the MPC of thorium.

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.

Mercury to be used in polarography as a dropping mercury electrode must be of the highest purity. The author has found that much of the commercial "triple-distilled" mercury as well as that which is repurified on site is not sufficiently pure and because of this, a study of mercury purification techniques was made and a very satisfactory procedure was tested thoroughly. This procedure is described in detail in this report.

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 …

Introduction: "The extensive use of uranium hexafluoride in the Nier-type mass spectrometers, where the ionization is produced by slow electrons, made a knowledge of the ionization potentials of the various ions desirable. This information was not available and work was accordingly begun to secure such data. The first measurement was made with a VGIA ion gauge and has been described in TEO report CD-310. With this apparatus it was not possible to identify the ionization products and it was presumed that the value reported was for the UF5 ion. When time and equipment became available, the work was continued and the critical potentials of the singly-charged ions determined."

Tests on twenty identically prepared 26 gauge Chromel-Alumel thermocouples have been completed. It appears that wires of this material without protection are unsatisfactory mechanically and thermoelectrically for service in atmospheres of CO₂ at 1000°C.