This technical report details a process in order to determine the densities of several uranium compounds.

The average energies of neutrons emitted from a graphite column at 22 degrees C were compared by measurement of the cross section of boron for neutrons which are stopped by cadmium. At a distance from the neutron source great enough to insure that the neutrons were in thermal equilibrium the average energies of the emerging neutrons were found to be proportional to the temperature within the limits of the experimental error. A measurement made with boron absorbers which had been thus standardized in the graphite column indicated neutrons emerging from the chain reacting pile to have an average temperature approximate 60 +- 50 degrees above that of thermal neutrons emerging from the graphite column at 22 degrees C. Such a measurement made inside the chain reacting pile indicated the average temperature of neutrons therein to be about 65 degrees +- 15 degrees above the average temperature of neutrons in the graphite column.

The temperature coefficient is calculated for various lattice arrangements, taking into account the variation of [formula], suggested by Fermi. Four contributions are included: leakage, levelling of the dip in thermal neutron density in the lump, resonance absorption, and hardening of the neutrons as they penetrate a metal lump. The departure of neutron temperature from lattice temperature decreases the total coefficient. Values are given for 3 typical piles; in general, the larger the uranium elements, the less stable the pile. A rod lattice tends to be more stable. A pile with metal lumps over 50 lbs. will be unstable.

Radial flattening of activity in the cores of spherical and cylindrical piles is discussed in connection with pile control and power improvement. Partial flattening as a result of k loss from temperature rise is also considered.

Abstract. A review of all work on uranium hydride published in the CC, CT, CN and CE reports to January 1, 1944, is presented. Some additional information not yet published has been included, so this report includes all data known from the above sources and at Ames to the above date. This report supersedes all previous report on uranium hydride coming out of the Ames laboratory.

Technical report. The effect of temperature during pile exposure on the fast-neutron-induced change in properties of graphite was studied. Temperatures up to 125 degrees C have no effect upon the rate of increase of elastic modulus; pieces exposed at 300 degrees C on the other hand show no change at all in elastic modulus. The increase in electrical resistance s an inverse function of the temperature of exposure at all temperatures in the range 60 to 300 degrees C.

The problem of lining a hollow aluminum sphere, 10 inches i.d., with lunes of heavy metal foil, was assigned to this group by Dr. E. Creutz. The work was carried out under the direct supervision of Dr. D.H. Gurinsky. the problem was divided naturally into tow parts: first, forming fitting the lunes, and second, cementing hem to the inside of the sphere.

Abstract. Temperatures are measured at two points in an internally heated jacketed slug which is cooled by water flowing in an off-center annulus around the slug. The variations of these temperatures with water velocity, water temperature, power, and the amount the annulus is off center are measured. The temperature near the slug surface which approaches and comes in contact with the water jacket does not increase as much as anticipated. The temperature near the slug surface on the side which is moved away from the water jacket increases nearly as much as on the side approaching the slug. An explanation for this unexpected increase of temperature as on side moving away from the jacket is given.

Abstract. Steady-state temperatures were measured in an electrically heated brass cylinder which was water cooled in a four-ribbed Al tube. Thermal transfer coefficients h were calculated from the measured temperatures. Curves of h values are presented for the regions of high and low ribs. the h curve is found to show a much sharper break in the region of high rib than in a low rib region. There is some evidence that h decreases linearly with annular thickness in the range considered. The low rib is found to exert a much greater effect than the high rib in decreasing the h value at points distant from the rib.

From introduction: "This article gives an account of the determination of the complete crystal structures of the normal orthophosphates of barium and strontium."

Introduction. the colorimetric determination of iron based on the formation of the colored ferrous-1,10-phenanthroline complex has been used successfully by a number of investigators. In this technical report, its adaptation to the routine determination of iron in cerium, thorium, and beryllium metals and their compounds is described.

Technical report describing the purification and separation by distillation of UO2F2 from D2O. In the experiment which is discussed 2,129.6 lbs of UO2F2 were dissolved in 6,605 lbs of D2O. The average isotopic purity of the D2O decreased during the distillation from 99.77% to 99.73%. The dissolved impurities were less than those present originally in the heavy water.

From abstract: "Experiments covering the coprecipitation of Thorium and Uranium peroxides are described on synthetic and actual 1300 cycle machine wash effluents."

Abstract. Samples of pile graphite, irradiated in a test-hole at Hanford for 15 months, have been assayed for radioactive C14, yielding 0.38 ± 0.04 microcuries per gram. At this level of activity, the pile graphite contains very valuable amounts of C14. The relation between the above assay and the probable average assay of pile graphite is discussed, and it is concluded that the latter is almost certainly above 0.3 uc/ gram. Controlled oxidation of this graphite, either with oxygen at ~ 750°C, or with chromic acid "cleaning solution" at room temperature, yields early fractions which are highly enriched in C14. Concentrations of 5-fold with oxygen, and 50-fold with CRO{sub3}, have been observed. The relation between the observed enrichment and the Wigner effect is discussed, and a mechanism accounting for the observations put forward. According to this, about 25% of the stable carbon atoms in the lattice have been displaced by Wigner effect, a large fraction of which have healed the migrating to crystal edges. All the C14 atoms have been displaced, and the same fraction of these migrate to the edges. The enrichment then results from surface oxidation, in the oxygen case. Predictions are made on the basis of this …

Abstract: Test distillations were made with Kinney and diffusion pump oils under vacuum in order to determine accurately the temperature range over which satisfactory distillate may be collected. Also recommendations are made as to the most advisable type of heating equipment necessary to produce the required heat and maintain the desired temperature. In addition, several important refinements in the distillation equipment were checked for operational characteristics and for their efficiency in aiding the production of uranium-free distillates.

The following report examines a set of beryllium metal rods through pile radiation, taking measurements, and analyzing differences between irradiated and radiated rod samples.

This summary of the research progress meeting on June 10, 1948 discusses the following topics: (1) 184-inch cyclotron (J. Vale); (2) Slow neutrons in the shielding of the 184-inch cyclotron (W. Benson); and (3) Fission of thorium with alpha particles (A. Newton).

The following memorandum outlines the procedures used on the neutralization of HNO3 in redox ICU and IAW streams, and the factors influencing their choice. The procedures involve a) hexone removal by evaporation in the presence of a retardant, b) destruction of the retardant, c) nitric acid elimination by boiling with aluminum and d) concentration of the remaining solution by evaporation.

Abstract: "The sensitivity to fast neutrons of a CP Meter ionization chamber of the type used for health physics beta and gamma survey measurements has been investigated."

Report discussing progress made by the National Research Corporation in developing preparation methods for ductile zirconium for the month of July, 1949.

The following report discusses the building design and development of the reactor building, Building 1105, for Argonne National Laboratory, that is meant to house the reactor.

Abstract: A report was submitted describing the apparatus which is proposed for further dissociation experiments and approval for necessary construction was requested. While awaiting approval, detailed designs were completed and some experimental work necessary for this design was carried out. The casting equipment was modified in accordance with experimental work for casting of zirconium. The apparatus was tested and it was found possible to form and withdraw and ingot of zirconium.

The following report describes polarographic methods that determine saturated aliphatic carbonyl compounds.

Report discussing progress made by the National Research Corporation in developing preparation of ductile zirconium for the month of October, 1949.