Report issued by the Argonne National Laboratory discussing the thermodynamics and electronic distribution of high temperatures. As stated in the introduction, "in the present paper, a model for computing is described which takes into account in detail the interactions between bound electrons and the average interaction of the bound electrons with the free ones" (p. 4). This report includes tables, and illustrations.

Report issued by the Argonne National Laboratory discussing engineering properties of diphenyl. As stated in the abstract, "data collected from the literature on the vapor pressure, enthalpy, liquid density, and vapor density of pure diphenyl are presented. A Mollier diagram, a temperature entropy diagram, and data on viscosity of diphenyl as a function of temperature are also presented" (p. 5). This report includes tables, and illustrations.

This report describes the specifications, materials and the sequence of operations used to found and fabricate the first charge of enriched uranium fuel in the Experimental Breeder Reactor.

This report was written by different scientist on various experiments of solid state, physical chemistry, radiochemistry and analytical, and special problems.

This report describes the first estimation of the beta half-life of Pu241 and was made by determining the beta activity associated with plutonium formed by (d,xn) reactions on U258.

The report is the third in a series of interim reports on the climatological studies which are being conducted at the Argonne National Laboratory. First report appeared as document ANL-4538 and covered the period July, 1949 through June, 1950; the second report, ANL-4793, covered the period July, 1950 through June, 1951. These annual reports are offered for purposes of information only; broad conclusions regarding the climate of this site must await the accumulation of a statistically significant amount of data.

The susceptibleness of certain "ceramic" substances to extreme radiation damage (such as that observed in graphite) as indicated by changes in dimensions and heat content is discussed in terms of the experimental evidence which is available.

On June 2, 1952, 15:52 hours, a large reactivity change was made manually in a ZPR-1 assembly causing a power excursion of about one kwh, which resulted in damage to the reactor core components and radiation exposure of some of the operating personnel to perhaps several rep. None of the contributing causes is reviewed here nor are the measures which were taken to reduce the probability of a recurrence discussed since these are considered administrative matters beyond the scope of this technical report. It is intended only to describe the incident, estimate the exposures and present available clinical data.

Water corrosion tests on mechanically jacketed and pinholed thorium slugs show that these slugs fail in a manner similar to that observed for mechanically jacketed and tested uranium slugs. The proposed mechanism for the water corrosion of these jacketed slugs is analogous to the water corrosion mechanism of jacketed uranium slugs presented in the project lecture. A bare thorium slug appeared to be more resistant to corrosion by water than a mechanically jacketed slug during the first half of the autoclave test. After approximately 90 hours of testing both the bare and the mechanically jacketed thorium slugs were severely corroded by water.

This supplement includes reports on (1) transmission measurements with the fast chopper, (2) a search for Pu244, (3) crystallographic studies, (4) resonance flux in CP-[gamma], (5) multigroup methods for concentrated fast assemblies, (6) work on the ZPR-1 Reactor, and (7) work on the ZPR-II Reactor.

An analytical method has been developed for zirconium and fluoride ions in the system resulting from the dissolution of fuel elements in hydrofluoric acid. The method is based on determination of the density and electrical conductivity of the dissolved metal solution.

This report deals with the (1.1) physical properties of graphite, (1.2) effects of pile irradiation on the properties of graphite, (1.3) effect of irradiation on "ceramic" materials, (1.4) effects of radiation on ice -- the x-ray induced luminescence of ice, (1.5) investigation of color centers and other optical properties of single crystals. (2.1) radiation chemistry of liquids, (2.2) application of mass spectrometry to chemical problems, (2.3) vapor pressure and heat of vaporization of uranium, (3.1) nuclear properties of Zr93 and Nb93m from fission, (3.2) mass distribution in the spontaneous fission of Cm242, (3.3) Upper limit to the lifetimes of the first excited states of Th236, U234, and Pu236, (3.4) on the one-body model of alpha radioactivity, (4.1) spectrographic analysis, (4.2) chemical analysis, (5.1) paramagnetic resonance measurements, and (5.2) the 60-inch cyclotron.

This report deals with the (1.1) physical properties of graphite, (1.2) effects of pile irradiation on the properties of graphite, (1.3) effect of irradiation on "ceramic" materials, (1.4) effects of radiation on ice -- the x-ray induced luminescence of ice, (1.5) investigation of color centers and other optical properties of single crystals. (2.1) radiation chemistry of liquids, (2.2) application of mass spectrometry to chemical problems, (2.3) vapor pressure and heat of vaporization of uranium, (3.1) nuclear properties of Zr93 and Nb93m from fission, (3.2) mass distribution in the spontaneous fission of Cm242, (3.3) Upper limit to the lifetimes of the first excited states of Th236, U234, and Pu236, (3.4) on the one-body model of alpha radioactivity, (4.1) spectrographic analysis, (4.2) chemical analysis, (5.1) paramagnetic resonance measurements, and (5.2) the 60-inch cyclotron.

A method for monitoring radiation damage irradiations using the change of the electrical conductivity of graphite is described. Results of monitoring operations in a number of locations are given. An attempt is made to explain the damage rate found in the converter at CP-3. An estimate of the flux spectrum in VT-4 and the converter of CP-3 is made and the damage rate is computed according to theories of Seitz and James. It is found that the experimental results are more in accord with the predictions of Seitz. A number of corrections to James' report, ORNL-307, are noted in an appendix. It is shown that some information about the fast flux spectrum can be inferred from the radiation damage rate.

The use of bromine trifluoride solution has been investigated for the preparation of purified uranium hexafluoride from ore concentrates. The best yields were obtained with the use of antimony pentafluoride solutions in bromine trifluoride, and less fluorine was consumed in the case of previously hydro fluorinated samples. This approach appears to be technologically sound and may prove economically superior to existing procedures in the case of newly constructed facilities.

The cup assembly of the Experimental Breeder Reactor (EBR) consists of blanket bricks, inner rings, and safety plug, all of natural uranium. The design of the finish machined brick is shown in Figure 1. These pie shaped bricks when stacked together, 12 bricks arranged in circular form and stacked seven rings high, comprise the cylindrical portion of the outer blanket, 17.875" I.D. x 30.875" O.D. after machining and canning. The inner ring, which is shown in Figure 2, fits inside the bottom layer of bricks. The circular opening in the center of the inner ring is closed by the safety plug shown in Figure 3.

Report issued by the Argonne National Laboratory covering the quarterly report from the Reactor Engineering Division. A summary of reactor programs, research, designs, development, and experiments are presented. This report includes tables, illustrations, and photographs.

This report describes the progress on the experimental breeder reactor. It focuses on the approach to critical experiments, calibration of controls and flues and flux distributions.

Experiments are described in which the pile-induced changes in electrical resistivity and elastic modulus of graphite were investigated as functions of the sample temperature during bombardment and the amount of bombardment. The data are for relatively low bombardment times (up to ca. 20 L-units) and temperatures (up to 340*C) and are not sufficiently extensive to permit unequivocal conclusions.

Corrosion rates of present reactor grade uranium were measured in boiling distilled water and were found to have higher values almost by a factor of two then previously reported corrosion rates of uranium. Mallinckrodt biscuit metal showed corrosion rates in the same medium somewhat lower than reactor grade uranium, and high purity metal prepared at Argonne National Laboratory corroded considerably less rapidly than the biscuit metal.

Through the efforts of the Hanford Engineer Works a quantity of neptunium-237 was separated from uranium waste solutions by a modification of the standard plutonium precipitation process, This material, as concentrates, was shipped to Argonne for final isolation and purification of the neptunium.

A spectrometer has been used with a hollow prism electrically heated to 70 C to measure the refractive indices of solutions of uranium hexafluoride in bromine trifluoride and uranium hexafluoride in bromine pentafluoride. The refractive indices of the two binary systems have been expressed as a function of composition.

Dissolution of the large number of samples obtained from the natural uranium blanket of the Experimental Breeder Reactor after approximately 485,000 kw.-hr. of operation has been completed, and analysis of these samples for uranium consumed and plutonium formed is well along. An attempt is being made to distinguish quantitatively between uranium-238 and uranium-235 fission in the blanket area by determining the ratio of ruthenium-106 to cesium-137 in the fission products.

A method is described for preparing plaster of Paris replicas of irradiated fuel slugs. An impression mold is made by pouring the plaster about a fuel slug held in a specially designed holder. The slug is removed from the holder and the impression mold issued to cast a replica, also made of plaster of Paris. The replicas, including one end only, are accurate reproduction of the original slug for surface features down to about one-half mil and for dimensions within one or two mills. Two dental impression plasters were found to give satisfactory results. With the limits mentioned, the process will serve the purpose of preserving models of radioactive specimens for use as "museum pieces." However, the procedures are very exacting in achieving such results.