The following report describes the high pressure and temperature homogeneous reactor experiment which has been started at Los Alamos, as well as the hazards and safety aspects for the experiments.

Abstract: "A completely Lagrangian scheme for differencing hydrodynamical equations in two dimensions is described. The method conserves mass exactly. The advantages of Lagrangian over Eulerian schemes are briefly mentioned. An appendix gives the generalization to three dimensions."

Introduction: "During the last quarter, members of the Chemical Development Group have been concerned with six major projects. (1) thermal and radiation properties of organic materials as moderators and coolants, (2) thermal and radiation stability of mirconium hydride, (e) reactor accessibility (transport of radioactive materials in cooling systems, ................. There have been, in addition, a number of smaller service projects, mostly of an analytical nature.:

This report studies the reactions between gaseous uranium hexafluoride and several gaseous reagents for possible analytical application that has been underway while using a buggy designed for gaseous titration studies. This study primarily focuses on methods to analyze gases containing uranium hexafluoride and physically absorbed uranium hexafluoride.

Abstract: "The information contained in this report consists of personnel exposures to radioactive dust resulting from a thorium rolling operation."

Gamma plutonium is found to be orthorhombic with eight atoms in a unit cell of dimension (1t 235 degree C) [formula]. The calculated density is [formula]. The space group is Fddd and the positions of the eight atoms are: [formula]. Each plutonium atom is bonded to ten others at an aver distance of [formula], four being at [formula], two at [formula] and found at [formula]. The mean linear coefficients of thermal expansion are found to be [formula].

Equations governing the variation of U235. U238, Pu239, Pu240, and Pu241 have been derived and their solutions plotted as a function of irradiation time. The initial U235 content of the uranium was varied from 0.5% to 2.0%. The range of conversion ratios was from 0.5 to 1.2. The irradiation was from 0 to 20,000 mwd/ton of fuel. Since a range of initial conversion ratios is associated with each value of enrichment, a solution results in a family of curves for each isotope, and, since the range of enrichments is large, the number of curves is quite large. Translation of the isotope curves to reactivity variation necessitates a calculation requiring a modest amount of time for a particular case but a prohibitive amount of time to cover the entire range of possible combinations of enrichment and initial conversion ratios. Reactivity variation as a function of irradiation time has been computed for a natural uranium reactor with an initial conversion ratio ranging from 0.7 to 1.2 and for 3 types of reactors in which there is a considerable current interest. Similar calculations for other reactors can be made by making use of the isotope curves and the calculation technique set forth in …

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

This quarterly report discusses ongoing research and experiments at Oak Ridge National Laboratory in the Metallurgy Division. This report discusses water cooled reactors, liquid metal cooled reactors, reactor development metallurgy, basic metallurgy, applied metallurgy, and aqueous corrosion.

Deposits of corrosion products form on heat transfer surfaces and in radiation flux zones at temperatures around 500F in stainless steel systems operating with circulating water. The report considers the possible harmful effects of such deposits on heat transfer and fluid flow, as well as factors involved in the origin of these corrosion products and in the mechanisms of deposition. The prevention of deposition by chemical, mechanical, and electrostatic methods is discussed.

Surrounding the core of the Experimental Breeder Reactor (EBR) is located the Internal Blanket (see Figure 2 of Reference 1). This blanket is compromised of natural uranium rods jacketed in stainless steel. The active portion of each rod is made up of five natural uranium slugs 0.873" diameter x 4.050" long. The slugs, stacked one of top of another, are held together and protected by a drawn-on stainless steel tube with welded and closures. These internal blanket rods are located inside the external blanket the manufacture of which has been described previously.

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.

From abstract: "The Standard Pile was first brought to criticality on July 25, 1953. The first two months of operation permitted calibration of the reactor and preparation of it for use as a neutron source in exponential experiments."

From abstract: "A monitor for detection of surface-adsorbed tritium beta particles has been developed. The detecting element is a windowless Geiger tube with the counting gas flowing through it. The normal limit of detection of a single-tube probe is 800 d/m of tritium, while a three-tube probe is probably limited to about 2000 d/m. Both probes have a counting efficiency of about 10% for tritium."

Laboratory studies have shown that the double salt, CaF2-PuF4, can be precipitated by rapid addition of hydro-fluoric acid to solutions containing 25 to 75 g Pu/1, caleium equimolar to plutonium, and 1 to 10 M HNO3. The precipitate, which is subsequently washed with water and dried to 300 degrees C in dehumidified, deoxygenated argon, can be reduced thermally by calcium to give high yields of plutonium metal.

Thirty gram patches of plutonium dioxide can be readily chlorinated by reaction with phosgene or carbon tetrachloride at temperatures of 350 and 450 C respectively. Plutonium trichloride prepared by either method can be reduced to the metal in a hermetically sealed bomb by reaction with calcium. On a twenty gram scale yields of approximately 97 per cent are obtained when a calcium-iodine booster is employed. It has been demonstrated that a method for reduction of plutonium trichloride to the metal without the use of a booster can be development.

Foils of plutonium 239 and uranium 235 have been mounted back to back in a dual ionization fission chamber in the diffracted beam of the Hanford neutron crystal spectrometer. A quantity proportional to the ration of fission cross sections of Pu239 to U235 has been measured as a function of neutron energy from 0.020 to 1.0 electron volts. The results of this investigation are presented graphically in the text.

Unanticipated radioactive contamination of the 200 Areas environs was discovered in the latter part of 1947, about 2.5 years after the startup of the Bismuth Phosphate Separation Plants. It was subsequently established that this contamination was due to radioactive particles emanating from the Separation Plants' stacks, and the need for exhaust ventilation air filtration equipment was recognized. Sand filters were installed in the fall of 1948 in the ventilation systems of the B and T Bismuth Phosphate Plants. These filter units essentially eliminated this contamination problem and have performed satisfactorily to the present time.

The automatic polarograph is ideally suited for the analysis of waste streams for uranium in the Metal Recovery Process, and with modification, it is applicable to other processes, pilot plants, and even to laboratory set ups. The instrument is simple, dependable, and relatively trouble free in operation. It provides an immediate record of the uranium in the waste and, through better control of the process, lower processing costs.

Many procedures for the chemical isolation of the microscopic angular inclusions in rolled uranium have been investigated. Four were selected as most satisfactory for this work and will be described in detail. The procedures are: (1) the copper displacement of the uranium, (2) the electrolytic displacement of the uranium, (3) the chemical dissolution of the uranium in an anhydrous solution of hydrogen chloride in methanol, and (4) the chemical dissolution of the uranium in an aqueous solution of hydrogen chloride and hydrogen peroxide.

Supervision and coordination of shutdown work are often made difficult by lack of visual contact between the front face, rear face and control room. Examples of such conditions are: Removal of process tubes, where close co-separation between front and rear elevator crews is required; Locating freshly discharged slugs accidently lodged on discharge face obstructions where radiation levels are high and optical viewing equipment inadequate; Monitoring of the transfer of hot samples from a process tube into a cask, where permissible exposure time is short and oral briefing of personnel who must perform subsequent operations is inadequate.

Various non-linear calculations for heat conduction in an istropic, homogeneous medium are presented.

This document is a sequel to HW-30226, "Steady State Temperature Distribution in a Solid Slug." A primary feature of the present as well as the former paper is a treatment of the stand heat flow equation in a manner which accounts accurately for the dependence of the thermal conductivity, K, on temperature, v.

In view of the increasing number of methods for determining plutonium in terms of weight rather than radioactivity, a need has arisen for a plutonium compound that can be used as a gravimetric standard. An easily prepared compound that dissolves readily in nitric acid is desirable. The present study was made to determine the feasibility of using plutonium triflouride as a plutonium standard. The preparation, composition, stability, and ignition of the compound are discuss, as are certain properties of the plutonium dioxide resulting from ignition of the trifluoride.