Technical report. Photomicrographs showing the effect of heating polished uranium surface at 600, 700, 850, and 1000 degrees C, and sandblasted and cut surface at 1000 degrees C are included.

Lecture notes from a training program. "It is the function of the section on radiation chemistry to determine the effects of all radiations and high energy particles produced under the various operating conditions on all the materials which will be exposed to them."

Purpose: "The purpose of the following experiments was to obtain data on the selective extraction of uranium over vanadiur from samples of vanadium ores by leaching with sodium carbonate or sodium bicarbonate solutions, with the object of establishing the time, temperature, and concentration conditions necessary for satisfactory extractions."

This technical report contains day by day experimental data reported in Engineer's Log Book, Electro-Chemistry Department, supporting Report No. EC-11 dated November 15, 1944, by W. L. Grube, Research Laboratories Division, General Motors Corporation.

Technical report describing the investigation of the short-lived activities produced in oxygen compounds by irradiation with pile neutrons. The most prominent of these activities in cooling water is a beta and gamma emitting activity of about 8 second half-life. Because of its production by epicadmium neutrons it was believed to be the 8 second N16 produced in the pile by n,p on O16. The identification has been accomplished and it is established that the 8 second activity is N16. Part 2 of the report deals with the determination of the recoil range of the Al28 atoms formed by pile n,p reaction on Al27.

The distribution of thermal neutrons in a W slug having a one centimeter aluminum end cap has been calculated on the basis of simple diffusion theory. It is found that the average neutron density, and therefore the power output, at the end of the slug is about 34% higher than the density far from the end cap. This result agrees well with the recent Argonne pile experiments (CP-1729).

In making various experimental heat studies a power producing metal slug is simulated by a slug with a graphite rod electrode of 3/8" diameter inserted lengthwise through it. There is a helium filled annular space between the graphite and the inner surface of the slug cylinder. Radiant heat passes from the electrode to the metal; with proper adjustment of the electrode current the slug in the steady state will therefor "produce" the same amount of energy from its exterior surface as it would under operating conditions. The question arises, however, as to how uniform the electrode temperature is along its length. And also, in some cases one end of the electrode is embedded in the slug metal; it is then desirable to know how much heat flows by conduction from the electrode into the slug.

.Technical report describing the transference experiments. The carrying of zirconium and columbium by ferric hydroxide has a very marked dependence on pH. In the experiments it was noticed that the concentration of Zr activity in various solutions changed with time This indicated that the Zr was being adsorbed on the glass. The carrier free trace is adsorbed on glass. This effect must be considered in experiments with Zr tracer in glass apparatus.

Abstract. It has been established that heating samples of graphite during exposure in a pile decreases substantially the observed changes in the elastic modulus and electrical resistance caused by the irradiation. The functional relationship between the percentage changes observed and the temperature of exposure resembles the relationship between the final percentage changes and the temperature of heat treatment after exposure (cf. report CC-1668). Anomalous results reported previously for higher temperatures in CC01669 are now shown to be attributable to a destructive influence on the graphite, probably oxidation of samples exposed in air.

The following report discusses ohmic characteristics in resistors, including methods for determining the polarization characteristics of high megohm resistors that may determine the suitability of these resistors for spectrometric measurements.

Abstract: "Experiments are described wherein uranium metal was heated in ten different refractory materials under conditions approximating those of the uranium J. The refractory crucibles containing the uranium were placed in graphite crucibles and heated in vacuum for four hours at 1800-1850 C by means of an induction furnace. MgO, W, and TiH were found to be unacceptable containers for uranium at these temperatures. BeO, ThO2 and Un showed some reaction with the uranium, whereas UO2, ZrH, CeS, and ThS were only very slightly affected by the uranium during the runs."

From Abstract: "The use of the oxalic acid method for the separation of uranium from mixed thorium-uranium peroxides has been investigated, and appears to be the most satisfactory of the obvious methods of separation. One oxalic acid leach removes nearly all of the uranium from the thorium with approximately one mg Th/L remaining in the uranium solution phase."

From abstract: "In estimating the activities of β-emitting materials used in the Biology Section, most measurements were made with Geiger-Mueller counters, although Lauritsen electroscopes were used in early work. All samples were mounted on flat porcelain capsules."

Abstract: In order to calculate the difference between the number of neutrons which cross the x = o plane before and after the channel has been introduced we consider the number of neutrons which cross an element of cylinder wall at a height x1 and in a direction between (see Figure 5).

Introduction: "The purpose of this work was to develop a high-frequency pulse generator that could be used in conducting research on high-rate trigger pairs and scaler circuits. The need for an instrument of this type arose because there was no parallel commercial instrument having this type arose because there was no parallel commercial instrument having a pulse recurrence frequency over approximately 200,000 pulses per second."

This summary of the research progress meeting on June 3, 1948 discusses the following topics: (1) Photomultipliers (L. Wouters); (2) Positive mesons (C.M.G. Lattes); and (3) Background work in 184-inch program (W. Panofsky).

The following report is based on the observations made during a visit to the Oak Ride National Laboratories of their Redox Pilot Plant equipment.

Summary: "Criticality was considered impossible in any contingency encountered in practice under either of the following conditions which include no safety factor: (a) In any isolated cylinder not more than 5 in. in disruptor, if the total amount of U235 present does not exceed 7.5 Eg. (b) In an isolated vessel of any shape and size, if the total amount of U235 present does not exceed 880 g. An "isolated" vessel is one which does not "see" more than 0.1 [...] other vessels containing fissionable material."

Equations are derived for the rates of heating of objects in induction furnaces and for the maximum temperatures attainable. The equations are primarily useful in designing conducting crucibles, shells, and cylinders so as to increase the power input and decrease heat losses. A very brief treatment is given of the factors which influence the current in the induction coil. The performances of various induction furnaces are compared.

The following report is meant to record the premises upon which the site plan for the NTR is already established.

The following report contains two parts on the analysis of astatine, neptunium and plutonium. Part A discusses a bent crystal focusing X-ray spectrometer that has been designed and built for the observation of the X-and gamma-rays emitted in association with radioactive decay. The instrument uses proportional counter detection and is described, as well as associated electronic circuits. The plutonium L X-rays from Cm-242 and the neptunium L X-rays from Am-241 have been measures. Values of the energies and abundances are reported. Then in Part B, it discusses some isotopes of astatine hitherto unreported that have been observed in bombardments of bismuth on the University of California 184" cyclotron.

Summary: "Six different types of solutions of various concentrations were used to deoxidize uranium chips on a laboratory scale. None of the solutions tested appears to be more desirable than 50% nitric acid for deoxidizing uranium chip on a production scale."

Quarterly progress report on various research projects conducted at the University of California Radiation Laboratory

This report provides a table that summarizes the data taken from investigations of gamma radiation of the Bulk Shielding Reactor in an iron-water mixture. The results are plotted on a graph also provided in this document.