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

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).

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."

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.

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."

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."

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."

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."

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).

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.

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."

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.

.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.

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.

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).