A set of 69 pile yield curves for the production of plutonium, americium, and curium isotopes in a neutron flux of 5 x 10<sup>14 cm<sup>-2 sec<sup>-1 is given. The differential analyzer of the University of California Radiation Laboratory was used in obtaining the curves. The curves are given also on log-log plots for comparison.

Initial rough measurements of the quality of the gamma radiation from Co-60 in air indicated agreement with the theoretical calculations of Spencer and Fano for an infinite water medium. Further experiments were performed, duplicating the conditions assumed in the calculations. Since the spectral region between 100 kev and 1 mev has already been examined by Hayward, it was decided to investigate in detail the region below 100 kev and above 1.0 mev. Total radiation dosage measurements were made in water using Victoreen ion chambers. The build-up factor was measured as a function of distance. Good agreement was obtained with the results of White. The spectrum below 150 kev was examined with a small NaI(Tl) scintillation counter and both the shape of the spectrum and the attenuation as a function of distance was in good agreement with the calculations. At distance less than 30 cm from the source the spectral shape changed, gradually broadening with the peak shifting to higher energies. The primary region above 1.0 mev was examined using a large NaI(Tl) crystal, and the gradual loss of resolution in the two primaries as a function of distance with an increase in lower energy events was shown. The measurements to …

Observations on sheep representing flocks in Utah adjacent to the Nevada Proving Ground were compared with findings made on experimental sheep exposed to various amounts of radioiodine. The Utah sheep showed no evidence of the radiation damage observed in experimentally treated sheep. Estimations of amounts of radioiodine on vegetation required to cause serious thyroid damage following a contamination event are included.

The first of two general methods are discussed based on the removal of the thin layer of aluminum to which graphite adheres. Two electro-polishing techniques, an electrolytic etch, an anodization-deanodication cycle and two chemical etches are described.

Abstract: "In a circulating-fuel reactor, the circulation of the fuel cause a damping of power oscillations of the reactor. This is demonstrated under the assumption, that there is no mechanical vibration coupled with the oscillation of reactor power, and that the shapes of the hydrodynamic flow does not vary with time."

Abstract: "Rare-earth analyses were performed on several samples of refined uranium oxide and nitrate, using a modified cellulose column procedure. Rare earths were not detectable in samples of 0.03 shotgun of less. Detection limits were from 0.0005 to 0.015 ppm. Negligible quantities of low-cross-section rare earths were found in less pure uranium samples, obtained during start-up operations of the pilot plant at the Feed Materials Production Center, primarily those rare earths of greater than average abundance in nature. No correlation was found between rare-earth content and shotgun values. Rare earths do not appear to be contributing significantly to the neutron absorption of refined uranium. A modified cellulose column procedure, which includes a preconcentration solvent-extraction step, is described. Radioactive tracer tests indicating rare-earth recoveries by the method of >98 per cent are reported."

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,

Introduction: "In the evaluation of pile designs it is necessary to know how the production varies with the number of tubes. It has been possible to solve the problem in terms of some general parameters whose values may be quickly computed for any specific design when the pertinent information is available."

This report is the culmination of a year of progress and planning in the high-energy particle field. During this year the Brookhaven Cosmotron has been successfully completed and brought into operation for research at 2.3 Bev. Preliminary experimental results with the copious output of π-mesons are in process of publication. Multiple production of mesons has been observed, a few V-particles detected, and the interactions of π-mesons in hydrogen have been studied. Yet it already appears that higher energies will be needed to produce and study the several new heavy particles detected in cosmic ray observations.

Thermal cycling tests on uranium have shown that the dimensional changes that occur on cycling in the alpha range are directly related to both the texture of the material and its grain size: cold rolled rods generally elongate in the direction of rolling, while the same rods, after a beta-treatment, grow at rates several orders of magnitude lower. This considerable improvement by beta-treatment has been attributed to the texture randomization accompanying the heat-treatment. In the course of this heat-treatment, however, considerable grain growth occurs, which ahs the effect of causing surface roughening on cycling (also referred to as "bumping"); fine grained material generally retains a smooth surface. These observations led to the speculation that the most desirable structure in uranium, from standpoint of dimensional stability, is one that combines both a random texture and a fine grain size. Heat treatment of rolled rod offered no easy method to obtain such a product; powder metallurgical techniques, however, appeared ideally suited for the purpose. To this end, early in 1949, the Sylvania Electric Products Company initiated a program to develop suitable techniques for producing uranium powder compacts having the above-mentioned desired characteristics. Because of the availability of thermal cycling equipment at Argonne, …

The very strong flux gradient in the MTR reflector might be thought to be some cause of worry. However, this gradient will be minimized by the presence of the large block of aluminum, which, because of its small effect on neutrons, will tend to flatten the neutron flux in its vicinity. Advantage should be taken of the shape of the test facility by placing the water hole corner closest to the MTR core. This placement should take best advantage of the flattening potentialities of the slowing-down flux from the test slugs, by placing the nearest (beryllium) moderator on the low flux side of the assembly.

The causes for loss of uranium originally adsorbed on strong base anion exchange resins from Rand cyanide residue leach liquors after prolonged passage of such liquors through resin columns were investigated.

The hydrogen contents of several types of fabricated uranium have been determined by a vacuum method and expressed in terms of ccH2/ccU. The data indicate that alpha-rolled metal contains about 0.25 ccH2(STP)/ccU whereas beta heat-treated uranium yielded values between 0.30 and 0.37 cc per cc. Restricted efforts were made to determine where in the heat treatment the 5 to 10 cc of hydrogen per slug were taken up. It appears that no one operation is wholly responsible for this additional gas, although reactions between beta heat treated surfaces containing microscopic defects, and nitric acid may possibly play a large role. In general it may be said that slug produced by powder metallurgical techniques contain less hydrogen than pieces produced by rolling and heat treatment.

A manipulator designed to support an irradiated slug at the bottom of the viewing basin, so that an operator could view it through a binocular telescope and be able to see all surfaces, was designed. Hydraulic power, using water, operates the manipulator and gears.

Quarterly updates on nuclear chemistry, bio-organic chemistry, general chemistry, chemical engineering (process chemistry).