The maximum nuclear accident which could occur in a Na-cooled, Be moderated, Pu and power producing reactor is estimated theoretically. (T.R.H.) 2O82 Results of nuclear calculations for a variety of compositions of fast, heterogeneous, sodium-cooled, U-235-fueled, plutonium- and power-producing reactors are reported. Core compositions typical of plate-, pin-, or wire-type fuel elements and with uranium as metal, alloy, and oxide were considered. These compositions included atom ratios in the following range: U-23B to U-235 from 2 to 8; sodium to U-235 from 1.5 to 12; iron to U-235 from 5 to 18; and vanadium to U-235 from 11 to 33. Calculations were performed to determine the effect of lead and iron reflectors between the core and blanket. Both natural and depleted uranium were evaluated as the blanket fertile material. Reactors were compared on a basis of conversion ratio, specific power, and the product of both. The calculated results are in general agreement with the experimental results from fast reactor assemblies. An analysis of the effect of new cross-section values as they became available is included. (auth)

An experiment is described in which an attempt is made to follow the path of oxygen in photosynthesis by the use of O{sup 18} as a tracer.

A method has been adapted from ion exchange studies for removal of the fission products, Cs-137, Sr-90, and the rare earths for both untreated urine samples and the supernates from the precipitation steps in the TTA procedure for plutonium. Because of the excessive amount of eluant necessary to separate the fission products and the resulting time required to run a separation, a method was developed to remove the Sr-Y, Ce and Pr by chemical means and Cs from the raffinate of this extraction by ion exchange. It should be noted that Cs is easily separated from Pu in the separations plant, and that is presence as a contaminate in the outer areas is not as probable as the other long-lived fission products. This fact has been born out in three years of analyzing contaminated samples from the 200 Area by the H.I. Development Divisions.

Two new positron active isotopes, B{sup 8} and Na{sup 20}, have been found to decay to excited states of Be{sup 8} and Ne{sup 20}, which in turn decay 'instantaneously' by alpha emission. Their half-lives are 0.65 {+-} 0.1 sec. and 1/4 sec. respectively. N{sup 12} is also found to have a low energy positron group which leads to an {alpha}-unstable excited state in C{sup 12}. The masses of B{sup 8} and Na{sup 20} are 8.027 and 20.015 respectively. B{sup 8} decays by a 13.7 {+-} 0.3 Mev positron, through the same excited state of Be{sup 8} as does Li{sup 8}. Estimates of the energies of the excited state in C{sup 12} and Ne{sup 20} are made.

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Observations on the shifts of nuclear resonances in metals (Id {sup 7}, Na {sup 23}, Ou {sup 63}, Be {sup 9}, Fe {sup 207}, A1 {sup 27} and Oa {sup 69}) due to free electron paramagnetism; comparison with theoretical values.

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Discussion of electronic paramagnetic resonance for the free radical a, a-diphenyl β-picryl hydrazyl as observed by its effect on the transmission of microwaves through a TE {sub 01} cavity with a small amount of the free radical placed approximately on the axis of the cavity; the half-width of this resonance at half maximum absorption was 1.45 oersteds.

Describes a simple model, based on nuclear shell considerations, which leads to the proper behavior of known nuclear quadrupole moments, although predictions of the magnitudes of some quadrupole moments are seriously in error.

This document will be used to record the major equipment items and arrangements for purposes of: guidance of the design effort; and information to be used in the preparation of the project proposal. The purpose of the P-10-X project is to increase production of tritium by adding slug storage, can opening, extraction lines, and shipping facilities. Part 1 describes changes to Building 108-B including process equipment, process handling facilities, contamination control, ventilation, air monitoring and air sampling, electrical services, architecture, and piping. Part 2 describes auxiliary facilities which includes facilities for transfer of fuel slugs to ARCO, storage facilities for fuel slugs, and special devices.

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Exploration of various types of power plant cycles for nuclear propelled aircraft has been continued during this quarter. The principal current objective of the project is the development of information which will make an intelligent choice of the basic power plant cycle possible. It is still hoped that this choice can be made late in 1950. The survey studies which have been under way for several months continued during the quarter. These consist of analyses and rough preliminary layouts for various types of aircraft, using each of the several basic cycles which have been seriously considered for each of the three phases of development. Although it is still extremely premature to discuss the relative merits of the various cycles, the information so for developed discloses some cycle differences which may, if confirmed by additional work, be significant. In this respect, there have been no recent major changes in the comparative standings of the cycles.

A study of the effect of feed and ether acidity on the extraction of vanadium and molybdenum from process solutions by ethyl ether is described. Results of batch and continuous extraction tests on the extraction of uranium from process slurries by tributyl phosphate-Gulfspray naphtha are presented, including studies of the effects of feed and scrub acidities on the concurrent extraction of molybdenum. The effect of temperature on the stripping of uranium from tributyl phosphate was studied briefly. Results from fractional precipitation of MgX from dilute sulfuric acid solutions indicate that, in the presence of sufficient iron, phosphate is precipitated as ferric phosphate, and not as uranyl pho sphate. (auth)

This volume is a quarterly progress report for the University of Chicago Toxicology Laboratory. Thirteen individual reports are contain herein and each has been separately indexed and abstracted for the database.

This quarterly progress report gives an overview of the University of Rochester Atomic Energy Project for April 1, 1950 thru June 30, 1950. Sections included are entitled (1) Biological Effects of External Radiation (X-rays and gamma rays), (2) Biological Effects of External Radiation (Infra-red and ultraviolet), (3) Biological effects of radioactive materials (polonium, radon, thoron, and miscellaneous project materials), (4) Uranium, (5) Beryllium, (7) thorium, (8) fluoride, (9) zirconium, (10) special materials, (11) Isotopes, (12) Outside services, (12) Project health, (13) Health physics, (14) Special Clinical Service, and (15) Instrumentation (Spectroscopy, electron microscopy, x-ray and nuclear radiation detectors, x-ray diffraction, and electronics).

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Authorization has been received in the form of Modification No. 5 to Directive HW-158, dated March 23, 1951 to provide the necessary equipment and piping in the currently planned UO{sub 3} plant to permit the segregation of UO{sub 3} arising from the processing of stored metal waste (TBP) from that arising from ``current`` pile operation (Redox). In anticipation of this, the S Division, Manufacturing Divisions, requested that a study be made of the feasibility and cost of providing facilities for such segregation. This report is the result of that study. It concludes that by providing additional liquid storage and handling equipment, the desired segregation can be accomplished at a cost estimated to be approximately $128,000. $106,500 would be for Construction and $21,500 for Engineering. The schedule for this work will be reflected in the forthcoming modification to the C-361 Project Proposal. The general method of operation is alternately to store and process solution from TBP and Redox. The solution from TEP will be of a composition equivalent to the formula UNH and will require five days each week to process in the decomposition pots. The solution from Redox is received as 60% UNH and is batch concentrated in the storage …

The start-up of the DR Pile at a time when every effort was being made to increase the power levels of the older piles, suggested the possibility of studying, during the early damage period, some of the conditions which were limiting the operating levels of the old piles. Of the operational limitations restricting the power level of the old piles, the maximum graphite temperature is the most severe and actually determines the operating level of the B, D, and F Piles and, to some extent, the H Pile. Though it was known that irradiation damage of the central part of the old piles had been arrested by the increased temperatures which resulted from the replacement of helium by carbon dioxide as the pile atmosphere, the extent of damage to be expected at the new DR Pile, where graphite temperatures were to be maintained as high as possible from the start, was not known, except for the H Pile startup where conditions were somewhat different. This report is intended to be a summary of the lattice conductance variations at the DR Pile during the first five months of operation. From the recorded conductances an attempt has been made to estimate the …

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