The analysis of a reactor model that is thermally nonlinear is presented. The significant sources of feadback in the closed-loop model ane dilatational changes of the fuel due to axial expansion caused by temperature and metallurgical phase changes. Ths dynamics of this phenomenon has been represented on the Pace electronic analog com puter. The model was subjected to unusually large inputs of sinusoidal power and did not show any drastic tendencies toward being unstable. (auth)

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This compilation was prepared to provide a comprehensive unified summary of the principal elements of the design, operation and nuclear characteristics of the Argonaut Reactor. Its primary content is made up of the theoretical and experimental evaluations of basic reactor parameters, both static and kinetic, which have been made to this date. The Databook includes also some practical information on the reaativity worths of fuel, moderator, and absorbers, as well as some data on radiation in the reactor vicinity. A list of Argonaut type reactors in all countries and a bibliography of Argonaut work are included. (auth)

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BRIC is a two-dimensional nuclear-thermal depletion program to study the effects of moderator boiling on the neutron flux distribution and the depletion of the timedependent isotopes. The program requires an IBM-704 with a memory of 32,768 words and ten tape units. (auth)

A monte Carlo method of solving the one-dimensional equations of nonlinear radiation transport is compared with the Sn "characteristics" method of solution. It is concluded that the Monte Carlo method is accurate and stable and furthermore for a given time-cycle length and space-zone size the Monte Carlo method is more accurate than the Sn method.

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The amounts and kinds of radioactivities produced by detonation of a nuclear explosive are dependent upon the specific design of the explosive. The two design extremes are a pure fission device, which will produce about 1.4 x 10/ sup 23/ fissions, and therefore about 2.8 x 10/sup 23/ fission products, per kiloton of energy released, and a pure thermonuclear device which would produce no fission products, but would produce approximately 10/sup 23/ atoms of tritium per kiloton. In both cases, interaction of escaping neutrons with the materials of the device itself, and with the surrounding media, could lead to further radioactivities. The behavior and ultimate fate of the activities produced by the explosion depend on the composition of the medium in which the detonation occurs, the nature of the detonation, and the chemical species involved. Some typical cases are described. (auth)

This report addresses a monthly progress report for the Chemical Technology Division for Chemical Development Section B during June 1959.

Nitrosyl and fluoride ions are formed in liquid anhydrous hydrogen fluoride when nitric oxide, nitrogen sesquioxide, nitrogen tetroxide, or nitrosyl fluoride, are dissolved. Vapor infrared analysis was used to study the solution composition and gaseous reaction products. These solutions react with metallic uranium, plutonium, zirconium, iron, and aluminum, as well as ceramic uranium oxide and uranium carbide, forming soluble nitrosyl metal fluoride complexes and liberating nitric oxide. The uranium compound identified as nitrosylium hexafluorouranate, NOUF/sub 6/, was made volatile by passing nitrosyl fluoride gas over the dry salt at 500 deg C. (auth)

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The discussion on the costs of nuclear power from stationary plants, designed primarily for the generation of electricity. deals with those plants in operation, being built, or being designed for construction at an early date. An attempt is made to consider the power costs on the basis of consistent definitions and assumptions for the various nuclear plants and for comparable fossil-fuel plants. Information on several new power reactor projects is included. (auth)

The detemnination of precision lattice parameters using a least-squares analytical treatment has been programmed into a computer. Although it was originally coded for the Argonne AVIDAC and GEORGE computers, it is now programmed for the IBM 704. The present program permits the determination of lattice parametsrs and standard errors for the orthorhombic system and for all other crystal systems of higher symmetry. The angular measurements of line positions from a Debye-Scherrer or symmetrical focusing camera or a diffractometer may be given in degrees or radians from several different wavelengths. Provision was made for using aa many as three separate correction terms for eccentricity, absorption, divergence, and others; however, one, two, three, or none at all, may be used. The exact trigonometric function or functions used in these correction terms may be selected from several of those previously suggested. If desired, a weighting factor may also be used for each reflection which may include an observation weight or trigonometric function or both. Examples will be given of lattice parameters obtained for various crystal systems using different correction terms with and without weighting. (auth)

By combining arc casting and electron beam melting, spectroscopically pure tantalum and alloys, suitable for containment of molten Pu-Fe alloys, were produced. The 0.1% W alloy was used for the first LAMPRE loading. The effects of a large number of additives on the corrosion resistance of tantalum were tested. Additions of up to 10% tungsten gave increasing endurance. Specimens of tantalum irradiated with neutrons until 3% converted to tungsten were stitl satisfactory in mechanical properties for reactor use. Either tungsten or the traces of yttrium remaining after arc melting can raise the one-hour recryatatlization temperature of tantalum by 400 deg C. Effects of internal strain, critical strain and precipitation hardening in tantalum alloys were studied. High-temperature annealed tantalum had superior corrosion resistance, while impact extruded and ironed material was better than deep-drawn metal. Mechanical tests on tantalum with added interstitial elements showed that their presence to the extent expected in LAMPRE would be unlikely to weaken the tantalum. Evidence was found that oxygen promotes plutonium attack on tantalum. Small amounts of hydrogen, nitrogen and carbon had no effect on corrosion. (auth)

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The results of the environmental monitoring program at Argonne National Laboratory for 1959 are given. The radioactive content of the environment was measured by performing radiochemical analyses and total activity measurements on several types of materials collected on the ANL site and from locations approximately 10, 25, and 100 miles from the Laboratory. The sampling locations are given in Part II. The average total activities in samples of water, material from the beds of lakes and streams (bottom silt), soil, and plants during 1959 are tabulated. For purposes of comparison, the results obtnined from 1952 through 1959 are included. Air-filter results are also tabulated. Fallout activity was present in most samples at all locations. The amount of fall-out was relatively high during the first part of the year, but decreased markedly during the latter half. By the end of the year the shorter-lived fission products from fall-out were at the lowest level since 1955. Airborne beta activity from fall-out decreased from a maximum of about 5 mu mu c/m/sup 3/ in April to less than 0.1 mu mu c/m/sup 3/ in December. The average for the year, about 2.3 mu mu c/m/sup 3/, was 25% less than for 1958, but …

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An examination was made of a prototype Elk River Reactor fuel element irradiated in the EBWR to a maximum burn-up of 1000 Mwd(t). The assembly, which consisted of an array of type 304 stainless-steel tubes fueled with pellets of 97 wt.% ThO/sub 2/-3 wt.% UO/sub 2/, showed insignificant dimensional changes. Irregular vertical packing of the fuel pellets gave a "banded" appearance to the fuel rods becase of preferential oxide deposition. The brazing material used in the center strap of the assembly showed noticeable corrosion effects. The fuel pellets showed no themal effects and exhibited little cracking. The dimensional stability was excellent. The fuel exhibited good gas-retention characteristics. (auth)

BS>Geologic investigations were made at the Chariot test site, at the mouth of Ogotoruk Creek in the vicinity of Cape Thompson, Alaska. IN the area within a 15-mile radius of the site, bedrock consists entirely of consolidated clastic and chemical sediments. The test excavation lies entirely in frozen mudstone which is complexly folded and faulted. Moisture determinations conducted within 10 ft of the surface indicated that the moisture content of the rock ranges from 3.1% in the thawed mudstone to 12.5% in the frozen mudstone. The use of refrigerated diesel fuel as drilling fluid in Holes Charlie and Dog in 1960 overcame the collapse of drill-hole walls owing to thawing of permafrost experienced in drilling by conventional techniques. Work on coastal processes was focused on establishing a physical background for ecological studies being conducted by other investigators and on characterizing the natural movement of sediment as an aid in evaluating the success and safety of the proposed nuclear test. Piston-core samples from lagoons which do not contain the mouths of rivers and streams showed that only about 10 cm of sediment were laid down in the lagoons since the last major rise of sea level. The shoreline history of the …

Discussions are given of the factors that determine a critical mass, consequences of attaining a critical mass, theory of chain reactions, and margins of safety. Critical and safe conditions are included for the fissionable materi als, U-233, U-235, snd plutonium, both as pure metals and when alloyed with other metals. Considerations are given for heterogeneously and homogeneously moderated systems, and interactions occurring between units in air and water. (B.O.G.)

An experimental and analytical study was made of the heat-transfer characteristics of a mist flow of steam and water droplets flowing vertically upward in a round tube. A simplified analytical model, based on momentum, mass, and energy considerations, was developed which shows qualitatively that severe temperature fluctuations are characteristic of such flows under constant-wall heat-flux conditions. The experimental data showed that the analytical model gave a fairly accurate qualitative description of the tube-wall temperature variation with length. The analysis of the data seemed to indicate that the assumptions of equilibrium between phases and constant values for the mass- transfer coefficient for droplets were incorrect. (auth)

Preliminary work on a new technique of isotopic dilution analysis useful in the measurement of radiogenic Ar content of rocks or mineral samples in age determination is reported. Argon-38 is added to the sampies as the diluting isotope dissolved in a solid glassy silicate which approximates the pertinent properties of the sample. Crushing as well as melting can be used to extract the representative portion of gas needed to apply the isotopic dilution method. In the preliminary investigations orderof-magnitude agreement was obtained with the Ar content of samples determined by conventional technlques. The possibilities of the method include elimination of uncertainties about complete extraction of Ar from samples, use of radioactive counting of argon-39 as a determinative technique, and preferential removai of air contamination by crushing to enabie extension of the K-Ar method to Younger ages. (auth)