This report provides uranium and other elemental data resulting from the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Craig quadrangle, Colorado.

This report provides uranium and other elemental data resulting from the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Dillon quadrangle, Montana/Idaho.

from Summary: This report describes work done in Hamilton, Montanan/Idaho, National Topographic Map Series (NTMS) quadrangle (1:250 000 scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

The work of the Laboratory has greatly expanded into applications of nuclear energy which are significant for national defense and security, but are not directly connected with weapons development. It was felt, therefore, that a description of the non weapons activities of the Laboratory would serve a useful purpose at this time. For classification reasons, it has been necessary to issue the report in three parts; the third part concerns power reactor experiments.

A uranium metal critical assembly consisted of a 15 inch diameter core with an average U235 content of 16-1/4%, surrounded by a 3 inch thick natural uranium reflector. The critical mass was 692 kg of core material.

The work of the Laboratory has expanded into applications of nuclear energy which are significant for natural defense and security, but are not directly connected with weapons development. It was felt, therefore, that a description of the nonweapons activities of the Laboratory would serve a useful purpose at this time.. For classification reasons, it has been necessary to issue the report in three parts; this is the first and is concerned with controlled thermonuclear reactions.

A new method to procure RaLa sources was proposed by Group CMR-10, Los Alamos Scientific Laboratory. This method depended upon irradiation of small-diameter U235 wire in the Materials Testing Reactor, Arco, Idaho. A procedure for cladding and sealing U235 wire in stainless steel tubing, by drawing, plugging the tube ends, and welding, was developed, tested, and proved to be satisfactory.

Certain oralloy (Oy) lattices were immersed in infinite water for determining critical masses at various low-Oy densities. Three Oy unit sizes were used. In a broad sense the experiment shows safe and unsafe conditions for handling heterogeneous Oy-water mixtures.

The transition region between short, but controlled, pile periods and uncontrolled, highly-supercritical conditions has been investigated with an unreflected, spherical uranium assembly (Godiva). This study was undertaken because knowledge of the behavior of supercritical systems is important in evaluation of reactor hazards and also the hazards of less standard operations involving possibly critical quantities of active material.

In this report, the stability of a pinched fluid is studied theoretically, under the combined influence of a longitudinal magnetic field and conducting exterior shell. Conditions allowing complete stability are found.

As an alternative to recovering Ba140 from the spent MTR fuel assemblies a new enriched-uranium fuel pin was designed for irradiation. Two specimens, each containing about 3 g. of uranium (93% enriched), were irradiated to 1.3% and about 18% burnup. Examination after irradiation indicated that design improvements were needed; photographs are presented to illustrate the damage incurred during irradiation. A simple inorganic chemical process using precipitation and filtration techniques was developed to separate Ba140 from other fission products and uranium.

The two plutonium-metal critical assemblies that have been studied at Pajarito Site are Jezebel, bare plutonium; and Popsy, a plutonium core in a thick normal uranium reflector. These assemblies and their properties are described.

The experiments described in this report were designed to explore the feasibility of precipitating plutonium from 35 percent TBP in Gulf BT using peroxide, fluoride, sulfide, sulfite, sulfate, cocalate, hydroxide, iodate and phosphate ions from anhydrous, dilute and concentrated aqueous sources.

A detailed study of the activation of low-reactivity UO2 particles toward HF by successive oxidation and reduction was carried out. The effect of repeated successive oxidation and reduction on the reactivity of the UO2 source material toward HF was evaluated by hydrofluorination.

Radiochemically determined mass-yield curves are given for the fission of U235 and U236 by 14.7-Mev neutrons.

Thermal neutron measurements made on five weapons during Operation Teapot indicated that these neutrons contribute at most 2 per cent of the total neutron dose in air. However, the total fluxes were high and thermal neutrons may become important under shielding conditions and may significantly affect the responses of the film badges and certain sensitive dose detectors, especially when the neutron to gamma flux ratio is high.

An analytical procedure for 0.04 to 1.6 percent ruthenium in plutonium metal was developed. Determination of ruthenium in metallic plutonium was investigated as part of a program for securing analytical procedures for various metals in plutonium. However, results of the investigation are given in this report with emphasis on the determination of ruthenium in plutonium chloride solutions. Specifically, this report is primarily concerned with the separation and determination of 40 to 400 micrograms of ruthenium in a hydrochloric acid solution of 25 to 100 milligrams of plutonium.

Reflected cylindrical exponential columns of bare and natural uranium were constructed of stacked plates of oralloy (93.4%) and tuballoy. Average concentrations of U235 ranging from 0,72% to 9.18% were investigated. Flux distributions, buckling values, and spectral indices were obtained. The indicated U235 concentration for infinite critical mass is about 5.5%.

A spectrophotometric method is described for the determination of aluminum in plutonium-aluminum alloys. The alloys are dissolved in parchloric acid and the diluted solution electrolyzed using a mercury cathode to remove any iron present which would interfere in the subsequent analysis. Then plutonium is then separated from the aluminum by precipitation as the insoluble iodate, and the aluminum determined in the supernatant solution using aluminon as a color reagent.

Two methods are described for the quantitative determination of vanadium in uranium-vanadium alloys. A procedure is also described for the quantitative determination of vanadium and chromium in uranium-chromium-vanadium alloys.

Data on critical configurations of fissionable metals are summarized in a form emphasizing the influence of conditions commonly of concern in nuclear safety questions.

This report describes a production scale procedure for purifying and concentrating the plutonium contained in the stripping solution from a tributyl phosphate extraction process. Conclusions from exploratory laboratory tests on the variables effecting the efficiency are included.

Plutonium sheet of uniform thickness and good surface can be made by the extrusion of a tube which is then split and flattened. This report describes the equipment and the operating conditions for making sheet 0.005 to 0.055 in. thick with areas up to 24 in. square.

The transmissions of neutrons through spherical shells of normal uranium, oralloy, and Pu239 are reported. One group of measurements was made using a pure fission neutron source produced by thermal neutrons. The other group of measurements was made using monoenergetic neutrons. From both groups of measurements, the inelastic scattering cross sections have been determined according to methods developed in Los Alamos Scientific Laboratory Report LA-1429 (Jaunary 1955).