The following report investigates part of the variability of the computed fall-out intensity patterns due to the variability of the winds, on the basis of winds from four Pacific shot days. An extreme case from Operation Sandstone is also considered.

The following report describes the findings of air samplings taken that followed the Wasp detonation of Operation Teapot.

Abstract: This document is a survey analysis of soil samples from Los Alamos, Pueblo, Bayo, and Mortandad canyons to determine the presence and activities of radioactive contaminants. Also included are the results of analyses of a few samples of grass and of surface water. This survey covers the period from spring 1953 to spring 1955.

By use of small magnetic probes inserted into the discharge, the magnetic field distributions in the interior of a high-power pinched discharge have been measured as a function of time. From these data the current distributions can be deduced. By applying a static pressure calculation, in the cases when the radical pinch accelerations are small, the plasma pressure nkT in the pinch has been determined, with superimposed axial magnetic fields, and for stable and unstable configurations.

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.

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.

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%.

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.

Kilogram quantities of delta-stabilized and pure plutonium turnings can be cast directly into ingots of normal quality with high yields. This report describes the equipment and process used.