From abstract: Between mid-May and late June 1976, 3409 water and water-transported sediment samples were collected from 1781 locations spread over an approximate 17 000 kilometer area of northwestern Montana. All of the samples were analyzed for total uranium at the LASL, using standardized procedures and rigorous quality controls--the waters by fluorometry and the sediment (and those waters with >10 parts per billion uranium) by delayed-neutron counting methods.

From introduction: This report describes work done in the Noatak and portions of the Baird Mountains and Ambler River, Alaska, National Topographic Map Series (NTMS) quadrangles (1:250 000 scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

Delta-stabilized plutonium can be welded to itself or almost any other metal using the inert-gas metal-arc process. Equipment and procedures suitable for the welding of delta-stabilized plutonium under various conditions are described.

Simple expression are derived for the time dependence of slowing down of neutrons in a simple media. In Section I, a method suggested by age theory is used, while in section II, a two parameter scattering function is employed. Results are compared with exact calculations.

Semi-empirical modifications of age theory have been made to interpret the critical masses of proton moderated assemblies, which may or may not have reflectors of various substances, in particular, water or steel. Section I shows that critical masses of untamped water moderated systems can be calculated by use of an appropriate age and linear extrapolation length. Assuming that all captures and fissions take place at thermal, a familiar expression can be set up which contains the age and extrapolation length which are not well determined by theory. An age value suggested by theory, (Sec. II) is taken and ORNL criticality data (K343) are used to find the best extrapolation length. With these values the K343 critical mases can be computed to bout +-5%, which is their estimated experimental uncertainty; this for H/U-235 atomic ratios between 43 and 755. Section II contains a theoretical discussion of effects which the simple "theory" of Sec I neglects. It is indicated that several of these effects compensate to make a simple theory more useful than one would believe at first sight. to take into account reflectors of water, water shield by cadmium, or steel of various thicknesses, it proves sufficient to alter the extrapolation …

Abstract: "A method for determining hydrogen in lithium hydride by heating samples with lead at 600 C, was developed. The hydrogen evolved during thermal decomposition of the hydride is purified and oxidized to water with cupric oxide at 400 C. The analysis is completed by collecting and weighing this water. Success in development of the analytical procedure has depended upon a careful design and assembly of equipment for handling samples in a dry, inert atmosphere. For seven pure hydride samples analyzed by the recommended method the estimates of the standard deviation varied between 0.12 and 0.41 percent lithium hydride (or 1.3 and 4.2 parts per thousand) for 8 to 18 determinations on each sample. The procedure is relatively insensitive to variations in certain conditions. For single-piece samples weighing 0.2 to 0.5 gram it was found to be more satisfactory than a method which uses mercury in place of lead for sample decomposition. For powdered lithium hydride samples the lead and mercury methods are equally satisfactory."

Abstract: A method for separating small amounts of scandium (1 to 10 mg.) from a gram of uranium depends upon formation of insoluble uranium peroxide while the scandium in solution is complexed with ethylenediamine-tetraacetic acid. The precipitated peroxide carries down less than 30 p.p.m. of scandium. Uranium left in solution, less than one milligram in amount, does not interfere when the scandium is precipitated as ammonium scandium tartrate and determined gravimetrically by ignition of the tartrate to the oxide.

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

The angular distribution of fission fragments from the neutron-induced fission of several isotopes has been studied. Distributions were observed for thermal neutrons on U233 and U235, Lady Godiva leakage neutrons on U235 and U238, and 14 Mev neutrons on U233, U235, U238, Th232, and Np237. No anisotropy was observed for thermal neutron fission, whereas for Lady Godiva neutrons and 14 Mev neutrons the probability of fission along the axis of the neutron beam was determined to be higher than for fission in the orthogonal direction. Experimental results are given on pages 10 and ll.

Report discussing a proposed electron probe that is connected to the discharge current from a device called the Perhapsatron. "The Perhapsatron is an apparatus for the study of the type of magnetic containment known as the 'pinch effect.'"

The operation of the Fast Reactor is considered in terms of normal equilibrium conditions and normal shut-down. The proposed loading, control rod adjustment and subsequent "floating" operation are discussed. Safety devices and interlocks are described. Temperature and reactivity changes are examined with respect to various system failures, phase changes, and "flashing" of the reactor. Slow changes due to faulty slug cooling are also considered. The calculations were initially based upon 10 kw operation. Performance tests of the mercury system now indicate that 20-kw operation may be feasible.

The following report examines the fission counter, fission plates and activation results of the neutron energy distribution in the center of the Los Alamos plutonium reactor.

Critical mass measurements on graphite-tamped, heterogeneous oralloy-graphite systems have been made as a safety guide for certain oralloy casting procedures. Various concentrations were obtained by alternately stacking 10.5 in. diameter oralloy and graphite plates. In the relation Oralloy critical mass = constant x (fraction of oralloy in the core volume) -n values for the exponent, n, in the neighborhood of 0.70 were obtained.

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.

Abstract: "Decontamination factors of the order of 10-4 were obtained for Beta and Gamma emitters present as fission products when uranium was precipitated from 50 mC activity level solutions as uranyl oxalate under normal uranium yield conditions for three cycles (~60%). Factors of the order of 10-3 were obtained by the use of this reaction with similar solutions under relatively high uranium yield conditions for three cycles (~90%). The uranium peroxide precipitation reaction proved to be of no value on such solutions, yielding decontamination factors of only 17.1 Beta emitters and 1.2 for Gamma emitters for three cycles."

The following report describes procedures taken to utilize the photelometer to procure the most rapid and reliable determinations, but the goal of the tests presented was to create satisfactory dispersions of particles to analyze.

It has been found relatively easy to form uranium in the gamma phase temperature range by hot pressing, forging, or extrusion. The metal is quite plastic and flows readily to form a shape. Several temperatures from 800 degree C to 1000 degree C were investigated. No forming difficulties were experienced with the metal at the several temperatures concerned. The major difficulty in gamma phase hot pressing or extruding was associated with the tools. Metals or ceramics were not successful as tools for one or more reasons concerned with: lack of hot strength, reactions with the uranium, failure in thermal shock, and tendency to spall. Graphite was found to be the best material available, but it is not entirely satisfactory because of low strength. Uranium formed in the gamma phase possesses some refinement of grain structure as compared with as-cast metal; however, the grain size is quite large. No physical properties of the gamma phase formed metal were determined.

A glass vacuum manifold and ionization chamber are evacuated and filled to atmospheric pressure with hydrogen and tritium. The hydrogen and tritium are evolved by dropping liquid, urine or water, on calcium metal and dried by passing through a suitable freezing bath. The current produced by the beta activity due to tritium is measured with a vibrating reed electrometer. The method has a precision of +3 per cent between the ranges of 100 and 1500 pc of tritium per liter. From O to 100 pc of tritium per liter the precision is +-5 to 10 per cent. The glass vacuum manifold has been constructed to fit in an aluminum suitcase which contains all the auxiliary equipment for the determination except the vacuum pump, vibrating reed electrometer, and the freezing bath solutions. The apparatus is sturdy and readily transported. The procedure is simple and adapted for use by untrained personnel.

From introduction: This report presents uranium and other elemental data resulting from the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Shiprock National Topographic Map Series (NTMS) quadrangle, New Mexico/Arizona, by the Los Alamos Scientific Laboratory (LASL).

From introduction: This report describes work done in the Sterling, Colorado, 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).

Part I of this report covers critical-mass determinations for pseudospheres of oralloy hydride composition (approximating UH3) in 8"-thick Tu and Ni tampers and in the Tu tamper with Ni liner. The critical mass of a hydride cube in the thick Tu also is given. Data on weight and dimensional changes of hydride pieces during the period of use are included. In Part II are presented the results of Rossi time-scale measurements on the hydride assemblies. Values of alpha at delayed critical and its variation with mass in the neighborhood of delayed critical are given. Measurements on the activation of various detectors within the hydride assemblies are described in Part III. Results as a function of radial position are given for Au, for Au shielded by Au and by Cd, for S and for fission catchers with U235 and U238. Reactivity changes resulting from the introduction of foreign materials into the hydride assemblies are discussed in Part IV. Apparent regularities with respect to Z and qualitative interpretations of variations with radius are pointed out. From data for various radial positions, changes in critical mass corresponding to small changes in composition and density are computed.

This paper is issued in two volumes: LA-1664 and LA-1665. In LA-1664, the fundamental properties of a shock in free air are described, including the reasons for failure of similarity scaling. The results of an analytic solution for strong shocks are presented, which permit a determination of the energy in a shock wave from its rate of growth without recourse to similarity assumptions; from it the scaling laws for both homogeneous and inhomogeneous atmospheres are explicitly shown. The total energy is evaluated in a machine calculation for the blast wave and from this evaluation, the free air wave form for all hydrodynamic variables is presented. The general nature of the laws governing thermal radiation from atomic bombs is deduced, a new figure of merit for thermal radiation is suggested to replace the concepts of “thermal energy” and “critical calories,” which are considered ambiguous. Partition of energy is considered negligible in most cases of interest; the waste heat concept is reconsidered and the failures of scaling to TNT are regarded primarily as a failure of the ideal gas law. LA-1665 is concerned with preparation of height of burst curves. In the reflection process over ideal surfaces, the usual subdivision into regions …

This paper is issued in two volumes: LA-1664 and LA-1665. In LA-1664, the fundamental properties of a shock in free air are described, including the reasons for failure of similarity scaling. The results of an analytic solution for strong shocks are presented, which permit a determination of the energy in a shock wave from its rate of growth without recourse to similarity assumptions; from it the scaling laws for both homogeneous and inhomogeneous atmospheres are explicitly shown. The total energy is evaluated in a machine calculation for the blast wave and from this evaluation, the free air wave form for all hydrodynamic variables is presented. The general nature of the laws governing thermal radiation from atomic bombs is deduced, a new figure of merit for thermal radiation is suggested to replace the concepts of “thermal energy” and “critical calories,” which are considered ambiguous. Partition of energy is considered negligible in most cases of interest; the waste heat concept is reconsidered and the failures of scaling to TNT are regarded primarily as a failure of the ideal gas law. LA-1665 is concerned with preparation of height of burst curves. In the reflection process over ideal surfaces, the usual subdivision into regions …

From introduction: This report describes work done by the Los Alamos Scientific Laboratory (LASL) for the United States Department of Energy (US DOE) over a 50 000-km2 area on the Seward Peninsula and vicinity, Alaska, in 1976 (Fig. 1). The DOE Grand Junction Office (GJO), in Colorado, is responsible for administering the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) as part of its National Uranium Resource Evaluation (NURE) program.