Report discussing a study regarding rolling as a technique for making uranium fuel elements that are flat-plate and aluminum-clad.

The following report presents a discussion of the method for hydrodynamic problems, together with some new considerations that have arisen concerning the method.

In studies of the fabrication of fuel subassemblies for the supercritical-water reactor, the limited ductility of stainless steel-UO₂ fuel sheet made the fabrication of corrugated-flat-plate-type subassemblies impractical. A fabricable MTR-type assembly, 5/8 in. square and 30 in. long, was developed. Methods for edge cladding fuel sheet were developed and a brazing alloy, GE-75, was found to be corrosion resistant in supercritical water.

Abstract: "The cross section for the reaction Al²⁷(p,3pn)Na²⁴ has been measured for proton energies between 30 and 350 Mev relative to the cross section for the reaction C12(p,3pn)C11, and the absolute magnitude determined by matching with data measured with a Faraday cup at 350 Mev and at 31.5 Mev."

Report discussing a test for lethals resulting from the recombination of X-chromosomes in ten different stocks wild-type Drosophila melanogaster.

Diffusion theory and transport theory approaches to the problem of a nuclear reactor with a transverse air gap are compared. It is suggested that the differences in results for thin gaps is due to the fact that diffusion theory does not adequately represent the flux distribution in the immediate vicinity of the gap. For mathematical conveniences previous treatments of the gap problem have made use of fictitious image piles which exaggerate the neutron losses. The extent of the error is estimated by direct neutron leakage calculations.

The absorption bands induced in α-Al2O3 by gamma and reactor irradiation have been studied. The slight coloration due to γ-rays saturates. Bands specific to reactor irradiation have been found and their growth studied.

The first highly productive phase in the development of organic scintillation detectors found physicists exploring the excitation and light emission properties of easily available organic chemicals. The second phase of this work which is now in progress can be characterized by the active participation of organic chemists in synthesizing new compounds for sturdy and setting standards of purity leading to the recognition by some chemical manufactures of a "scintillation grade".

An investigation of the materials for use in the water-moderated and cooled Aray Package Power Reactor (APPR) operating at about 500°F was made. The available literature was analyzed, and the results of the different investigators were compared and averaged. Twenty different materials, including stainless steels, nickel alloys, Stellites and others, were investigated from the point of view of physical properties, susceptibility to radiation damage, and corrosion resistance. Corrosion rates were established for all the materials under various conditions, such as irradiation, flow weld, stress, and various water conditions. Type-304 stainless steel was selected as the basic structural material. Operating conditions, to maintain minimum corrosion, were established also.

From abstract: "An instrument was developed to detect cracks within 1/8 inch of the surface of cylindrical uranium fuel slugs. The instrument measures changes in eddy currents that are induced at a frequency of 2 KC."

Four uranium alloys containing nominally 0.5, 1.0, 1.5, and 2.0 w/o molybdenum were investigated with respect to their response to hardening by heat treatment. The several alloys were heated at elevated temperatures to secure solid solution, then quenched and reheated at lower temperatures to obtain hardening. The procedure followed the well known industrial practice of solution treatment and precipitation hardening. The results showed that all the alloys could be hardened by a suitable heat treatment. No specific temperatures are recommended; however, within the limits of the investigations, a solution treatment at 850 degree C followed by a water quench and reheat at 450 degree C gave a considerable increase in hardness. The time at temperature to secure maximum hardness would need to be determined as a function of mass and section shape. It is presumed that other mechanical properties of the alloys would be influence by heat treatment in a similar manner corresponding tot he effect upon hardness.

A method of numerical solution is developed for calculating the Lapre coolant pressure drop and power output with variable coolant inlet pressure, flow rate, and reactor solution temperature. The results of a series of calculations are presented that show excessive pressure drops and sonic exit flow as the flow rate is increased and the inlet pressure is decreased. Both supercritical and subcritical coolant flow regions are investigated. Reactor power is shown to be strongly dependent on the solution temperature in the region of 70O-75O degree F. At the design flow of 12 gal/min, excessive coolant pressure drops are encountered at inlet pressures of 2000 lb/in. and below.

The opacity and thermodynamic properties of air at temperatures above 10 e.v. and densities below normal have been calculated under the guidance of H. Mayer in accordance with the prescription given in AECD 1870 (LA-647). Corresponding to given densities and temperatures, self-consistent distributions of electrons in bound states and their eigen energies are determined. With this information we compute the thermodynamic properties of air and the frequency-dependent absorption coefficients. Finally the opacity--a weighted average of the latter--is found

Am III and Pu III have been recovered on a plant scale by extraction with tributyl phosphate from slag and crucible and other recovery solutions. Process losses were 0.03% Am and 0.01% Pu. The product stream contained 0.08 gram Am per liter and 0.15 gram Pu per liter. The final solution cleanup to allow discard (total alpha activity equivalent to less than 10(-4) gram Pu per liter) was accomplished by tributyl phosphate extraction of Pu III under conditions of low acidity and high nitrate.

"Heat production resulting from the absorption of gamma ray photons in thermal shields and the leakage of neutrons and photons from ferritic thermal shields are investigated. The gamma rays considered arise from three types of reactor radiation -- thermal neutrons, fast neutrons, and core and reflector gammas. The energy spectra of the fast neutron leakage and absorption have been investigated in some detail because of the significant contribution of fast neutrons to the heating of the concrete biological shield."

"Scale-up work on high temperature fuel recovery processes has progressed to the point where the (high temperature) vacuum furnace for several operations to the hot cells has been completed and tested under operating conditions. Small scale experiments on high temperature methods for processing molten irradiated uranium fuel have been made with spent X-10 fuel slug pieces. The results of direct Pu evaporation, treatment with fused fluorides and oxide scavenging were every similar to those found with tracer experiments."

"Engineering pertinent to the development of the sodium-cooled, graphite-moderated type of reactor was continued. This included work on problems related to the zirconium canned moderator, low enrichment uranium fuel, sodium piping, secondary coolant system, shielding, and the control and safety elements. A large fraction of the work was devoted specifically to problems of the proposed Sodium Reactor Experiment (SRE) configuration. In this connection, an integrated effort was initiated to prepare a complete preliminary design of the SRE by an early date. In addition, two alternate sodium-graphite reactor configurations were studied. One was an intermediate size, 145 thermal megawatt, unit optimized for the production of low cost plutonium. The second was a low power 10 thermal megawatt intended for power production, but in which sodium circulation through the core was entirely dependent upon thermal convection."

An investigation of the materials for use in the water-moderated and cooled Aray Package Power Reactor (APPR) operating at about 500°F was made. The available literature was analyzed, and the results of the different investigators were compared and averaged. Twenty different materials, including stainless steels, nickel alloys, Stellites and others, were investigated from the point of view of physical properties, susceptibility to radiation damage, and corrosion resistance. Corrosion rates were established for all the materials under various conditions, such as irradiation, flow, weld, stress, and various water conditions. Type-304 stainless steel was selected as the basic structural material. Operating conditions, to maintain minimum corrosion, were established also.

A resin-in-pulp process was developed using a series of fixed-screen or Winchester cells. Various laboratory and pilot plant models were constructed and tested under simulated plant conditions. The fixed-screen device proved very effective in the recovery of uranium and/or vanadium by a continuous, resin-in-pulp process.

The results of this paper show that a variation is sensing voltage produces an error in timing which increases logarithmically with time interval. Also, variation in supply voltage produces the same type of errors, but the errors are decreased by the ratio of the sensing to supply voltage. An interesting conclusion from this analysis is that if the ratio of supply to sensing voltages is maintained constant, no change in timing will result.

Experiments are described which show that magnetic fields can exert a controlling influence on the operating characteristics of point contact transistors. The effect is especially evident when the transistor is operated in its negative resistance region. The frequency of an oscillator can be varied, or a switch made to trigger by applying a magnetic field to the transistor. Some applications of the principle are suggested; many more are evident.