A kinetic study was made of the formation of very thin anodic oxide films on niobium at constant current over the temperature range --10 to 70 deg C. Formation voltages were limited to the range below the oxygen evolution potential to eliminate possible interaction of an electronic component of the current with the measured formation field. It was found that the measured temperature dependence of Tafel slope agreed with that predicted by the theory of Mott and Cabrera. Using this theory, a zero field interfacial barrier height of 1.19 ev and a half-jump distance of 2.40 A were obtained. Values of the differential formation field are reported at current densities of 1000, 100, 10, and 1 mu a/ cm/sup 2/ at ten degree intervals over the temperature range studied. (auth)

Plutonium hexafluoride is decomposed by heat, by its alpha radiation, and by reactions with most materials of construction. Laboratory experiments were performed to investigate means by which plutonium losses due to these reactions can be minimized during vapor-phase transfers of the compound. The experiments showed that plutonium hexafluoride vapor could be transferred satisfactorily through well fluorinated nickel equipment in a stream of fluorine or helium. The decomposition product of plutonium hexafluoride was refluorinated at 250 deg C by fluorine. (auth)

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Experiments are described that have been designed to measure separately annihilation and reaction cross sections for antiprotons of approximately 450 MeV on oxygen, copper, silver, and lead. A new and more luminous spectrograph has been built for this experiment. The antiproton cross sections a r e compared with total proton cross sections, and are found to be larger by a factor varying from 1.74 for oxygen to 1.39 for silver. Calculations based on the optical model give a reasonable connection between these cross sections and the 6-p and 6-n cross sections. Finally, the information available on antiproton production cross sections is collected. There are indications that a free nucleon is several times as effective as a bound one for producing antiprotons.

This is the monthly report of the Hanford Laboratories Operation, March, 1957. Metallurgy, reactor fuels, chemistry, dosimetry, separation processes, reactor technology, financial activities, visits, biology operation, physics and instrumentation research, and employee relations are discussed.

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A system for concentrating uranyl nitrate solutions was designed and installed in the Thorex Pilot Plant. A total of 16,060 g of uranium was concentrated in the system in 68 batch runs. A total of 14,400 g total uranium (14.180 g U/sup 233/) was recovered as product suitable for shipment. Uranium loss to the evaporator condensate was 0.03% of ihe total uranium processed. The material balance across the system was 98.4%. The average concentration of uranium in the evaporator feed solution was 29 g/liter; the average concentration in the evaporated solution was 298 g U/liter and in the product solution was 199 g/liter. Radiation readings of bottles containing product solutions were taken with a hard-shell cutie pie immediately after each run, and these readings ranged from 35 to 1100 mr/hr. The radiation levels of the bottles of product solution shipped averaged 78 mr/hr. Bottles of product solution reading in excess of 300 mr/hr, maximum allowable for shipment. were reprocessed in the second-cycle solvent extraction system (Thorex) and reconcentrated. The products from seven runs had radiation levels in excess of 300 mr/hr at the time of concentration, or the activities had grown to that level by the time of shipment. The …

Experimental evidence that several ionic and molecular crystals become conductors in the metallic range at ~ 250,000 atm. is presented. For some the transition pressure is roughly defined. (T. R.H.)

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A methed is descrihed for the treatment of radioactive neutralized nitric acid waste solutions. The process consists of electrolysis of sodium nitrate solutions and recycle the caustic formed to neutralize incoming nitric acid ate. Removal of a large fraction of the bulk inert substances by this method allows greater reductions in waste volume than conventional treatment by evaporation alone. Process chemistry studies show that a large fraction of the nitrate ion in alkaline solution can be electrolytically reduced to gaseous nitrogen reduction products at reasonable current efficiencies. Process engineering studies have resulted in the development of a prediction equation for the design of electrolysis cells used in the process. Pilot plant studies using cold'' nitric acid waste have demonstrated the feasibility of the electrolytic recycle methed. A preliminary cost estimate was performed which iadicates a cost of from 75 to 95 per initial gallon of waste processed. Basis for this estimate is a conceptual design of a plant capable of handling the highlevel waste produced in reprocessing one ton of uranium metal per day. These costs are considered reasonable in a nuclear power economy, and indications are that ultimate disposal of the concentrated waste in clay may be possible. (auth)

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This study has investigated the feasibility of installing a gas generator-free turbine type power plant in the R3Y aircraft, using a circulating fuel reactor as a power source. Two variations of the cycle were considered. The split flow cycle bleeds high temperature, high pressure air from the gas generator directly to the free turbine in the wing. The through flow cycle partially expands the high temperature, high pressure air through the compressor turbine of the gas generator then directs the compressor-turbine exhaust air to the free turbine in the wing. Design parameters of pressure ratio, radiator depth, radiation flow density, and hot gas duct size were optimized to give minimum weight per shaft horsepower of the complete power plant. The weight of a split flow power plant capable of supplying 22,000 shaft horsepower was found to be 116,600 pounds. The weight of a similar through flow power plant was found to be 119,900 pounds. The reactor power required in both cases was 70 megawatts. The nominal gross weight of the R3Y airplane is 175,000 pounds. With pay loads of approximately 20,000 pounds, either nuclear conversion will have a gross weight of 200,000 pounds. It was found that either cycle could …

The diffusion zones formed during the bonding of nickel-plated uranium cores to aluminum sheaths were identified by correlating the appearance of these zones with those identified in diffusion couples. A relationship between the structure and the strength of the bend was observed. (auth)

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This summarizes the work done to date on the development of an epoxy resin bonded explosive (HMX). The original target values have been satisfied and further investigations will be on a semi-pilot plant scale.

This report summarizes the work done to date on the development of an epoxy resin bonded explosive (HMX). The original target values have been satisfied and further investigations will be on a semi-pilot plant scale. The following characteristics have been determined on laboratory specimens. Compressive strength, 11-12,000 psi; sensitivity (50 % height) 31 cm; density, 1.81 gm/cc; vacuum stability (cc gas/gm/24 hrs at 100{degrees}C), .42 cc/gm.

The purpose of this work was to investigate the possibilities of producing a plastic bonded explosive having greater mechanical strength than that of presently existing plastic bonded explosives. This interim report details activities and progress through July 15, 1957.

A simple method is described for producing parabolic mirrors by revolving a horizontal pan of liquid plastic and allowing it to harden into the parabolic shape which has been assumed by the liquid platic. This surface can be plated without further polishing into a mirror of a quality suited to various laboratory and industrial applications.

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The two most important considerations in the disposal of radioactive wastes are safety and economy. All other steps in the waste disposal complex must be tuned to accomplish these two goals. In general, the hazardous waste in the nuclear power complex affect the cost of the nuclear power reactor fuel cycle, the general environment since disposal must exclude radioactivity from the environment for over 500 years, the costs and/or methods of waste treatment including fission product utilization, the methods of shipping, the location of chemical processing plants and waste disposal sites, the methods of disposal best suited for a particular type of waste or site location, and potential public damage and third-party liability.

The developing fetal skeleton of the rat was used to study the microscopic localization of the rare earth Ce/sup 144/ in bone. Nineteen-day-old rat fetuses were injected with Ce/sup 144/ in isotonic sodium citrate via the umbilical vein. They were sacrificed one-haif hour after the injection by immersion in 80% alcohol fixative. The fetuses were embedded in paraffin and sectioned at 10 to 12 mu . Semiserial sections were treated with periodic acid- Schiff stain for mucopolysaccharides, and by the von Kossa technique for calcium. Contract x-ray-film autoradiographs and NTB stripping-film autoradiographs were prepared. Photographs of representative sections and their respective autoradiographs are presented for various bones. This material strongly suggests that the initial binding site of Ce/sup 44/ in the skeleton is in the organic matrix of cartilage and bone, especially where this matrix is just entering the calcifiable state. This conclusion is highly dependent upon the specificity of the von Kossa stain for calcium. (auth)

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>A summary of the cooling load data for the SRE sodium coolant pump freeze seals is presented. (J.R.D.)