The reaction of He with the epsilon phase of the 50 wt. % U--Zr alloy is studied using a sensitive vacuum microbalance apparatus to prepare the alloys, a sensitive McLeod gage to measure the dissociation pressures, and x-ray diffraction analyses to determine the phases present in the alloy. Although the reaction of H/sub 2/ with the alloy is very rapid at 100 deg C for oxide free surfaces, homogenization is very slow. Hydrogen alloys are prepared in the composition range of U/sub 0.28/Zr/sub 0.72/H/sub 0.0007/to U/sub 0.28/Zr/sub 0. 72/H/sub 0.121/ and the dissociation pressure measurements determined in the temperature range of 300 to 600 deg C. Due to the slow processes of homogenization, the hydride ZrH/sub 1.2/ is not readily precipitated below 400 deg C. On heating to 525 deg C and cooling, the hydride is readily formed for compositions of U/sub 0.28/Zr/sub0.72/H/sub 0.035/ and higher. For lower H/sub 2/ compositions, the hydride is not found in the x-ray diffraction patterns on heating these compositions to 525 deg C and cooling. It is suggested that small hydride nuclei are formed which are not observable by x-ray diffraction methods. Due to a slow rate of metallic diffusion, these nuclei cannot grow. …

A key punch is discussed which would be useful in any automatic coding system requiring the initial input to be made via cards with 12 rows such as the standard IBM card. The proposed key punch consists of a keyboard connected to a punch and a electric typewriter so that if a character is struck, it is both punched in a single card column and typed on a sheet of paper. Each character key contains three characters which may be used in superscript, subscript, or main line position. (M.H.R.)

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The tensile properties, hot hardness, and heattreatment characteristics of urarnium alloys containing up to 2.9 at.% aluminum or 4.0 at.% zirconium are described. The data shown that zirconium has a favorable effect upon the grain size, hardness, and tensile strength of uranium without materially affecting ductility. Additions of 3.8 at. % zirconium raised the tensile strength of uranium at room temperature fiom about 100,000 psi to about 200,000 psi, while the elongation in 2 in. increased from 14 to 22% and the grain size decreased from about 0.20 mm to less than O.01 mm. The data show that aluminum raises the yield strength, that it has very little effect on either the grain size, hardness, or tensile strength of uranium, and that it decreases ductility. The addition of 2.6 at.% aluminum decreased ihe roomtemperature ductility of ur-anium from l4 to 4%. (auth)

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Methods of melting uranium and its alloys are examined including vacuum induction melting and consumable and non-consumable electrode arc melting. The equipment and procedures are outlined with the limitations and uses of each method. In addition, the preparation and properties of Al--U, Cr-U, Mo--U, U-- Nb, U--Si, and U-Zr, and Nb--U--Zr alloys are described. Special techniques of agitation during freezing to produce fine castings are listed along with a discussion of the advantages of centrifugal casting. (J.R.D.)

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A number of equipment revisions have been recommended by the Engineering Department for conversion of Recuplex to a manufacturing facility. These revisions include three items affecting the critical mass safety of the solvent extraction system: replacement of the bottom disengagement section of the H-3 stripping column with an always safe unit; replacement of the H-9 and H-10 intercolumn, organic phase surge tanks with always safe tanks; and replacement of the colorimetric plutonium monitors in the aqueous and organic raffinate streams with units insensitive to stream contaminants. This memorandum is intended to clarify the needs for these equipment revisions in achieving a safe and flexible operating system and to indicate the relative effects of revising each of the various equipment pieces separately. The general bases for the present criticality control measures in the solvent extraction system are reviewed briefly prior to discussion of the individual revisions.

Hydrogen sorption isotherms have been measured between 542 and 798 deg C at pressures of 0.001 to 70 cm of Hg. The isotherms give the terminal solubility of S in the initial alloy phases and the limiting compositions of new phases containing H/sub 2/. Values for the heat of solution of H/sub 2/ at all concentrations are presented. A comparison of the data with that of the H-- Zr system indicates that, above a minimum H/sub 2/concentration, the alloy breaks down to give V and Zr. The alloy then behaves, to some extent, as the H--Zr system modified by the presence of U. X-ray diffraction studies give support to this interpretation (auth)

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This report details the evaluation of the prototype Gamma Monitor system which demonstrated more sensitivity for rupture detection than the C Beta Monitor in agreement with earlier tests at H pile. In one instance a rupture was indicated several hours earlier by the experimental gamma installation.

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A nozzle plate cartridge for the extraction section and a mixed plate cartridge containing both stainless steel and fluorothene sieve plates for the scrub section were developed. In 3- and 4-in.-diameter glass columns, these cartridges have a urnnium-extraction efficiency as good as, or better than, the present cartridge; they have a scrubbing efficiency, based on the transfer of chloride ion, which is about the same as the present cartridge. (auth)

Studies were continued on the laberatory evaluation of Canadian gravity concentrate, processing of Th-containing U concentrates, extraction of U in a HNO/ sub 3/--TBP--UNH system, corrosion rates of stainless steel in 70% HNO/sub 3/, denitration process, corrosion resistance of chrome-plated drum dryer to raffinate solutions, UO/sub 2/F/sub 2/ reduction process, process studies in the UO/sub 3/ to UF/sub 4/ process, effects of reduction temperature and degree of hydration on reactivity of UO/sub 2/ pellets, conversion of ammonium diuranate to UF/sub 4/, reduction of UF/sub 4/, melting and casting of Nb--U alloys, production of U washers, recovery of U from scrap material, and fabrication of Th electrodes. New processes, special problems, and wet chemical and spectrochemsical development were considered. (For preceding period see NLCO- 601.) (J.R.D.)

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