Resting cells of eleven microorganisms were exposed to radioactive carbon dioxide for 40 minutes. The radioactive compounds formed during this time were separated and identified by paper chromatography. Resting cells of Lactobacillus casei fixed no carbon dioxide and growing cells fixed carbon dioxide primarily in malic and aspartic acids. All of the radioactive compounds formed could have become radioactive by reversal of known decarboxylation reactions.

A kinetic product study of the carbonate cleavage of malonic ester has been made, and it is shown that the formation of carbonate from malonic ester in alkaline solution involves the direct fission of the half acid ester.

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Comparative studies of a series of halogenated solvents, as carriers for TTA in the chelate process for plutonium extraction, indicate that ortho-dichlorobenzene most nearly satisfies the requirements that are set forth. A complete process design is presented for use with this solvent, and flow data and equipment capacities are given for dissolver solution and for uranium-free fission product solution as alternate feeds to the process. Vertical mixer-settlers are recommended as the contractors, although pulsed columns or packed columns are also believed to be suitable. The size of such units is estimated from the best available rate and equilibrium data, and the effects of several operating variable are considered.

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The colorimetric method of Murray and Ashley for the determination of nickel has been adapted to the determination of the element in uranium materials. A prior separation of uranium as the tetraoxide

The feasibility study of the Purex flowsheet in pulse column equipment has been completed in the ORNL Purex Pilot Plant. Eleven runs have been made in the pilot plant at a throughput of 75 kg to 125 kg of uranium per day.

The following tabulation includes information on all uranium slug failures which have occurred through September 26, 1951. The four suspect slugs which are listed were discharged from tubes which gave strong indication of containing ruptures. Although no obvious rupture could be found among the slugs from these tubes, the listed pieces exhibited defects which may be incipient ruptures.

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It is shown that the use of Iron-Limonite shielding concrete and a steel frame structure can afford a saving of $1,351,000.00 when compared to 105 DR-H construction and material costs. C-431-B costs are not complete enough to use as basis except for the concrete materials. This study is based on actual records where possible and shows direct costs only. No allowances for transportation or tooling have been allowed in either case. An overall time saving on reactor shield construction of 30--60 days may be possible, but no significant change in the field erection time is anticipated.

At the request of the ``S`` Division, a study has been made regarding the feasibility of simplifying operations by standardizing the amounts of chemical additions made at the reduction step as is the current practice in the purification operation. The investigation included a study of the following items, which are discussed under separate headings: (1) variation in feed; (2) maximum variation in booster ratios and per cent excess calcium using the method; and (3) chemicals handling and storage procedures. The process reduces plutonium fluoride to the metal.

The colybdenum-uranium equilibrium diagram has been studied, and the results are presented up to 50 atomic per cent molybdenum. Additions of molybdenum raise the melting point of uranium, forming a peritectic at about 1285 C. The solubility of molybdenum in gamma uranium is extensive. It decreases from 42 atomic per cent at the peritect temperature to 30 per cent at lower temperatures. Allots of about 28 to 30 per cent molybdenum content have been found to contain a metastable gamma. It can be transformed by cold work and prolonged annealing at temperatures below 575 to 600 C. X-ray diffraction studies of the transition product in epsilon phase indicate tht it has a tetragonal structure. The beta-uranium region is lowered by molybdenum additions to produce a eutectoid transformation at 658 ± 5 C. The maximum beta solubility is about 1.0 atomic per cent molybdenum. The alpha-uranium solubility is less than in the beta region, or about 0.5 per cent molybdenum at 600 C.

Experimental results indicate that the production of UO/sub 3/ by the continuous calcination process is practicable. (W.L.H.)

Data is presented from the separations technology division, May 14, 1951, to compare plutonium recovery from leaches of N-1 to corresponding hold-up data of plutonium.

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It is concluded that austenitic stainless steels in the fully solution- heat-treated state will give satisfactory service in concentrated UNH solutions. (M.H.R)

This report addresses the corrosion of zirconium in 600°F water and in 750°F superheated steam.

Possible hazards involved in the Mallinckrodt procedures for processing l%-enriched U are analyzed, and necessary precautions are specified. No danger is possible inhandling any amount of nominally l% U in the reduction of UF/sup 4/ to metal, cooling, or remelting. Critical amounts might conceivably be accumulated during the rolling to 3/4'' rod, in which case an''always safe'' amount is indicated. (B.J.H.) 2l92 A neutron burst from an untamped cylindrieal enriched U assembly occurred si ihe Pajarito Remote Control Laboratory ai 1800 hours on 18 April, 1952. The circumstances causing the burst and a description of the assembly involved are given. There was no personnel hazard. Normal operations could have been resumed on other assemblies within two or three hours after the burst. No evidence of damage to the enriched U was observed. Also reported are some results of computations and past-burst tests and a discussion of probable time behavior of power level during the burst. (auth)

Thorium forms a tetragonal lower hydride of composition ThH{sub 2}. The hydrides ThH{sub 2}, ThD{sub 2} and ZrD{sub 2} have been studied by neutron diffraction in order that hydrogen positions could be determined. The hydrides are isomorphous, and have a deformed fluorite structure. Metal-hydrogen distances in thorium hydride are unusually large, as in UH{sub 3}. Thorium and zirconium scattering amplitudes and a revised scattering amplitude for deuterium are reported.

On 2/8/1950, there was mined from process tube 2273 in D pile at Hanford a quantity of graphite power, which was expected to show the most extensive radiation damage of any graphite available at that time. A series of samples of this powder were annealed in 100 degrees increments from 100 degrees to 2000 degrees C at this labaoratory. There were returned to Hanford and shipped by them to the National Bureau of Standards for total stored energy measurements. The present memorandum is comprised of a description of the annealing procedure used here, curves giving the detailed annealing history of each sample, and various curves derived from data obtained from these samples at Hanford and at the National Bureau of Standards.

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A. M. Gaudin and collaborators have published a curve of refining costs versus ore grade in terms of dollars per pound of U308 recovered on the basis of 90% recovery.

Mechanization of the 300 Area slug canning facilities is required to obtain uniform high quality product and to eliminate variables introduced by the human element. The work to be covered by this brochure will cover requirements for mechanization of only the operations occurring within the aluminum-silicon canning bath: can and cap preheating and wetting, canning assembly, and quenching operation. Briefly, this machine will be required to insert a prepared uranium slug into an aluminum can and close the can opening with an aluminum cap. All assembly operations are to be carried out underneath a molten bath of aluminum-silicon bonding alloy. The uranium slug is preheated and prewetted before being transferred to the assembly furnace; however, the process must be so timed that proper preheating and wetting is attained before the slug is inserted. After assembly the completed canned slug is transferred to the quenching station, where the components are to be firmly held together until the molten Al-Si has frozen, forming a homogeneously bonded assembly.