From abstract: "Two samples, each containing an estimated 10 curies (2 mg) of polonium-210, were purified by vacuum distillation and evaporated onto oblique sections of X-ray targets made of copper. Four lines of the K series and ten lines of the L series of the X-ray spectrum of polonium were recorded with a one-meter transmission crystal spectrograph and a 25-centimeter Bragg spectrograph, respectively. Measured wavelengths agree approximately with values predicted by extrapolation of Moseley's law and with those claimed by Hulubei. Decay of polonium-210 (half life = 138 days) and growth of lead-206 (stable) were observed over a period of 180 days."

From abstract: "This report presents the progress in the laboratory development of a continuous solvent recovery process for the tributyl phosphate-diluent mixture used in the Purex Process. Investigations were made with 1/2" diameter pulse columns, using a nine foot sodium carbonate contacting column and a four foot water wash column."

From abstract: "The following report presents a summary of operating experience with decelerating receivers for ion beam reception. Sample calculations for design of such a receiver for the isotopes of lithium are presented. Estimates of maximum production and requirements to attain such production are given. The maximum ion beam envisioned is 17 amperes obtained from extrapolation of experimental results."

From abstract: "Data obtained in laboratory studies of the 'fumelses dissolving' of irradiated uranium are presented. Procedures for handling dissolver off-gases are proposed."

This quarterly progress report discusses ongoing research and experiments at Oak Ridge National Laboratory in the Metallurgy Division. This report discusses thorium research, the mechanical properties of metals including thorium, uranium, inconel, and z-nickel, the ANP program (including the following topics: the physical chemistry of liquid metals, and welding research), and the materials testing reactor program.

Much of the shielding work carried out with the Bulk Shielding Reactor (BSR) has yielded data of particular interest for the design of swimming pool type reactors, However, it is often difficult for a reactor designer to locate such data since it may be recorded in a report primarily concerned with shielding problems. Therefore, this memorandum presents a bibliography of reports from the Bulk Shielding Facility arranged according to the application of data to the various aspects of reactor design.

Semiannual Progress report of the Oak Ridge National Laboratory Chemistry Division providing updates on various projects, experiments, and other work in inorganic and physical chemistry, nuclear chemistry, organic chemistry, chemical physics, chemistry of separation processes, radiation chemistry, and reactor chemistry.

Progress report of the Oak Ridge National Laboratory Biology Division providing updates on various projects, experiments, and other work. This report includes a summary of scholarly output from the division and departmental activities in cytology and genetics, mammalian genetics and development, microbial protection and recovery, mammalian recovery, pathology and physiology, general physiology, biochemistry, enzymology and photosynthesis, microbiology, plant biochemistry, and biophysics.

The reactor equipment cell is expected to be completed by February 15. While filled with water, the tank was inspected for leaks, and the few leaks found will have been repaired by February 15. All orders for construction materials placed prior to this quarter have been received. New requisitions issued during the quarter total $16,000. Work orders were issued, and fabrication of all low-pressure-system components was begun in the ORNL shops. The thermal shield around the reactor vessel was specified as a 2-ft-thick cylindrical concrete wall. With this shield, the fast-neutron flux in the equipment area will be reduced to 7 x 109 neutrons/cm2/sec, the slow flux to 4 x 107 neutrons/cm2/sec, and the gamma intensity to less than 105 r/hr. The possible blast effects from a rupture of the pressure vessel were studied and are judged to be sufficient to justify the inclusion of a 1.5. to 2-in.-thick blast shield around the pressure vessel. The blast shield eliminates the danger of damaging the leak tight equipment-cell liner. Pressures in the reactor equipment cell, as a result of vessel failure, were calculated in order to arrive at a safe design pressure for the reactor equipment cell. For the case of …

Gram amounts of americium were separated quantitatively from kilogram quantities of lanthanum to yield an americium product approaching 90% purity. The remaining impurity was chiefly yttrium. Elution of americium from 25% loaded Dowex 50 resin column with 0.15 M citric acid— 0.10 M diammonium citrate — 0.3 M ammonium nitrate, pH 3.3 gave a product containing 99% of the americium with a La/Am ratio of 1/100 or less in one fourth of a column volume, in this case about 1 100-fold volume reduction. Approximately 9 g of americium was purified by this method. Elution with 12.8 M hydrochloric acid from a 20 to 30% loaded column gave 90% of the americium in two column volumes of product with a La/Am ratio of about 1/4. About 1 g of americium was purified by this method.

Technical report outlining the fabrication of twenty-five fuel assemblies and three shim-safety rod fuel sections for use in the Materials Resting Reactor Mock-Up Critical Experiments. Results show that two of the assemblies exceeded tolerance in a few of the key dimensions, but were considered acceptable and as a consequence, production was carried out with no rejects. [From Abstract]

From summary: "Construction of the HRE facility was essentially complete on November 15, 1951 except for minor revisions and final testing. A program of engineering and nuclear tests of the system hasbeen drawn up, and the tests will be started early in the next quarter. The only major HRE items for which design is not complete are the samplers for the fuel, [gas], and reflector systems. These will be completed in time to be installed before critical experiments begin; meanwhile, temporary sampling devices have been installed for use during the testing program."

Report issued by the Oak Ridge National Laboratory discussing quarterly progress of the Homogeneous Reactor Project. Progress of operations, design, development, and analysis is presented. This report includes tables, illustrations, and photographs.

Report documenting the ongoing research and developments of the Oak Ridge National Laboratory's Homogeneous Reactor Project.

Report documenting the systems, operating procedures, and design of the Oak Ridge National Laboratory's gas-cooled reactor.

Report documenting the systems, operating procedures, and design of the Oak Ridge National Laboratory's gas-cooled reactor.

Two revised Excer process flowsheets are presented for the production of UF4 from urnayl nitrate solution. In both, the uranium is sorbed on a cation-exchange resin and eluted with aqueous HF. In one, the resulting UO2F2 in dilute HF is mixed with dilute sulfuric or hydrochloric acid and electrolytically reduced in a cation-exchange-membrane cell, and the precipitated UF4·0.75H2O is dried and dehydrated to anhydrous UF4. A cost of 20¢ per pound of reduced uranium is estimated. In the other, ammonium fluoride is also added to the uranyl fluoride solution before the electrolytic reduction step, and the precipitate is UF4·04NH4F. A flowsheet for preparing UF4 from raw ore is also shown. The uranium is sorbed on an anion-exchange resin from a sulfuric acid leach liquor and eluted with dilute HCl. Ammonium fluoride and HF are added to the UO2Cl2-HCl solution before the uranyl ion is electrolytically reduced to precipitate UF4·0.4NH4F. Decontamination factors as high as 45 and 9 for gross beta and gamma activities and of 10 to 5000 for light metal impurities were obtained in the electrolytic reduction step.

For Co60 source at 15 meters, the air-scattered gamma dose rate predicted by theory is excerpted from ORNL-1575, pp. 167-203. This is compared with experimental measurements for the same source and comparable geometry reported by Convair in CVAC-170T. After applying an appropriate correction for ground scattering as estimated in Mart-55-16T (Convair), the two results are found to be in substantial agreement.

The Aircraft Reactor Experiment (ARE)was successfully concluded in November of 1954, and a detailed report of the operation was published the following year. At that time it was thought that an extensive examination of the reactor and system components after disassembly was warranted. It was realized, of course, that the level of radioactivity of the components would necessitate extensive delays in the examinations. Since examination of a few critical ARE samples showed nothing unexpected, much of the planned hot-cell inspection was postponed and complete examination of all but a few specimens was indefinitely suspended. The few examinations that were completed are described in this report, along with a description of the disassembly of the ARE system. Diagrams of the fuel system, sodium system, and off-gas system are presented in Figs. 1, 2, and 3 for reference use in visualizing the disassembly process.

This progress report discusses new additions to the Mathematics Panel and discusses new and further work happening at Oak Ridge National Laboratory relating to the Mathematics Panel, of particular note is the Oak Ridge computer which is being fabricated at Argonne National Laboratory and the Technitrol Company.

A series of critical experiments with blocks of 2% U235-enriched UF4-C25H52 has been initiated at the ORNL Critical Experiments Facility. Thus far assemblies with H:U235 atomic ratios of 195 and 294 have been built in parallelepipedal and simulated cylindrical geometries, both reflected and unreflected. From the results the minimum critical masses for reflected spheres have been determined to be 16.3 and 8.5 kg of U235 for fuel mixtures with H:U235 atomic ratios of 195 and 294, respectively. The minimum critical masses for unreflected spheres of these two fuel mixtures are 24.3 and 12.7 kg of U235, respectively.

The radiolytic decomposition of tributyl phosphate has been show by burr to product gases, acids, and polymers. the acids that are formed can limit the usefulness of tributyl phosphate for the processing of radioactive materials. The study of acid formation on radiolysis therefor becomes important to us for the understanding of the mechanism of acid formation, the influence of added materials and the effect of the structure of organo- phosphorous compounds. Samples of purified esters have been irradiated in the ORNL cobalt source. Conclusions: (1) The formation of acid from tributyl phosphate during irradiation with cobalt gamma rays involves a mechanism that is not a primary step. Evidence has been obtained for a secondary reaction that is minimized by the presence of certain compounds. (2) Toluene acting as an inhibitor for radiolytic formation of acid may indicate the usefulness of an aromatic hydrocarbon diluent in processing. (3) The aromatic hydrocarbon, when phenyl, was not effective when it was part of the molecule. (4) First tests revealed that dibutyl butyl-phosphonate produced less acid the TBP and may warrant further consideration for process application.

A letdown valve design is described which reduces erosion of the sealing surfaces. It also provides for water flushing of the sealing surface before closing.

.Recalculations were made of HRT cell pressures in the event of a simultaneous rupture of the reactor core vessel and the fuel and blanket heat exchangers. These calculations will be applicable after the replacement fuel heat exchanger is installed. The pressure rise in the cell is plotted as a function of time. A maximum cell pressure of 34 psig is achieved ~7 sec after rupture.