This report discusses the production of large-diameter zirconium crystal bars in a 16 inch diameter, Hastelloy B, de Boer unit in order to increase production efficiency.

Report that communicates a new permissible activity level of plutonium and uranium.

The following report describes work carried out to investigate whether the Hanford IB column as designed in a previous report will decontaminate the uranium adequately from plutonium, particularly if there's any slowness in either the rate of reduction or transfer of the plutonium.

From summary: "Uranium billets deficient in U235 were subjected to the normal successive steps in the slug fabrication process; viz., rolling, machining, and canning. No unusual behavior was observed at any point in the process, thus indicating that the depleted metal from the standpoint of mechanical properties can be considered equivalent to normal uranium."

Abstract: "The potential of the Np(IV)-Np(V) couple is not directly measurement since the couple does not establish reversible equilibrium at an inert electrode. Reproducible potential measurements were obtainable, however, in solutions containing Np(IV), Np(V), Pe(II), and Pe(III) ions in oxidation-reduction equilibrium. The expected fourth power hydrogen ion dependence of the Np(IV)-Np(V) couple was confirmed over the range 0.25-1.0 molar perchloric acid concentration. The heat of the reaction NpO2+ + 1/2 H2 + 3H+ = Np-(+4) + 2 H2O in 1 molar perchloric acid solution was determined from the electromotive force temperature coefficient to be -36.3 +/- 0.3 kg.-cal. The formal potential of the Np(IV)-Np(V) couple is -0.746 v. at 25 degrees in 1 molar perchloric acid solution."

This report follows an investigation on Great Lakes Carbon with the objectives to demonstrate their ability to make and F process purify reactor carbon on a commercial scale; and construct an F process pilot plant and use it in a survey of U.S. petroleum cokes to discover additional supplies of raw coke suitable for making reactor grade carbon.

Abstract: Some proportional fission neutron counters are described with information on methods of preparation and details of a circuit for a portable model. The portable instrument has an efficiency of .01% for neutrons from polonium beryllium sources.

Abstract: "A series of experiments was carried out to determine the precision of the spectrochemical procedure for the isotopic analysis of uranium, especially at low uranium 235 concentrations. Standards were prepared from uranium hexafluoride which had been assayed on the mass spectrometer with a 95 per cent confidence interval of 0.5 per cent of the amount present. For a determination consisting of 9 separate measurements, the best precision obtained at normal concentration on the 95 per cent confidence interval was 0.711 +/- 0.112 per cent uranium 235 (16 per cent of the amount present)."

A report intended to correlate the RA and RC Column uranium equilibrium data presented in the reports cited in the introduction.

Technical report outlining the determination of the effective resonance integral for U238 as a function of the mass ratio for cylinders of 5/8" to 3" diameter. Also gives a linear approximation of the effective resonance integral with infinite shielding in the form of a function. [From Abstract]

Technical report presenting a summary of the flowsheets, equipment, and progress for the Oak Ridge National Laboratory (ORNL) pilot plant development of the Purex Process and of the ORNL Metal Recovery Program. As of this report, conversion of the Purex pilot plant equipment in Buildings 3019 and 3503 is 90% complete. The building structure for the ORNL Waste Metal Recovery plant had been completed, and 15% of the process equipment had been installed. The first hot runs for this plant were scheduled for June, 1951. [From Abstract; Introduction]

Technical report outlining how uranium hexaflouride was prepared be the direct combination of irradiated uranium metal with elemental fluorine and subsequently decontaminated by adsorption, filtration, and sublimation on a laboratory scale. Report proposes a survey of other methods of preparing UF6 from uranium metal, a study of adsorption techniques for removing plutonium from UF6, and an investigation of fractional distillation for removing the volatile fission product fluorides from UF6. [From Abstract, Summary]

Technical report outlining the construction progress of the Oak Ridge digital computer at Argonne. Included is the schedule of events for the Mathematical panel and programs during the presentation of contributed papers for the Biometric Society [From Summary]

Technical report covering experiments happening on the Analytical Chemistry Division's sites at the Oak Ridge National Laboratory. Includes information on ionic analyses, radiochemical analyses, spectrochemical analyses, service analyses, inorganic preparations, analytical chemical control of homogeneous reactor solution, optical and electron microscopy, and service analyses. [From Abstract]

Technical report detailing corrosion tests of Type 347 stainless steel for two weeks in boiling uranyl nitrate, sulfuric acid media, with and without additions of Al+3 and F-1 in a 2:1 mole ratio. The results of these tests show that although the presence of aluminum greatly reduces the deleterious effect of fluoride, the corrosion rates are still three to four times greater than when no fluoride is present. [From Abstract]

Technical report covering chemistry of source, fissionable, and structural elements, nuclear chemistry, radio-organic chemistry, chemistry of separations processes, chemical physics, radiation chemistry, and instrumentation at the Oak Ridge National Laboratory for the period ending September 30, 1950. [From Abstract]

A complete investigation was made of the r-f field in the 1/10-scale Materials Testing Accelerator (Mark I) cavity

An accidental burst of radiation occurred at the laboratory on 1 February 1951 during remote control operation of a critical experiment. There was no personnel hazard. Normal operations were resumed within 24 hr, and the active material involved in the burst returned to service within three weeks. An unforeseen brief excursion into the prompt critical region was engendered in the act of scramming the assembly at the end of a series of measurements. This report describes the effects of the burst and analyzes the probable causes in some detail.

A tentative nickel-plutonium constitutional diagram was based on data obtained by thermal analysis, metallography, and x-ray-diffraction techniques. The systema is a complex one with the following important features. Nickel is soluble in epsilon plutonium, extending the epsilon field to 4.3 at.% nickel at 465 deg C. Nickel and plutonium form six intermetallic compounds, PuNi, EnNi/sub 2/, PuNi/sub 3/, PuNi/sub 4/, PuNi/sub 5/, and PuNi/sub 9/. The compound PuNi/ sub 5/ forms congruently from the melt at approximately l300 deg C, whereas the other compounds form peritectoidally. The extended epsilon field terminates in a eutectoid reaction at 415 deg C and l.5 at.% nickel. Epsilon plutonium and the compound PuNi form a eutectic system at 465 deg C with a eutectic composition of l2.5 at,% nickel. Nickel and the compound PuNi/sub 9/ form a eutectic system at l2l0 deg C with a eutectic composition of 92 at.% nickel. Plutonium forms a limited solid solution with nickel.