Report discussing the status of ductile zirconium preparation by the National Research Corporation up to February 20, 1950.

The following report describes data from the continuation of investigations which led to the observation and characterization of five artificial radioactive chains collateral to the natural radioactive families that has lead to the partial identification of one additional chain, collateral to the actinium family.

This report discusses the state of stress caused by pressure in process tubes, elaborating on five "theories of failure" that each explain the stress in process tubes in a different manner. These theories, which are depicted in a graph, include maximum normal stress, maximum strain, maximum shear stress, maximum strain energy, and maximum strain energy of distortion.

The four types of respirator cartridges used at the 202 S Building were tested against aerosols found at that location, and in the laboratory against non-radioactive gaseous ruthenium tetroxide. Positive penetration of two types of cartridges was shown with one process aerosol. Gaseous ruthenium tetroxide penetrated all types of cartridges tested. Leaks were found in some of the cartridges. Particle size of aerosol particles was measured by means of cascade impactor samples and electron photomicrographs. A high percentage of the aerosol particles was found to be less than 0.2 microns in diameter. Ru¹⁰³ + Ru¹⁰⁶ and Zr⁹⁵ + Nb⁹⁵ were shown to be present in the process aerosol by gamma ray spectrometer analysis. Possible causes of penetration of respiratory equipment by ruthenium are discussed and suggestions made for alleviating the problem.

From abstract: "Various physical and mechanical properties have been determined for high- and low-carbon base uranium, uranium-chromium, and uranium-zirconium alloys. These data complement those obtained at ANL on the same materials."

From abstract: "The purpose of this note is to consider the feasibility of conducting kiloton-weapons tests in underground holes sufficiently deep so that the explosion will be effectively contained. Such a shot would have the advantage that it could be detonated independently of weather conditions, and thus would allow greater freedom in the test program."

Observations of the effects of neutron damage to zirconium oxides led to the conclusion that the cubic form of ZrO2 is more stable to such damage than the monoclinic form. It has been reported that zirconium corrodes more rapidly in certain liquids when exposure is made under radiation (neutrons and fission products). It is well known that on heating monoclinic ZrO2 a transformation, monoclinic to tetragonal (very similar to cubic), occurs at about 1500°C. The transformation involves sufficient atomic rearrangement that pieces of ZrO2 normally crack and crumble. It is suggested that the effects of neutrons on monoclinic ZrO2 may be similar so that a protective oxide film on the metal would be destroyed soon after its formation. It might be possible, therefore, that the protective oxide film on zirconium metal which is normally monoclinic might be less resistant to corrosion under radiation damage than a similar film which was cubic.

Consideration has been given to various forms of fissionable material for use in atomic reactors, including the pure metals, their alloys and compounds. Of particular interest is the dioxide of uranium which is refractory and corrosion resistant in some environments.The oxide is useful in both granular and bulk forms. Small grains of uranium oxide can be mixed with other materials to form matrix type elements where they serve either as a convenient or necessary form of fuel or fertile material. For other applications the oxide may be fabricated in bulk form such as pellets, rods, plates, or blocks.There is a need for knowledge of the properties of the properties of this oxide, particularly as it affects fabrication in the various forms required. This knowledge is also required by reactor designers and engineers. There is in addition a challenging field for basic studies of sintering rates, oxidation behavior and other phenomena. Fabrication techniques have been developed to produce uranium oxide in various forms with consideration given to the economy of production. The continued application of basic knowledge of these materials has led to simpler. more practical means of fabrication and has thus widened the scope of their use in atomic reactors.

A method for calculating the frequency response of weighted voids (proportional to reactivity of steam voids) as a function of reactor power is presented.

This report is presented in order to provide a satisfactory system of symbols and identifications for process-instrumentation equipment and to promote a uniformity of practice that will simplify and expedite instrumentation work. It is intended that the systems presented here should be capable of designating and identifying the multitude of instrumentation items which are used for control and operation of conventional processes, as well as for specialized work peculiar to ORNL. Instrument Society of America standards have been adhered to whenever practical.

A relationship is derived the mean square fluctuating current of a hot wire anemometer and the sic turbulent Reynolds stresses in the stream-coordinate system without employing the usual low turbulent intensity approximation. The relatively simple result is a consequence of assuming proportionality between the wire current reading and the perpendicular velocity component instead of the non-linear dependence required by King's law. The assumption is valid for instruments equipped with the proper linearizing circuitry. The stream-coordinate Reynolds' stresses are then related to the cylindrical polar Reynolds stresses.

This report considers the HFIR reflector design criteria and presents a summary of the reflector design. The reflector type chosen as complying best with the established criteria consists of a 3 in. thick removable beryllium annulus utilizing four concentric cylinders with cooling water flowing through the annuli between cylinders, and an outer 9 in. thick permanent beryllium annulus with axial circular coolant holes. Reflector support structures and experimental facilities are described and probable beryllium replacement costs are indicated.

To date, three types of metal-to-metal seal disconnects have been subjected to thermal cycling and make-break tests. In addition, a commercial disconnect has been procured for testing.

From Abstract : "The solubilities of the individual rare earth lactates and α-hysroxyisobutyrates in water at 20 and 60° were determined for comparison with the rare earth glycolate solubilities determined earlier."

The calibration of mercury vapor detectors has always posed a problem because of the difficulty of generating known concentrations of mercury vapor in air. The purpose of this study was to design an apparatus that would generate and chemically measure known concentrations of mercury vapor in air for calibration work.