This report follows a study that was aimed at the collection of experimental data needed to estimate the maximum safe temperatures and dispersed UO2 contents for MoSi2--UO2 fuel elements exposed to air.

The following report follows the inspections of a number of eddy-current instrument procedures. The objectives of these tests were to detect both weld defects and lack of integrity of the body of the fuel elements.

The following report examines the most suitable enamels recommended for protection of aluminum slug cans.

The creep strength and tensile properties-were determined in vacuum for beta-quenched, derby uranium. The stresses to produce a secondary creep rate of- 0.0001 per cent per hr at 100, 250, 400, and 500 deg C were 48,000, sile strengths were 114,500, 35,100, 11,100, and 8,500 psi at temperatares of 28, 300, 500, and 700 deg C, respectively. The creep and tensile strengths decrease quite rapidly with increasing temperature in the temperatare range 250 to 400 deg C.

This report follows work performed to determine the effects of large boron additions on the fabricability and room-temperature tensile properties of various steels for reactor shielding.

The following report describes two methods of extrusion cladding of uranium fuel plates that were investigated and evaluated.

This report follows critical-assembly studies made to provide engineering and physics data to aid in developing the Gas Cooled Reactor Experiments.

This report follows ciritical-assembly studies on: the effect on reactivity caused by changes in axial reflector materials; the effect on reactivity and the power perturbation caused by fast safety control-blade guides; the effect of changes in fuel-element material composition; the effect of changes in fuel-elements spacing designed to produce uniform radial power-generation rates.

Abstract: "The effects of a number of ternary additions on the constitution, casting, and fabricating characteristics and the physical properties of aluminum-35 w/o uranium were investigated. Initial investigations were concerned with the effects of 3 w/o ternary additions on the microstructure and press-forging characteristics of the alloy. It was found that additions of this magnitude often introduced extrinsic phases in the alloy. At the 3 w/o level, additions of germanium, silicon, tin or zirconium inhibited the formation of UAl4 and thereby increased the content of the aluminum matrix in the alloy. It was also noted that these additions decreased the pressures required for extruding, and the tin addition also improved the homogeneity of cast shapes. Lead and palladium also improved the homogeneity of the cast material; however, neither of these was an effective inhibitor of UAl4 and free lead was detected in the alloy to which lead had been added at the ternary. From these studies it appears that tin and zirconium are as effective as silicon in enhancing the fabricating characteristics of aluminum-35 w/o uranium alloys, and may prove superior when evaluated on the bases of casting qualities and recycling characteristics."

This report follows a series of tests run to determine the shielding properties of beryllium oxide, conducted at the Battelle Lid-Tank Shielding Facility. Neutron and gamma penetrations through and behind beryllium oxide were measured.

This report analyzes the stability and feasibility of a reflector-control system for a boiling heterogeneous reactor.

The following report summarizes the results of the laboratory-scale work and pilot-plant scale work of a salt-batch composition that reduces the hydrogen pickup by uranium rods during the beta heat treatment, and the study of the influence of humidity over the salt bath on hydrogen pickup.

From introduction: "On February 1, 1956, Batelle was awarded a contract by the Army Reactor Branch (ARB) to select, develop, and test core materials which could be used successfully in conducting a Gas Cooled Reactor Experiment (GCRE). The prime objective of the GCRE would be to evaluate small portable reactor systems for military application...The present report is concerned with the GCRE activities at Batelle during approximately the 7 months' period following the first report of this series, BMI-1133. It is primarily concerned with a detailed evaluation of the reference materials as well as of the impact of one material upon the other."

The following report studies an intermediate solid-fuel reactor system for aircraft propulsion.

Abstract: "The oxidation resistance of thin sheets of iron-28 w/o chromium-2.67 to 10.0 w/o alloys, nominally 0.004, 0.006, 0.008, 0.012, and 0.016 in. thick, was determined by exposure in static air for 100 hr at 2100 and 2300 F. A minimum of 3.67 and 9.37 w/o aluminum was necessary to prevent excessive oxidation of 0.004-in.-thick sheet material at 2100 and 2300 F, respectively. Correspondingly, specimens of lower aluminum content and greater thickness withstood the oxidation attack. Oxidation of iron-chromium-aluminum alloys appeared to be related to the diffusion of aluminum to surfaces of the sheet to form an adherent protective layer of Al2O3."

The following report presents neutron-flux measurements with the Mark I element, which include neutron-flux distribution and flux depression within the element.

Abstract: "In a study of the preparation and properties of delta-phase zirconium hydride it was found that large, sound bodies of the hydride can be prepared by direct combination of the elements if the rate of the reaction is retarded by limiting the supply of available hydrogen. Specimens up to 1-in. diameter were prepared using this technique. Because delta phase zirconium hydride does not readily form eutectics with iron-and nickel-base alloys below 1800 F these materials may be utilized for clodding the hydride. Delta-phase zirconium hydride is unaffected by exposure to liquid NaK or to nitrogen gas at temperatures below 1000 F. The hot hardness of delta-phase zirconium hydrid is about 130 kg per mm-2 at room temperature and 40 kg per mm-2 at 1500 F. The mean coefficient of thermal expansion (68 to 1337 F) is 6.5 x 10^-6 per deg F. The thermal conductivity varies from 5.7 Btu/(ft)(hr)(F) at 300 F to 5.1 Btu/(ft)(hr)(F) at 1300 F."

Abstract: A study has been made of the cladding of solid and powdered delta-phase zirconium hydride is both red and flat shapes with stainless steel. The program included investigations of metallurgical bonding, both with and without the sore of metallic barrier materials. Types 304 and 347 stainless steel were used for cladding material. The intermediate barrier-layer materials used were niobium, molybdenum, a combination of copper and molybdenum, and a combination of copper and niobium. The pressure-bonding techniques, involving the use of gas pressure at elevated temperatures, was employed in this study. Variable times and temperatures with a constant pressure of 10,000 poi were utilized by produce bonding. In this study, the best results were archived is cladding delta-phase zirconium hydride directly with Types 304 or 347 stainless steel. Good bonds were obtained by pressure bonding at 1600 F for 3 or 4 hr subsequent to pressure bonding at 1900 F for 1 to 2 hr at a pressure of 10,000 poi. Partial bonding was achieved between niobium and zirconium hydride and molybdeum and girconium hydride.

The following report presents neutron-flux measurements made with a concentric-cylinder element (Mark II) and includes axial, radial, and peripheral flux distributions.

From introduction: "This report deals with a part of the research and development studies which preceded the manufacture of fuel elements for the Gas Cooled Reactor Experiment (GCRE)." The studies evaluate the effects of varying the type and size of UO2 particles, stainless steel matrix powders, blending procedures, compacting pressures, sintering times, temperatures and atmospheres, roll-cladding temperatures and reduction rates, total cold reduction, and heat-treating times and temperatures has been made for UO2 stainless steel dispersion fuel elements."

"Centrifugal-casting techniques were investigated as a method of producing hollow cylindrical extrusion billets of aluminum-35 w/o uranium. Among the variables evaluated were melt temperature, mold and pouring-spout configurations, mold speed, and method of pouring. With the equipment employed it was found that the best castings were produced stilizing a pouring temperature of 2400 F, a heavy-walled steel cylinder rotating between 700 to 900 rpm for the mold and bottom-pouring technique employing a retractable pouring spout. Sound, nonporous billets 26 in. long and 5 in. in diameter were produced with a yield after machining of over 75 per cent of the original charge. The major losses occurred in the pouring spout-and-cup assembly. This loss is relatively unaffected by the casting length; and, therefore, coatings of greater length than 26 in. should results in even greater recoveries.

From introduction: "The work described here was part of an integrated investigation of the fundamental properties of uranium oxides done for the Mallinckrodt Chemical Works. Electrical measurements were employed to characterize the oxides produced by various processes from different starting materials. The basic objective of the program was to determine those factors which affect the sintering characteristics of uranium dioxide."

Abstract: A description is given of the design and operation of a windowed autoclave system employed in the study of corrosion by pressurized hot water. The device has been used to obtain time-lapse motion pictures of the swelling and rupture of deliberately defected zirconium-clad uranium specimens. A method is described by which corrosion rates were calculated from pressure and temperature measurements. A typical set of pictures taken during a test is presented, and corrosion rates are reported for uranium-0, 5, 10, 15, and 20 w/o zirconium alloys subjected subjected to 600 F water.

Abstract: The nonmetallic inclusions in both as-reduced and fabricated dingot uranium have been studied for comparison with those in ingot uranium. Special attention was paid to the hydride for the purpose of determining the amount and distribution in the various types of uranium. The types and distribution of other inclusions were also studied. It was found that the dingot uranium was of a higher quality than ingot uranium and was comparable to as-reduced derby uranium on the basis of over-all inclusion count. The hydrogen content in dingot uranium, however, was found to be appreciably higher than in either ingot or derby uranium.