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 abstract: "A Method has been developed for the uniform coating of graphite tubes with carbides of niobium, tantalum, and zirconium by thermal composition of their respective halide vapors."

This report discusses tests on the preparation and cladding of hot-pressed and pressure-bonded titanium-boron. It explores the properties of titanium-boron as a control material in reactors.

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.

Report discussing a study aimed at pinpointing the cause of banding segregation in arc-melted uranium-niobium alloys and suggesting possible methods for eliminating banding.

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.

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.

Abstract: "Fabrication techniques for producing dispersion fuel elements with cores of 30 volume per cost of UC, U2Tl, U3Si, or U6Ni dispersed in Zircology 2 and 30 volume per cent of UC or UN dispersed in Type 18-8 stainless steel have been investigated. Roll-clad plate-type elements of all these compositions may be fabricated by powder-metallurgy methods in such a manner that good core-to-cladding bonds and cores with uniform dispersions of discrete uranium-composed particles are obtained. From the standpoint of fabricability, elements containing UC is Zircology 2, UC in stainless steel, and UN in stainless steel are the most promising. The UN in stainless steel has the best corrosion resistance in 680 F degassed water; however, UC in stainless steel has the best resistance to corrosion in 700 F NaK."

The following report follows the procedures to compact blends of uranium tetrafluoride and magnesium, describing how lubrication of the compact effects the outcome of the blends.

The following report follows an experimental study that was made on the mass transport of chromium in polythermal inconel-fluoride fuel systems, followed by the technique of adding radioactive chromium-51 to the system as either CrF3 in the salt or as elemental chromium in the solid phase.