Abstract: A definitive investigation of the boron-carbon equilibrium system is being made by X-ray diffraction, metallographic, and thermal analytical techniques. On the basis of metallographic and X-ray diffraction studies it is concluded that boron carbide has a range of solubility from approximately 10 to 20 atomic per cent carbon at 1500 degrees to 2000 degrees Celsius. The melting point of the carbide-graphite eutectic has been established as 2325-2350 degrees Celsius. No reversible allotropy of the beta-rhombohedral structure has been observed. The solubility of carbon in boron is very small. The melting point of dilute carbon alloys is found to be essentially the same as that of pure boron (2040 degrees to 2050 degrees). No metallographic evidence of a three-phase reaction of dilute alloys is observed.

Summary: "The low carbon 18-8 stainless steels containing approximately 1.7 per cent boron used for vertical safety rods at Hanford were found to be structurally stable in the temperature range 0-450 C. The addition of boron decreases the stability of this metastable austenitic alloy. Sufficient ferrite formation is induced by sub-zero temperature treatments to result in dimensional changes and a magnetic alloy. The difficulties encountered in machining this material are believed to be due primarily to segregation in the castings resulting in small areas of the hard intermetallic compound, FeB."

Report discussing the progress made on a study of electric propulsion for space travel during the period from July 1, 1958 to December 31, 1958 at the Lawrence Radiation Laboratory in Livermore, California.

Abstract: Tuballoy can be effectively separated from tantalum filaments by chlorination of the filaments and subsequent distillation and condensation of tantalum chloride. Apparatus for chlorination of filaments and distillation separation in one unit is under consideration. Chemical methods of separation of tuballoy from distillation residues are being tested.

Technical report outlining the effect of strain rate on the tensile properties of thorium. It has been found that the yield strength increases slightly with increasing strain rate, and that tensile strength increases but to a less extent. Studies on the fabrication of thorium by extrusion and drawing have continued, as have studies on the extrusion cladding of thorium and uranium with zirconium. [From Summary}

Abstract: This technical report summarizes all core physics experiments performed on SM-1 Core I and SM-2 Rearranged and Spiked Core I throughout core life. These measurements were obtained on site during the 16.4 MWYR lifetime of SM-1 Core I and 1.6 MWYR lifetime of SM-1 Rearranged and Spiked Core I. SM-1 Core I was the first stainless steel - UO2 dispersion core to burn out in the Army Nuclear Power Program. Experimental techniques are described and a complete history of fuel movements in the core presented. Measurements include control rod bank positions during all core conditions, temperature and pressure coefficients, control rod calibrations, transient poison effects, source multiplication, and stuck rod positions. The effect of core rearrangement and spiking on core reactivity and core life is also reported. Applicable measurements from the SM-1 zero power experiments are included.

This study was started in May 1949 to find methods of reducing the number of element failures in the salt bath bronze furnaces. Determining the cause of the failure and methods of eliminating them is followed to completion.

Previously, W. S. Figg and T. W. Ambrose (HW-51767 Rev) have investigated the problem of flow decay following electrical power loss to the PRTR primary coolant pumps. However, since the time of their study many reactor piping changes have been made in the design; therefore, it has become advisable to re-examine the problem incorporating these changes.

This report is an amendment to the Preliminary Hazards Summary Report (1) and the Operating Procedures and Emergency Plans (5) for the Dresden Nuclear Power Station, submitted to the United States Atomic Energy Commission on September 3, 1957, and June 5, 1958, respectively.

In the HRP Welding program, a major part of the welding and fabrication, and some of the testing, is performed using an inert atmosphere. the use of the inert gas consumable arc welding process and dry box welding or other work in a dry box comes within this category. Since much of the work in the project make use of, or requires, inert atmospheres, a general discussion follows of the methods used, description of equipment, processes, quality of atmospheres, purity requirements, kinetics of metal-gas reactions, and the proper application of the equipment and methods use din obtaining the desired results.