The hot-water corrosion resistance and mechanical properties of niobium and a number of its alloys were evaluated relative to their usefulness in pressurized-water thermal reactors. Unalloyed niobium was found to be rapidly attacked by 600 and 680 deg F water and 750 F steam. A number of alloying additions were found which markedly improve the corrosion resistance of niobium. Of these, binary and ternary combinations of chromium, molybdenum, titanium, vanadium, and zirconium were among the most effective. Many of these alloys exhibited as low or lower weight gains than those obtained for Zircaloy-2 under similar test conditions. Most of the niobium-base alloys tested for strength exhibited excellent resistance to creep at temperatures up to 1200 deg F under stresses through 20,000 psi. (auth)

The external holdup of expensive materials and associated capital costs for the heat removal systems of fluid fuel breeders were determined. The aqueous homogeneous and molten salt breeders were found to contain substantially less uranium holdup external to the core than the liquid metal fueled breeder. The cost of heat removal and turbogenerator plant equipment for the three systems was compared. (auth)

This monthly document details activities of the Hanford Operations Office during the month of April 1960. (FI)

Abstract. The cross section of photoneutron production in Be9 at energies of 1.692, 1.720, and 1.78 Mev has been investigated using radioisotope gamma-ray sources. Neutron counting was by manganous sulfate bathe and a long counter. Gamma-ray counting was by a scintillation spectrometer consisting of a NaI(T1) scintillation crystal and a 256 channel pulse-height analyzer. A theoretical treatment of the P [right arrow] S transition near threshold using square-well potentials is also presented.

Critical mass experiments to be conducted at HAPO will require dilute and concentrated plutonium solutions. Since very high plutonium concentrations (~2,000 g/l) cannot be attained in pumpable solutions, solid plutonium compounds will be utilized for this phase of the work. Mixtures of plutonium oxide and polyethylene, methyl methacrylate or paraffin compacted in containers have been considers for use in highly-concentrated plutonium systems of known hydrogen to plutonium atomic ratio (H/Pu).