PROGRESS RELATING TO CIVILIAN APPLICATIONS DURING MAY 1957

Data are reported on the creep properties of annealed Zircaloy-2 and -3A. Efforts directed toward the improvement of the extrusion-cladding process were continued. A program of research concerned with the development of melting and casting techmiques for the production of sound, homogeneous Al-- U extrusion billets containing up to 50 wt.% U is in progress. Uranium oxides are being studied to determine how processing variables affect the reactivity of the dioxide in subsequent steps in the production of U. The study of the effects of N/ sub 2/ on the electrical properties of UO/sub 2/ was continued. Investigations were continued on the corrosion of Type 304 ELC stainiess steel by chloride- and fluoride-contaminated HNO/sub 3/ solutions such as might occur during the recovery of HNO/sub 3/ from U processing plants. Hydrogen pickup by U rods heat treated in pilot-plart-scale beta heat-treating salt baths is being studied. The compacting of briquettes of UF/sub 4/ and Mg was offered as a means of improving the efficiency of the bomb-reduction process. Nuclear fuel elements utilizing the refractory materials BeO and graphite as matrices for UO/sub 2/ are being investigated. Data are reported on the tensile properties of U--Nb alloys containing 7, 10, and 15 wt.% Nb. The mechanism of aqueous U corrosion is being studied in order to develop corrosion-resistant alloys for reactor fuels. Research on the fundamental properties, corrosion resistance, and radiation resistance of U-- Zr alloys is reported. Long-term corrosion studies pertaining to the development of corrosion-resistant Zr and Zr-base alloys were continued in elevated-temperature water and steam. Data are reported on the oxidation behavior of binary Nb alloys tested in air at 1000 tained C. Tensile test data are presented for martensitic U--Ti alloys. The reaction of oxygen and nitrogen with USi/sub 3/, U/sub 3/Si/sub 2/, USi/sub 2/, USi, and UAl/sub 2/ was investigated. Investigations of corrosion problems associated with the recovery of spent reactor fuel elements were continued. A reflector method of control for a boilingwater heterogeneous reactor is being investigated. The behavior of Ta expcsed to 1200 tained F peak-temperature sodium is being investigated using forced-convection flow-loop apparatus. Creep testing of annealed Ta sheet was continued. A new and particularly sensitive method for the determination of oxygen in sodium is being developed. (For preceding period see BMI-1181.) (W.L.H.