8 5 F 5 ; 9 6 9 7 4 / 1 < =15% cold-worked Zircaloy-2 at 290, 345, and 400 deg C is being continued. Research to identify factors affecting irradiation-induced volume changes in graphite by means of sink- float density measurements was oontinued. The program to simulate conditions after a postulated loss-of coolant incident within the PRTR was completed. Lapsed-time motion pictures are being made through a windowed autoclave of the corrosive action of high-temperature water on defected Zircaloy2 U specimens. Progress on the development of an isotopic-exchange leak-detection systems is summarized. A program to develop a thermal-neutron-flux munitoring system for the Hanford reactors is reported. A project is being conducted to determine the temperature and approximate composition of the ternary eutectic in the Al--U--Ni alloys. A feasibility study to determine if Ca coatings can be successfully put on Ni by arc-spraying methods is reported. Work was continued on the valence effects of oxide additions (CaO and La/sub 2/O/sub 3/) to UO/sub 2/. An investigation is being made of the effects of combined high pressure and temperature on UO/sub 2/. Postirradiation data are presented on fueled specimens of ZrH/sub 1.65/--2 wt.% U. An evaluation of the effect of irradiation on the mechanical properties of AISI Type 347 stainless steel is being conducted. Hothardness data are presented for high-purity Nb, Nb-- Zr, Nb-V, Nb-Ti, Nb-Fe, Nb-Cr, Nb-V-Ti, Nb-V-Mo, Nb-V-Fe, Nb-V-Cr, Nb-V-Al, Nb-Zr-V, Nb-ZrTi, Nb-Zr-Mo, Nb-Zr-Cr, and Nb-Zr-Fe. A summary is presented of corrosion results obtained on Nb, Nb-Zr, Nb-W, Nb-Mo, Nb-V, Nb-Fe, Nb-Ti, Nb-Ti-Cr, Nb-Ti-Mo, and Nb-Ti-V alloys exposed in high-temperature water and steam. Corrosion data are given for Nb-U alloys in air, CO/sub 2/, NaK, water, and steam. Techniques are being developed for the preparation and cladding of cermets containing 60 to 90 vol.% of fuel dispersed in metal matrices of Nb, Mo, Cr, and stainless steel. The gas- pressurebonding process is being investigated as a method of fabricating fuel elements clad with Mo or Nb. The hightemperature irradiation behavior of dispersion fuel elements consisting of 24 wt.% UN and UC dispersed in stainless steel is being evaluated. Hot-pressing techniques are being used to investigate the kinetics and mechanism of solid-state bonding of metals by the application of heat and pressure. Methods of producing dense UC pellets by powder metallurgy are being investigated. Data are presented on the effect of carbon content and impurities on corrosion resistance of UC in 60 deg C water. The effects of carbon content on density and electrical resistivity of UC are reported. Fundamental studies are being made of the reaction of Nb with N/sub 2/, and the diffusion and terminal solubilities of N/sub 2/ in the metal. A U--Nb constitution study utilizing diffusion couples to establish the composition limits of the gamma -phase immiscibility gap in the system is in progress. Data are presented on time-temperature relationship using induction heating on a UO/ sub 2/-- graphite sphere. The dissolution of 25 fuel pins in a Ni-o-nel dissolver by the Sulfex-- Thorex process has demonstrated the necessity of solution annealing all weldments in order that the sever integranular attack be prevented. A Ti 75 A dissolver used for the dissolution of 25 fuel pins by the Darex-- Thorex process underwent negligible attack except in areas around weldments in the vapor phase. The development of binary Ta alloys as container materials for LAMPRE applications is reported. The gas-pressure-bonding process is being investigated as a backup effort for the preparation of Zircaloy-2-clad compartmented flat-plate fuel ele
