Abstract: "Four brazing methods and one other joining process were evaluated for the joining of aluminum spacer fins to flat-plate aluminum-clad fuel elements. None of these methods appear completely suitable for use in a mass-production operation. Furnace brazing and salt-bath brazing were most promising. However, the mechanical problems involved in the application of either process deter their recommendation. Resistance brazing and torch-brazing were proven impractical. The great difference in mass between the two pieces being joined prevents the use of either the resistance or torch method. Pressure bonding is not applicable because of the excessive deformation of parts being joined."

This report is part one of a series of two parts to a memorandum. The work discussed here presents the results of extensive calculations on the attention of gamma rays by shields of lead and iron.

The Turco 4501 process is recommended for the decontamination of the PRFR pilot leaching plant equipment. The caustic-tartrate-nitric acid process is recommended for the decontamination of the cell and the equipment exterior.

The preliminary process design of a PRFR pilot leaching plant, which is proposed to be located in Cell B of Building ORNL, is considered. Chemical, physical, and nuclear parameters are investigated in order that the leaching operations may be carried out without any chemical or nuclear hazards.

The nil-ductility-transition (NDT) temperature, as defined by the Naval Research Laboratory drop-weight test, was determined on the A212B carbon-silicon steel used in the pressure vessel of the N. S. Savannah nuclear reactor. Correlations were made with the Charpy-V-notch impact energy at NDT. Specimens taken at two different thickness location from materials used in the upper closure head of the reactor vessel yielded NDT temperatures of 0 - 20°F which correspond to Charpy-V-notch impact energies of 11-19 ft-lb. Testing of as-received material used in the lower closure head indicated that the NDT temperature was 50°F which was equivalent to an average Charpy-V-notch impact energy of 12 ft-lb. After normalizing and stress-relieving this material, in order to more closely approximate the final condition of the reactor vessel, NDT was reduced to less than 10°F.