Metallographic examination has been completed on samples from the Nichrome V wire mesh furnace belt in the 232-Z building incinerator. During service the furnace belt had broken in several places where the wire was welded together. A grain boundary phase was found in weld metal during metallographic examination of the as received material. It is probable to conclude that the failure during service was caused by accelerated corrosion of the weld and that the accelerated corrosion in that area was related to the structure of the weld metal. It would be informative to examine welds from the furnace belts that have not failed to further study the cause for the failure.

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The two small reactors (B and D) currently utilize a flat aluminum horizontal control rod consisting of three cooling tubes surrounded by boron carbide-aluminum neutron absorber rings and an outer casing of aluminum. Two adverse and complementary characteristics of these rods have served to limit the functional reliability of the rods under current and anticipated reactor operating conditions. The construction of the rod presents a relatively high resistance to transfer of heat from the sheath to the cooling water and the neutron to transfer of heat from the sheath to the cooling water and the neutron absorber rings show evidence of significant dimensional increase with high accumulated exposure to neutrons. With poor heat transfer and current reactor operating levels, the rod sheath temperature may exceed that for which aluminum is suited and the material loses its strength by annealing. Swelling of the neutron absorber rings further aggravates the overheating by increasing the cooling tube to ring gap. The net result is a tendency for hot spots to occur in the rod sheath and in the more advanced cases, these develop into e step plug. blisters which cause the rod to bind in the channel and/or the step plug. A new …

This report describes the results of work done during the period from March 2 through March 8, 1965 at Hanford. Discussed topics include: pressure testing of Zr-2 tubing at high temperature, Zr-Al corrosion, and poison -- target combinations.

This report provides the status of production test control tube loadings in reactor process tubes containing significant amounts of SS materials.

Declassified 28 Aug 1973. Several uranium oxide fuel materials were prepared for evaluation. Included was a 2-pound sample of plasma jet spheroidized. 30- to 60- mu UO/sub 2/ of precisely controlled stoichiometry containing less than 50 ppM metallic impurities. Six 1-pound samples of 30- to 60- mu U0/sub 2/ were prepared which contained calcium oxide, thorium oxide, or yttrium oxide stabilizing agents in solid solution. These powders were coated with 8 to 10 mu of tungsten by hydrogen reduction of tungsten hexaflouride in a fluidized bed. Seven 1-pound samples of 30- to 60- mu U0/sub 2/ containing various concentrations of yttrium oxide in solid solution were also prepared. Finally, a 1-pound sample of less than 5- mu UO/sub 2/ containing 10 mole% yttrium oxide was produced. Procedures were developed for applying metallurgically bonded tungsten coatings to the edges of W-U0/sub 2/ cermet fuel elements. These coatings were effective in reducing the U0/sub 2/ loss in high- temperature tests at NASA. Of several techniques examined for producing a halide- free tungsten coating on 30- to 60- mu U0/sub 2/ powder. the most promising were (a) vacuum evaporation of tungsten using electron beam heating, and (b) electrostatically bonding fine WO/sub 2/ powder …

This report describes the analysis performed in determining the lowest pemissable insulation resistance for the exposed junction copper/constantan thermocouples to measure outer reflector drum annulius, drum vane and beryllium exit gas temperature.

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This report details activities of the N-Reactor Department during the month of December 1964.

This report summarizes the results of apparent strain tests conducted on both temperature-compensated and uncompensated Microdot weldable strain gages as requested by the Sensor Application Engineering group.

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