Evaluation of dry films for application on spur gears for - servicing components of a gas-cooled nuclear reactor was performed. Commercial dry film lubricants were screened in wear tests to obtain the optimum lubricant which was in turn used in gear teats. A MoS/sub 2/, graphite, and sodium silicate binder lubricant (Everlube 811 or equivalent) applied to M 50 tool steel gears resulted in the optimum combination based on stress cycle tests. Tests were performed on uniubricated worm gears at simulated loads, speeds, and environment of the charging machine for the above reactor to determine wear rates and efficiencies. (auth)

>The basic fuel element consisted of a uniform dispersion of fuel in a 1 1/2 inch diameter graphite sphere. Ceramic coatings for the retention of fission products were studied. It was found-that molecularly deposited'' ceramics such as alumina, siliconized silicon carbide, and pyrolytic carbon were excellent barriers to fission product leakage. The most advantageous location for ceramic coatings was found to be on the individual fuel particles, where the coating was subject to smaller forces and where a larger thickness-todiameter ratio could be used than if the coating were on the surface of the graphite sphere. Fuel elements were irradiated to burnups ranging up to about 6 at.% U/sup 235/. In all specimens containing a uniform dispersion of fuel, the graphite spheres were found to retain their structural properties after irradiation. Data are given on fuel particle coatings of A1/sub 2/O/sub 3/, pyrolytic carbon, and metals: surface coatings of siliconized silicon carbide, pyrolytic carbon, and metal carbides; properties of and the effects of irradiation on graphite spheres; the use of natural graphite in preparing a high-density matrix material; graphite fueling by thorium nitrate infiltration; subsurface metal and metal carbide coatings for graphite; and an in-pile loop program on the behavior …