A six-inch diameter "O" ring from the HRT Mockup was examined metallographically after 2452 hours exposure to uranyl sulfate solution at 300C. surface defects, except for cold work defects were found only in areas exposed to uranyl sulfates. Defects found were pits, transgranular cracks, surface cracks, and grain attacks.

It has been reported in the literature that prolonged soaking of 16 wt & uranium-aluminum alloys at elevated temperatures induces a microstructural changed termed "conglobulation". this process is essentially a spheroidization of the UAl4 eutectic. Conclusions of the tests: (1) Extended soaking of 48 wt $ uranium-aluminum alloy billets at 600 C does not improve their hot-rolling characteristics. (2) Soaking periods of 50 hours and greater reduce the tensile and yield strengths of these alloys. (3) Soaking for 50 hours results in complete spheroidization of the eutectic in 48 wt % uranium-aluminum alloys.

Experiments in the controlled melting of irradiated fuel specimens, particularly of the APPR, STR, and MTR types have confirmed that prolonged heating in air at temperatures in excess of the melting point results in the release of a large portion of the radioactivity. On the other hand, a moderate amount of heating in air or steam sufficient only to melt a specimen results mainly in the partial volatilization of the rare gases; the halogens, iodine and bromine; and the alkali metals, cesium and rubidium. In the presence of air or water vapor, strontium and other fission products are not released. At trace concentration of fission products, slow melting of the APPR plate at 1525 C in air or steam effected the release of 50 percent of the rare gases, 33 percent of the iodine, 9 percent of the cesium and traces of strontium. After 25% burn-up, the cesium value increased to about 60 percent. Aluminum alloy of the MTR type, also at trace concentration, upon melting at 700 C released up to 2 percent of the iodine, 10 percent of the rare gases, and negligible portions of other fission products. Zirconium alloy of the STR type after 15 percent burn …