Quantitative differential thermal analysis study of the U/sub 3/O/sub 8/-Al thermite reaction

Concerns about proliferation resistance of nuclear fuel cycles and fuels have prompted a reinvestigation of U/sub 3/O/sub 8/-Al cermet fuels currently being used in research and test reactors. In particular, higher loadings of U/sub 3/O/sub 8/ are being considered. These new fuel compositions are in the region of maximum possible thermal energy release from the high-temperature thermite reaction between the U/sub 3/O/sub 8/ and aluminum components. This study was initiated to quantitatively measure the amount of reaction heat evolved. A differential thermal analysis system was calibrated with materials of known heat of reaction. Subsequently, specimens of high-uranium-loaded U/sub 3/O/sub 8/-Al powder mixtures were analyzed. Thermite reaction heat measured for these specimens was much lower than expected. Possible reason(s) for this behavior are discussed in the report.