For several nuclear graphites, the Auence required to contract to a minimum volume and expand back to the original volume is much greater at 1250°C than for temperatures near 1000%. This occurs because, at the higher temperature, the graphite initially contracts to a smaller minimum volume and its expansion rate following the minimum volume is lower. The mechanism for this is believed to be an increased irradiation creep constant that allows plastic deformation rather than fracture to accomodate the differential crystal strains. Data for two nuclear graphites show that the fluence corresponding to the minimum graphite volume is nearly temperature independent in the range 400~8OO"C, but then quickly decreases to about half the low-temperature value for the range 950-1300°C. Arguments are presented to show that similar behavior is to be expected for most nuclear graphites. The saturation electrical resistivity is about double the unirradiated value for irradiation temperatures over the entire range 400-1000°C but only about 1.5 times the unirradiated value for irradiation temperatures near 1250°C. The difference is apparently related to the decrease that occurs upon annealing at temperatures above 1200%.