In-Reactor Creep Rupture Behavior of the D19 and 316 Alloys

In-reactor creep rupture data on one heat and two cold work levels of the D9-type alloy and on two heats of cold worked 316 stainless steel have been obtained from the Materials Open Test Assembly (MOTA) experiment in the Fast Flux Test Facility (FFTF). The on-line detection of creep ruptures using a tag gas technique has provided in-reactor creep rupture data for irradiation temperatures of 575, 605, 670, and 750°C to a peak fluence of 9 × 10²² n/cm² (E > 0.1 MeV). Similar thermal creep rupture data have been accumulated for exposure temperatures of 650, 704, and 760°C to exposure times of 10 000 h. In general, the in-reactor rupture times are comparable to or less than those exhibited by the thermal testing. The 10% cold worked condition of D9 exhibits slightly better creep rupture resistance when compared to the 20% cold worked condition. The inreactor failure strains are less than those of the thermal controls for a given temperature.