Thermal creep tests on irradiated specimens

Post-irradiation thermal creep tests have been carried out with CuCrZr/CuCrZr and CuCrZr/316L joints. This was a part of the project related to "Technical specification for in-pile creep relaxation and post-irradiation thermal creep test". Six specimens have been tested; three CuCrZr/CuCrZr joints irradiated up to 0.69 dpa and three CuCrZr/316L joints, also irradiated to 0.69 dpa. The thermal creep tests were carried out at 250°C, with the applied stress just below the ultimate tensile stress. Creep fracture times were supposed to be approximately one week.The CuCrZr/CuCrZr joints failed in less than a week, most probably because the applied stress was a bit too high. The CuCrZr/316L joints failed in about a week as predicted by the creep stress calculations.SEM observations showed that intergranular fracture was present for the CuCrZr/CuCrZr specimens, subjected to fast rupture. Leaflet like feature were present on all specimens, being an indication that fractured occurred in the HIP zone. Very flat fracture surfaces were found for the CuCrZr/316L joints.