Specimens of annealed Type 316 stainless steel were irradiated in Experimental Breeder Reactor II at temperatures ranging from 900 to 1450°F and to fluences from 0.2 to 7 × 1022 n/cm2 (En > 0.1 MeV). Uniaxial and biaxial creep tests were performed at 1000, 1100, 1200, and 1400°F with rupture times from <1 to >1000 h. The test data show that rupture life changes due to irradiation can be substantial. The stress, fluence, and temperature dependence of rupture life are reduced to a mathematical form, , where A and B are temperature-dependent terms and the term ti/tn is temperature and fluence dependent.