Type 316L(N) stainless steel plate material has been irradiated up to 10 dpa at temperatures of 80, 225, 325, and 425°C in the High Flux Reactor (HFR) of Petten. Tensile tests have been performed in the temperature range from RT to 575°C at a conventional strain rate of 5×10⁻⁴ s⁻¹. The results of the tensile tests are analyzed in terms of irradiation hardening and loss of ductility due to irradiation. Tensile properties saturate in the early stage (within 0.65 dpa) at the lowest applied irradiation temperature. It is indicated that the most severe degradation of tensile ductility occurs in the temperature range of 275 to 350°C. Comparison with literature data revealed a large scatter in irradiation hardening at irradiation temperatures above 325°C.