[en] Prior to initiating a qualification test on safety-related equipment, the testing sequence for thermal and irradiation aging exposures must be chosen. Likewise, the temperature during irradiation must be selected. Typically, U.S. qualification efforts employ ambient temperature irradiation, while French qualification efforts employ 70⁰C irradiations. For several polymer materials, the influence of the thermal and irradiation aging sequence, as well as the irradiation temperature (ambient versus 70⁰C), has been investigated in preparation for Loss-of-Coolant Accident simulated tests. Ultimate tensile properties at completion of aging are presented for three XLPO and XLPE, five EPR and EPDM, two CSPE (HYPALON), one CPE, one VAMAC, one polydiallylphtalate, and one PPS material. Bend test results at completion of aging are presented for two TEFZEL materials. Permanent set after compression results are presented for three EPR, one VAMAC, one BUNA N, one Silicone, and one Viton material