[en] The usefulness of intermediate annealing to periodically mitigate the deleterious effects of nuclear radiation on reactor pressure vessel steels is explored. Test materials are intermediate and high copper content weld deposits made commercially. Irradiation and reirradiation exposures were at 288 degrees C. Annealing-induced properties recovery and resistance to reembrittlement by irradiation are qualified for 454 degrees C and 399 degrees C heat treatments and a total fluence of 2.7 x 10¹⁹n/cm². Tendencies toward a saturation of radiation embrittlement were observed in annealed material. With 454 degrees C annealing, embrittlement levels were lower than those observed after irradiation to 1.5 x 10¹⁹n/cm² without intermediate annealing. The method shows high promise for radiation-sensitive pressure vessel steels for increasing their fracture-safe service lifetimes. 22 refs., 27 figs., 5 tabs