Photoactivation Approach to the Determination of Long-lived Nickel Isotopes in NPP Structural Materials

— A photoactivation method has been developed for determining the activity of long-lived nickel isotopes by the 60 Co activity in metallic structural materials of a reactor core. The error of this method is 5–10%, and the sensitivity is 0.5 Bq/g if semiconductor γ-ray spectrometers with high-purity germanium detectors are used. Following the proposed approach, it is possible to significantly simplify the identification, testing, and certification of metallic structural materials at the stage of reactor decommissioning as well as to significantly reduce the cost of these works compared to the radiochemical methods.