A method for mitigating general corrosion and crack initiation and growth on the surface of a metal components in a water-cooled nuclear reactor. A compound containing a non-noble metal such as zirconium or titanium is injected into the water of the reactor in the form of a solution or suspension. This compound decomposes under reactor thermal conditions to release ions or atoms of the non-noble metal which incorporate in the surfaces of the components, including the interior surfaces of any cracks formed therein. The preferred compounds are zirconium compounds such as zirconium acetylacetonate, zirconium nitrate and zirconyl nitrate. Zirconium incorporated in the oxided surface of a metal component will reduce the electrochemical corrosion potential at the surface to a level below the critical potential to protect against intergranular stress corrosion cracking without the addition of hydrogen.