| 摘要 |
<p>Decontamination of metal components carrying an oxide layer in a nuclear powered water cooled reaction comprises introducing a low concentration of zinc ions into the water to cause loosening of the oxide layer from the metal surface. Independent claims are also included for the following: (i) the passivation of a metal surface comprising immersing the metal surface initially free of oxide surface layer in water at elevated temperature in the presence of zinc at low concentration for at least 100 hours; and (ii) the decontamination of metal components carrying an oxide layer comprising exposing the component to an aqueous solution of zinc ions to cause loosening of the oxide layer from the metal surface. Preferred Features: The zinc ions are introduced in a concentration of at least 30 ppb, preferably 1-500 ppb. The water temperature is at least 450[deg]F, preferably 455-550[deg]F. The metal surface carrying the oxide layer is exposed to the zinc ions for at least 100 hours, preferably 2000 hours. The zinc ion is devoid of 64>Zn. The zinc ion is added by dissolving zinc oxide in water. The zinc ion is added as a water-based paste, a water-based slurry or a water-based solution.</p> |
