The copper-assisted dissolution of magnetite in hydrazine-based inorganic solution

A protective oxide layer forms on the material surfaces of a Nuclear Power Plant during operation due to high temperature. These deposited oxides are iron oxides such as Fe3O4, Fe2O3, and mixed ferrites such as nickel ferrites, chromium ferrites, and cobalt ferrites. Developing a new chemical decontamination technology for domestic CANDU-type reactors is challenging due to variations in oxide compositions from different structural materials in a Pressurized Water Reactor (PWR) system. The Korea Atomic Energy Research Institute (KAERI) has already developed a chemical decontamination process for PWRs called 'HyBRID' (Hydrazine-Based Reductive metal Ion Decontamination) that does not use organic acids or organic chelating agents at all. To improvise this chemical decontamination technology for the Pressurized Heavy Water Reactor (PHWR) system, we investigated the role of Cu in magnetite dissolution. The redox cycle of copper in the presence of hydrazine and magnetite in the solution does provide a good dissolution behavior of magnetite.