METHOD FOR DECOMPOSING AN OXIDE LAYER

摘要

The invention relates to a method for decomposing an oxide layer containing chromium, iron, nickel, and radionuclides by means of an aqueous oxidative decontamination solution, which contains permanganic acid and a mineral acid and which flows in a circuit (K1), wherein the oxidative decontamination solution is set to a pH value ≦2.5.

主权项

1. Method for decomposing an oxide layer containing chromium, iron, nickel, and optionally zinc and radionuclides using an aqueous oxidative decontamination solution containing permanganic acid and a mineral acid, flowing in a circuit (K1), wherein the oxidative decontamination solution is adjusted to a pH≦2.5, especially for decomposing oxide layers deposited on the interior surfaces of areas or components of a nuclear power plant,
wherein the oxidation of the oxide layer and its dissolution takes place in a single treatment step with the aid of the aqueous decontamination solution, that sulfuric acid is used as the mineral acid for adjusting the pH, and that after degradation of the permanganic acid, while maintaining the flow in the circuit, the solution flows over a bypass line to a cation exchanger in which divalent cations and divalent radionuclides present in the solution are fixed with simultaneous liberation of sulfate and dichromate anions.