Abstract: A method to remove deposits containing magnetite and copper from a container, particularly from a steam generator of a nuclear power plant. In a first step, the container is treated using an alkaline cleaning solution containing a complexing agent forming a soluble complex with iron ions, a reducing agent, and an alkalizing agent. In a second step a further complexing agent forming a more stable complex with iron III ions than the complexing agent used in the first step and an oxidant are added to the cleaning solution of the first step present in the container.

Abstract: A method to remove deposits containing magnetite and copper from a container, particularly from a steam generator of a nuclear power plant. In a first step, the container is treated using an alkaline cleaning solution containing a complexing agent forming a soluble complex with iron ions, a reducing agent, and an alkalizing agent. In a second step a further complexing agent forming a more stable complex with iron III ions than the complexing agent used in the first step and an oxidant are added to the cleaning solution of the first step present in the container.

Abstract: A cleaning method for removing deposits containing magnetite out of a pressure vessel of a power plant, during which the deposits are treated with an aqueous cleaning solution, which contains a reducing agent and which is heated to an elevated cleaning temperature above ambient temperature, in order to reduce iron III ions to iron II ions. The cleaning solution is introduced into the pressure vessel. This cleaning solution contains an initial substance that releases the reducing agent under the conditions existing during cleaning. Hexamethylenetetramine is preferably used as the initial substance.

Abstract: A method for cleaning steam generating devices of a pressurized water reactor treats the devices on their secondary sides at high pressure and high temperature. An aqueous cleaning solution is employed with EDTA, a reducing agent, and an alkalizing agent. Morpholine is used as the alkalization agent. A molar morpholine-concentration, which is at least as great as the molar concentration of EDTA, is selected. Hydrazine and/or formaldehyde are/is used as the reducing agent at a ratio to EDTA between 1:6 and 1:1.

Abstract: A method for monitoring the corrosion of C-steel of a vessel, in particular of a steam generator, when the vessel is being cleaned using at least one chemical which releases a gas, in particular nitrogen, during the cleaning process. It is envisaged that the volumetric ratio or quantitative ratio between hydrogen and the gas released is determined in the gas/vapor mixture which forms during the cleaning process and this ratio is compared with a threshold value. The cleaning process is interrupted in the event the threshold value is exceeded.