The present invention relates to a cleaning composition for the decontamination of surfaces, in particular radioactive surfaces, and the related decontamination method.

Devices for eliminating radioactive contamination of radioactive waste by providing adaptive processing of the decontamination solution for reuse. The plant for electrochemical decontamination of metal radioactive waste includes a pipe equipped with shut-off valves, a radioactive waste processing module that comprises a unit for electrochemical decontamination connected by a ventilation channel to the ventilation module and pipe for decontamination solution supply and discharge equipped with shut-off valves. The plant is equipped with a decontamination solution preparation module connected with a pipe for decontamination solution supply and discharge, at least one pump, while the module for decontamination solution receiving is equipped with devices for cleaning and pH correction of decontamination solution, and the unit for electrochemical decontamination of metal radioactive waste, the module for decontamination solution receiving and the decontamination solution preparation module are equipped with pH measurement elements.

The invention relates to a method for decontaminating a radioactively contaminated metal surface, wherein the metal surface is brought in contact with a decontamination solution, which comprises a complexing agent and a transition metal. The invention further relates to such a decontamination solution and to the use thereof to decontaminate a metal surface.

A method for treating waste water from the decontamination of a metal surface in a primary coolant circuit of a nuclear reactor comprises discharging a predetermined amount of an oxidation solution from the primary coolant circuit into a reduction zone connected to the primary coolant circuit and reacting the oxidation solution with a reducing agent to form a reaction solution that is freed of oxidizing agent, and passing the reaction solution over an ion-exchange resin in order to form a desalinated solution, and returning the desalinated solution to the primary coolant and/or disposing of the desalinated solution. A waste water treatment apparatus for carrying out the method is also provided.

A decontamination method that includes the steps of decontaminating an object containing radioactive contaminated metals or alloys with a chemical decontamination agent including sulfuric acid (H.sub.2SO.sub.4) and forming a Ba or Sr precipitate by adding a Ba or Sr cation and a hydroxylion or halogen anion salts to the decontamination waste water.

The invention relates to a method for decontaminating a radioactively contaminated metal surface, wherein the metal surface is brought in contact with a decontamination solution, which comprises a complexing agent and a transition metal. The invention further relates to such a decontamination solution and to the use thereof to decontaminate a metal surface.

A process for recovering uranium from components contaminated with uranium oxide includes providing a cleaning apparatus with a cleaning solution for dissolving the uranium oxide of the components, carrying out a cleaning process by introducing a batch of components into the cleaning apparatus, and carrying out a measurement for determining the uranium content of the components. The cleaning and the measuring are repeated if a limit value for the uranium content is exceeded. The components are discharged from the process if the uranium content falls below a limit value. The cleaning is carried out on a plurality of successive batches of components until a control measurement indicates an unsatisfactory cleaning action of the cleaning solution. The uranium oxide dissolved in the cleaning solution is recovered after indication of the unsatisfactory cleaning action.

A chemical decontamination method includes a dissolution step in which a radioactive insoluble substance containing a metal oxide, the radioactive insoluble substance being adhered to a decontamination object including carbon steel, is dissolved in a decontamination solution and a metal-ion removal step in which the decontamination solution containing the metal ion, the decontamination solution being produced in the dissolution step, is brought into contact with a cation-exchange resin in order to remove the metal ion, the dissolution step including a reductive dissolution step conducted using a decontamination solution containing formic acid, ascorbic acid and/or erythorbic acid, and a corrosion inhibitor.

Provided is a chemical decontamination method that shortens the decomposition time of a reduction decontamination agent. An oxidization decontamination, a decomposition of an oxidization decontamination agent, and reduction decontamination using an oxalic acid aqueous solution are performed on a target piping of a BWR plant. After that, the oxalic acid is decomposed (S7). That is, a part of the oxalic acid is decomposed by irradiating the oxalic acid aqueous solution with ultraviolet rays upstream of a decomposition device (S8), and Fe.sup.3+ in the aqueous solution is converted to Fe.sup.2+. Hydrogen peroxide is supplied to the decomposition device (S9). In the decomposition device, the oxalic acid is decomposed by a catalyst and hydrogen peroxide, Fe.sup.2+ and hydrogen peroxide react to produce Fe.sup.3+ and OH*, and the oxalic acid is decomposed by OH*. A corrosion potential of the aqueous solution flowing out from the decomposition device is measured (S11). A concentration ratio calculation device obtains Fe.sup.3+/Fe.sup.2+ (concentration ratio) based on the corrosion potential (S12), and A control device controls the supply amount of hydrogen peroxide to the decomposition device based on Fe.sup.3+/Fe.sup.2+ (S14 and S16).).

A waste liquid treatment facility according to an exemplary embodiment of the present invention includes: a filter connected to a system of a nuclear power plant; a demineralizer connected to the filter; a reactor connected to the demineralizer and including a first lamp and a second lamp of different wavelengths connected in succession; a buffer tank connected to the filter, demineralizer, and reactor; and a circulation pipe portion connecting the filter, demineralizer, reactor, and buffer tank to form a circulation structure of a solution together with the system, wherein the solution sequentially passes through the first lamp and the second lamp.