Decontamination of metal surfaces from radioactive deposits

Abstract

The utility model relates to the field of decontamination of equipment surfaces, primarily pipelines used in the extraction and transportation of hydrocarbon raw materials, and can be used to remove sediments containing radioactive elements. The pipe surface decontamination unit includes a sealed chamber connected to a system for supplying decontaminating liquids under pressure up to 60 MPa, a high-pressure pumping station, a temperature and pH control unit, a circulation and filtration system, and three separate tanks with SNK, NOX, and CBL liquids, providing sequential three-stage treatment. The first stage involves removing paraffin and oil contaminants using SNK fluid with a pH of 9.5-10.5 at a temperature of 20-220°C; the second stage involves destroying sediments containing radioactive elements using NOX fluid with a pH of 1.5-2.0 at a temperature of 5-30°C; and the third stage involves neutralizing acidic residues and passivating the pipe surfaces using CBL fluid with a pH of 11-12.5 at a temperature not exceeding 60°C. The filtration system ensures separation of the solid and liquid phases and the return of purified liquids to the working tanks. This utility model improves the efficiency of decontamination of the internal and external surfaces of pipes, reduces residual radioactive contamination, prevents corrosion, and enables pipe reuse. The technical result is improved equipment and pipe decontamination efficiency, reduced radioactive waste volume, and increased equipment service life.