Decontaminant for radioactive contamination on metal surface and using method of decontaminant

Abstract

The invention relates to the field of chemistry and chemical engineering, in particular to a decontaminant for radioactive contamination on the metal surface and a using method of the decontaminant. The decontaminant is characterized in that the decontaminant is an equal-volume mixture of an oxidizing agent and a complexing agent; the oxidizing agent is an aqueous solution containing 5-10% of Cl<-1> and 5-10% of ClO<-1>, the complexing agent is a series of aqueous solutions of inorganic negative ion water-soluble compounds, wherein the series of aqueous solutions and positive ions such as Fe<+2,3>, Ni<+2>, Cr<+2,3> and Co<+2,3> form water-soluble complexes in the aqueous solutions. The using method comprises a mist spraying method, a wiping method and a soaking method. The decontaminant for the radioactive contamination on the metal surface and the using method of the decontaminant have the advantages that the etching decontamination speed is moderate, and the etching reaction speed, the etching depth and the like are controllable; the decontaminant is especially suitable for efficiently removing radioactive contaminants on the inner surface of a closed system, and the content of decontamination factors is high; and according to the using method, in the decontamination process, NO2 and acid mist which pollute the environment and corrode other equipment are not generated, dangerous substances such as explosive gas H2 are not generated, waste liquid generated in the decontamination process is treated properly, and secondary waste which cannot be treated by a nuclear facilitywaste treatment facility is not generated.

Description

technical field [0001] The invention relates to the field of chemistry and chemical engineering, in particular to a metal surface radioactive pollution decontamination agent and a use method thereof. Background technique [0002] During the operation of nuclear facilities, it is often necessary to decontaminate various radioactively contaminated metal parts; in the field of nuclear facility decommissioning, it is often encountered in glove boxes, fume hoods, and processes for operating radioactive substances In the dismantling and decommissioning of pipelines, these devices usually have serious radioactive surface contamination. Before dismantling, they must be decontaminated before dismantling to avoid threats to the radiation safety of workers and the environment during dismantling and dismantling operations. [0003] At present, the technologies involved in the decontamination of metal surfaces mainly include: ① brush the peelable film on the contaminated surface, and aft...

AI Technical Summary

Problems solved by technology

[0003] At present, the technologies involved in the decontamination of metal surfaces mainly include: ① brush the peelable film on the contaminated surface, and after the film is peeled off, the radioactive material will remove the surface radioactive contamination with the film. The substance diffuses randomly. This method can only remove the loose pollution on the polluted surface, and the fixed pollutants that go deep into the shallow surface of the base material cannot be completely removed; For example, the patented technology with publication number 200510134673.7 adopts the formula of HNO 3 -(NH 4 ) 2 Ce(NO 3 ) 6 The decontamination agent removes radioactive contamination on the metal surface, but these two types of methods will produce a large amount of acid mist and NO 2 , pollute the environment, corrode other useful equipment in the facility, and produce a large amount of radioactive decontamination waste liquid that cannot be disposed of in time, ③ combined decontamination method based on electrolytic electrochemical corrosion + ultrasonic, the published patent applications for this technology include: Publication No. For CN101079334, CN101210343, CN1080333, CN1986904, CN201220974, CN101714414A and CN101260527 etc., the common feature of these technologies is that the technological process is complicated, and a certain amount of explosive gas hydrogen can be produced in the decontamination process, and this method can not solve the problem in pipelines, containers, etc. Decontamination of surfaces