Pollutant removing process and pollutant removing agent for radioactive pollution metal

A decontamination agent and metal technology, applied in radioactive purification, nuclear engineering, etc., to achieve high decontamination coefficient, reduce pretreatment cost, and fast decontamination rate

Inactive Publication Date: 2007-06-27
CHINA INST FOR RADIATION PROTECTION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a safer, more efficient and economical radioactively contaminated metal decontamination process and the decontaminat

Method used

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  • Pollutant removing process and pollutant removing agent for radioactive pollution metal

Examples

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Effect test

Embodiment 1

[0013] The loop circulation method is used to decontaminate radioactively contaminated metals, followed by rinsing and drying. The loop circulation method is a well-known decontamination method, which specifically refers to the need to establish a Decontaminant injection (circulation) systems that allow decontamination to flow through process piping systems or the interior of large off-line equipment to decontaminate them. Its process flow is shown in Figure 1.

[0014] The decontamination process steps are as follows:

[0015] (1) Radioactive contamination level measurement or radioactive analysis before decontamination.

[0016] (2) Detergent preparation: using industrial (NH 4 ) 2 Ce(NO 3 ) 6 ·6H 2 O, industrial nitric acid and deionized water preparation nitric acid concentration is 0.1~6.0mol / L, Ce (IV) concentration is the detergent of 0.001~1.00mol / L. The specific concentration of Ce(IV) depends on the degree of decontamination required. If the degree of radioac...

Embodiment 2

[0023] Decontamination of radioactively contaminated metals is carried out by bath immersion method, followed by rinsing and drying. The tank soaking method is a well-known decontamination method. Specifically, when decontaminating off-line small parts, pipe fittings, and radioactively contaminated metal parts after disassembly and disassembly, a decontamination tank needs to be established, and the parts to be decontaminated are directly decontaminated. Soak in the detergent in the decontamination tank for soaking and decontamination.

[0024] The decontamination process steps are as follows:

[0025] (1) Radioactive contamination level measurement or radioactive analysis before decontamination.

[0026] (2) Detergent preparation: using industrial (NH 4 ) 2 Ce(NO 3 ) 6 ·6H 2 O, industrial nitric acid and deionized water preparation nitric acid concentration is 0.1~6.0mol / L, Ce (IV) concentration is the detergent of 0.001~1.00mol / L. The specific concentration of Ce(IV) ...

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PUM

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Abstract

This invention relates to a method for removing radioactive contamination on object surfaces and an eradicator, which applies a loop circulation method or a tank dipping method to remove the contaminated metal then rinses and dries it. The eradicator prepared with deionized water includes: HNO3 0.1-6.0mol/L and (NH4)2Ce(NO3)60.001-1.00mol/L, the decontamination temperature is 1-40deg.C and continuous time lasts for 0.1-48.0h and the circulation flow rate of the fluid is 0.5-5.00m/s when applying loop circulation method.

Description

technical field [0001] The invention relates to a method for removing radioactive pollution on material surfaces and a decontamination agent thereof. Background technique [0002] During the decommissioning process of nuclear facilities, there will be a considerable amount of radioactively contaminated metals and α-waste. Reducing the amount of radioactively contaminated metals and minimizing α-waste is not only related to environmental safety, but also worthy of attention from an economic point of view. For this reason Various chemical decontamination processes have been developed at home and abroad. [0003] The decontamination process developed abroad using tetravalent cerium salt and other inorganic acid solutions as decontamination agents has the following obvious disadvantages in view of the actual situation in our country: (1) high operating temperature (80-90 ℃), safe and reliable process Poor; (2) Detergent contains SO 4 2- , Cl - , the decontamination waste liq...

Claims

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Application Information

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IPC IPC(8): G21F9/00
Inventor 马鹏勋任宪文张涛革
Owner CHINA INST FOR RADIATION PROTECTION
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