Waste liquid decomposition treatment monitoring device for decontamination of nuclear power plants and its operation method

Abstract

Provided is a waste liquid decomposition monitoring device for decontamination of nuclear power plants. The waste liquid decomposition processing device for decontamination of nuclear power plants includes a UV reaction tank connected to a first flow path and performing UV treatment on the waste liquid input thereto, a waste liquid decomposition flow path that supplies the waste liquid discharged from the UV reaction tank to the first flow path, a waste liquid decomposition sensor that analyzes components of the waste liquid supplied from the waste liquid decomposition flow path to detect whether a set condition is satisfied, and a purification flow path that purifies the waste liquid supplied from the UV reaction tank and supplies it to the first flow path when the set condition is satisfied.

Description

[Technical field]

[0001] The present invention relates to a waste liquid decomposition process monitoring device and an operation method thereof. [Background technology]

[0002] Wastewater from the decontamination of nuclear power plants can be decomposed and purified using filters, UV equipment, and ion exchange resins. In order to check whether the wastewater decomposition is complete during this process, samples can be taken before and after the UV device and the organic carbon concentration can be measured using a TOC (Total Organic Carbon) device. Sample measurements are performed by collecting samples directly on-site, which raises concerns about exposure to radiation for workers and makes it difficult to collect and measure samples in real time. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to provide an apparatus for monitoring the decomposition process of waste liquids produced by decontamination at a nuclear power plant, which reduces the number of times that workers must take samples, thereby reducing exposure to radiation from the workers.

[0004] Another object of the present invention is to provide a waste liquid decomposition treatment monitoring device that can confirm in real time using a monitoring device whether or not waste liquid from decontamination of a nuclear power plant has been decomposed.

[0005] Another object of the present invention is to provide a monitoring device for the decomposition of waste liquid from decontamination at nuclear power plants, which can prevent iron precipitation by measuring pH in real time and can also be used for the maintenance of UV reaction tanks by checking the pH when cleaning the lamps inside the UV reaction tanks.

[0006] Another object of the present invention is to provide a monitoring device for wastewater decomposition treatment in decontamination of nuclear power plants, which can solve the phenomenon that iron precipitation occurs and is deposited on the outer walls of pipes and UV lamps, reducing the wastewater decomposition rate.

[0007] Another object of the present invention is to provide a monitoring device for the decomposition of waste liquid produced by decontamination of a nuclear power plant, which is capable of visually checking the progress of decomposition by using a carbon dioxide monitoring sensor.

[0008] The object of the present invention is not limited to the above-mentioned objects, and other objects not mentioned herein will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0009] To achieve the above object, one embodiment of the present invention provides a waste liquid decomposition processing monitoring device for decontamination at a nuclear power plant, comprising: a UV reaction tank connected to a first flow path for UV-treating the waste liquid input thereto; a waste liquid decomposition flow path for supplying the waste liquid discharged from the UV reaction tank to the first flow path; a waste liquid decomposition sensing unit for analyzing components of the waste liquid supplied from the waste liquid decomposition flow path to detect whether or not a set condition is satisfied; and a purification flow path for purifying the waste liquid supplied from the UV reaction tank and supplying it to the first flow path when the set condition is satisfied.

[0010] The system further includes an input side sensor for sensing components of the waste liquid input into the UV reaction tank, and a discharge side sensor for sensing components of the waste liquid discharged into the UV reaction tank and supplied to the waste liquid decomposition flow path.

[0011] The system further includes a buffer tank that receives the waste liquid from the UV reaction tank, and a carbon dioxide sensor that detects whether carbon dioxide is detected in the buffer tank. The carbon dioxide is generated by the UV treatment of organic acids in the waste liquid. If the carbon dioxide sensor detects that no carbon dioxide is detected, the waste liquid in the buffer tank is present at a value within a preset appropriate hydrogen ion concentration (pH, potential of hydrogen) range, and the organic acid in the waste liquid in the buffer tank is decomposed to a reference value corresponding to the value of the appropriate hydrogen ion concentration range.

[0012] Moreover, the range of values ​​of the appropriate hydrogen ion concentration is at least a range of 2.7 to 3.0.

[0013] Moreover, the organic acid is decomposed by 90% or more in the waste liquid.

[0014] The apparatus further includes an initial supply flow path that supplies the waste liquid supplied from the first flow path to the UV reaction tank, a pressure reducing unit that reduces the pressure of the waste liquid supplied from the first flow path on the initial supply flow path and supplies it to the filtering unit, and a filtering unit that filters the waste liquid supplied from the first flow path on the initial supply flow path.

[0015] In addition, the input side sensor, the discharge side sensor, and the waste liquid decomposition sensor measure the proper hydrogen ion concentration of the waste liquid, and may further measure at least one of the oxidation reduction potential (ORP) and electrical conductivity.

[0016] The system further includes an integrated process monitoring unit for collecting, monitoring and analyzing sensing information sensed by the input side sensing unit, the discharge side sensing unit, the waste liquid decomposition sensing unit and the carbon dioxide sensing unit.

[0017] The UV reaction tank further includes a cleaning tank for circulating a cleaning solution to the UV reaction tank to perform a cleaning operation, the cleaning operation including cleaning an oxide film and an oil film on the surface of the UV lamp in the UV reaction tank.

[0018] In addition, the UV reactor is configured such that the wastewater inside the UV reactor is set to an appropriate hydrogen ion concentration corresponding to a reference value through the cleaning operation, and the cleaning solution includes an inorganic acid including phosphoric acid or nitric acid. Effect of the Invention

[0019] The waste liquid decomposition process monitoring device and its operating method according to the present invention as described above have one or more of the following advantages.

[0020] According to the present invention, it is possible to provide a waste liquid decomposition treatment monitoring device which reduces the number of times an operator must take samples, thereby reducing the operator's exposure to radiation.

[0021] It is also possible to provide a waste liquid decomposition treatment monitoring device that can confirm in real time by the monitoring device whether or not the waste liquid has been decomposed.

[0022] In addition, by measuring pH in real time, it is possible to prevent iron precipitation, and a waste liquid decomposition processing monitoring device can be provided that can also be used for maintaining the UV reaction tank by checking the pH when cleaning the lamps in the UV reaction tank.

[0023] In addition, a waste liquid decomposition treatment monitoring device can be provided that can solve the problem of iron precipitation on the outer walls of pipes and UV lamps, which reduces the waste liquid decomposition rate.

[0024] Furthermore, a waste liquid decomposition treatment monitoring device can be provided that allows the progress of decomposition to be confirmed with the naked eye by using a carbon dioxide monitoring sensor. [Brief description of the drawings]

[0025] [Figure 1] 1 is a configuration diagram showing the configuration of a waste liquid decomposition treatment monitoring device according to an embodiment of the present invention;

[0026] [Diagram 2] 4 is a flowchart sequentially illustrating a method for operating the waste liquid decomposition process monitoring device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The advantages and features of the present invention, as well as the methods of achieving them, will become clear with reference to the drawings and the embodiments described below. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the embodiments are provided merely to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art to which the present invention pertains. The present invention is defined only by the scope of the claims. Like reference numbers refer to like elements throughout the specification.

[0028] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same reference numbers will be given to the same or corresponding components regardless of the drawing numbers, and duplicate descriptions related thereto will be omitted.

[0029] Referring to FIG. 1, a waste liquid decomposition process monitoring device 100 according to one embodiment of the present invention may include a UV reaction tank 120, a cleaning tank 1252, an initial supply flow path 130, a pressure reduction section 131, a filtering section 132, a purification flow path 135, a waste liquid decomposition flow path 140, a waste liquid decomposition sensor 145, an input side sensor 150, a discharge side sensor 160, a buffer tank 170, a carbon dioxide sensor 180, and an integrated process monitoring section (not shown).

[0030] Here, the UV reaction chamber 120 is connected to the first flow path 110 and treats the waste liquid input thereto with UV light. The waste liquid decomposition channel 140 supplies the waste liquid discharged from the UV reaction chamber 120 to the first channel 110 .

[0031] The waste liquid decomposition sensor 145 analyzes components of the waste liquid supplied from the waste liquid decomposition channel 140 to detect whether a preset condition is met. The purification flow path 135 purifies the wastewater supplied from the UV reaction tank 120 when a set condition is met.

[0032] The purification flow path 135 supplies the purified waste liquid to the first flow path 110 . The input side sensor 150 senses the components of the waste liquid input into the UV reaction chamber 120 .

[0033] The discharge side sensor 160 senses the components of the waste liquid discharged into the UV reaction chamber 120 and supplied to the waste liquid decomposition flow path 140 . The buffer tank 170 receives a supply of waste liquid from the UV reaction tank 120 .

[0034] At this time, the carbon dioxide detector 180 detects whether carbon dioxide (CO2) is detected in the buffer tank 170. The carbon dioxide is generated by decomposing the organic acid in the waste liquid through UV treatment.

[0035] If the carbon dioxide sensor 180 determines that no carbon dioxide is detected, it is assumed that the waste liquid in the buffer tank 170 is present at a value within a preset appropriate hydrogen ion concentration range.

[0036] Here, the organic acid in the waste liquid in the buffer tank 170 may be decomposed to a standard value corresponding to the range of the appropriate hydrogen ion concentration. The appropriate hydrogen ion concentration range corresponds to at least a range of about 2.7 to about 3.0. The organic acid is decomposed by 90% or more in the waste liquid.

[0037] The initial supply flow path 130 supplies the waste liquid supplied from the first flow path 110 to the UV reaction chamber 120 . The pressure reducing unit 131 reduces the pressure of the waste liquid supplied from the first flow path 110 on the initial supply flow path 130 . Therefore, the pressure reducing unit 131 can prevent the filtering unit 132 from being damaged or broken due to the pressure of the waste liquid supplied to the filtering unit 132 .

[0038] The filtering unit 132 filters the waste liquid supplied from the first flow path 110 on the initial supply flow path 130 .

[0039] The input side sensing unit 150, the discharge side sensing unit 160, and the waste liquid decomposition sensing unit 145 measure at least one of the appropriate hydrogen ion concentration, the oxidation-reduction potential, and the electrical conductivity of the waste liquid, but it is preferable to measure the appropriate hydrogen ion concentration as a required parameter.

[0040] The integrated process monitoring unit 190 collects the sensing information sensed by the input side sensing unit 150 , the discharge side sensing unit 160 , the waste liquid decomposition sensing unit 145 , and the carbon dioxide sensing unit 180 . The sensory information thus collected can be utilized by autonomous or external means for monitoring analysis.

[0041] The cleaning tank 1252 circulates and supplies a cleaning solution to the UV reaction bath 120 to perform a cleaning operation. Here, the cleaning operation may include cleaning the oxide film and oil film on the surface of the UV lamp 121 of the UV reaction chamber 120.

[0042] The UV reaction chamber 120 can set the wastewater inside the UV reaction chamber 120 to an appropriate hydrogen ion concentration corresponding to a preset reference value through the cleaning operation. The cleaning solution may include inorganic acids, including phosphoric acid or nitric acid.

[0043] The purification flow path 135 is provided with a first ion exchange unit 1351 for primary ion exchange treatment of the waste liquid, and a second ion exchange unit 1352 for secondary ion exchange treatment of the waste liquid.

[0044] Here, the first ion exchange section 1351 is provided with a cation exchange resin, and the second ion exchange section 1352 is provided with an anion exchange resin.

[0045] The first ion exchange unit 1351 and the second ion exchange unit 1352 are intended to remove metal ions, radioactive substances, and residual organic acids. After the waste liquid decomposition process is completed or when iron precipitates occur due to an increase in pH, metal ions (Fe, Cr, Ni, etc.), radioactive substances, residual organic acids, etc. can be removed by ion exchange resin.

[0046] FIG. 2 is a flow chart sequentially illustrating a method for operating the waste liquid decomposition process monitoring device according to one embodiment of the present invention.

[0047] Referring to FIG. 2, in the method of operating the waste liquid decomposition process monitoring device, in step S110, waste liquid inputted into a UV reaction chamber 120 connected to a first flow path 110 is UV-treated.

[0048] In S120, the waste liquid discharged from the UV reaction chamber 120 is supplied to the first flow path 110 in the waste liquid decomposition flow path 140.

[0049] In step S130, the waste liquid decomposition sensor 145 analyzes the components of the waste liquid supplied from the waste liquid decomposition channel 140 to detect whether or not the components satisfy a preset condition.

[0050] In S140, when the set condition is satisfied in the purification flow passage 135, the waste liquid supplied from the UV reaction chamber 120 is purified and supplied to the first flow passage 110.

[0051] As described above, an embodiment of the present invention has been described with reference to the accompanying drawings. However, a person having ordinary skill in the art to which the present invention pertains can understand that the present invention can be embodied in other specific forms without changing its technical concept or essential features. Therefore, it should be understood that the above-described embodiment is illustrative in all respects and is not limiting.

Claims

1. A monitoring device for decomposition of waste liquid from decontamination of a nuclear power plant, a UV reaction tank connected to the first flow path for UV treatment of wastewater; a buffer tank to which waste liquid is supplied from the UV reaction tank; a waste liquid decomposition flow path that supplies the waste liquid discharged from the buffer tank to the first flow path; a carbon dioxide detector for detecting whether carbon dioxide is detected in the buffer tank; a waste liquid decomposition sensor for detecting whether a component of the waste liquid supplied from the waste liquid decomposition flow path satisfies a preset condition by analyzing the component of the waste liquid; a purification flow path that purifies the wastewater supplied from the UV reaction tank via the buffer tank when the set condition is satisfied, and supplies the purified wastewater to the first flow path; an input side sensor that senses components of the waste liquid input into the UV reaction tank; a discharge side sensor that senses components of the waste liquid discharged from the UV reaction tank and supplied to the buffer tank; A waste liquid decomposition processing monitoring device for decontamination of nuclear power plants, in which the carbon dioxide is generated by UV treatment of the organic acids in the waste liquid, and when the carbon dioxide detection unit determines that the carbon dioxide is not detected, it means that the waste liquid in the buffer tank is present at a value within a preset appropriate hydrogen ion concentration range, and the organic acids in the waste liquid in the buffer tank have been decomposed to a standard value corresponding to the value in the appropriate hydrogen ion concentration range.

2. 2. The monitoring device for decomposition treatment of waste liquid due to decontamination of a nuclear power plant according to claim 1, wherein the range of values ​​of the appropriate hydrogen ion concentration is at least within a range of values ​​from 2.7 to 3.

0.

3. 3. The waste liquid decomposition treatment monitoring device for decontamination of a nuclear power plant according to claim 2, wherein the organic acid is decomposed by 90% or more in the waste liquid.

4. an initial supply flow path that supplies the waste liquid supplied from the first flow path to the UV reaction tank; a filtering unit configured to filter the waste liquid supplied from the first flow path on the initial supply flow path; 4. The device for monitoring waste liquid decomposition treatment due to decontamination of a nuclear power plant according to claim 3, further comprising a pressure reducing section which reduces the pressure of the waste liquid supplied from said first flow path on said initial supply flow path and supplies it to said filtering section.

5. A method for operating a monitoring device for decontamination of a waste liquid decomposition process at a nuclear power plant, comprising: the waste liquid decomposition monitoring device includes a UV reaction tank connected to a first flow path for performing UV treatment of the waste liquid input thereto; a buffer tank to which the waste liquid is supplied from the UV reaction tank; a waste liquid decomposition flow path for supplying the waste liquid discharged from the buffer tank to the first flow path; a carbon dioxide sensor for detecting whether carbon dioxide is detected in the buffer tank; a waste liquid decomposition sensor for analyzing components of the waste liquid supplied from the waste liquid decomposition flow path and detecting whether a set condition is satisfied; a purification flow path for purifying the waste liquid supplied from the UV reaction tank via the buffer tank and supplying it to the first flow path when the set condition is satisfied; an input side sensor for detecting components of the waste liquid input to the UV reaction tank; and a discharge side sensor for detecting components of the waste liquid discharged from the UV reaction tank and supplied to the buffer tank, performing a UV treatment on wastewater inputted into the UV reaction chamber connected to the first flow path; detecting whether carbon dioxide is detected in a buffer tank that receives a waste liquid from the UV reaction tank; analyzing the components of the waste liquid supplied from the waste liquid decomposition flow path to the first flow path in the waste liquid decomposition sensing unit to sense whether a preset condition is satisfied; and purifying the wastewater supplied from the UV reaction tank through the buffer tank in the purification flow path when the set condition is satisfied, and supplying the wastewater to the first flow path, A method for operating a waste liquid decomposition processing monitoring device for decontamination of a nuclear power plant, wherein the carbon dioxide is generated by UV treatment of organic acids in the waste liquid, and when the carbon dioxide detection unit determines that the carbon dioxide is not detected, the waste liquid in the buffer tank is present at a value within a preset appropriate hydrogen ion concentration range, and the organic acid in the waste liquid in the buffer tank has been decomposed to a standard value corresponding to the value in the appropriate hydrogen ion concentration range.

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