WO2018016775A1 - Decontamination method and decontamination system for radioactive waste resin - Google Patents

Abstract

The present invention relates to a decontamination method and a decontamination system for radioactive waste resin. The decontamination method for radioactive waste resin comprises: a desorption step of mixing radioactive waste resin generated in a nuclear power plant with water and treating the mixture by ultrasound waves to desorb foreign substances adhered to the waste resin; a first separation step of separating the waste resin and the water containing foreign substances; a second separation step of separating the water containing the foreign substances separated in the first separation step into magnetic foreign substances, non-magnetic foreign matters and filtered water by using magnetic force; and a third separation step of separating the waste resin separated in the first separation step into a magnetic waste resin and a non-magnetic waste resin by using magnetic force.

Description

Radioactive waste resin decontamination method and decontamination system

The present invention relates to a radioactive waste resin decontamination method and decontamination system.

The present invention is the result obtained while performing the task supported by the Government of the Republic of Korea, the task number of the task is 20151520302100, the Ministry of Commerce, Industry and Energy, the Ministry of Trade, Industry and Energy Agency, the Korea Institute of Energy Research, the name of the research project energy development project The project name is C-14-containing nuclear waste resin treatment and stabilization technology, the host organization is Huvis Water Co., Ltd., and the research period is 2015.09.01 ~ 2018.02.28.

This application claims the priority of Korean Patent Application No. 10-2016-0091313 for which it applied on July 19, 2016, The whole content is taken in here as a reference.

The steam generator converts water into steam using heat supplied from the primary side, and is composed of a primary tube for supplying heat and water transferred through a water supply pipe.

In the case of water supply to the steam generator, Fe contained in the water is strictly controlled to 1 ppb or less, but the film is oxidized in the form of Fe ₂ O ₃ , Fe ₃ O _{4 on} the inner wall of the aged water supply pipe. As a result, some of the coating is separated by the flow rate in the pipe and flows into the steam generator.

For this reason, the iron component introduced into the steam generator gradually accumulates, and due to the high pH (9.5) inside the steam generator, it is present in the form of a cred (fixed form of impurities or foreign substances) instead of ions. . The accumulated iron component and radioactive material (Co, Cs) leaked by the crack of the primary tube are physically or chemically bonded, and are mixed and continuously accumulated because they cannot be discharged through the steam.

In the case of the steam generator, a blow out operation is performed for internal pressure control and water quality control. The accumulated radioactive material is contained in the withdrawal water and flows out, and the withdrawal water is flash tank, The heat exchanger, CCW, and filter are used to reach the ion exchange resin tower.

Crudes and sludges reaching the ion exchange resin tower accumulate on top of the resin layer, and physically bind to the ion exchange resin over time. Since the ion exchange resin combined with the clad or sludge has a small amount of radioactivity, it can not be disposed of itself and stored in drums or sacks according to the radioactivity level in the site of the power plant.

Although the amount of waste resins stored in each power plant is different, the storage area in the power plant is decreasing due to the continuously generated waste resins, and the Cs-137, Co-60, and C-14 nuclides contained in the waste water have a long half-life. Even after long-term storage, radioactivity is not completely extinguished, and the importance of waste resin treatment is gradually increasing due to the risk of fire, bad smell, and internal exposure.

The present applicant has filed an invention for a method and a system for removing radionuclides in a trace amount of radioactive contaminated waste resin as No. 10-2015-0155034 (2015.11.05.).

The patent invention is a technology for removing particulate foreign matter and radioactive radionuclides in the form of wastes by surface treatment process and deep treatment process, and removes the particulate foreign matter and radioactive radionuclides in the form of contaminants on the surface of waste resin. Surface treatment process, surface treatment wastewater treatment process for treating the surface treatment wastewater generated in the surface treatment process, to remove particulate foreign substances and radioactive radionuclides in the form of contaminants in the porous porous resin And a deep treatment wastewater for treating the deep treatment wastewater generated in the deep treatment process.

However, the patent invention has a disadvantage in that a large amount of secondary waste is generated in the surface treatment wastewater treatment process and the deep treatment wastewater treatment process.

In particular, depending on the characteristics of the waste resin stored, a cartridge filter for treating surface treated wastewater, and a cartridge filter for removing particulate matter and radioactive radionuclides in the deep treatment wastewater, when there are many foreign matters and clad material The cartridge filter is clogged due to heavy loads, or the cartridge filter replacement time is shortened, and a large amount of secondary waste is generated. The treated water contains foreign particles of fine size, making it difficult to reuse (use). There are also disadvantages.

When the load is applied to the cartridge filter, not only the decontamination efficiency of the decontamination apparatus itself is lowered, but also the exposure of the worker is increased when the filter is replaced, so it is important to supplement and modify the wastewater treatment method of the cartridge filter method.

In order to solve the above problems, it is an object of the present invention to provide a radioactive waste resin decontamination method and decontamination system capable of minimizing secondary waste and reusing purified water.

The present invention, in order to achieve the above object, a desorption step of desorbing foreign matter adhered to the waste resin by ultrasonic treatment after mixing the radioactive waste resin and water generated in the nuclear power plant; A first separation step of separating water containing waste resin and foreign matter; A second separation step of separating the water containing the foreign matter separated in the first separation step into magnetic foreign matter, nonmagnetic foreign matter and filtered water by using magnetic force; And a third separation step of separating the waste resin separated in the first separation step into magnetic waste resin and non-magnetic waste resin using magnetic force.

In the desorption step according to the present invention, the water is mixed at a weight ratio of 5 to 6 times the waste resin, the ultrasonic strength is 1 KW to 1.5 KW, and the ultrasonic treatment time may be 30 to 60 minutes.

In the present invention, the first separation step is performed using a mesh separation tank having a mesh network and a stirrer, the pore size of the mesh network is 50 mesh to 60 mesh, the stirring speed may be 200 rpm to 300 rpm.

In the second separation step according to the present invention, the water containing the foreign matter is introduced from the lower portion of the magnetic separator equipped with the magnet and then moved to the upper portion, the magnetic foreign matter is attached to the magnet, and the non-magnetic foreign material having a high specific gravity remains at the bottom. Water can be reused.

In the third separation step according to the present invention, the waste resin from which foreign substances are removed is introduced with water from the lower portion of the magnetic separator provided with magnets and then moved to the upper portion, and the magnetic waste resin is attached to the magnet, and the non-magnetic waste resin is with water. It can be discharged outside the magnetic separator.

In the present invention, air bubbles are injected from the lower portion of the magnetic separator, and the magnet type is at least one selected from neodymium magnets, ferrite magnets, and electromagnets, and the magnetic strength may be 6,000 G to 10,000 G.

The method according to the invention may further comprise a fourth separation step of separating the non-magnetic waste resin and water.

The fourth separation step according to the present invention is carried out using a mesh filtration tank, a solid / liquid separator or a cyclotron, the pore size of the mesh filter of the mesh filtration tank is 250 mesh to 350 mesh, the filtered water can be reused.

The method according to the invention may further comprise a drying step of drying the separated waste resin and foreign matter.

In the drying step according to the present invention, the drying pressure is reduced or normal pressure, the drying temperature is 20 ℃ to 150 ℃, the drying time may be 20 minutes to 60 minutes.

Co-60 and Cs-137 radioactivity concentrations in the waste resin after decontamination according to the present invention may be 0.1 Bq / g or less.

The present invention also provides an ultrasonic treatment tank for ultrasonically treating a mixture of radioactive waste resin and water generated in a nuclear power plant to desorb foreign substances attached to the waste resin; A mesh separation tank connected to the ultrasonication tank, having a mesh network and a stirrer, and separating water containing waste resin and foreign matter; A first magnetic separator connected to the mesh separation tank, having a magnet, and separating water containing foreign substances into magnetic foreign substances, nonmagnetic foreign substances and filtered water using magnetic force; And a second magnetic separator connected to the mesh separation tank, having a magnet, and separating the waste resin into the magnetic waste resin and the non-magnetic waste resin using magnetic force.

The system according to the present invention is connected to the ultrasonic treatment tank, the waste resin mixing tank for mixing the waste resin and water; A filtration tank connected to the second magnetic separator to separate the non-magnetic waste resin and water discharged therefrom; A treated water storage tank connected to each of the waste resin mixing tank, the ultrasonic treatment tank, the mesh separation tank, the first magnetic separator, and the filtration tank, and storing the treated water in the first magnetic separator and the filtration tank; A foreign matter storage tank connected to the first magnetic separator and storing the foreign matter separated therefrom; A magnetic waste resin reservoir connected to the second magnetic separator to store the magnetic waste resin separated therefrom; A non-magnetic waste paper storage tank connected to the filtration tank and storing the non-magnetic waste paper separated therefrom; A drying apparatus connected to the foreign matter storage tank, the magnetic waste resin storage tank, and the nonmagnetic waste resin storage tank, respectively, and drying the foreign matter and waste resin; It may further include at least one.

The method according to the invention can minimize secondary wastes generated during the treatment of radioactive waste resins and can reuse the purified treated water.

1 is a flow chart of a radioactive waste resin decontamination method according to the present invention.

2 and 3 is a block diagram of a radioactive waste resin decontamination system according to the present invention.

4 is a schematic view of the steam generator blow-out system.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a flow chart of a radioactive waste resin decontamination method according to the present invention, Figures 2 and 3 is a block diagram of a radioactive waste resin decontamination system according to the present invention.

The radioactive waste resin decontamination method according to the present invention comprises a desorption step of desorbing foreign matter adhered to the waste resin by ultrasonic treatment after mixing the radioactive waste resin and water generated in the nuclear power plant; A first separation step of separating water containing waste resin and foreign matter; A second separation step of separating the water containing the foreign matter separated in the first separation step into magnetic foreign matter, nonmagnetic foreign matter and filtered water by using magnetic force; And a third separation step of separating the waste resin separated in the first separation step into magnetic waste resin and non-magnetic waste resin using magnetic force.

The material to be treated in the present invention is a radioactive waste resin generated in a nuclear power plant, for example, an ion exchange resin used in a steam generator extraction system desalination unit. Figure 4 is a schematic diagram of the steam generator blowdown system, the steam blowdown system (Blowdown) to control the chemical composition of the steam generator secondary water supply during normal operation, to recover the heat with the blown water before the blown water goes to the condenser and the steam generator tube Remove any debris that has accumulated on the support plate. The withdrawal system consists of a continuous withdrawal tank, a high flow withdrawal train, a heat exchanger and a demineralizer.

The steam generator extraction system demineralization tower uses nuclear-grade cation, anion, and interphase exchange resins for the purpose of water purification to remove the radioactive material in the case of leakage of steam generator tubules and to prevent the diffusion of secondary systems. . Table 1 shows the physicochemical properties of nuclear ion exchange resins.

division Cation Exchange Resin Anion exchange resin Mixed ion exchange resin Product Name DOWEXHGR NG (H) DOWEXSBR LC NG (OH) GRAVEXGR 3-16 N matrix Polystylene-DVB shape Gel Functional group -SO ₃ ^- -(CH ₃ ) ₃ N ⁺ Cation: -SO ₃ ^- Anion:-(CH ₃ ) ₃ N ⁺ Ion type H ⁺ OH ^- Cation: Anion ⁺ H: OH ^- Ion exchange capacity (eq / L) 2.0 1.2 Cation: 2.4Anion: 1.2 Moisture content (%) 46-52 60 Cation: 36-42Anion: 53-59 Particle size range (mm) 0.4-1.2 Heavy weight 1.22 1.08 - Maximum operating temperature (℃) 130 60 - PH range 0-14

The desorption step is a step of desorption of foreign substances adhering to the waste resin by mixing the radioactive waste resin and water generated in the nuclear power plant and then ultrasonically treating. The mixing of waste resin and water may be performed in a separate waste resin mixing tank, and the desorption step may be performed in an ultrasonic treatment tank. The waste resin mixing tank and the ultrasonic treatment tank may be connected through a pipeline, and a connection pump may be installed in the connection line. The waste resin mixing tank may be provided with waste resin suction means and water supply means (pump) and the like. The ultrasonic treatment tank may include a waste resin input means, a container for receiving a mixture of water and waste resin, an ultrasonic generator installed outside and / or inside the container, a stirrer for stirring the mixture of water and waste resin and the like. As the ultrasonic generator, a magnetostrictive ultrasonic generator and / or a piezoelectric ultrasonic generator may be used.

By supplying a mixture of waste resin and water to the ultrasonic treatment tank and applying ultrasonic waves using an ultrasonic generator, foreign matter adhering to the radioactive waste resin can be effectively desorbed. The stirrer serves to mix the waste resin while the ultrasonic wave is applied to effectively desorb the foreign matter. In order to increase the ultrasonic treatment efficiency, water may be mixed at a weight ratio of 5 to 6 times the waste resin, the ultrasonic intensity may be 1 KW to 1.5 KW, and the ultrasonic treatment time may be 30 minutes to 60 minutes.

The first separation step is to separate the waste resin and the water containing foreign substances. The first separation step may be performed by using a mesh separation tank including a vessel containing a mixture of waste resin and (foreign substance + water), a mesh network and an agitator installed in the vessel. The mesh separation tank may be connected to the ultrasonic treatment tank through a pipeline, and a connection pump may be installed in the connection line. The first separation step is a process for separating the mixture containing the waste resin after the ultrasonic process into the waste resin and foreign matter, and put the waste resin in the mesh separation tank containing the mesh network, and then stirred at a constant speed using a stirrer to waste water It separates the paper and foreign matter, and supplies water at a constant flow rate from the bottom of the waste paper, and discharges the waste water to the side of the mesh separator tank. To increase the separation efficiency, the pore size of the mesh network may be 50 mesh to 60 mesh, the stirring speed may be 200 rpm to 300 rpm.

The second separation step is a step of separating the water containing the foreign matter separated in the first separation step into magnetic foreign matter, nonmagnetic foreign matter and filtered water using a magnetic force. The second separation step may be performed by using a first magnetic separator having a container having an inlet line and an outlet line, a magnet installed in one or more of the container, and the like. The first magnetic separator may be connected through a mesh separation tank and a pipeline, and a connection pump may be installed in the connection line. The magnet can be fixed using a bracket or the like installed inside the container. The size of the magnet is smaller than the vessel diameter, and the shape of the magnet may be a plate, rod, sphere, polyhedron, or the like. A plurality of magnets may be arranged at regular intervals up and down and / or left and right.

In the second separation step, if the foreign matter discharged with the water from the mesh separation tank is introduced into the lower part of the first magnetic separator and suspended at a given flow rate, the foreign matter that is magnetic while moving to the upper layer adheres to the internal magnet. As a result, foreign substances that are not magnetic and have a high specific gravity remain at the bottom of the first magnetic separator. Bubbles may be injected from the lower portion of the first magnetic separator to increase the magnetic separation efficiency while increasing the specific gravity of the foreign matter. Purified treated water discharged to the upper portion of the first magnetic separator can be reused by moving to the treated water storage tank (water tank), which is present in the magnetic generator (magnet) of the first magnetic separator and the lower portion of the first magnetic separator. Foreign substances can be discharged to the bottom after removing the magnetic force of the magnetic separator. To increase the magnet separation efficiency, the magnet type may be a neodymium magnet, a ferrite magnet and / or an electromagnet, or the like, and the magnet strength may be 6,000 G to 10,000 G.

The third separation step is a step of separating the waste resin separated in the first separation step into magnetic waste resin and non-magnetic waste resin using magnetic force. The third separation step may be performed using a second magnetic separator having a container having an inlet line and an outlet line, and a magnet installed in one or more of the container. The second magnetic separator may be connected through a mesh separation tank and a pipeline, and a connection pump may be installed in the connection line. The magnet can be fixed using a bracket or the like installed inside the container. The size of the magnet is smaller than the vessel diameter, and the shape of the magnet may be a plate, rod, sphere, polyhedron, or the like. A plurality of magnets may be arranged at regular intervals up and down and / or left and right.

In the third separation step, the waste resin from which foreign substances have been removed is introduced with water from the lower portion of the second magnetic separator provided with magnets and then moved to the upper portion. The magnetic waste resin is attached to the magnet, and the non-magnetic waste resin is separated from the second waste water with water. It can be discharged outside the magnetic separator. Specifically, the waste resin in which foreign matters are separated is introduced together with water at the bottom of the second magnetic separator, and when the flow rate is increased, the magnetic waste resin and the magnetic foreign matters are attached to the magnets inside the non-magnetic waste water while moving upwards by the flow rate. The paper may be discharged to the upper discharge line or lower discharge line without sticking. In order to float the waste resin having a high specific gravity, air bubbles may be injected from the lower portion of the second magnetic separator to increase the waste resin separation efficiency. Radioactive contaminants can be attached to and removed from the magnet. The treated water containing the nonmagnetic material may be separated through a separate filtration process (solid / liquid separation, etc.), and the separated treated water may be reused. To increase the magnet separation efficiency, the magnet type may be a neodymium magnet, a ferrite magnet and / or an electromagnet, or the like, and the magnet strength may be 6,000 G to 10,000 G.

The method according to the invention may further comprise a fourth separation step of separating the non-magnetic waste resin and water. The fourth separation step can be carried out using a mesh filtration tank, solid / liquid separator or cyclotron. The mesh filtration tank may be connected to the second magnetic separator. For example, the method using a mesh filtration tank is to separate the wastewater discharged from the second magnetic separator (nonmagnetic waste resin + water) into non-magnetic waste resin and treated water using a fine mesh, and to supply wastewater from the bottom. When the waste water containing the non-magnetic waste resin is suspended, the non-magnetic waste resin is not filtered through the fine mesh filter, and the treated water can be passed and reused. To increase the separation efficiency, the pore size of the mesh filter may be 250 mesh to 350 mesh.

The method according to the invention may further comprise the step of drying the separated waste resin and foreign matter. The drying step can be performed using a dehydration / drying device. In order to increase the drying efficiency, the vessel pressure of the drying apparatus may be reduced pressure or normal pressure, the drying temperature may be 20 ℃ to 150 ℃, the drying time may be 20 minutes to 60 minutes.

As described above, the decontaminated waste resin satisfies the self-disposable allowable concentration (Co-60, Cs-137: 0.1 Bq / g or less) and can be disposed of by itself.

2 and 3, the radioactive waste resin decontamination system according to the present invention is an ultrasonic treatment tank for ultrasonically treating a mixture of radioactive waste resin and water generated in a nuclear power plant to desorb foreign substances attached to the waste resin; A mesh separation tank connected to the ultrasonication tank, having a mesh network and a stirrer, and separating water containing waste resin and foreign matter; A first magnetic separator connected to the mesh separation tank, having a magnet, and separating water containing foreign substances into magnetic foreign substances, nonmagnetic foreign substances and filtered water using magnetic force; And a second magnetic separator connected to the mesh separation tank, having a magnet, and separating the waste resin into magnetic waste resin and non-magnetic waste resin using magnetic force.

The system according to the present invention is connected to the ultrasonic treatment tank, the waste resin mixing tank for mixing the waste resin and water; A filtration tank connected to the second magnetic separator to separate the non-magnetic waste resin and water discharged therefrom; A treated water storage tank connected to each of the waste resin mixing tank, the ultrasonic treatment tank, the mesh separation tank, the first magnetic separator, and the filtration tank, and storing the treated water in the first magnetic separator and the filtration tank; A foreign matter storage tank connected to the first magnetic separator and storing the foreign matter separated therefrom; A magnetic waste resin reservoir connected to the second magnetic separator to store the magnetic waste resin separated therefrom; A non-magnetic waste paper storage tank connected to the filtration tank and storing the non-magnetic waste paper separated therefrom; A drying apparatus connected to the foreign matter storage tank, the magnetic waste resin storage tank, and the nonmagnetic waste resin storage tank, respectively, and drying the foreign matter and waste resin; It may further include at least one.

The treated water storage tank may be connected to a waste resin mixing tank, an ultrasonic treatment tank, a mesh separation tank, and the like, and each connection line may be provided with a transfer pump. The treated water stored in the treated water storage tank may be supplied to a waste resin mixing tank, an ultrasonic treatment tank, a mesh separation tank, and reused. The foreign substance reservoir, the magnetic waste reservoir, and the non-magnetic waste reservoir may be a movable portable reservoir. The foreign matter stored in the foreign matter storage tank is a high radioactive material and may be stored or treated separately after dehydration / drying. The magnetic waste resin stored in the magnetic waste resin reservoir is a low radioactive material and can be disposed of by itself. The non-magnetic waste paper stored in the non-magnetic waste paper reservoir is a non-radioactive material and can be disposed of by itself.

Experimental Example

1. Comparison of radioactivity before and after separation of foreign matter from waste resin

Waste resins generated at nuclear power plants contain a large amount of foreign substances. After separating the foreign substances using mesh nets and magnets, the radioactive concentrations of H-3, C-14 and Co-60, etc. The liquid scintillation counter (PerkinElmer Quantullas 1220) and gamma nuclide analyzer (CANBERRA ISOCS) were analyzed and summarized in Table 2. The waste resin contained 5 to 9 wt% (3 vol%) of foreign matter, and radionuclides were more contaminated by foreign matter attached to the surface of the resin than the waste resin itself. Table 2 shows the results of radionuclide analysis before and after separation of waste resin and foreign substances.

Separation Method Item Before separation After separation Waste resin Waste resin Foreign substance Mesh Mesh Separation Weight (g) 1,000 950 50 Weight ratio (%) 100 95 5 Co-60 (Bq / g) 1.55 0.54 12.70 C-14 (Bq / g) 4.28 0.96 3.91 H-3 (Bq / g) 8.90 - - Magnetic Separation Volume (ml) 100 97 3 Volume ratio (%) 100 97 3 Weight (g) 72.4 65.6 6.2 Weight ratio (%) 100 91 9 Co-60 (Bq / g) 1.55 0.29 10.00 C-14 (Bq / g) 4.28 1.81 3.77 H-3 (Bq / g) 8.90 - -

2. Analysis of Metal Components in Waste Resin

The foreign matter separated from the waste resin was magnetic, and in order to check the components and composition ratio more accurately, the mesh separation foreign matter, the magnetic separation foreign matter and the residue after the waste resin burned were treated with acid and hydrogen peroxide, and then inductively coupled plasma (ICP). Table 3 summarizes the results of the analysis. As a result, Fe (> 98%), Ni (> 1%), Mn (> 0.2%) and Cr (0.1%) were present in the order, Co was found to be less than 0.02%. Table 3 shows the analysis results of metal components in the waste resin foreign substances (based on the sum of five items as 100%).

sample Composition Fe Ni Mn Cr Co Mesh separation Concentration (mg / L) 466,251 5,510 1,422 524 83 Composition ratio (%) 98.41 1.16 0.3 0.11 0.018 Magnetic separation foreign matter Concentration (mg / L) 545,419 6,909 1,384 679 109 Composition ratio (%) 98.36 1.25 0.25 0.12 0.02 After combustion Concentration (mg / L) 294,584 3,444 1,068 771 62 Composition ratio (%) 98.22 1.15 0.36 0.26 0.02

3. Ultrasonic separation process using ultrasonic wave

Waste resins generated by Hanbit Nuclear Power Plant contain a considerable amount of foreign matters.They are separated into waste resins and foreign matters using mesh nets, magnets, and ultrasonic waves. The gamma nucleus analyzer (CANBERRA ISOCS) and the liquid scintillation counter (PerkinElmer Quantullas 1220) were analyzed and summarized in Table 4.

The waste resin contained about 10 wt% of foreign matter, and radionuclides were more contaminated in the separated foreign matter than in the waste resin itself. The separation performance of foreign substances from waste resin is not only more effective than ultrasonic separation but also using mesh and magnet, and the concentration of Co-60 and C-14 is less than the self-disposable allowable concentration. It was found to be suitable for the decontamination process. Table 4 shows the results of radionuclide analysis before and after segregation of waste resin and foreign substances.

Separation Method Item Before separation After separation Waste resin Waste resin Foreign substance Mesh Network Separation Weight (g) 1,000 950 50 Weight ratio (%) 100 95 5 Co-60 (Bq / g) 1.55 0.54 12.70 C-14 (Bq / g) 4.28 0.96 3.91 Magnetic Separation Weight (g) 72.4 65.6 6.2 Weight ratio (%) 100 91 9 Co-60 (Bq / g) 1.55 0.29 10.00 C-14 (Bq / g) 4.28 1.81 3.77 Ultrasonic separation Weight (g) 30.2 20.1 3.1 Weight ratio (%) 100 67 10 Co-60 (Bq / g) 0.77 MDA 6.4 C-14 (Bq / g) 1.32 0.17 12.78

EXAMPLE

As illustrated in FIGS. 1 to 3, waste resin and water were mixed in a waste resin mixing tank. Next, the foreign matter adhering to the waste resin was desorbed using the ultrasonic generator in the ultrasonic treatment tank. Next, the mesh separation tank was separated into (waste resin) and (foreign material + water) using a mesh network. Next, after separating the separated (foreign material + water) into the foreign matter and water using a first magnetic separator, the foreign matter was stored in the foreign matter storage tank, the purified water was stored in the treated water storage tank and reused. Next, the waste resin from which foreign substances were removed was separated into magnetic waste resin and non-magnetic waste resin using a second magnetic separator, and the magnetic waste resin was stored in the magnetic waste resin storage tank. Next, after separating the non-magnetic waste resin and water in the mesh filtration tank, the non-magnetic waste resin was stored in the non-magnetic waste resin storage tank, the purified water was stored in the treated water storage tank and reused. Next, the waste resin and foreign matters were dried to measure their respective radioactivity.

Table 5 shows the waste resin decontamination results. The decontaminated resin satisfies the self-disposable allowable concentration (Co-60, Cs-137: 0.1 Bq / g or less) and was self-disposable.

Process sample Weight (g) Radiation concentration (Bq) Co-60 CS-137 Before treatment Waste Resin + Foreign Material (Dry) 40.59 16.76 N / D Mesh separation Waste - 1.05 N / D Foreign substance separation Dry 4.9 16.7 N / D water - N / D N / D Waste Resin Separation Magnetic waste balance (Dry) 17.1 1.15 N / D Non-magnetic waste balance (Dry) 18.3 N / D N / D Mesh filtration water - N / D N / D

Claims (14)

A desorption step of desorbing foreign matter adhered to the waste resin by ultrasonic treatment after mixing the radioactive waste resin and water generated in the nuclear power plant; A first separation step of separating water containing waste resin and foreign matter; A second separation step of separating the water containing the foreign matter separated in the first separation step into magnetic foreign matter, nonmagnetic foreign matter and filtered water by using magnetic force; And A radioactive waste resin decontamination method comprising a third separation step of separating the waste resin separated in the first separation step into magnetic waste resin and non-magnetic waste resin using magnetic force. The method of claim 1, In the desorption step, the water is mixed in a weight ratio of 5 to 6 times the waste resin, the ultrasonic intensity is 1 KW to 1.5 KW, the ultrasonic treatment time is 30 minutes to 60 minutes, characterized in that the radioactive waste resin decontamination method. The method of claim 1, The first separation step is performed using a mesh separation tank having a mesh network and a stirrer, the pore size of the mesh network is 50 mesh to 60 mesh, the stirring speed is a radioactive waste resin, characterized in that 200 rpm to 300 rpm Decontamination method. The method of claim 1 In the second separation step, water containing foreign matter is introduced from the lower part of the magnetic separator equipped with the magnet and then moved to the upper part, magnetic foreign matter is attached to the magnet, and non-magnetic foreign material having a high specific gravity remains at the lower part, Radioactive waste resin decontamination method, characterized in that for recycling the discharged water. The method of claim 1, In the third separation step, the waste resin from which the foreign matter is removed is introduced with water from the lower portion of the magnetic separator equipped with the magnet and then moved to the upper portion. The magnetic waste resin is attached to the magnet, and the non-magnetic waste resin is separated from the magnetic separator with water. Radioactive waste resin decontamination method characterized in that the discharge. The method according to claim 4 or 5, Injecting air bubbles from the bottom of the magnetic separator, the magnet type is at least one selected from neodymium magnets, ferrite magnets, electromagnets, radioactive waste decontamination method, characterized in that the magnetic strength is 6,000 G to 10,000 G. The method of claim 5, A radioactive waste resin decontamination method further comprising a fourth separation step of separating the non-magnetic waste resin and water. The method of claim 7, wherein The fourth separation step is performed using a mesh filtration tank, a solid / liquid separator or a cyclotron, and the pore size of the mesh filter of the mesh filtration tank is 250 mesh to 350 mesh, and the filtered water is reused. Way. The method of claim 1, Radioactive waste resin decontamination method further comprising the step of drying the separated waste resin and foreign matter. The method of claim 9, The drying pressure in the drying step is a reduced pressure or normal pressure, the drying temperature is 20 ℃ to 150 ℃, the drying time is a radioactive waste resin decontamination method, characterized in that 20 minutes to 60 minutes. The method of claim 1, Co-60 and Cs-137 radioactivity concentration in the waste resin after decontamination is less than 0.1 Bq / g radioactive waste salt decontamination method. An ultrasonic treatment tank for ultrasonically treating a mixture of radioactive waste resin and water generated in a nuclear power plant to desorb foreign substances attached to the waste resin; A mesh separation tank connected to the ultrasonication tank, having a mesh network and a stirrer, and separating water containing waste resin and foreign matter; A first magnetic separator connected to the mesh separation tank, having a magnet, and separating water containing foreign substances into magnetic foreign substances, nonmagnetic foreign substances and filtered water using magnetic force; And A radioactive waste resin decontamination system connected to the mesh separation tank, having a magnet, and comprising a second magnetic separator separating the waste resin into magnetic waste resin and non-magnetic waste resin using magnetic force. The method of claim 12, A waste resin mixing tank connected to the ultrasonic treatment tank and mixing waste resin and water; A filtration tank connected to the second magnetic separator to separate the non-magnetic waste resin and water discharged therefrom; A treated water storage tank connected to each of the waste resin mixing tank, the ultrasonic treatment tank, the mesh separation tank, the first magnetic separator, and the filtration tank, and storing the treated water in the first magnetic separator and the filtration tank; Radioactive waste resin decontamination system further comprising at least one of. The method of claim 13, A foreign matter storage tank connected to the first magnetic separator and storing the foreign matter separated therefrom; A magnetic waste resin reservoir connected to the second magnetic separator to store the magnetic waste resin separated therefrom; A non-magnetic waste paper storage tank connected to the filtration tank and storing the non-magnetic waste paper separated therefrom; A drying apparatus connected to the foreign matter storage tank, the magnetic waste resin storage tank, and the nonmagnetic waste resin storage tank, respectively, and drying the foreign matter and waste resin; Radioactive waste resin decontamination system further comprising at least one of.

Images