KR101224725B1 - Method and apparatus for disposing radioactive wastewater - Google Patents

Abstract

PURPOSE: A method and an apparatus for disposing of radioactive wastewater are provided to extend the lifetime of a processing device. CONSTITUTION: A separating film device(10) concentrates liquid waste using a filtration membrane and a reverse osmosis membrane. An evaporative concentration device(20) concentrates the concentrate concentrated in the separating film device. An evaporative drying device(30) reduces water content of concentrate and a solid material and comprises a main body(31), a screw(36), a band heater(34), and a vapor exhaust pipe(35). A pyrolysis device(40) comprises a main body(41), a screw(45), band heaters(43,44), and a gas exhaust tube(47). [Reference numerals] (AA,BB) Vapor; (CC) Vapor, gas; (DD) Gas

Description

Radioactive Liquid Waste Treatment Method and Apparatus {Method and Apparatus for Disposing Radioactive Wastewater}

The present invention relates to a method and apparatus for treating radioactive liquid waste, and more particularly, to a method for treating radioactive liquid waste by concentrating, drying, and pyrolyzing the radioactive liquid waste using a membrane technique and an evaporative concentration technique. Relates to a device.

Radioactive waste refers to liquids and solids that contain radioactive materials. Radioactive waste decreases over time with a half-life, but some radioactive materials have a very long half-life, which requires long-term storage in a radioactive waste storage facility in order to attenuate it, and in recent years the site of radioactive waste storage facilities worldwide. Due to the difficulty in securing, there is an urgent need for measures to minimize the volume of radioactive waste.

In nuclear power plants, ethanolamine (ETA) wastewater from the secondary system, ethylenediamine tetraacetic acid (EDTA) wastewater from chemical cleaning to remove metal oxides deposited on the steam generator secondary system, Radioactive liquid wastes, such as decontamination wastewater generated by decontaminating equipment contaminated with radioactive material, are continuously generated.

Nuclear power plants are deposited inside steam generators because metal oxides (mainly iron sludge) are generated by corrosion of the base metal in the steam generator secondary system as the operating cycle increases and are deposited inside steam generators, resulting in defects in steam generator customs. Periodic chemical cleaning is performed using EDTA to remove the metal oxides.

EDTA reacts with metals to form complexes and easily dissolves in water, so it is easy to flush the steam generator after chemical cleaning of the steam generator, and after forming complexes with metals, the bonds are not easily disassembled. Metal oxides including radioactive materials can be stably removed.

On the other hand, the chemical cleaning of the steam generator secondary system is divided into high concentration washing (EDTA 18% or more) and low concentration washing (EDTA 2.5% or less), depending on the purpose. Especially, in the case of high concentration washing, the complex with metal is not formed after washing. On average, more than 5% of unreacted free EDTA remains, which causes the pyrolysis system to corrode easily when pyrolyzing EDTA wastewater.

The complex of EDTA and metal begins to decompose at high temperatures of 245 ° C or higher. Using this property, Patent No. 956975 (Method and Apparatus for Treating Wastewater Containing Radioactive Material Using High Temperature Plasma Technology) concentrates wastewater with an evaporative concentrator and cleans it inside a plasma flame using a plasma torch. Radioactive liquid waste is sprayed to decompose EDTA in the liquid waste.

In addition, Patent No. 1008491 (a steam generator cleaning radioactive liquid waste treatment system and a method using the same) uses an evaporation concentrator to concentrate wastewater and decompose EDTA in radioactive liquid waste by using an electric furnace.

The process of pyrolysis by spraying cleaning radioactive liquid waste on the plasma torch in the 956975 patent invention requires high voltage to generate a plasma flame, which requires high power consumption, and requires cooling water piping to be installed on the torch to improve durability of the plasma torch. In addition, even if the coolant is injected into the plasma torch, the durability of the torch is drastically reduced due to the high temperature of the plasma, so periodic maintenance is required, and there is a problem in that the entire apparatus is stopped for the maintenance of the plasma torch.

In addition, when the air is injected into the electric furnace in the invention 1008491, pyrolysis that does not self-decompose by heat does not occur well, and combustion occurs by oxygen, and by directly spraying liquid high concentration radioactive liquid waste into the electric structure. Thermal stress is generated in the internal structure of the furnace, causing bending deformation and cracking, and due to the intense boiling, evaporation, and drying of EDTA (including free EDTA) contained in cleaning radioactive liquid waste, There is a serious problem.

In addition, the combustion temperature increases due to the oxidation reaction caused by the air injection, while the by-products and carbides in the form of metal oxides are generated in the combustion by-products generated by the combustion of the metal-EDTA complex, thereby increasing the amount of the final waste to be treated as radioactive waste. In addition, due to the high temperature caused by the rapid oxidation reaction, the temperature inside the furnace rises above 800 ℃, and due to the characteristics of the electric furnace that cannot install the refractory material inside the furnace, it causes deformation of the furnace structure due to the high temperature, making it impossible to operate for a long time. There is this.

In addition, in the two patent inventions, the vapor rising through the bubble generator in the process of concentrating the EDTA wastewater through evaporation concentration may include radioactive material in the condensate by droplet entrainment accompanied by droplets. This is necessary and if the concentration of EDTA to more than 40% is precipitated crystal of EDTA there is a problem that the pipe is clogged when pumping it.

KR 10-0919771 B (Method and treatment apparatus for chemical cleaning waste solution of nuclear power plant steam generator containing chelate drug and radioactive material) 2009.10.6. KR 10-1008491 B (Steam generator chemical cleaning waste treatment system and method using the same) 2011.1.14. KR 10-0956975 B (Method and apparatus for treating waste liquid containing radioactive material using high temperature plasma technology) 2010.5.11. KR 10-0991864 B (Method and System for Chemical Cleaning of Steam Generator in Nuclear Power Plant Using Aggregation and Filtration Technology) 2010.11.4.

In order to solve the above problems, the present invention consumes less energy, induces pyrolysis rather than combustion, and generates less end waste to be treated as radioactive waste, and alleviates deformation due to substrate corrosion and high temperature due to EDTA. It is an object of the present invention to provide a method and apparatus for treating radioactive liquid waste which can prolong the life of the apparatus, prevent clogging caused by solids precipitated when the EDTA is concentrated in high concentration, and operate the treatment apparatus without interruption.

In order to achieve the above object, the radioactive liquid waste treatment apparatus of the present invention, a membrane device for concentrating the liquid waste by using a nano-membrane and reverse osmosis membrane, an evaporation concentrator for condensing the concentrated liquid concentrated in the membrane device, the It is coupled to the lower portion of the evaporation concentrator is connected to the evaporation drying apparatus for reducing the water content of the concentrated liquid and solids concentrated in the evaporation concentrator and the pyrolysis device for pyrolyzing the solids, separated concentration, evaporation concentration, evaporation drying and pyrolysis It is a device that can perform continuously.

On the other hand, the radioactive liquid waste treatment method of the present invention, the membrane concentration step of concentrating the liquid waste by using the nano-membrane and reverse osmosis membrane, the evaporation concentration step of evaporating and condensing the concentrate concentrated in the membrane concentration step, the evaporation concentration step The evaporation drying step of reducing the water content of the concentrated concentrate and the solid and the pyrolysis step of pyrolyzing the solid are sequentially performed.

In the present invention, in treating radioactive liquid waste, the concentration of the liquid waste to be evaporated and concentrated is reduced since it is concentrated in a separator before the evaporative concentration step, and thus the energy can be saved because high power is not used.

In addition, since the present invention complexes the unreacted free EDTA in the EDTA concentrated in the evaporation concentrator with metal beads and dry the solids to thermally decompose, base metal corrosion is alleviated and generation of thermal stress due to moisture is alleviated. It has the effect of extending the life.

In addition, since the present invention thermally decomposes at a temperature of 500 ° C. or less by an oxygen-free pyrolysis method, the amount of metal oxides and carbides generated by oxidation is reduced, thereby minimizing the amount of final radioactive solid waste.

In addition, by transporting the solid precipitated at the time of high concentration of EDTA with a screw, there is no pipe blockage caused by the solid, thereby stably treating the radioactive liquid waste without interrupting the operation of the processing apparatus.

1 is a block diagram of an embodiment of a cleaning radioactive liquid waste treatment apparatus of the present invention,
Figure 2 is a block diagram of an embodiment of a cleaning radioactive liquid waste treatment method of the present invention.

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

Radioactive liquid waste treatment apparatus of the present invention, as shown in Figure 1, using a nano-membrane and reverse osmosis membrane membrane device 10 for concentrating the liquid waste, concentrated by evaporating the concentrate concentrated in the membrane device (10) The evaporation concentrator 20, which is coupled to the lower portion of the evaporation concentrator 20 to thermally decompose the evaporation drying apparatus 30 and the solids to reduce the water content of the concentrated liquid and solids concentrated in the evaporation concentrator 20 The pyrolysis device 40 is connected in sequence, and is a device capable of continuously performing separation concentration, evaporation concentration, evaporation drying and pyrolysis.

The separation membrane device 10 is a device for increasing the concentration of impurities dissolved in the liquid waste by filtering the incoming liquid waste into the nano-membrane and reverse osmosis membrane, and includes a nanofiltration unit and a reverse osmosis unit. And, connected to the liquid waste container (1) through the inflow water pipe (11), connected to the evaporation concentrator 20 through the concentrated water pipe (13), radioactive liquid waste management of the power plant through the filtered water pipe (12) It is connected to the system (Liquid Radwaste System, LRS).

In order to prevent impurities having a large particle diameter from flowing into the nanomembrane and reverse osmosis membrane, it is preferable to install a pretreatment filter (not shown) in the separation membrane device 10, and when the pretreatment filter is installed, it is installed before the nanomembrane. . Separation technology and pre-treatment filter using the nano-membrane and reverse osmosis membrane is a well-known technology, so description thereof will be omitted.

The evaporation concentrator 20 is an apparatus for further concentrating by heating the concentrated liquid concentrated in the separator 10 under atmospheric pressure. The main body 21 has an upper portion thereof and a flange 26 at the lower portion thereof. Is coupled to the evaporation drying device 30 having a flange 33 to the top. Therefore, the evaporation concentrator 20 and the evaporation drying apparatus 30 are coupled to each other through the flanges 26 and 33, and the inside thereof penetrates each other. In addition, the main body 21 is connected to the separator device 10 by the concentrated water pipe (13). The shape of the main body 21 is preferably a water tank shape, but is not limited thereto.

The evaporation concentrator 20 forms metal complexes with unreacted free EDTA when a corrosive liquid such as EDTA is introduced, thereby relieving corrosion of the evaporation concentrator 20 base metal. The main body 21 has a metal net 25 installed at the lower end so that the beads 23 do not escape downward and a demister 22 for preventing the radioactive material from being entrained by water vapor during evaporation and concentration. It is provided inside.

In addition, the evaporation concentrator 20 has an electric heater 24 for heating the contents therein, it is preferable that the electric heater 24 is charged in the main body 21. In addition, the steam generated by the heating of the liquid waste is discharged to the upper opening of the main body 21, in order to facilitate the discharge of the steam can be installed in the upper opening of the main body 21, a discharge fan (not shown) is discharged In order to condense and recycle the condenser (not shown) may be installed.

The evaporation drying apparatus 30 heats the concentrated liquid and the solid introduced from the evaporative concentrator 20 to evaporate and dry the moisture contained in the concentrated liquid and the solid, and at the same time, thermally decomposes the solid with the screw 36. An apparatus for transferring to a furnace is composed of an elongated main body 31, a screw 36 therein, a band heater 34 attached to an outer lower surface thereof, and a steam discharge pipe 35 provided above. In addition, a demister 351 is provided in the steam discharge pipe 35 to prevent the radioactive material from being entrained by the steam.

In addition, the evaporation drying apparatus 30 may be coupled to the evaporation concentrator 20 by installing a flange 33 corresponding to the flange 26 of the evaporation concentrator 20 on a part of an upper portion of the main body 31. The upper cover 32 is installed on a part of the upper part of the main body 31 so that the internal cleaning and the inspection of the device can be performed.

At the right end of the evaporation drying apparatus 30, the main body 31 is provided with a connecting pipe 38 connected to the pyrolysis device 40 and a rotary pump 381 is installed at the connecting pipe 38. It is preferable to install the evaporation drying apparatus 30 with an inclination angle such that the right end is located at a position higher than the left end so that an angle of 5 to 30 degrees is formed. (In the present invention, 'left' and 'right' are referred to for convenience. 'Left' and 'Right' may be interpreted as 'Right' and 'Left')

The screw 36 of the evaporation drying apparatus 30 uses a screw without a shaft to enable the transfer of solids even if bending deformation occurs due to thermal stress at a high temperature of 100 ° C. or higher. The shaftless screw 36 is driven by the drive motor 361.

The pyrolysis device 40 is a device for pyrolyzing solids dried in the evaporation drying device 30, the long body 41, the screw 45 installed inside the body 41, the body 41 of the main body 41. It consists of a low temperature band heater 43 attached to the outer lower surface, the high temperature band heater 44 and the gas discharge pipes 46 and 47 provided on the upper portion of the main body 41.

In addition, a connection pipe 48 connected to the solids collection container 50 is installed at the right end, and a rotary pump 481 is installed at the connection pipe 48. In addition, it is preferable to provide air filters 461 and 471 and expansion joint pipes 462 and 472 in the gas discharge pipes 46 and 47, respectively. In addition, it is preferable to install an exhaust gas treatment device (not shown) for treating exhaust gas in accordance with environmental standards at the rear end of the gas discharge pipes 46 and 47.

The screw 45 of the pyrolysis device 40 uses a shaftless screw 45 capable of transporting solids even when bending deformation occurs due to thermal stress at a high temperature. The shaftless screw 45 is driven by the drive motor 451.

In addition, the radioactive liquid waste treatment device of the present invention may be provided with an automatic control device (not shown) for controlling the treatment device, the evaporation concentrator 20, the evaporation drying device 30 and the pyrolysis device 40. It is preferable to prevent the heat loss by wrapping the insulation with heat insulating material to prevent the heat from being released to the outside.

On the other hand, the radioactive liquid waste treatment method of the present invention, as shown in Figure 2, the membrane concentration step (S1) for concentrating the liquid waste using the nano-membrane and reverse osmosis membrane, by evaporating the concentrate concentrated in the membrane concentration step Evaporation concentration step (S2) to concentrate, the evaporation drying step (S3) to reduce the water content of the concentrate and solids concentrated in the evaporation concentration step (S3) and pyrolysis step (S4) to pyrolyze the solids in a sequential manner.

In the membrane concentration step (S1), the radioactive liquid waste stored in the liquid waste container (1) is introduced into the membrane device (10) through the inflow water pipe (11) to pass the nano membrane and the reverse osmosis membrane in order to concentrate the liquid waste. .

The concentrated liquid thus obtained is introduced into the evaporation concentrator 20 through the concentrated water pipe 13, and the filtered water generated by the concentration of the liquid waste is drained to the LRS through the filtered water pipe 12. Filtrates produced by the concentration of such liquid wastes do not normally contain radioactive material, but are drained to the LRS to increase the stability of radioactive waste treatment.

In order to prevent impurities having a large particle size from flowing into the nanomembrane and reverse osmosis membrane in the separation membrane concentration step (S1), a pretreatment filter is installed in the membrane device 10 so that the radioactive liquid waste passes through the pretreatment filter, and then the nanomembrane and reverse osmosis membrane. It is preferable to pass through in order.

In the evaporation concentration step (S2) when the concentrate concentrated in the membrane concentration step (S1) is introduced into the main body 21 of the evaporation concentrator 20 through the concentrated water pipe (13) electric heater 24 Heated to generate water vapor for further concentration. The upper part of the main body 21 of the evaporation concentrator 20 is open so that the concentrated liquid is heated under atmospheric pressure, and water vapor generated by the heating is discharged through the opening of the upper part of the main body 21. Due to this heating, the concentrate is further concentrated and at the same time solids precipitate.

The metal beads 23 filled in the main body 21 of the evaporation concentrator 20 form a complex with the unreacted free EDTA when the corrosive liquid such as EDTA is introduced, and serves to alleviate the base metal corrosion. After discharging the concentrated liquid concentrated in the concentrating device 20 to the evaporation drying device 30, it also serves to mitigate thermal shock when the concentrated liquid concentrated at room temperature flows from the membrane device (10).

By measuring the weight loss of the metal beads 23 filled in the main body 21 of the evaporation concentrator 20, the concentration of non-reactive free EDTA and corrosiveness present in the liquid waste can be measured. The degree of corrosion occurring in the radioactive liquid waste treatment unit can be checked and used as an index for predicting the life of the treatment unit.

If a discharge fan is installed in the upper opening of the main body 21 of the evaporative concentrator 20 in order to facilitate the discharge of the steam generated by the heating of the concentrated liquid, the discharge and concentration of the steam is made faster, and the condenser is installed and discharged. Condensed water vapor can also be recycled.

On the other hand, the demister 22 installed in the upper portion of the main body 21 of the evaporation concentrator 20 serves to prevent the radioactive material from entraining by the water vapor during the evaporation concentration, the inside of the main body 21 The metal mesh 25 installed at the lower end serves to block the metal beads 23 from escaping downward.

In the evaporation drying step (S3), when the concentrated liquid and solids further concentrated in the evaporation condensation step (S2) are introduced into the evaporation drying apparatus 30, the concentrate and the concentrated liquid are generated by the heat generation of the band heater 34 on the bottom surface of the evaporation drying apparatus 30. As the water contained in the solid evaporates and the concentrate is concentrated to a high concentration, new solids are precipitated. The dried solid is transferred to the right end of the evaporative drying apparatus 30 by the operation of the shaftless screw 36 and then flows through the connection pipe 38 by the rotary pump 381 to the pyrolysis apparatus 40.

Water vapor evaporated from the concentrated liquid and the solid by the heating by the band heater 34 is discharged through the steam discharge pipe 35 and then condensed and recycled to the condenser, and the demister 351 installed in the steam discharge pipe 35 is Prevents radioactive material from entraining by water vapor.

Screw 36 of the evaporation drying apparatus 30 does not have a shaft can transfer the solids even if the bending deformation occurs due to thermal stress at a high temperature of 100 ℃ or more, periodically the upper cover 42 of the evaporation drying apparatus 30 It is advisable to open and inspect and clean the interior.

On the other hand, if the evaporation drying device 30 is installed so that the right end is located at a position higher than the left end so that an angle of 5 to 30 degrees is formed, the concentrate is further evaporated while being concentrated under the gravity by the gravity and the screw 36 is Since only the solid material is transferred to the right end of the evaporation drying apparatus 30, it can be evaporated to dry more efficiently.

In the pyrolysis step (S4) to thermally decompose the solid dried in the evaporation drying step (S3). Pyrolysis refers to a reaction in which a weak bond is broken when a molecule is activated by applying heat from the outside to form a new substance. When the compound has an endothermic reaction, the entropy increases more than the internal energy (enthalpy). Anaerobic pyrolysis refers to the decomposition of substances by blocking air and breaking weak rings of molecules with only a heat source.

As described above, the solid dried in the evaporation drying step (S3) is transferred to the right end of the evaporation drying apparatus 30 by the operation of the screw 36 and then to the pyrolysis apparatus 40 through the connecting pipe 38. Inflow.

In the pyrolysis apparatus 40 of the present invention, since the inflow of external air is blocked by the rotary pumps 381 and 481, combustion by oxygen does not occur, so the pyrolysis apparatus 40 is operated at a low temperature. The pyrolysis device 40 of the present invention separates into a low temperature section in which drying occurs and a high temperature section in which pyrolysis occurs, and the low temperature section controls the internal temperature at 200 to 300 ° C. and the high temperature section to control the internal temperature at 400 to 500 ° C. FIG. The temperature control is controlled by the low temperature band heater 43 and the high temperature band heater 44 attached to the outer lower surface of the main body 41 of the pyrolysis apparatus 40.

In general, when combustion occurs in the pyrolysis apparatus, the internal temperature rises to 900-1,000 ° C., and this temperature causes significant thermal stress on the pyrolysis apparatus, causing deformation of the pyrolysis apparatus, but the pyrolysis apparatus of the present invention generates combustion. It does not have a structure and is separated and controlled by drying section and pyrolysis section, so that thermal stress by moisture is minimized, so that almost no deformation occurs, thus extending the life of processing equipment.

The solids transferred to the pyrolysis device 40 are dried in a low temperature section while being transferred in the direction of the right end of the pyrolysis device 40 by a screw 45, and are then anaerobic pyrolyzed in a high temperature section. This final pyrolyzed solid is transferred to the right end of the pyrolysis device 40 by a screw 45 and then collected by the rotary pump 481 through the connection pipe 48 to be collected in the solid collection container 50.

The screw 45 of the pyrolysis device 40 is driven by the drive motor 451, and the screw is a shaftless screw, so that even if bending deformation occurs due to thermal stress at a high temperature, solids can be transferred.

Exhaust gas generated by pyrolysis in the pyrolysis device 40 is discharged through the gas discharge pipes 46 and 47, and it is preferable to install the exhaust gas treatment device to treat the exhaust gas in accordance with environmental standards.

The gas discharge pipes 46 and 47 may withstand the contraction or expansion due to the rapid temperature change of the exhaust gas by the action of the expansion joint pipes 462 and 472 respectively installed at the lower portions thereof. Screws 36, 45, heaters 24, 34, 43, 44 and rotary pumps 381, 481 of the radioactive liquid waste treatment apparatus of the present invention are automatically controlled by an automatic control device.

Although the present invention has been described based on the embodiments, the present invention is not limited thereto and various changes and modifications can be made within the scope of the technical idea of the present invention. Therefore, the scope of the present invention is not limited by the above description.

In addition, the reference numerals described in the detailed description of the present invention and the claims are added by reference for easy understanding of the present invention, the present invention is not limited to the drawings.

The present invention can be widely used for the treatment of radioactive liquid waste, such as the treatment of ETA wastewater generated in the secondary system of nuclear power plants and the treatment of the cleaning radioactive liquid waste generated after steam generator chemical cleaning.

1: liquid waste container 10: separator device
11: influent piping 12: filtered water piping
13: concentrated water pipe 20: evaporative concentrator
21: main body 22: demister
23: metal beads 24: electric heater
25: metal mesh 26: flange
30: evaporation drying apparatus 31: main body
32: top cover 33: flange
34: band heater 35: steam discharge pipe
351: demister 36: screw
361: drive motor 38: connector
381: rotary pump 40: pyrolysis device
41: main body 42: top cover
43: low temperature band heater 44: high temperature band heater
45: screw 451: drive motor
46: gas discharge pipe 461: air filter
462: expansion pipe 47: gas discharge pipe
471: air filter 472: expansion joint pipe
48: connector 481: rotary pump
50: solids collection container

Claims (16)

In the radioactive liquid waste treatment apparatus,
Separation membrane device 10 for concentrating the liquid waste by using the nano-membrane and reverse osmosis membrane, the evaporation concentrator 20 for evaporating and condensing the concentrate concentrated in the membrane device 10, the lower portion of the evaporation concentrator 20 Combined with the evaporation drying device 30 to reduce the water content of the concentrated liquid and the solids concentrated in the evaporation concentrator 20 and the pyrolysis device 40 for pyrolyzing the solids in sequence, separation concentration, evaporation concentration, evaporation Drying and pyrolysis are carried out continuously,
Forming a complex compound with EDTA in the evaporation concentrator 20 to prevent the metal bead 23 and the metal bead 23 from being lowered to lower the corrosion of the base material of the evaporation concentrator 20 Radioactive liquid waste treatment apparatus comprising a metal net (25).
delete delete delete delete The method of claim 1,
The evaporative drying apparatus 30 has a long body 31, a band heater 34 attached to the screw 36 inside the main body 31 and an outer lower surface of the main body 31, and a steam discharge pipe installed at an upper portion thereof ( 35),
Radioactive liquid waste treatment apparatus, characterized in that the screw 36 is a shaftless screw capable of transferring solids even if bending deformation occurs due to thermal stress at a high temperature.
delete delete The method of claim 1,
The pyrolysis apparatus 40 has a long body 41, a screw 45 installed inside the body 41, a low temperature band heater 43 and a high temperature band heater 44 attached to the outer lower surface of the body 41. ) And gas discharge pipes 46 and 47 installed on the upper part of the main body 41,
The screw 45 is a radioactive liquid waste treatment apparatus, characterized in that the shaft-free screw that can be transported even if the bending deformation occurs due to thermal stress at a high temperature.
delete delete In the radioactive liquid waste treatment method,
Separator concentration step (S1) for concentrating the liquid waste by using the nano-membrane and reverse osmosis membrane, the evaporation concentration step (S2) to evaporate and concentrate the concentrate concentrated in the membrane concentration step, the concentrate and solids concentrated in the evaporation step Evaporation drying step (S3) to reduce the moisture content and pyrolysis step (S4) to pyrolyze the solids are sequentially performed,
In the evaporation concentration step (S2) by filling the metal beads 23 in the body 21 of the evaporation concentrator 20,
When a corrosive liquid such as EDTA is introduced, it forms a complex with EDTA to mitigate base metal corrosion and discharge the concentrated solution concentrated in the evaporation concentrator 20 to the evaporation dryer 30, and then concentrate the room temperature concentrated in the membrane device 10. Radioactive liquid waste treatment method characterized in that the thermal shock is mitigated when the concentrated solution is introduced. delete delete delete delete

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