KR100978312B1 - Treatment method and its process for protective products manufactured by polyvinylalcohol - Google Patents

Abstract

PURPOSE: A method and a device for processing a polyvinyl alcohol protection article are provided to reduce the amount of radioactive waste and operation costs of a nuclear power plant by using heat medium and catalyst. CONSTITUTION: A pyrolysis/oxidation reactor pyrolyzes and oxidizes an organic material included in a polyvinyl alcohol solution. A catalyst oxidation reactor(210) processes the organic material included in a processed gas from the pyrolysis/oxidation reactor. A heat exchanger(120) cools and collects the waste heat included in the oxidized organic gas. The condensate generated from the heat exchanger is stored in a condensate storage tank. The condensate is outputted to a plant after the neutralization and filtering.

Description

Treatment method and its process for protective products manufactured by polyvinyl alcohol} by Polyvinylalcohol

The present invention relates to a treatment method and apparatus for a disposable protective article (hereinafter referred to as "PVA protective article") made of polyvinyl alcohol (PVA) used in nuclear power plants, which is generated during dissolution and concentration of PVA protective articles. The present invention relates to a method and apparatus for treating a protective article made of PVA material which can be completely oxidized with CO ₂ and H ₂ O using a pyrolysis / catalytic oxidation technique.

Treatment methods for reducing radioactive wastes generated by nuclear power plants can be divided into “in-house treatment” and “self-disposal” methods. The “in-house treatment” method is mainly a method of discharging and managing liquid and collectable wastes by treating them with stable materials on the site of nuclear power plants using solidification treatment or oxidation treatment technology. On the other hand, the “self-disposal” method is a waste treatment method in which radioactive materials in solid waste such as metal waste or concrete and soil are removed to “deregulated” concentrations and then recycled off-site or landfilled in landfills.

The present applicant has applied for a technology capable of "self-disposing" a disposable protective article made of polyvinyl alcohol (PVA) used in the nuclear power plant (Application No. 10-2009-0111039). The polyvinyl alcohol (hereinafter referred to as “PVA”) protective article disposal method is to dissolve the PVA protective article in water at a concentration of 10wt% in 95 ℃ or more water, and then add a oxidant to dissolve the PVA and dissolved PVA protective suit 200Torr The flocculation process can be concentrated to 35wt% PVA solution under vacuum condition, and the concentrated 35wt% PVA solution is discharged to the flocculation tank to form flocs by adding cationic and anionic polymers to form gamma nuclides dissolved in 35wt% PVA solution. It is composed of a system capable of self-disposing of the final 35 wt% PVA concentrate after removal of gamma nuclide by removing the floc using a filter after adsorption.

However, in order to “self-dispose” the final decontaminated 35wt% PVA solution, it is inconvenient to obtain the consent of the nuclear regulatory agency, and liquid waste increased to 35/100 of the amount by converting solid waste into liquid phase. There are problems such as having to transfer to a temporary storage for several months.

In addition, Patent No. 10-0823961 discloses a PVA protective article treatment method for high-temperature incineration using a plasma incinerator, the registered patent incinerates a large amount of nitrogen oxide as the treatment method incinerates the PVA solution at a high temperature of 1000 ℃ or more. And additional technical factors that need to be supplemented, such as increased operating costs due to the use of auxiliary fuel for two-stage combustion, generation of soot due to unburned reaction during liquid combustion containing high concentrations of PVA material for the use of plasma generators. Doing.

As such, the introduction of PVA protection products that can drastically reduce the amount of combustible waste generated from domestic nuclear power plants, in order to reduce the operating cost of nuclear power plants and to reconstruct the eco-friendly image of the nuclear power business, is a treatment method that can fully utilize the eco-friendly characteristics of PVA protection products. It is a reality that needs to be developed urgently.

The present invention has been made to solve the problems encountered in domestic nuclear power plants as described above, an object of the present invention is to produce a conventional polyvinyl alcohol (PVA) by pyrolysis and catalytic oxidation of the PVA solution generated during concentration In addition to self-disposable disposable protective article, it is to provide a treatment method and apparatus capable of treating the decontaminated PVA solution in-house.

In addition, an object of the present invention is to dissolve, concentrate, and oxidize PVA protective articles in water to remove organic matter first, and then use a small pyrolysis and catalytic oxidation reactor to completely replace PAV substances in PVA solution with CO ₂ and H ₂ O. It is to provide a method and apparatus for the treatment of protective articles made of polyvinyl alcohol which can be oxidized.

The protective article processing method made of the polyvinyl alcohol of the present invention comprises: 1) a waste liquid pyrolysis oxidation step of thermally decomposing and oxidizing an organic substance in a filtrate treated using a dissolution concentration tank at a high temperature; 2) a catalytic oxidation treatment step for treating organic substances present in untreated and discharged gas after pyrolysis and oxidation treatment; 3) an exhaust gas cooling step of recovering and cooling waste heat in the oxidized organic gas; 4) a condensate collection step of collecting the condensate generated in step 3); 5) condensate neutralization step of neutralizing the pH of the collected condensate to meet the discharge water quality standards; And 6) condensate discharge step of filtering particulate matter in the final discharged condensate to be discharged to the power plant LRS (Liquid Release System) system.

In addition, the step before the step 1), the collection / separation step of separating the insoluble material by collecting in the field; A washing step of removing radioactive material deposited on the PVA protective article; PVA protective article dissolution / concentration step of dissolving and concentrating the PVA protective article after washing; Concentrate discharge step of discharging the dissolved PVA solution from the solution concentration tank to the flocculation tank; A concentrate primary filtration step of primaryly separating particulate matter present in the PVA concentrate transferred to the coagulation tank with a filter; Flocculant dosing / stirring step to remove radioactive material present in the primary filtered PVA solution; And a secondary pillaring step of removing the floc formed by the flocculant.

In the concentrate primary filtration step, the macroparticles are removed by a filter and the PVA solution is oxidized by allowing the organic material and the oxidant to be mixed well using a pump rotating at a high speed.

In addition, in step 1), the pyrolysis oxidation reactor is operated at 550 to 600 ° C. to oxidize the PVA solution.

In step 2), the catalytic oxidation reactor is operated at 500 to 550 ° C. to oxidize the PVA solution.

In addition, in step 1), the PVA solution is sprayed in the atomized state, and the sprayed PVA solution is heated and oxidized by the heat storage medium and the jacket heater.

In the step 2), a catalyst made of platinum (Pt), palladium (Pd) and alumina (Al ₂ O ₃ ) is used.

On the other hand, the protective article processing apparatus made of the polyvinyl alcohol of the present invention comprises: a waste liquid pyrolysis oxidation reactor for thermally decomposing and oxidizing an organic substance in a filtrate treated with a dissolution concentration tank at a high temperature; Catalytic oxidation reactor for treating organic matter present in untreated gas discharged from the gas treated in the pyrolysis / oxidation reactor; A heat exchanger for recovering and cooling waste heat in the oxidized organic gas; And a condensate storage tank for collecting condensate generated by the heat exchanger, and neutralizing the condensate stored in the condensate storage tank to meet the effluent water quality standard to filter particulate matter in the final discharged condensate. Allow the system to drain.

And between the waste liquid pyrolysis oxidation reactor and the dissolution concentration tank to remove the large particles with a filter and using a pump that rotates at high speed so that the organic matter and oxidant can be mixed well so that the coagulation tank is provided to oxidize the PVA solution.

In addition, the pyrolysis oxidation reactor is operated at 550 ~ 600 ℃.

And the catalytic oxidation reactor is to be operated at 500 ~ 550 ℃.

In the pyrolysis oxidation reactor, the PVA solution is sprayed in an atomized state, and the sprayed PVA solution is heated and oxidized by the heat storage medium and the jacket heater.

The pyrolysis oxidation reactor is then supplied with air heated by a heater.

In addition, the heat storage medium is made of a ceramic material.

And the catalyzed oxidation reaction is to treat the PVA solution using a catalyst consisting of platinum (Pt), palladium (Pd) and alumina (Al ₂ O ₃ ).

According to the present invention, by thermally decomposing and catalyzing the PVA solution generated during dissolution and concentration, not only the disposable protective article made of conventional polyvinyl alcohol (PVA) can be disposed of by itself, but also the decontaminated PVA solution is prepared. By miniaturizing the facilities that can be handled in the facility, there is an economic effect such as the suppression of large-scale power use due to the large size.

In addition, according to the present invention, the implemented facility is less power consumption amount is less restricted by the equipment installation space, it is possible to implement a small mobile equipment has the effect that can be installed in a narrow space.

In addition, according to the present invention, the use of a catalyst and heat medium is very beneficial in terms of equipment operation, the introduction of PVA protection supplies of domestic nuclear power plants can be expected to have various effects in terms of reducing the operating cost of nuclear power plants, reducing the amount of radioactive waste generated and workers' protection and hygiene. .

1 is a block diagram showing a method for processing a protective article made of the polyvinyl alcohol of the present invention.
Figure 2 is a block diagram showing a protective article processing apparatus made of a polyvinyl alcohol of the present invention.
3 is a schematic view showing a pyrolysis oxidation reactor shown in FIG.
Figure 4 is a photograph showing the PVA solution treated by the protective article processing method and apparatus made of the polyvinyl alcohol of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. These embodiments are provided to explain in detail the present invention to those skilled in the art. Accordingly, the shape of each element shown in the drawings may be exaggerated to emphasize a more clear description.

The present invention is achieved by the following method as shown in FIG.

As shown in FIG. 1, the used protective clothing is collected / separated (S1); Washing step (S2) to remove the radioactive material on the PVA protective article; Dissolving and concentration after dissolving PVA protective article after washing to maximize organic matter treatment (S3); Concentrate discharge step of discharging the PVA solution from the solution concentration tank to the flocculation tank (S4); A primary filtration / oxidation step (S5) of inducing separation of particulate matter present in the PVA concentrate transferred to the coagulation bath and oxidation of the untreated PVA material; Coagulant input / stirring step (S6) to remove radioactive material in the primary filtered PVA solution; Secondary filtration to remove floc formed by the flocculant; Filtrate discharge step of transferring the second filtered PVA solution to the waste liquid storage tank; A thermal decomposition and oxidation treatment step (S9) for thermally decomposing and oxidizing an organic substance in a PVA solution at high temperature; A catalytic oxidation treatment step (S10) for treating organic substances present in untreated and discharged gas after pyrolysis and oxidation treatment; An exhaust body cooling step (S11) for recovering and cooling the waste heat in the gas; A condensate collecting step of collecting the condensate generated in the step; A condensate neutralization step of neutralizing the pH of the collected condensate; It comprises a condensate discharge step of filtering particulate matter in the condensate and discharge it to the power plant LRS system.

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 to 3.

Collection / separation step to separate insoluble materials by collecting them on site ( S1 )

In this step, PVA protective articles used in nuclear power plants are collected and stored in certain areas. The collected protective goods are separated into a fixed volume unit that can be processed by the dissolution concentrate tank 100 at a time.In this case, insoluble foreign matter is separated through visual inspection to minimize system failure factors, and protective clothing is separated according to the degree of contamination. Step by step from low pollution protective clothing to high pollution protective clothing.

PVA  Washing step to remove the radioactive material attached to the protective article first ( S2 )

In this step, the PVA protective article contaminated with radioactive material is washed with a laundry facility to remove particulate matter and gamma nucleus primarily, thereby minimizing the radioactive material present in the solution when dissolving the PVA protective article, thereby reducing filter consumption. Untreated radioactive material can minimize contamination of pyrolysis and oxidation treatment facilities.

The cleaning liquid generated in the washing process can be discharged in connection with the nuclear power plant LRS system without additional treatment, thereby reducing the burden on the generated waste liquid treatment.

Dissolving / concentrating the protective article after washing ( S3 )

PVA material to be treated in this step is characterized by dissolving in water of 90 ~ 100 ℃ can be used to prepare a PVA solution of a specific concentration. In order to prepare the PVA solution, the first decontaminated PVA protective article through the washing process (S2) is allowed to enter a certain throughput through the protective article inlet at the top of the concentration tank. After the PVA protective article is added, the condensate stored in the condensate storage tank 130 is introduced into the dissolution concentrate tank 100 by the condensate purification pump. The condensate storage tank 130 is equipped with a level sensor, when the condensate circulation pump operates when the level signal is above a certain level, the electric valve is opened and the condensate is discharged to the power plant LRS system by gravity and closed. Thereafter, the condensate circulation pump is operated to supply the condensate to the concentration solution 100 until the water level becomes a predetermined amount by the signal of the level sensor.

That is, the dissolution concentrate tank 100 can be made very simply to minimize the contamination of the dissolution concentrate tank 100 by the accumulation of radioactive material during dissolution / concentration of PVA protective article.

 The condensate stored in the PVA protective article and the condensate storage tank 130 is recycled to the dissolution concentrate tank 100, and the condensate that is added is put in 1 L per kg of protective clothing. When water is supplied to the dissolution concentration tank 100 through the condensed water supply line (L10), by operating the heater to heat the water in the heater tank 110 to 100 ~ 110 ℃. The heated water forms a high temperature steam and flows into a heating jacket (not shown) installed at the side of the dissolution concentration tank 100 to heat the dissolution concentration tank 100. In the heated dissolution concentrate tank 100, when the internal temperature reaches 95 ° C., PVA begins to dissolve in water. After 30 minutes, 95% or more of PVA dissolves in water.

In addition, dissolution of the PVA protective article is carried out after preparing a solution of 5 ~ 8w / v% solution without adding an oxidizing agent.

At this time, when the concentration process starts, the hydrogen peroxide and the iron salt solution are respectively introduced into the 0.8 ~ 1L _{H 2 O 2} / kg _{PVA protective suit,} 0.4 ~ 0.8L _{iron salt solution} / kg _{PVA protective suit} by the chemical supply pump 150, respectively _, and the organic matter under high PVA concentration. Effectively oxidize to CO ₂ and H ₂ O. The final concentrate is evaporated, concentrated and oxidized until a PVA solution of 35-40 w / v% is based on the initial PVA protective clothing input.

On the other hand, the heat of oxidation generated by the Fenton reaction can supply energy for dissolving PVA, thus acting as a stable energy source without a heater. In addition, the PVA solution is maintained at 98 ~ 100 ℃ by the heat energy generated by the Fenton reaction to evaporate the water in the PVA solution. Water evaporated in the dissolution step is collected in the condensate storage tank 130 via the heat exchanger (120). This water evaporation may be closer to the concentration (35-40 w / v%) to be obtained in the present invention by evaporating the water added in the initial excess, and the radical hydroxide ion generated by the hydrogen peroxide and iron salt reaction in the concentrated state It can effectively decompose PVA material.

Next, when the dissolution is completed, by operating a vacuum pump (not shown) connected to the heat exchanger 120 maintains the interior of the dissolution concentration tank 100 to 100 ~ 300 Torr to concentrate the PVA solution. At this time, the technique of concentrating the solution under vacuum conditions can shorten the concentration time because of the excellent water evaporation efficiency in the waste liquid containing a high concentration of organic matter.

Concentrate discharge step ( S4 )

In this step, the concentrated PVA solution is discharged from the dissolution concentrate tank 100 through the concentrate discharge line L1 by operating the filter pump when the pressure inside the dissolution concentrate tank 100 reaches atmospheric pressure. Discharge through the coagulation tank 160 through. The filter pump (not shown) operates by receiving a signal from a level sensor installed in the dissolution concentration tank 100. Features of the PVA solution discharged from the dissolution concentrate tank 100 to the flocculation tank 160 are as follows.

When the filter pump is operated to discharge the PVA solution stored in the dissolution concentration tank 100, the filter pump is operated until the level of water level installed in the dissolution concentration tank 100 reaches a minimum point. When the filter pump is operated, an automatic valve of a line (not shown) connected to the filter 170 side is automatically opened. The temperature discharged from the initial dissolution concentration tank is 70 ~ 75 ℃ level can cause thermal damage to the filter 170 is cooled to below 50 ℃ through the water-cooled heat exchanger 171 through the filter 170 through the coagulation tank 160 To be captured. When the water level (not shown) of the melt concentration tank 100 reaches the lowest point, the operation of the filter pump is stopped. In discharging the concentrated PVA solution, the concentrate is collected in the coagulation tank 160 via the filter 170.

When the PVA solution is completely discharged from the dissolution concentrate tank 100 to the flocculation tank 160, the collection / sorting step (S1) proceeds continuously to the concentrate discharge (S4).

Concentrate primary filtration step ( S5 )

In this step, the incompletely dissolved organic matters may be firstly removed when the PVA protective article is dissolved, thereby reducing the amount of organic matters to be treated in the pyrolysis oxidation reactor 200 and the catalytic oxidation reactor 210.

When the concentrate is transferred to the coagulation tank 160, the incompletely dissolved organic matter is removed using the filter 170. The filter 170 preferably has a filtering capability of 50 ~ 0.2㎛. In addition, the filter pump is operated at high speed at 3600 rpm, and the turbine impeller (not shown) mounted inside allows the PVA solution to be mixed at high speed, and completely removes hydrogen peroxide and iron salt which are unreacted in the PVA concentrate. Mixing can induce a secondary Fenton reaction and the radical hydroxide ions thus produced can lead to further degradation of the PVA material. The filter pump is preferably a Wesco type pump capable of high speed operation.

Table 1 shows the organic removal rates for each process.

division concentrate Primary filtration moisture 90.9% 95.4% Volatile Solids 8.2% 4.2% Non-volatile solids 0.9% 0.4% Sum 100% 100%

As can be seen from Table 1, the organic substance concentration of the concentrated solution when prepared using the process according to the invention 35wt% PVA solution it may be seen as very low as 8.2%, which is the organic substance by the Fenton reaction in the dissolution / concentration process CO ₂ And it can be seen that more than 70% oxidized with H ₂ O, about 48.8% of the organic matter is further removed through the primary concentrate filtration step (S5).

Gamma  Flocculation for removal ( S6 ) And secondary filtration steps ( S7 After the filtrate discharge step ( S8 )

In this step, a coagulant capable of removing gamma nuclides is injected for further decontamination of radioactive substances present in the primary filtered PVA solution.

In order to promote effective floc formation by adding a flocculant, it is preferable to introduce a flocculant containing iron salt before the flocculant is added.

In this step, acrylamide-based polymers are effective for removing gamma nuclides present in solutions containing high concentrations of organic substances such as PVA solutions. The appropriate dosage is 0.2-1.0 mL _polymer / L _{PVA solution} . More preferably, the dose of 0.5 mL _polymer / L _{PVA solution} is titrated.

The injected polymer can remove all gamma nuclides with positive and negative charges present in solution.

In order to increase the amount of non-volatile inorganic substances in the process, the amount of fly ash can be increased during the pyrolysis and oxidation treatment of the PVA solution, so that fly ash accumulates in the pyrolysis oxidation reactor 200 and the catalytic oxidation reactor 210 and thus gamma Enrichment of the nuclides may occur.

Therefore, in order to fundamentally block the concentration of fly ash, it is preferable to form a neutralization step prior to discharging the PVA solution after oxidation treatment.

That is, the present invention is a device that completely oxidizes the PVA solution and discharges it to CO ₂ and H ₂ O to completely remove the gamma nuclides present in the PVA solution by discharging the final generated condensate in connection with the power plant liquid discharge system (LRS). Doing so can simplify the gamma nucleation removal process.

Meanwhile, when the filtrate is finally transferred to the waste storage tank 180, the filtration and discharging process of the PVA solution is completed, and the concentrated liquid first filtration step after performing the filtrate discharge step (S8) 30 minutes before the concentrate discharge step (S4). The circulation is repeated from (S5) to the filtrate discharge step (S8).

For example, the solution is circulated between the solution concentration tank 100, the filter 170, and the coagulation tank 160 by using the concentrate discharge line L1 and the filtrate circulation line L3, and the filtrate transfer line L4 is maintained in a blocked state. Done.

division Primary filtration Secondary filtration moisture 95.4% 95.9% Volatile Solids 4.2% 3.8% Non-volatile solids 0.4% 0.28% Sum 100% 100%

The elemental content of the PVA solution passed through the secondary filtration process is as follows.

Analysis item C (%) H (%) O (%) N (%) S (%) Molecular formula PVA solution 50.5 7.0 41.2 N.D. N.D. C ₄ H ₇ O ₃

PVA  Solution pyrolysis oxidation step ( S9 )

The PVA solution from which the gamma nuclide is removed through the above-described process is transferred to the waste liquid storage tank 180 through the filtrate transfer line L4. Before the PVA solution is introduced into the pyrolysis oxidation reactor 200, the internal temperature of the pyrolysis oxidation reactor 200 is increased to about 550 ° C. The air supplied into the pyrolysis oxidation furnace is supplied to the heater 270 through the heat exchanger 220 from the outside, the supplied air is heated to about 550 ~ 600 ℃ using the heater 270 to supply an air supply line (L7) The heat storage medium 203 of the ceramic material, which is filled in the pyrolysis oxidation reactor 200, can be stored. In this case, a partition wall 204 is provided inside the pyrolysis oxidation reactor to prevent the heat storage medium from blocking the air supply line. In addition, a jacket heater 202 is installed outside the pyrolysis oxidation reactor 200 to help increase the temperature of the heat storage medium 203, and the control of the jacket heater 202 is installed inside the pyrolysis reactor 200. By a temperature sensor (not shown).

Next, when the pyrolysis oxidation reactor 200 is heated to 550 ° C., the PVA solution is supplied into the pyrolysis oxidation reactor 200 through the waste solution supply line L5. At this time, the pyrolysis oxidation reactor 200 is provided with a nozzle 201 connected to the waste liquid supply line, so that the supplied waste liquid can be sprayed in the form of fine particles through the nozzle.

In particular, the heat storage media 203 filled in the pyrolysis oxidation reactor 200 can induce a long residence time of the gas under high temperature conditions, thereby effectively decomposing organic substances present in the PVA solution.

On the other hand, the PVA solution into the pyrolysis oxidation reactor 200 is operated above the lowest level of the waste liquid storage tank 180, it is preferable that the waste liquid supply pump (P4) is automatically stopped below the lowest point.

PVA  Solution secondary catalytic oxidation step ( S10 ) And Exhaust  Cooling stage ( S11 )

This step is a step for the second step in the catalytic oxidation reactor 210 untreated organic material in the above-described process.

The catalyst used in this step is preferably made of platinum (Pt) / palladium (Pd) / alumina (Al ₂ O ₃ ), it is preferable to operate the catalytic oxidation reactor at a high temperature of 500 ~ 550 ℃.

In addition, the exhaust gas discharged from the catalytic oxidation reactor 210 preheats the air supplied to the pyrolysis oxidation reactor 200 while passing through the air-cooled heat exchanger 220, air-cools the discharged gas, and air-cooled exhaust gas. Form a temperature of about 200 ~ 250 ℃ secondary to the cooling to room temperature through the water-cooled heat exchanger (230). The cooled exhaust gas is separated from the gas liquid and the condensate is collected in the condensate storage tank 240.

Neutralization of Condensate S12 ) And filtration / ejection steps ( S13 )

In this step, the condensate collected in the condensate storage tank 240 is detected by a level sensor (not shown) provided in the condensate storage tank when the predetermined water level is reached, and the detected condensate is automatically opened in sequence by an electric valve (not shown). After the condensate circulating pump (not shown) is operated. If the value of the pH sensor (not shown) provided in the condensate storage tank is 6.0 or less after the operation of the condensate circulation pump, the electric valve (not shown) connected to the chemical tank 250 is automatically opened, and the chemical supply pump (not shown) It is operated is supplied with 35wt% NaOH aqueous solution stored in the chemical tank (250). When the pH value of the condensate is maintained for 6.0 or more for 3 seconds by supply of NaOH, the chemical supply pump is stopped and the electric valve is stopped to neutralize the condensate.

Next, when the neutralization of the condensate is completed, the electric valve (not shown) connected to the filter 260 is automatically opened, and the electric valve (not shown) located below the condensate storage tank 240 is closed to pass through the filter 260. Condensate is discharged to the power plant LRS system, the filter 260 installed at this time is preferably equipped with a 3㎛ filter. Discharge of the condensate proceeds only until the level sensor (not shown) installed between the condensate storage tank 240 and the filter 260 reaches the lowest point. When the water level reaches the lowest point, the operation of the condensate circulation pump stops, and the condensate The electric valve provided between the storage tank and the filter and the electric valve provided under the condensate storage tank are sequentially closed to complete the condensate filtration / discharge step S14.

For example, the exhaust gas discharged by the catalytic conversion reactor 210 undergoes air cooling and water cooling, and the temperature drops to room temperature.

The water present in the exhaust gas dropped to room temperature is collected in the condensate storage tank 240, and the pH is adjusted to 6.0 ~ 6.5 to meet the water quality standards, and then the fly ash that may be present in the condensate is removed through a filter and discharged to the power plant LRS. Will be done.

On the other hand, as shown in Figure 4, the sample collected in the filtrate discharge step (S8) (left side of the figure) and the sample (right side of the figure) taken in the condensate filtration / discharge step (S14). As can be seen in Figure 4 PVA protective article treated through the present invention is able to treat the COD concentration of the final effluent to about 15ppm.

In the present invention, the condensate neutralization step (S13) and the condensate filtration / discharge step (S14) are automatically operated and controlled by a water level sensor (not shown) installed in the condensate storage tank 240 to increase the convenience of facility operation. In the condensate collection step (S12), the condensate filtration / discharge step (S14) is automatically repeated by a water level sensor (not shown) of the condensate storage tank 240.

Along with the method for treating protective articles made of a water-soluble material consisting of the steps of the present invention, the present invention provides a radioactive material processing apparatus for use in the treatment method.

Through this process, water-soluble protective articles including PVA-based protective articles generated from nuclear power plants can be treated in a power plant, thereby maximizing the permanent disposal cost of flammable waste and the efficiency of using protective articles.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

Claims (15)

A protective article processing method made of polyvinyl alcohol for treating a radioactive substance attached to a PVA protective article by a dissolution concentration tank,
1) a waste liquid pyrolysis oxidation step of thermally decomposing and oxidizing an organic substance in a filtrate treated using a dissolution concentration tank at a high temperature;
2) a catalytic oxidation treatment step for treating organic substances present in untreated and discharged gas after pyrolysis and oxidation treatment;
3) an exhaust gas cooling step of recovering and cooling waste heat in the oxidized organic gas;
4) a condensate collection step of collecting the condensate generated in step 3);
5) condensate neutralization step of neutralizing the pH of the collected condensate to meet the discharge water quality standards; And
6) condensate discharge step of filtering the particulate matter in the final discharged condensate discharged to the power plant LRS (Liquid Release System) system;
Before the step 1),
A collection / separation step of collecting in situ to separate insoluble materials;
A washing step of removing radioactive material deposited on the PVA protective article;
PVA protective article dissolution / concentration step of dissolving and concentrating the PVA protective article after washing;
Concentrate discharge step of discharging the dissolved PVA solution from the solution concentration tank to the flocculation tank;
A concentrate primary filtration step of primaryly separating particulate matter present in the PVA concentrate transferred to the coagulation tank with a filter;
6) a flocculant addition / stirring step to remove the radioactive material present in the first filtered PVA solution; And
7) a secondary filler step of removing the floc formed by the flocculant; protective article treatment method made of polyvinyl alcohol comprising a .
delete The method of claim 1,
In the primary filtration step of the concentrate, the protective article for treating the protective article made of polyvinyl alcohol, wherein the PVA solution is oxidized by removing the large particles by a filter and allowing the organic material and the oxidant to be mixed well using a pump rotating at a high speed. .
The method of claim 1,
In the step 1), the method for treating protective articles made of polyvinyl alcohol, characterized in that to operate the pyrolysis oxidation reactor at 550 ~ 600 ℃ to oxidize the PVA solution.
The method of claim 1,
In the step 2), the method for treating protective articles made of polyvinyl alcohol, characterized in that the catalytic oxidation reactor is operated at 500 ~ 550 ℃ to oxidize the PVA solution.
The method of claim 4, wherein
In the step 1), the PVA solution is sprayed in an atomized state, and the sprayed PVA solution is a protective article processing method made of polyvinyl alcohol, characterized in that the heat oxidized by the heat storage medium and jacket heater.
The method of claim 5, wherein
In the step 2), a protective article treatment method made of polyvinyl alcohol, characterized in that to use a catalyst consisting of platinum (Pt), palladium (Pd) and alumina (Al ₂ O ₃ ).
A protective article processing apparatus made of polyvinyl alcohol for treating a radioactive substance attached to a PVA protective article by a dissolution concentration tank,
A waste liquid pyrolysis oxidation reactor for pyrolyzing and oxidizing organic substances in a filtrate treated with a dissolution concentrator at high temperature;
Catalytic oxidation reactor for treating organic matter present in untreated gas discharged from the gas treated in the pyrolysis / oxidation reactor;
A heat exchanger for recovering and cooling waste heat in the oxidized organic gas; And
And a condensate storage tank for collecting condensate generated in the heat exchanger.
In the pyrolysis oxidation reactor, the PVA solution is sprayed in the atomized state, and the sprayed PVA solution is heated and oxidized by the heat storage medium and the jacket heater,
Neutralizing the condensate stored in the condensate storage tank to meet the discharge water quality standards to filter the particulate matter in the final discharged condensate produced by polyvinyl alcohol characterized in that the discharge to the power plant LRS (Liquid Release System) system Protective equipment processing device.
The method of claim 8,
The coagulation tank is provided between the waste liquid pyrolysis oxidation reactor and the dissolution concentration tank to remove large particles with a filter and to allow the organic material and the oxidant to be mixed well by using a pump rotating at a high speed so as to oxidize the PVA solution. Protective article processing apparatus made of polyvinyl alcohol.
The method of claim 8,
The pyrolysis oxidation reactor is a protective article processing apparatus made of polyvinyl alcohol, characterized in that for operating at 550 ~ 600 ℃.
The method of claim 8,
The catalytic oxidation reactor is a protective article processing apparatus made of polyvinyl alcohol, characterized in that it is operated at 500 ~ 550 ℃.
delete The method of claim 8,
Protective equipment processing apparatus made of polyvinyl alcohol, characterized in that for supplying air heated by a heater to the pyrolysis oxidation reactor.
The method of claim 8,
The heat storage medium is a protective article processing apparatus made of polyvinyl alcohol, characterized in that made of a ceramic material.
The method of claim 11,
The catalytic oxidation reaction is a protective article processing apparatus made of polyvinyl alcohol, characterized in that to treat the PVA solution using a catalyst consisting of platinum (Pt), palladium (Pd) and alumina (Al ₂ O ₃ ).

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