JP2671068B2 - Equipment for reducing radioactively contaminated water resulting from decontamination of radioactive pollutants - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is used in a nuclear power plant or the like, to a reduction RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants.

[0002]

The inventor of the present invention previously invented a method for decontaminating radioactive contaminants with methylene chloride,
A patent application was filed (Japanese Patent Application No. 3-68862). Since the present invention relates to an improvement of the above-mentioned applied invention and is also used for decontamination of other radioactivity, the above-mentioned applied invention will be described first. The device of the present invention, as described above,
The present invention is not limited to the above disclosed invention, and it is needless to say that the present invention is also applicable to radioactive contaminated water generated by decontamination of radioactive pollutants in an apparatus using another water-based decontamination solution.

The disclosed invention discloses radioactive pollutants (generally, the above-mentioned pollutants generated in a nuclear power plant are various devices,
Equipment and the like, which are usually coated with epoxy resin in many cases. ) Is first dipped in a methylene chloride solution to swell the coating and the like, sprayed with a methylene chloride solution for cleaning, dissolved and peeled off, the methylene chloride solution used for this cleaning is filtered, and then distilled. The methylene chloride solution itself is decontaminated, and the decontaminated methylene chloride is used for washing the radioactive contaminants.

On the other hand, most of the radioactive contaminants washed with methylene chloride as described above are decontaminated by the washing. However, since this decontamination alone cannot completely decontaminate, the next step is to wash the washed contaminants with a chelate aqueous solution and by applying ultrasonic vibration.
In this way, the pollutant was almost completely decontaminated by being supplemented by both the organic solvent and the water-based decontamination solution, and after rinsing with fresh water, the radioactivity was measured with a Geiger counter. The radioactivity was 0 CPM.

[0005]

However, it has been found that the above invention still has the following problems. In the above invention, the radioactive contaminants are washed with the chelate aqueous solution as described above, and this aqueous solution is already contaminated by the radioactivity due to the above washing. A large amount of this contaminated water is generated and packed in drums or the like and stored in waste poles or the like, which requires a huge space.

In order to avoid the use of this huge space, the radioactive polluted water is treated with an ion exchange resin. Then, the radioactivity of the polluted water is transferred to the ion exchange resin, and the water is fresh water. However, instead of this, a large amount of ion-exchange resin contaminated by radioactivity is generated, and this is packed in a drum and stored in the waste trash, etc. Therefore, it is unavoidable that a huge space is required. Regarding such a situation, the radioactivity of the object is not limited to the case where the radioactive pollutant is washed with the chelate aqueous solution described above, but generally an aqueous decontamination solution such as water or a solution composed of water and other substances is used. In the case of decontamination, for example, in the case of electro-deletion dyeing, etc., it is an inevitable problem.

The above water-based decontamination solution can be decontaminated by distillation. However, in such a case, water has a large latent heat of vaporization and consumes a large amount of power, resulting in a huge expense. Further above
There are various chemical problems that are inevitably attached to the problem.
When using dyeing equipment, the parts used for each of those decontamination equipment
There is no cocking. Conventionally used rubber
The system packing is bombarded by the radiation emitted by radioactive contaminants.
It loses its properties and cannot be used. Also as mentioned above
As a pre-process of the water-based decontamination solution, usually an organic solvent-based decontamination reagent,
For decontamination using methylene chloride as an example,
Do not decontaminate the contaminants attached to the ethylene chloride.
And, methylene chloride is almost all packing
Can be decontaminated industrially, as it will dissolve
There is no. The present invention has been made to solve such a problem, and its purpose is industrial and practical.
The radioactive contaminated water produced by decontamination of radioactive pollutants used when decontaminating radioactive pollutants using water-based decontamination solutions such as water or a solution consisting of water and other substances. /> is to provide a down RyoSo location.

[0008]

The present invention, which achieves the above-mentioned object, will be described by using a radioactive decontaminant 1 and an aqueous decontamination solution 2 such as water or a solution consisting of water and other substances .
Perfluoroelastomer packing 5 for decontamination
Decontamination apparatus 13 using 3; provided in the subsequent stage of the decontamination apparatus 13
The pollutant 4 in the water-based decontamination liquid 2 thus obtained is added to the coagulant 3
Perfluoroelastomer packing, which is agglomerated using
A flocculating tank 16 and a flocculant supply device 15 using a ring 53?
A flocculating device 14 consisting of;
Using perfluoroelastomer packing 53
Filtration device 17; after the filtration device 17 and in the decontamination device
Made of perfluoroelastomer provided in the front stage of the device 13.
Supplying device for the water-based decontamination liquid 2 using packing 53
19; characterized in that it consists of a reduction RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants.

Further, the radioactive pollutant 1 is replaced with water or water and other substances.
Decontamination using an aqueous decontamination solution 2 such as a solution consisting of
-Decontamination equipment using fluoroelastomer packing 53
Place 13: The water system provided at the latter stage of the decontamination device 13
The contaminant 4 in the decontamination liquid 2 is aggregated using the aggregating agent 3.
Using a packing 53 made of perfluoroelastomer
Flocculating device 1 comprising flocculating tank 16 and flocculant supplying device 15
4; Perfluoroe provided in the latter stage of the aggregating device 14
Filtration Device 17 Using Lastomer Packing 53:
A filter of the filtration device 17, which is provided in the latter stage of the filtration device 17.
Purfluoroelast to purify fresh water 6 generated by filtration
Purification device 7 provided with a packing 53 made by Ma;
7 is provided after the decontamination device 13 and after the decontamination device 13.
In addition, perfluoroelast, which supplies the water-based decontamination liquid 2
Supply equipment 19 using mer made packing 53; and wherein <br/> to consist of a reduction RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants. In addition, the decontamination device 13 is supersonic
It has a wave vibration device 21 and is clean as the water-based decontamination liquid 2.
Wherein a decontamination tank 22 which accommodates the door liquid 10 is reduced RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants.
In addition, the decontamination device 13 is an electrolysis device, and the water-based decontamination liquid 2 is electrically charged.
It is a lysate . Wherein a reduction RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants.

[0010]

The present invention is configured as described above, and is an aqueous decontamination solution.
The pollutant 4 in 2 is treated with the coagulant 3 in the coagulation device 14.
It can be aggregated by using the filtration device 17.
By filtering, it is refined by the refinement device 7 which has also been filtered.
Water used for decontamination is used repeatedly by
Therefore, the amount of radioactive polluted water discharged to the outside can be greatly increased.
Can be reduced to Moreover, decontamination used for this
Device 13, coagulation device 14, filtration device 17, water-based decontamination liquid 2
Supply device 19 and a purification device 9 for further purifying fresh water,
Is a packing 53 made of perfluoroelastomer
Radiation emitted by the pollutant 4 by using
The degree of loss of elasticity due to
Contamination caused by being used in the previous step of using the water-based decontamination solution 2
The organic solvent adhering to the dyeing substance 4, for example, most of the
Soluble in methylene chloride
Never do. Therefore, the decontamination of the pollutant 4 is industrial
In fact, it can easily be done.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 is a radioactive contaminant, which is contained in a decontamination device 13. And this decontamination device 13
As an example, the decontamination tank 22 stores the chelate solution 10 as the water-based decontamination solution 2 and is vibrated by the ultrasonic vibration device 21. In addition, the chelate solution 10 has an inlet 2
5, it is circulated by the outlet 26.
Incidentally, 27 is a flow-down passage, and 28 is a valve. Next, 14 is a flocculating device, which comprises, for example, a flocculating agent supply device 15, a flocculating tank 16, and a stirring device 29. Two coagulant supply devices 15 are shown, one for supplying a polymer coagulant and the other for supplying an inorganic coagulant.
In the present invention, the coagulant also acts as an aggregating agent because it acts almost similarly to the aggregating agent. That is, in the present invention, the aggregating agent refers to all the agents which cause aggregation or coagulation of the pollutant 4 in the aqueous decontamination liquid 2.

The aggregate 5 is separated into a frog 30 and a sludge 31. Next, 17 is a filtering device, and the filtering material 32
And a filter tank 33. 34 is a PH meter, 35
Indicates a conductivity meter. 6 shows fresh water generated by filtration.
Further, 36 is a communication pipe, 37 is a pump, 19 is a supply device of the above-mentioned water-based decontamination solution, and comprises a tank 38, a pump 39, a decontamination agent supply device 40 and the like. The decontaminating agent supplying device 40 is a chelating agent supplying device as an example in this case. However, when the water-based decontamination solution 2 is an electrolytic solution, unlike this, it can be changed to an acid or alkali agent or salt supply device. Next, 7 is a refining device, 41 is a housing, 4
Reference numeral 2 denotes a stainless steel tubular casing having a hole, in which activated carbon 43 is accommodated, and a nylon splice or cotton splice 44 is wound around the outer periphery of the casing 42. 45 is a tank, 46 is an adsorption layer made of ion exchange resin, 47 is a second tank, 48
Indicates a pump. The operation of the above-described apparatus will be described. First, the radioactive contaminant 1 is removed from the decontamination tank 22.
After being decontaminated, the water-based decontamination liquid 2 is washed with the chelating liquid 10 and by using the ultrasonic vibration device 21.
Moved to 4. Then, first, pH adjustment is performed, alkali is added, and the liquid (addition device not shown) is made alkaline. You. Next, a liquid electrolyte as an aggregating agent, for example, aluminum sulfate is added from one aggregating agent supply device 15 and agitated by an agitation device 29, and during this agitation, a polymer aggregating agent from the other aggregating agent supply device 15, an example The polyacrylamide-based polymer flocculant was supplied as. Then, agglomeration and precipitation occur, and agglomerates 5 are produced. Same aggregate 5
Is separated into frog 30 and sludge 31. Next, the agglomerate 5 opens the valve 28, is supplied to the filter device 17 with the water-based decontamination liquid 2, is filtered by the filter medium 32, and is separated into the agglomerate 5 and the fresh water 6. Then, the fresh water 6 is inspected by a PH meter 34 and a conductivity meter 35 to determine the presence of Fe ions, and if it is within a predetermined range, a supply device 19 for supplying the water-based decontamination liquid 2 from a communication passage 36 by a pump 37. Then, as an example, the chelating agent is supplied from the decontaminating agent supply device 40 and is supplied to the decontaminating device 13 by the pump 39.

When the Fe ions in the fresh water 6 are more than a predetermined range, they are sent to the purifying device 7 in the next stage, adsorbed and purified by the activated carbon 43, and sent to the supplying device 19. When the water is finally taken out, it is passed through the ion exchange resin layer 46. Further, the above refining device 7
Is not limited to the one using activated carbon, and any kind of device can be used as long as it can be purified.

Next, FIG. 2 shows another embodiment of the present invention in which the decontamination device 13 is formed in substantially the same manner except that it is different. The decontamination device 13 in FIG. 2 is an electrolysis device. In the figure, 50 is an anode, 51 is a cathode,
1 is a radioactive pollutant made of metal. The water-based decontamination solution 2 is an electrolytic solution in this case, and an aqueous solution of sodium chloride was used as an example.

After the decontamination by electrolysis is performed in the decontamination apparatus 13 shown in the same figure, the electrolytic solution is repeatedly circulated through the steps substantially the same as the steps shown in FIG. The decontamination apparatus 13 is treated in the same manner thereafter, such as when high-pressure injection of external water for electrolysis and other washing with water or an aqueous solution of acid or alkali is performed, and the decontamination apparatus 13 is circulated as described above. It can be used repeatedly, and the discharge of polluted water to the outside can be greatly reduced.

Next, the conventional decontamination of the water-based decontamination liquid 2 itself also has the problems as described in the conventional example. That is, the packing between the container, the device, the pipe, etc., which contains the water-based decontamination solution 2 loses elasticity to the α rays, β rays, γ rays, etc. generated by the water decontamination solution 2 and the like. That is. Ordinarily, before the decontamination with the water-based decontamination liquid 2,
Decontamination is performed with a solvent. In that case, as an example
Use methylene chloride, which gives the best decontamination .
This methylene chloride turns into radioactive pollutants as described above.
It adheres and enters the water-based decontamination liquid 2. And methylene
Chloride dissolves most of the packing,
It makes the King useless. Therefore, the inventor of the present invention solves this problem by using a special packing that can solve the above problems and providing it between the above-mentioned containers, devices and piping. Regarding this special packing, it is a packing made of perfluoroelastomer, which is manufactured and sold by DuPont, USA and is called Kalrez under the trade name. By using the packing made of this perfluoroelastomer and also for the valve of a pump or the like, water or the water-based decontamination liquid 2 itself can be decontaminated, and methylene chloride can also be used, which is excellent. I was able to get the device. In FIGS. 1 and 2, 53
Indicates packing with the above-mentioned perfluoroelastomer, and is provided between the decontamination device 13, the coagulation device 14, the filtration device 17, the supply device 19 of the water-based decontamination liquid 2 and the pipe 54, etc., as shown in the figure. It is also provided between the electrolyzer and the pipe 54.

By forming the pipes in this way, the pipes 54 can be removed from various devices, and thus the insides of these devices and the pipes 54 can be easily decontaminated. And the above-mentioned perfluoroelastomer, against the α rays, β rays, γ rays generated by water or the water-based decontamination liquid 2,
The loss of elasticity is much less than that of general rubber, and it does not cause any problems after being used for a long time in practical use. Moreover, it is practically unaffected by the methylene chloride and the like.

[0018]

The present invention is configured as described above, and the contaminant 4 in the water-based decontamination liquid 2 can be aggregated in the aggregating device 14 by using the aggregating agent 3, and the agitation device 1
The water used for decontamination can be used repeatedly by purifying the purified water by filtering with 7 and the purified fresh water with the refining device 7. Therefore, the radioactive polluted water discharged to the outside can be greatly reduced. Can be made. Then up to now
All packings present are radiation emitted by pollutants
Elasticity disappears due to the line, and in fact, normal decontamination equipment
Oki could not operate continuously. This
In the device of the invention, the decontamination device 13 and the aggregating device 1
4, each of the filtration device 17 and the supply device 19 of the water-based decontamination liquid
By using perfluoro elastomeric packing 53 Les practical difference for the first time the elastic loss by radiation
It can be put in a range that does not support,
It was possible to make continuous operation possible. Also, the atom
Various equipment at power plants are generally coated with epoxy resin.
In this case, the maximum
Methylene chloride, which has excellent decontamination effect, is currently available
This has melted all existing packing, which is why
Unable to use methylene chloride for decontamination
It is a thing. For the first time in this invention, each device
By using a loro-elastomer packing,
As a step after decontamination using Tiren chloride, water
When decontamination is performed with a system decontamination solution, it is attached to contaminants
It can withstand the methylene chloride that is used and can operate continuously.
You can.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention and schematically showing a device for reducing contaminated water generated by decontamination of radioactive contaminants.

FIG. 2 is a diagram showing another embodiment of the present invention and corresponding to FIG. 1;

[Explanation of symbols]

 1 Radioactive Pollutants 2 Aqueous Decontamination Solution 3 Flocculant 5 Flocculant 6 Clean Water 7 Purification Device 8 Purified Water 13 Decontamination Device 14 Flocculation Device 15 Flocculant Supply Device 19 Aqueous Decontamination Solution Supply Device

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-1-193700 (JP, A) JP-A-62-266499 (JP, A) JP-A-62-121593 (JP, A) JP-A 64-- 16852 (JP, A)

Claims (4)

(57) [Claims] The method according to claim 1 radioactive contaminants 1, decontaminated using an aqueous decontamination solution 2 solution such as a solution consisting of water or water with other substances, Pas
-Decontamination equipment using fluoroelastomer packing 53
Place 13: The water system provided at the latter stage of the decontamination device 13
The contaminant 4 in the decontamination liquid 2 is aggregated using the aggregating agent 3.
Using a packing 53 made of perfluoroelastomer
Flocculating device 1 comprising flocculating tank 16 and flocculant supplying device 15
4; Perfluoroe provided in the latter stage of the aggregating device 14
Filtration device 17 using a packing 53 made by Rustomer;
Behind the filtration device 17 and before the decontamination device 13
Perfluoroelastomer packing 53 provided
The aqueous decontamination liquid 2 supply device 19 with; and wherein the this <br/> consisting reduced RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants. 2. A radioactive decontaminant 1 is decontaminated with an aqueous decontamination solution 2 such as water or a solution consisting of water and another substance ,
-Decontamination equipment using fluoroelastomer packing 53
Place 13: The water system provided at the latter stage of the decontamination device 13
The contaminant 4 in the decontamination liquid 2 is aggregated using the aggregating agent 3.
Using a packing 53 made of perfluoroelastomer
Flocculating device 1 comprising flocculating tank 16 and flocculant supplying device 15
4; Perfluoroella provided at the latter stage of the aggregating device 14
Filtration device 17 using Stormer packing 53;
Filtration of the filtration device 17 provided at the latter stage of the filtration device 17.
Purifying the fresh water 6 produced by
-Refining device 7 using packing 53 made by Mfg .;
Provided in the latter stage and in the former stage of the decontamination device 13,
Perfluoroelastomer for supplying the water-based decontamination liquid 2
Supply unit 19 using a manufacturing packing 53; characterized in that it consists, reduced RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants. 3. The decontamination device 13 has an ultrasonic vibration device 21.
And containing the chelate 10 as the water-based decontamination liquid 2.
According to claim 1 or 2, wherein the dyeing tank 22, reducing RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants. 4. The decontamination device 13 is an electrolysis device, and is a water-based decontamination device.
Liquor 2 Ru electrolyte der. According to claim 1, reduction RyoSo location of radioactive contaminated water caused by decontamination of radioactive contaminants.