JP2539716B2 - Decontamination method and equipment for decontamination of radioactive pollutants using methylene chloride. - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for decontaminating radioactive pollutants using methylene chloride, which is used for decontaminating radioactive pollutants in nuclear power plants and the like.

[0002]

2. Description of the Related Art A number of prior arts have been found in the past regarding methods for decontaminating radioactive pollutants. An example thereof is the invention described in JP-B-59-36240. This invention stores fluorocarbons, perchlorethylene, etc. in a container, heats them, and vibrates them using an ultrasonic vibration device, puts the contaminants in these solutions for decontamination Of. However, the above conventional method has the following drawbacks. First, the fluorohydrocarbon and perchlorethylene both have low radioactivity decontamination ability. This low decontamination ability is extremely low, as will be apparent from the results of experiments for comparison with the present invention described later.

Next, the fluorohydrocarbon and perchlorethylene both cause pollution. As is well known about the pollution caused by fluorohydrocarbons, it destroys the ozone layer surrounding the earth and forms ozone holes, so that the absorption of solar ultraviolet rays by ozone is extinguished, thereby increasing the number of cancer patients worldwide. Has been requested to be prohibited from
The Montreal Protocol by member states of the United Nations has banned manufacturing and use by the end of the century. Also, perchlorethylene has a carcinogenic property, and when it is released into the air, it causes poisoning by contact with skin and ingestion from the mouth and causes pollution. The permissible concentration of perchlorethylene in the air is 100 ppm. Perchlorethylene is banned from being manufactured and used in the United States in 1996.

Next, the above-mentioned perchlorethylene decontaminates perchlorethylene itself, which is a decontaminating agent, in the decontamination process of radioactive pollutants, that is, decontamination of perchlorethylene itself by distillation. In this decontamination, the high boiling point (boiling point 121.2 C) consumes a large amount of power and inefficiency is inevitable. In addition, the above-mentioned perchlorethylene is added with an appropriate organic substance as a stabilizer, but as described above, the amount of the stabilizer becomes small at the time of decontamination of perchlorethylene itself, and if it is used as it is, it damages the metal. It has some drawbacks. Further, the above-mentioned perchlorethylene is generally inferior in stability to electromagnetic waves. Perchlorethylene is oxidized by ultraviolet rays and converted to trichloroacetyl chloride. Moreover, even if it is exposed to sunlight for a long time, it is hydrolyzed and converted into trichloroacetic acid and hydrochloric acid. Therefore, α rays and β emitted from radioactive pollutants
There is a risk of being changed by rays, γ rays, etc.

The present invention has been made to solve the above-mentioned various problems, and its purpose is to have a far higher radioactivity decontamination capacity than that of the prior art decontamination methods, resulting in remarkable pollution. In addition, even in the case of decontaminating the decontaminating agent itself in the middle of the decontamination process, the power consumption is much smaller than that of the above-mentioned prior art, and therefore the efficiency is good and there is an obstacle to decontamination of the decontaminating agent itself. It is to provide a decontamination method and a decontamination apparatus for radioactive pollutants that use a decontaminating agent that is relatively stable and decontaminating against radiation generated from radioactive contaminants.

Next, as another problem, there is a method by electrolysis as a conventional method for decontaminating radioactive contaminants. However, as described above, the contaminants are usually coated with an epoxy resin, and the coating layer becomes a resistance during electrolysis, and good electrolysis cannot be performed. In the past, no method has been found for removing the coating layer sufficiently and effectively. Therefore, when the coating layer was removed, it could not be completely removed, and the remaining portion of the coating layer could not be electrolyzed. Therefore, the decontamination method by electrolysis could not exert a sufficient effect. Further, as another problem, there is a case where the uppermost layer of the above-mentioned contaminant coating layer has a special coating layer which does not dissolve in an ordinary solvent, and in such a case, decontamination cannot be performed using the solvent. .

The present invention has been made to solve the above-mentioned various problems, and an object thereof is to provide an electrolytic method and apparatus capable of decontaminating more effectively than before. Another object of the present invention is to provide a decontamination method and apparatus capable of decontaminating the above-mentioned contaminants in which the uppermost layer of the coat layer is not dissolved by an ordinary solvent.

[0008]

The present invention, which achieves the above-mentioned object, is described as follows. Various devices for radioactive decontamination are connected by a connecting pipe using perfluoroelastomer as packing 15. A method for decontaminating radioactive contaminants using methylene chloride, which comprises decontaminating radioactive contaminants 4 with methylene chloride 1 using a dyeing device.

Further, a decontamination device in which various devices for decontamination of radioactivity are connected by a connecting pipe using a perfluoroelastomer as a packing 15 is used, and the abrasive 2 and the methylene chloride 1 are attached to the radioactive contaminant 4. This is a method for decontaminating radioactive contaminants by the above-mentioned methylene chloride, which is simultaneously decontaminated. Further, the radioactive contaminant 4 is decontaminated by causing the abrasive material 2 to act thereon, and the decontaminated radioactive contaminant 4 is connected by a connecting pipe using a perfluoroelastomer as packing 15 between various decontamination devices. A method for decontaminating radioactive contaminants using the above-mentioned methylene chloride, wherein the decontamination apparatus described above is used to further effect decontamination by causing methylene chloride 1 to act.

A decontamination device in which various devices for decontamination of radioactivity are connected by a connecting pipe using perfluoroelastomer as a packing 15 is used to decontaminate radioactive contaminants 4 with methylene chloride 1. The decontaminated radioactive contaminant 4 is further placed in an electrolytic cell 6 containing an electrolytic solution 5,
A method for decontaminating radioactive contaminants using the above-mentioned methylene chloride that is electrolyzed for decontamination as one electrode 7. or,
The radioactive contaminant 4 is made to act on the abrasive material 2 to decontaminate the contaminant 4, and the decontaminated contaminant 4 is packed with a perfluoroelastomer as packing 15 between various devices for decontaminating radioactivity. A methylene chloride which is decontaminated by using a decontamination device connected by a connecting pipe and is decontaminated by using methylene chloride 1 and the decontaminated radioactive contaminant 4 is electrolyzed as one electrode 7 in an electrolytic cell 6. Is a method for decontaminating radioactive pollutants.

The action of the abrasive 2 on the radioactive contaminant 4 is a method of decontaminating the radioactive contaminant using the methylene chloride 1 which is carried out simultaneously with the methylene chloride 1. Further, the methylene chloride 1 acting on the radioactive contaminant 4 is removed by the separators 14 and 14a from the radioactive contaminant 4, and the decontamination apparatus 2 is used.
6 and 26a, the methylene chloride 1 itself is decontaminated, and the decontaminated methylene chloride 1 is a method for decontaminating radioactive contaminants using the methylene chloride. The radioactive contaminant 4 is decontaminated with methylene chloride and then decontaminated with a chelate solution.

Further, the radioactive contaminants 9 are attached to the nozzles 11, 11
Decontamination chamber 9 for injecting methylene chloride by a: separator 1 connected to the decontamination chamber 9 for separating contaminants
4, 14a: connected to the separators 14 and 14a,
Decontamination device 26, 26 for distilling methylene chloride
a: the decontamination device 26, 26a, the tank 39, the pump 1
Nozzles 11, 11 of the decontamination chamber 9 connected via 2
a: A connecting pipe for connecting the respective decontamination devices: a methylene chloride characterized by comprising a perfluoroelastomer packing 15: provided between the connecting pipe and the respective decontamination devices. This is a decontamination device for radioactive contaminants.

A decontamination device for radioactive contaminants using the above methylene chloride is combined with a polishing device 45 for decontaminating by polishing radioactive contaminants. Also, the nozzle 11
Is a decontamination device for radioactive contaminants using the methylene chloride, which is connected to a hopper 13 for supplying the abrasive 2. Further, the decontamination device for radioactive contaminants using the methylene chloride is combined with an electrolytic bath 6 for electrolyzing and decontaminating radioactive contaminants. Further, the decontamination chamber 9 has a decontamination device using a chelate solution that decontaminates the radioactive contaminants decontaminated in the decontamination chamber 9 in correspondence with the decontamination chamber 9. Decontamination equipment.

[0014]

The present invention uses the decontamination apparatus constructed as described above, in which various apparatuses for decontamination of radioactivity are connected by the connecting pipe using perfluoroelastomer as the packing 15, and radioactive contaminants 4 By applying methylene chloride 1 to the above, almost all packings were dissolved by methylene chloride in the past and the problem that could not be actually used was solved. Outstanding results enable decontamination.

Moreover, the elasticity of the perfluoroelastomer used as the packing 15 is extremely reduced by the radiation emitted from the radioactive contaminants. Further, the methylene chloride does not cause significant pollution as in the decontamination method using fluorohydrocarbon and perchlorethylene. Also, since perchlorethylene is extremely unlikely to deteriorate due to ultraviolet rays, sunlight, etc.,
It can be expected that the radiation caused by the contaminants is less likely to be deteriorated.

Further, using the above apparatus, methylene chloride 1
Those which actuate the abrasive before or simultaneously with the action of 1) can further enhance the decontamination ability of methylene chloride 1. Further, when decontaminating with methylene chloride using the above-mentioned apparatus, and then further decontaminating by electrolysis, the surface of the metal, which is sufficiently exposed by methylene chloride, is electrolyzed and can be effectively decontaminated. .

Further, in the above-mentioned apparatus, decontamination with methylene chloride 1 and distillation and reuse of this methylene chloride 1 can reduce the amount of methylene chloride 1 to be used by adding an injection method in air. .
In addition, decontamination with methylene chloride using the above equipment and decontamination with a chelate solution afterwards can be decontamination with different properties, decontamination with an organic solvent and desorption by encapsulation of ions, and both are complementary. It can be decontaminated sufficiently by fitting.

[0018]

EXAMPLES In FIG. 1, 1 is methylene chloride and 2 is an abrasive. The abrasive 2 is a grit of shot blast or a sand of sand blast or an abrasive of a barrel polisher. Reference numeral 3 denotes a decontamination liquid formed by the above-mentioned items 1 and 2. 4 is a radioactive pollutant, and the pollutant 4 is not limited to any kind, but as an example, there is a deposit on the outer surface of a metal, and the deposit has a coating layer made of an epoxy resin as an example. Alternatively, although not shown, a coating layer which is insoluble in an ordinary solvent may be provided on the uppermost layer of the coating layer.

Reference numeral 5 denotes an electrolytic solution contained in an electrolytic bath 6,
An aqueous solution of sodium chloride was used as an example. Reference numeral 7 represents an electrode. Next, 9 is a housing, and 10 is a turntable on which the radioactive contaminant 4 is placed. Reference numeral 11 denotes a nozzle, which is capable of rotating in an arc shape in the direction of arrow 11, and the abrasive material 2 in the hopper 13 is mixed in the nozzle 11 by the operation of the pump 12 by an ejector type. The decontamination liquid 3 is formed and ejected to impact the contaminant 4.
Although not shown, the contaminant 4 may be immersed in the methylene chloride 1 in advance before the impact. By soaking (for example, about 20 minutes), the layer of the epoxy resin swells like a jellyfish and is easily peeled off. Therefore, when it is swollen and then impacted as described above, it peels off very easily. However, it does not matter if it is not swollen.

Next, 14 is a separator, which is provided so as to communicate with the bottom of the housing 9. Reference numeral 15 is a packing, which is an elastic body that does not dissolve in methylene chloride, is a perfluoroelastomer, manufactured and sold by DuPont, USA, and is called a trade name Kalrez.
The elasticity of the packing 15 is very little reduced by radiation. It was the first time that the methylene chloride 1 could be used for the above decontamination by finding the packing 15 having these two properties.

It was impossible to decontaminate with methylene chloride until the inventor of the present invention found the backing 15 made of perfluoroelastomer. The reason is that the above methylene chloride could not be formed into a device because almost all the usual packings were dissolved. Next, inside the separator 14, the grit layer 1
6, a methylene chloride layer 17, a water layer 18 (by water vapor in the air, etc.) and a paint layer 19. The water layer 18 and the paint layer 19 are separated from the first separation port 20 and filtered by a filter device 21, It is dried by the vacuum drying device 22, the glass is sealed by the glass sealing device 23, and the storage facility 24
Be stored in.

The filtered water is made clean by the ion exchange resin 25. Next, the methylene chloride layer 17 is sent to a decontamination device 26 for decontaminating the methylene chloride itself. The decontamination device 26 is a distillation device, 27 is a casing, 28 is a heater, 29 is a gas liquefaction device, 30 is a cooling water inlet, and 31 is an outlet. Next, 32 is a second filtering device. The grit filtered by the second filtering device 32 is dried by the drying device 33, transferred to the second hopper 34, and pumped to the hopper 13 by the pump 35. .

Next, 37 is a second tank, 38 is a pump, 3
9 shows a tank. Further, 40 is a device for recovering gaseous methylene chloride 1 using activated carbon. 41 indicates a fan.
Further, 4 is the radioactive contaminant decontaminated by the decontamination solution 3. To describe the method of this embodiment, first, as the radioactive contaminant 4, for example, an iron member having a count value of 2000 CPM (count per minute) of a Geiger counter was used. This member was bombarded with the decontamination liquid 3 of methylene chloride containing the abrasive 2 from the nozzle 11, and the decontamination reduced the pressure to 30 CPM. In this case, when the solvent used in the above-mentioned prior art and other solvents were tested by the same method, the respective results were obtained as shown in Table 1.

Next, using the above methylene chloride,
Decontamination of high levels of radioactive contaminants has taken place. Two kinds of the same pollutant were used, and the count number of each was 100,000 CPM and 45,000 CPM, for example. Then, when each of the above contaminants was bombarded with the decontamination liquid 3 formed by the methylene chloride 1 to which the abrasive 2 was added, the numerical values shown in the following Table 2 were obtained.

[Table 1]

[Table 2]

Then, the decontamination liquid 3 used for decontamination as described above is transferred from the housing 9 to the separator 14 and separated into layers in the separator 14 by gravity, and then from the second separation port 36 to methylene chloride itself. Is transferred to a decontamination device 26 for decontamination of the gas, heated by a reheater 28, gasified, and liquefied by a liquefaction device 29 to be decontaminated to become OCPM. In this case, the boiling point of methylene chloride is 40,4 ° C, which is extremely low, and therefore the power consumption used for the decontamination can be extremely reduced.
The decontaminated methylene chloride 1 was pumped by the pump 38.
Is sent to the tank 1 by
After that, the abrasive 2 is mixed and jetted, and then repeatedly used.

Next, the water layer 18 and the paint layer 19 taken out from the first separation port 20 are filtered by a filtering device 21, dried, sealed in glass, and stored in a storage facility 24. On the other hand, water or the like is made clean by the ion exchange resin 25. Also, the grit layer 16 discharged from the separator 14
Is filtered by the second filtering device 32, dried, and sent from the second hopper 34 to the hopper 13 for repeated use. The methylene chloride 1 separated in the second filtration device 32 is sent to the decontamination device 26. Next, the radioactive contaminant 4 decontaminated as described above is housed in an electrolytic bath 6 having an electrolytic solution 5, and is connected to an electrode 7 to be electrolyzed. In this case, the contaminant 4 is 10 shown in Table 2 above.
What was decontaminated from 0000 CPM to 1300 CPM was used. Then, after the electrolysis, the surface was rinsed with fresh water, dried, and measured to find 0 CPM.

In addition, as shown in Table 1 above, when the number after decontamination with methylene chloride is reduced to about 30 CPM, a chelate solution in which a chelating agent is dissolved is used without electrolysis, although illustration is omitted. Decontaminate by applying ultrasonic vibration. However, electrolysis may be performed after decontamination with the chelating agent.

In the above method, the apparatus is of a circulation type, but in addition to this, as shown in FIG. 2, a barrel type polishing machine 45 may be used for a batch type. In this method, first, as a first-stage decontamination method, decontamination is performed using a barrel polishing machine 45, and the decontaminating contaminants 4 and the polishing material 2 are separated by a sorting device 46 such as a screen, and the decontamination is performed. The contaminant 4 is placed on the rotary table 10 in the injection housing 9, and the methylene chloride 1 is injected from the nozzle 11a by the pump 12. In this case, prior to this injection, the decontaminated contaminant 4 may be previously immersed in the liquid of methylene chloride 1 as described above to swell the residual paint after decontamination.

The steps after the above injection are almost the same as the method shown in FIG. However, in the apparatus shown in FIG. 1, the grit layer 16 was separated by the separator 14,
In the method shown in FIG. 2, the sorting device 46 is used as described above.
That point is different because it has already been separated in.
Then, the abrasive material 2 sorted by the sorting device 46 is directly supplied to the barrel abrasive material 45 and reused. It should be noted that this abrasive 2 is used several times and the cleaning device 47 shown in FIG.
Thus, methylene chloride 1 is sprayed for cleaning.
Reference numeral 48 is a cylindrical wire mesh container which rotates in the direction of arrow A48 and sprays methylene chloride 1 onto the abrasive 2 from a pipe inside the container to clean it.

The cleaned abrasive 2 is supplied to the barrel polisher 45 as described above. On the other hand, the methylene chloride 1 containing the paint or the like generated by the washing is separated in the second separating device 50 as shown in the drawing, the methylene chloride 1 is in the decontaminating device 26a, and the coating layer 19a is in the separating device 21.
And then processed in the same manner as the process shown in FIG.
In the method of the present invention, as shown in Table 1 above, methylene chloride is far superior in decontamination to the above-mentioned conventional fluorocarbons, perchlorethylene, and other chlorine-based solvents. It is clear that it has an effect.

The toxicity of methylene chloride is the lowest in the chlorine-based solvent, and the permissible concentration in the air is 500 ppm, which is five times that of the perchlorethylene. Further, methylene chloride has a boiling point of 40.4 ° C., which is extremely low, and therefore requires very little power consumption when decontaminating the solvent itself by distillation. Further, methylene chloride has the most stable molecular structure in a chlorine-based solvent, and therefore, there is no fear of alteration of perchlorethylene due to heating and cooling during distillation. Further, since there is no risk of deterioration such as perchlorethylene caused by ultraviolet rays, sun rays, etc., it can be expected that there is no fear of deterioration due to radiation emitted by contaminants. Also, the electro-deletion dyeing can be sufficiently performed because the coating layer is completely removed.

[0032]

Industrial Applicability The present invention is constructed as described above and uses various decontamination devices for decontamination of radioactivity, which are connected by a connecting pipe using perfluoroelastomer as the packing 15 for radioactive contamination. Methylene chloride 1 to product 4
By the action of the above, almost all the packings were dissolved by methylene chloride in the past, and the problem that could not be actually used was solved, and as shown in Table 1 in the appendix, excellent results were obtained in comparison with other solvents. Can be decontaminated. Moreover, the elasticity of the perfluoroelastomer used as the packing 15 is extremely reduced by the radiation emitted from the radioactive contaminants.
Further, the methylene chloride does not cause significant pollution as in the decontamination method using fluorohydrocarbon and perchlorethylene. Further, methylene chloride is extremely unlikely to be deteriorated by ultraviolet rays, sun rays, etc., so that it can be expected that there is little fear of deterioration of the radiation caused by the contaminants. In addition, the one in which the abrasive is made to act before or at the same time as the action of methylene chloride by using the above device can further enhance the decontamination ability of methylene chloride. Decontamination with methylene chloride using the above equipment,
When decontamination is further performed by electrolysis after that, the surface of the metal, which is sufficiently exposed by methylene chloride, is electrolyzed, and decontamination can be effectively performed. Further, in the above-mentioned apparatus, decontamination with methylene chloride, distillation of this methylene chloride and reuse thereof can reduce the amount of methylene chloride used by adding an injection method in air. In addition, decontamination with methylene chloride using the above equipment and decontamination with a chelate solution afterwards can be decontamination with different properties, decontamination with an organic solvent and desorption by encapsulation of ions, and both are complementary. It can be decontaminated sufficiently by fitting.

[Brief description of drawings]

FIG. 1 is a view showing an example of the present invention and schematically showing an apparatus used in a method for decontaminating radioactive contaminants with methylene chloride.

FIG. 2 shows a second embodiment of the present invention and corresponds to FIG.

[Explanation of symbols]

 1 Methylene chloride 2 Abrasive 4 Radioactive contaminant 5 Electrolyte 6 Electrolyzer 7 Electrode 9 Decontamination chamber 11, 11a Nozzle 12 Pump 13 Hopper 14, 14a Separator 15 Packing 26, 26a Decontamination device 39 Tank 45 Polishing device

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-2-22596 (JP, A) JP-A-60-208500 (JP, A) Industrial materials, 31-5! , P. 31-34 (1983) Adhesion, 26-12! , P. 545-548 (1982)

Claims (13)

(57) [Claims] 1. A packing is provided between various devices for decontamination of radioactivity.
Connecting pipe using perfluoroelastomer as ring 15
Using the decontamination equipment connected by
A method for decontaminating radioactive pollutants using methylene chloride, characterized in that decontamination is carried out by acting on ethylene chloride 1 . 2. A packing is provided between various devices for decontaminating radioactivity.
By using a perfluoroelastomer as the coupling,
The ligated decontamination apparatus using Ri, abrasive radioactive contaminants 4
A method for decontaminating radioactive contaminants using methylene chloride, characterized in that decontamination is carried out by simultaneously acting 2 and methylene chloride 1. 3. An abrasive 2 is applied to a radioactive contaminant 4.
Various equipment for decontamination and decontamination of radioactive contaminants 4
The packing 15 is the space between the
Using a decontamination device connected by a connecting pipe,
A method for decontaminating radioactive contaminants using methylene chloride , characterized in that decontamination is effected by the action of chloride 1 . 4. A packing is provided between various devices for decontamination of radioactivity.
Connecting pipe using perfluoroelastomer as ring 15
Using a decontamination device connected by
1 to decontaminate the radioactive contaminants 4, and the decontaminated radioactive contaminants 4 are further treated in an electrolytic cell 6 containing an electrolytic solution 5
A method for decontaminating radioactive contaminants using methylene chloride, characterized in that the other electrode 7 is electrolyzed for decontamination. 5. An abrasive 2 is caused to act on a radioactive contaminant 4,
The contaminant 4 is decontaminated, and the decontaminated contaminant 4 is released.
A packing 15 is used as a space between various devices for radiation decontamination.
-Connected with a connecting pipe using fluoroelastomer
Use a decontamination device and decontaminate with methylene chloride 1.
The radioactive contaminant 4 that has been dyed and decontaminated is placed in an electrolytic bath 6.
And a method for decontaminating radioactive contaminants using methylene chloride , characterized in that one electrode 7 is electrolyzed . 6. The action of abrasive 2 on radioactive contaminants 4 .
Claims which is carried out simultaneously with methylenechloride Rye de 1 5, wherein
Decontamination method of radioactive contaminants using methylene chloride 1. 7. A methylene chloride that has acted on the radioactive pollutant 4.
Loride 1 is the above contaminant due to the separators 14 and 14a.
Decontamination device 2 which removes the exfoliation thing exfoliated from 4
6, 26a, the methylene chloride 1 itself is
After decontamination, the decontaminated methylene chloride 1 is released as described above.
Claims 1, 2, 3, 4 or 5 which act on emissive contaminants 4.
Is a radioactive pollutant using methylene chloride described in 5.
Decontamination method . 8. The radioactive contaminant 4 is methylene chloride 1.
After being decontaminated by the
Release using methylene chloride according to claim 1, 2 or 3
Decontamination method for radioactive contaminants. 9. The radioactive contaminant 4 has nozzles 11 and 11a.
Decontamination chamber 9 for spraying methylene chloride by:
Separator 1 for separating contaminants, which is connected to the dyeing chamber 9
4, 14a: connected to the separators 14 and 14a,
Decontamination device 26, 26 for distilling methylene chloride 1
a: the decontamination device 26, 26a, the tank 39, the pump 1
Nozzles 11, 11 of the decontamination chamber 9 connected via 2
a: a connecting pipe for connecting the respective decontamination devices: with the connecting pipe
Perfluoroelastomer provided between the above decontamination devices
Characterized by consisting of Tomer packing 15:
Decontamination equipment for radioactive contaminants using methylene chloride. 10. A method for decontaminating a radioactive contaminant 4 by polishing it.
10. A methylene according to claim 9, in which a polishing device 45 is associated.
Dividing SomeSo location of radioactive contaminants using chloride. 11. The nozzle 11 is a hook for supplying the abrasive 2.
The methylene chlora according to claim 9, which is connected to the par 13
Equipment for decontamination of radioactive contaminants using ids. 12. Electrolysis for decontaminating a radioactive contaminant by electrolysis.
12. Tanks 6 are combined, claims 9, 10 or 11.
Decontamination equipment for radioactive pollutants using on-board methylene chloride
Place. 13. The decontamination chamber 9 corresponds to the decontamination chamber 9.
Cleaner for decontaminating radioactive contaminants decontaminated in the decontamination chamber 9.
10. A decontamination device using a solution 0 or 1
Removal of radioactive pollutants using methylene chloride described in 1.
Dyeing equipment.