TW201810291A - A method of decontamination operation for a high-activity nuclear waste polluted storage hole - Google Patents

Abstract

A method of follow-up decontamination operation for the polluted storage hole of a high-activity nuclear waste storage facility, using needle and steel brushes driven by pneumatic tools for brushing the bottom and the inner wall of the storage hole to remove contaminants, and a multi-level filter system for removing pollutants in the storage hole and for air pollution filtration, and a cover suitable for use with the pneumatic tools and the multi-level filtration system to cover the storage hole, thus effectively block the exposure of contaminants of the storage hole to the external environment, achieving effective decontamination of radioactive waste and reducing spreading to the environment.

Description

High activity pollution hole decontamination method

The invention relates to a method for decontamination in a high-activity polluted hole, in particular to a method for decontaminating a contaminated hole which is simple in operation, low in cost, good in decontamination effect and can effectively prevent secondary diffusion of pollutants.

Since the use of a waste nuclear facility with a high activity substance is removed from the storage hole, there is still a high activity of the radioactive material remaining. During the decommissioning of the subsequent nuclear facility, the high activity pollution in the storage hole will be the operation. Personnel cause a hazard of excessive doses. Therefore, in order to comply with the ALARA principle and consider reducing the exposure of personnel to the environment, decontamination operations in high-activity pollution storage holes must be carried out before decommissioning operations to reduce the radiation intensity of the working environment and avoid air-floating pollution, thereby minimizing the dose received by the personnel and the body. Contamination; in general, the decontamination in the storage hole must remove the fixing contaminants in the hole wall, the bottle neck and the bottom to reduce the radiation intensity in the storage hole, and then collect most of the pollutants and reduce the radioactive contamination. Volume to reduce secondary waste.

At present, the dry sand blasting and decontamination method commonly used in the market uses dry ice as a sand material for sandblasting collision, so that the pollutants fall to achieve the decontamination effect, and after the blasting is completed, the dry ice rapidly evaporates into a gas, leaving only the pollutants to be easily removed. Therefore, the secondary waste pollution can be effectively reduced. However, the dry ice blasting technology has many limitations. For example, the sand made of dry ice has insufficient hardness, and if it is applied to steel decontamination, the effect is poor, and the dry ice blasting equipment is expensive and bulky. Dry ice sand material is not easy to store, it is difficult to seal when sandblasting operation, and air float pollution control tube is not easy to handle; especially The problem of air-floating pollution is the key point of control. If high-pressure air used in sandblasting operations is used in storage holes, it will inevitably spread the airborne pollutants.

Therefore, how to reduce the radiation dose of workers who may be infected and reduce the generation of secondary waste and avoid air pollution is a problem faced by the current operation of handling high-pollution holes.

In view of the above-mentioned drawbacks of the conventional method for decontaminating contaminated pores, the inventors have studied the improvement of these disadvantages, and finally the present invention has been produced.

The main object of the present invention is to provide a high activity polluted hole decontamination method, which uses a pneumatic tool to drive a steel brush and a needle brush to remove contaminants, because the air pressure used in the pneumatic tool is lower than that of dry ice blasting. And the operation time is short, and the cover is covered to maintain airtightness, the radioactive pollutants can be concentrated in the closed storage hole to avoid air floating pollution in the working environment, and the storage hole is hollowed out by using a multi-level filtration system. The floating pollution filtration treatment can effectively reduce the possible air-floating pollution, so the overall effect of air-floating pollution diffusion is less significant, and it is easier to deal with radioactive pollution protection. The efficiency of collecting radioactive pollutants is higher than that of dry ice blasting. Effectively prevent secondary spread of radioactive pollution.

Another object of the present invention is to provide a high activity polluted hole decontamination method, which has high brushing efficiency due to pneumatic tools (grinding machines), especially using steel brushes and needle brushes for metal corrosion and solidification. The pollution removal effect is remarkable. Moreover, the steel brush and the needle brush have a more uniform distribution than the dry ice blasting, which can produce a more significant decontamination effect; in addition, compared with the general power tool The weight of the pneumatic tool is lighter, which can improve the convenience of manual operation, and it is not easy to generate the problem of excessive running temperature when used, and the pneumatic tool can be used. The semi-automatic operation is carried out with the lifting control mechanism to reduce the operation time of the personnel in the operation, so as to effectively reduce the radiation dose received by the personnel.

Another object of the present invention is to provide a method for decontaminating a high-activity polluted hole, wherein the pneumatic tool used is also simply modified for the mass-produced product that has been developed, and the unit price is of course lower than that of the dedicated system, and the related consumables are cheaper. It is also easy to obtain, so the cost of continuous decontamination is relatively low. Compared with the dry ice blasting system, it is necessary to purchase high-priced machines, and the dry ice consumables are also relatively expensive. The invention has the effect of significantly reducing the development and use cost.

In order to achieve the above object and effect, the technical means adopted by the present invention include: a step of "building a cover plate to replace the original sealing cover on the storage hole", and providing a cover plate on the cover plate a tool jack and a suction tube jack are penetrated, and the original sealing cover on the preset storage hole is replaced by the cover; a "radiation intensity recording before decontamination" step is used before decontamination The radiation instrument detects the radiation intensity in the storage hole and records it; a "Building a multi-level filtration system" step is to set up a multi-level filtration system having a suction tube for introducing pollutants. And at least one pre-filter tank for filtering pollutants; a "first removal of air pollution" step, the suction tube of the multi-level filtration system is inserted into the storage hole through the suction tube jack of the cover plate The middle part, and the multi-level filtration system is turned on for the air pollution removal operation, and most of the pollutants in the air are concentrated in the pre-filter tank; a step of "cleaning the bottom of the storage hole" step is Pneumatic needle brush tool Set at the front end of a preset extension rod and extend into the bottom of the storage hole through the tool socket of the cover plate to remove the contaminants at the bottom of the storage hole; a step of "absorbing the bottom contaminant" is to multi-level The suction pipe of the filter system is connected with an extension pipe of sufficient length to extend into the bottom of the storage hole through the suction tube insertion hole of the cover plate to absorb the pollutants removed by the pneumatic needle brush tool; Steps to remove air pollution, with multiple levels The suction pipe of the filter system extends to the middle of the storage hole to reduce the floating pollutants in the storage hole; "the cover is combined with the continuous pneumatic wheel tool, and the cover is replaced by the cover a step of installing a constant-type pneumatic grinding wheel tool through the tool socket on the cover plate, and replacing the sealing cover plate with the cover plate of the straight pneumatic grinding wheel tool on the storage hole; The multi-level filtration system is combined with the cover plate, the suction pipe of the multi-level filtration system is inserted into the middle of the storage hole through the suction pipe insertion hole of the cover plate; The grinding wheel tool removes the pollution of the hole wall and synchronously absorbs the air floating pollution by the multi-layer filtering system. The straight pneumatic pneumatic wheel tool moves along the axial direction of the storage hole to remove the fixing of the inner wall of the storage hole. Contaminant, at the same time, the suction pipe of the multi-layer filtration system absorbs airborne pollutants in the storage hole, and concentrates most of the pollutants in the air in the pre-filter tank; , for the third time to remove the empty The step is to move the straight pneumatic grinding wheel tool to the outside of the storage hole after the completion of the pollution of the hole of the storage hole, and continuously remove the air pollution by the multi-layer filtration system, and concentrate most of the pollutants in the air on the hole. In the front filter canister; a "sucking hole wall contaminant" step, the suction pipe of the multi-level filtration system is connected to the extension pipe of sufficient length, and the suction pipe insertion hole of the cover plate is inserted into the storage hole At the bottom, the pollutants removed by the straight-type pneumatic grinding wheel tool are removed; the determination step of "radiation intensity detection after decontamination meets the target value" is determined after the decontamination is completed and the suction pipe is removed from the cover. Using a radiation instrument to detect the intensity of the radiation in the storage hole and recording to confirm whether the radiation dose in the storage hole after the decontamination meets the target value, and if the judgment result is negative "N", it means the radiation after decontamination If the dose still exceeds the target value, repeat the above steps of "the combination of the cover and the permanent pneumatic wheel tool, and then replace the sealing cover on the storage hole with the cover", and the subsequent steps, and if the result is judged Affirmative "Y", it means that the radiation dose after decontamination has reached the target value, then the next step; a "cover in exchange for the In the original sealing cover step, after the decontamination operation in the hole is completed and the detection radiation intensity meets the target value, the cover plate is removed, and the original sealing cover plate is returned to the storage hole to reseal the storage hole. .

According to the above structure, the steps of "first removing air pollution", "second removing air pollution", and "combining the multi-layer filtration system with the cover plate" are the suction of the multi-level filtration system. The tube extends to the position of the bottom of the upper section.

According to the above structure, the "second removal of air pollution" step is performed by suction through the suction pipe for at least 10 minutes.

According to the above structure, before the step of "combining the cover with the permanent pneumatic wheel tool and replacing the sealing cover on the storage hole with the cover", a "replacement of the cover as the original sealing cover" is performed in advance. After the completion of the removal of the contaminant at the bottom of the storage hole, before the straight pneumatic grinder tool and the cover are not completed, the cover is replaced by the original sealing cover to reseal the storage hole to avoid contamination. External diffusion.

According to the above structure, the step of "cleaning the bottom of the storage hole" after the operation is completed, in the process of removing the pneumatic needle brush tool out of the cover plate, the pneumatic needle brush tool must be covered to avoid the adhesion pollution. The objects are scattered.

According to the above structure, in the step of "cutting the hole wall contamination brushing, performing the third removal of the air pollution", after the operation is completed, the straight type pneumatic wheel tool must be covered in the process of moving the straight pneumatic wheel tool outside the storage hole. Pneumatic grinding wheel tool to avoid scattered contaminants.

In order to achieve a more specific understanding of the above objects, effects and features of the present invention, the following figures are illustrated as follows:

S11‧‧‧Build a cover to replace the original sealing cover on the storage hole

S12‧‧‧ Record of radiation intensity before decontamination

S13‧‧‧Building a multi-level filtration system

S14‧‧‧First removal of air pollution

S15‧‧‧Clean the bottom of the storage hole

S16‧‧‧Absorbing bottom pollutants

S17‧‧‧Second removal of air pollution

S18‧‧‧Replace the cover as the original sealing cover

S19‧‧‧The cover plate is combined with the continuous pneumatic wheel tool, and the cover plate on the storage hole is replaced by the cover plate

S20‧‧‧ Combine the multi-level filtration system with the cover

S21‧‧‧Start the straight pneumatic wheel tool to remove the contamination of the hole wall and simultaneously absorb the air pollution by multi-level filtration system

S22‧‧‧ hole wall pollution brushing is completed, the third time to remove air pollution

S23‧‧‧Sucking hole wall contaminants

S24‧‧‧Measurement of radiation intensity after decontamination, whether it meets the target value

S25‧‧‧Change the cover back to the original sealing cover

1‧‧‧ cover

11‧‧‧Tool socket

12‧‧‧Sucking tube jack

2‧‧‧Multi-level filtration system

21‧‧‧Sucking tube

22‧‧‧Pre-filter cans

23‧‧‧ vacuum cleaner

24‧‧‧Air filter unit

25‧‧‧Negative pressure exhaust

26‧‧‧ Extension tube

3‧‧‧ Storage hole

31‧‧‧ lower section

311‧‧‧ bottom

32‧‧‧上段

321‧‧‧ openings

4‧‧‧Pneumatic needle brush tool

41, 51‧‧‧Extension pole

5‧‧‧Straight pneumatic grinding wheel tool

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing the method of implementation of the present invention.

Fig. 2 is a schematic view showing the basic structure of a cover plate, a multi-layer filtration system of the present invention.

Fig. 3 is a schematic view showing the state of the present invention when air pollution is removed.

Figure 4 is a schematic view showing the state of the present invention when the contaminants at the bottom of the storage hole are removed.

Figure 5 is a schematic view showing the state of the present invention when it absorbs contaminants.

Figure 6 is a schematic view showing the action of the present invention in removing contaminants from the pore walls of the storage.

Referring to Fig. 1, it can be seen that the main method of the present invention includes: "Building a cover plate to replace the original sealing cover on the storage hole" S11 step, "radiation intensity record before decontamination" S12 step, "Building Set up a multi-level filtration system" S13 step, "first remove air pollution" S14 step, "clean out the bottom of the storage hole" S15 step, "absorb the bottom pollutant" S16 step, "Second removal of air pollution S17, "Replace the cover as the original sealing cover", step S18, "This cover is combined with the permanent pneumatic wheel tool, and replace the sealing cover on the storage hole with the cover". Step S19, "This will be Multi-level filtration system combined with the cover plate" S20 step, "Start the straight pneumatic wheel tool to remove the contamination of the hole wall, and simultaneously remove the air pollution by the multi-layer filtration system" S21 step, "hole wall pollution brushing is completed , the third step of removing air pollution, S22 step, "sucking hole wall contaminant" S23 step, "radiation intensity detection after decontamination, whether it meets the target value" S24 judgment step, "replace the cover plate back to the original seal cover Board" S25 steps, etc.; A detailed description of each step will be made with reference to Figures 2 through 6.

First, a step of "building a cover plate to replace the original sealing cover on the storage hole" S11 is provided with a cover plate 1 on which a tool insertion hole 11 and a suction pipe are provided. The socket 12 is replaced with the cover plate 1 to replace the original sealing cover on the predetermined storage hole 3.

In a general case, the storage hole 3 is composed of a lower inner diameter 31 having a smaller inner diameter and a upper inner diameter 32 having a larger inner diameter. A bottom portion 311 is formed on the bottom surface of the lower portion 31 and formed above the upper portion 32. An opening 321 is defined, and the cover 1 is attached to the opening 321 to connect the tool insertion hole 11 and the suction tube insertion hole 12 with the upper portion 32.

Furthermore, the "pre-decontamination radiation intensity recording" step S12 is performed by using a radiation instrument to detect the radiation intensity in the storage hole 3 before performing the decontamination operation, and recording.

In the step S13 of the "establishing a multi-level filtering system", a multi-level filtering system 2 is provided. In the embodiment, the multi-level filtering system 2 is a pre-filter tank 22 and a vacuum cleaner 23 connected in sequence. An industrial vacuum cleaner is preferably provided, an air filtering device 24 and a negative pressure exhausting device 25, and a suction pipe 21 for introducing contaminants is disposed at the front end of the pre-filter can 22.

The "first removal of air pollution" step S14 extends the suction tube 21 of the multi-level filtration system 2 through the suction tube insertion hole 12 of the cover plate 1 into the storage hole 3 and extends to the upper portion. The bottom of 32 (about 80 cm deep) and the multi-level filtration system 2 is opened all the way, and the floating pollutants in the storage hole 3 are sucked into the pre-filter tank 22 via the suction pipe 21, and most of the pollutants in the air are made. The concentrated filter canister 22 is concentrated in the pre-filter canister 22, and the filtered air is discharged to the outside through the vacuum cleaner 23, the air filter device 24, and the negative pressure exhaust device 25.

The step of "scraping the bottom of the storage hole contaminant" S15 is to extend an extension rod 41 through the tool insertion hole 11 of the cover plate 1 into the bottom of the storage hole 3, and is fixed to the extension rod 41 by a pneumatic needle brush tool 4. The front end uses the pneumatic needle brush tool 4 to remove the contaminants of the bottom portion 311 of the storage hole 3, and after the operation is completed, the pneumatic needle brush tool 4 is removed to the outside of the cover plate 1 while covering the pneumatic needle brush tool 4 To avoid the scattered contaminants.

The step of "sucking the bottom contaminant" S16 is to connect the suction tube 21 of the multi-layer filtration system 2 to the extension tube 26 of sufficient length, and extend into the storage hole through the suction tube insertion hole 12 of the cover plate 1. 3 is close to the portion of the bottom portion 311 to absorb the contaminants removed by the pneumatic needle brush tool 4 described above.

The "second removal of air pollution" step S17 is performed by suction pipe 21 of the multi-stage filtration system 2 extending to the bottom of the upper portion 32 of the storage hole 3 (about 80 cm deep) for at least 10 minutes to lower the storage hole 3 Floating pollution inside.

The step of replacing the cover plate as the original sealing cover S18 is performed after the bottom portion 311 of the storage hole 3 is removed, and the cover plate 1 is replaced by the original sealing cover to reseal the storage hole 3 to avoid pollution. Spread out.

The "the cover plate is combined with the permanent pneumatic wheel tool, and the cover plate is replaced by the cover plate" S19 step, and an extension rod 51 is inserted into the storage hole through the tool insertion hole 11 of the cover plate 1. The bottom of the 3 is fixed to the front end of the extension rod 51 by a constant-type pneumatic wheel tool 5, and the cover plate 1 of the combination of the straight pneumatic wheel tool 5 is mounted on the storage hole 3 instead of the sealing cover.

In a possible embodiment, the extension rod 51 can be disposed on a mechanism that can be operated to lift and lower, whereby the straight pneumatic wheel tool 5 can be driven to automatically move up and down.

The step of combining the multi-layer filtration system with the cover plate S20 is to insert the suction pipe 21 of the multi-layer filtration system 2 into the storage hole 3 through the suction pipe insertion hole 12 of the cover plate 1. The bottom of the upper section 32 (about 80 cm deep).

The "starting the straight pneumatic grinding wheel tool removes the contamination of the hole wall and is multi-layered The secondary filtration system synchronously absorbs the air-floating pollution" step S21, the straight-type pneumatic grinding wheel tool 5 is opened, and is moved in the axial direction in the lower section 31 of the storage hole 3 to remove the inner wall of the storage hole 3 At the same time, the pollutants in the storage hole 3 are sucked out by the suction pipe 21 of the multi-layer filtration system 2, and most of the pollutants in the air are concentrated in the pre-filter tank 22.

After the "hole wall contamination brushing is completed, performing the third removal of air pollution" step S22, the straight pneumatic wheel tool 5 is moved to the outside of the storage hole 3 after the hole wall of the storage hole 3 is removed. The straight pneumatic wheel tool 5 is coated to prevent the deposited contaminants from scattering, while the multi-layer filtration system 2 continuously removes the air pollution, and the majority of the pollutants in the air are concentrated in the pre-filter tank 22.

The step of removing the hole wall contaminant S23 is to connect the suction pipe 21 of the multi-stage filtration system 2 to the extension pipe 26 of sufficient length, and extend into the storage hole through the suction pipe insertion hole 12 of the cover plate 1. 3 At the bottom of the lower section 31, the pollutants removed by the aforementioned straight pneumatic wheel tool 5 are removed.

The "respecting the radiation intensity after decontamination, whether the target value is met" S24 is determined by using the radiation instrument to detect the radiation intensity in the storage hole 3 after the decontamination is completed and the suction tube 21 is removed from the cover 1 Recording to confirm whether the radiation dose in the storage hole 3 after the decontamination meets the target value, and if the judgment result is negative "N", it means that the radiation dose after the decontamination still exceeds the target value, repeating the above "this The cover is combined with the continuous pneumatic wheel tool, and the cover plate is replaced by the cover plate in the step S19, and the subsequent steps, and if the judgment result is affirmative "Y", it means that the decontamination is If the radiation dose has reached the target value, the next step is performed.

Finally, the step of "replace the cover plate back to the original sealing cover" S25 is performed after the decontamination operation in the hole is completed and the detected radiation intensity meets the target value, and then the cover plate 1 is removed, and the original sealing cover plate is re-opened. Covering the storage hole 3 to reseal the storage hole 3.

In summary, the high activity polluted hole decontamination method of the present invention can achieve the functions of easy operation, low use cost, improved decontamination effect and prevention of secondary diffusion of pollutants, and is truly novel and progressive. The invention is made in accordance with the law, and the above description is only for the preferred embodiment of the present invention. Any changes, modifications, alterations or equivalent substitutions of the technical means and scope of the present invention, It is also within the scope of the patent application of the present invention.

Claims (6)

A method for decontaminating a high-activity polluted hole includes at least one step of “building a cover plate to replace the original sealing cover on the storage hole”, and providing a cover plate, and the cover plate is provided with a through-opening a tool jack and a suction tube jack, and replacing the original sealing cover on the preset storage hole with the cover; a "radiation intensity recording before decontamination" step is performed by using a radiation instrument before decontamination Measure the radiation intensity in the storage hole and record it; a "Building a multi-level filtration system" step is to set up a multi-level filtration system having a suction tube for introducing pollutants, and at least a pre-filter tank for filtering pollutants; a "first removal of air pollution" step, the suction tube of the multi-level filtration system is inserted into the middle of the storage hole through the suction tube socket of the cover plate, And the multi-level filtration system is opened to carry out the air pollution removal operation, and most of the pollutants in the air are concentrated in the pre-filter tank; a step of “cleaning the bottom of the storage hole contaminant” is a pneumatic needle brush Tool is fixed to a preset The front end of the long rod extends through the tool insertion hole of the cover plate into the bottom of the storage hole to remove the contaminant at the bottom of the storage hole; and the step of "absorbing the bottom contaminant" is the suction of the multi-level filtration system An extension tube of sufficient length is connected to the bottom of the storage hole through the suction tube insertion hole of the cover plate to absorb the pollutants removed by the pneumatic needle brush tool; a "second removal of air pollution" step The suction pipe of the multi-level filtration system is extended to the middle of the storage hole for suction to reduce the floating pollutants in the storage hole; "the cover is combined with the continuous pneumatic wheel tool, and the cover is replaced by the cover. The sealing cover on the hole is a step of installing a constant-type pneumatic grinding wheel tool through the tool socket on the cover plate, and replacing the sealing cover plate with the cover plate of the straight pneumatic grinding wheel tool for storage. a step of "combining the multi-layer filtration system with the cover plate", the suction pipe of the multi-level filtration system is inserted through the suction tube insertion hole of the cover plate into the middle portion of the storage hole; "Start the straight-type pneumatic grinding wheel tool to remove the contamination of the hole wall and synchronously absorb the air-floating pollution by the multi-layer filtration system" step, and move along the axial direction of the storage hole with a straight pneumatic grinding wheel tool to remove the storage hole Contaminants fixed on the inner wall, and suctioning the floating air pollutants in the storage holes by the suction pipe of the multi-layer filtration system, and concentrating most of the pollutants in the air in the pre-filter can; After the completion of the hole wall contamination brushing, the third step of removing the air pollution is performed, and after the hole wall of the storage hole is removed, the straight pneumatic wheel tool is moved outside the storage hole and continuously removed by the multi-layer filtration system. Air pollution, the majority of the pollutants in the air are concentrated in the pre-filter tank; a "sucking hole wall contaminant" step, the suction pipe of the multi-level filtration system is connected to the extension pipe of sufficient length, Extending through the suction tube of the cover plate The bottom of the storage hole is used to absorb the contaminants removed by the straight-type pneumatic grinding wheel tool; a determination step of "radiation intensity detection after decontamination, whether the target value is met" is determined after the decontamination is completed and the suction tube is removed from the cover After the board, use the radiation instrument to detect the radiation intensity in the storage hole and record it to confirm whether the radiation dose in the storage hole after the decontamination meets the target value. If the judgment result is negative "N", it means that after decontamination If the radiation dose still exceeds the target value, repeat the above-mentioned "the combination of the cover and the permanent pneumatic wheel tool, and then replace the sealing cover on the storage hole with the cover", and the subsequent steps, and if judged If the result is positive "Y", it means that the radiation dose after decontamination has reached the target value, then the next step is performed; a step of "replace the cover plate back to the original sealing cover" is completed in the hole and the decontamination operation is completed. After the detected radiation intensity meets the target value, the cover is removed and the original sealing cover is returned to the storage hole. Upper to reseal the storage hole. The method for decontaminating a high-activity polluted hole according to the first aspect of the patent application, wherein the "first removing air pollution", "second removing air pollution", and "the multi-level filtering system and the The steps of the cover assembly and the like extend the suction tube of the multi-level filtration system to the position of the bottom of the upper section. The high activity polluted hole decontamination method according to claim 1, wherein the "second decontamination" step is performed by a suction pipe for at least 10 minutes. The method for decontaminating a high-activity polluted hole according to the first aspect of the patent application, wherein the step of "combining the cover with the permanent pneumatic wheel tool and replacing the sealing cover on the storage hole with the cover" is performed. Previously, a step of “replace the cover as the original sealing cover” was performed in advance to complete the removal of the contaminant at the bottom of the storage hole before the straight pneumatic grinding wheel tool and the cover were not combined. The plate is replaced by the original sealing cover to reseal the storage hole to prevent contamination from spreading outward. The method for decontaminating a high-activity polluted hole according to the first aspect of the patent application, wherein the step of "removing the contaminant at the bottom of the storage hole" is performed after the operation is completed, and the pneumatic needle brush tool is removed from the cover plate. The pneumatic needle brush tool must be covered to prevent the attached contaminants from scattering. For example, in the high activity pollution hole decontamination method described in claim 1, wherein the "hole wall pollution brushing is completed, the third removal of air pollution" step is performed after the operation is completed, and the straight pneumatic grinding wheel is used. During the process of moving the tool out of the storage hole, the straight pneumatic wheel tool must be covered to prevent the attached contaminants from scattering.