JP2016003856A - Remote decontamination method and remote decontamination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote decontamination method capable of decontaminating an apparatus or a structure without scattering outside a radioactive contaminant generated during a decontamination work.SOLUTION: A remote decontamination method comprises a spray step for scattering spray liquid over the surface of a decontamination object contaminated with a radioactive material, a blast decontamination step for jetting out a blast material onto the decontamination object covered with the spray liquid, and a suction recovery step for sucking and recovering scattered objects scattered into the air during the blast decontamination step.

Description

  The present invention relates to a remote decontamination method and a remote decontamination apparatus for decontaminating equipment and structures contaminated with radioactive substances.

  In the event of a major disaster at a nuclear power plant, radioactive materials may be released into the reactor building and adhere to equipment such as piping and reactor structures. However, since the reactor building is in a high radiation environment and entry of workers is restricted, it is necessary to perform decontamination work of radioactive contaminants remotely.

  As such a remote decontamination means, a blast decontamination method using dry ice as a blast material is known (Patent Documents 1 and 2). This blast decontamination means decontaminates by spraying pelletized or granular dry ice together with compressed air onto an object to be decontaminated. Specifically, dry ice particles collide with the object to be decontaminated, and the surface temperature of the object to be decontaminated is drastically lowered, and solid dry ice is sublimated into gas. The pulverization force is generated by decontamination, and decontamination is performed by separating and scattering the contaminants fixed on the surface of the object to be decontaminated.

  This blast decontamination means is widely used because it can peel only radioactive contaminants without destroying the paint layer or coating layer on the surface of the object to be decontaminated.

Japanese Patent Laid-Open No. 11-58242 Japanese Patent No. 4656601

By the way, in the blast decontamination method using dry ice, since the decontamination work is performed in a dry state as compared with the water decontamination method, the contaminants become fine particles during the blast decontamination work. The air dose may increase as airborne dust increases.
Therefore, in the conventional blast decontamination method disclosed in Patent Document 1, the suction hood is brought into close contact with the object to be decontaminated, and the blast decontamination and the scattered matter are collected inside the suction hood.

However, since there are many and complicated pipes and devices in the actual nuclear power plant, these pipes and devices become obstacles, and the suction hood becomes a decontamination target. In some cases, it cannot be adhered. In that case, since the blast decontamination is performed in a state where the suction hood is separated from the object to be decontaminated, a part of the scattered matter may be scattered in the reactor building.
As a result, the amount of airborne dust and the air dose in the nuclear building increased, and there was a problem that radioactive contamination expanded, decontamination work was prolonged, and work efficiency was reduced.

  The present invention has been made to solve the above-described problems, and provides a remote decontamination method and a remote decontamination apparatus that can efficiently remove and collect radioactive contaminants attached to a reactor structure or the like. With the goal.

  In order to solve the above problems, a remote decontamination method according to the present invention includes a spraying step of spraying a spray liquid on the surface of a decontamination target contaminated with a radioactive substance, and a decontamination target covered with the spray liquid. It has a blast decontamination process which injects a blast material to a thing, and a suction collection process which sucks and collects the scattered matter scattered in the air at the blast decontamination process.

  The remote decontamination apparatus according to the present invention includes an articulated arm having a spray nozzle attached to the tip, a spray liquid container, a pump for supplying the spray liquid to the spray nozzle, and a self-propelled type equipped with them. A remote spraying device comprising a carriage, an articulated arm having a blast injection nozzle attached to the tip, a blast material container, a compressor for supplying blast material to the blast injection nozzle, and at least one equipped with them A blast decontamination device composed of a self-propelled trolley, a multi-joint arm with a suction hood attached to the tip, and the scattered matter generated by blast decontamination is suctioned and collected via the suction hood A suction recovery device including a recovery unit and a self-propelled carriage equipped with the recovery unit is provided.

  According to the present invention, it is possible to efficiently remove and collect adhering radioactive contaminants without scattering to the outside.

The block diagram of the remote spraying apparatus which concerns on 1st Embodiment. The block diagram of the blast decontamination apparatus which concerns on 1st Embodiment. The lineblock diagram of the suction recovery device concerning a 1st embodiment. The block diagram of the remote decontamination apparatus which concerns on 2nd Embodiment. (A) is a side view of the spray nozzle which concerns on Example 1 of 3rd Embodiment, (b) is the AA arrow directional view. (A) is a side view of the spray nozzle which concerns on Example 2 of 3rd Embodiment, (b) is the BB arrow directional view. (A) is a side view of the spray nozzle which concerns on Example 3 of 3rd Embodiment, (b) is the CC arrow directional view. (A) is a side view of the spray nozzle which concerns on Example 4 of 3rd Embodiment, (b) is the DD arrow line view. (A) is a side view of the spray nozzle according to Example 5 of the third embodiment, and (b) is a side view of the spray nozzle according to Example 6. The conceptual diagram of the remote control system which concerns on 4th Embodiment. The 1st example which shows the process drawing of the remote decontamination method concerning this embodiment. The 2nd example which shows the process drawing of the remote decontamination method concerning this embodiment. The 3rd example which shows the process drawing of the remote decontamination method concerning this embodiment.

Hereinafter, embodiments of a remote decontamination method and a remote decontamination apparatus according to the present invention will be described with reference to the drawings.
[First Embodiment]
A remote decontamination method and a remote decontamination apparatus according to the first embodiment will be described with reference to FIGS.

(Constitution)
The remote decontamination apparatus according to this embodiment includes a remote spray apparatus 10, a blast decontamination apparatus 20, and a suction apparatus 30.

  The remote spraying device 10 is a spray liquid composed of a liquid such as water on the surface of the decontamination target prior to the blast decontamination process in order to prevent floating contaminants from scattering from the decontamination target during the blast decontamination. Spray.

As shown in FIG. 1, the remote spray device 10 includes a self-propelled carriage 8a, a spray liquid container 1 in which the spray liquid is stored, a multi-degree articulated arm 7a having a spray nozzle 3 attached to the tip, The pump 2 and the pipes 4a and 4b for supplying the spray liquid in the liquid container 1 to the spray nozzle, and the observation device 5 for illuminating and imaging the object to be decontaminated are configured.
The blast decontamination apparatus 20 peels and decontaminates the contaminants attached to the decontamination target by spraying a blast material such as dry ice onto the decontamination target.

  As shown in FIG. 2, the blast decontamination apparatus 20 includes a multi-joint arm 7b having a blast injection nozzle 13 attached to the tip, a blast material container 11 in which a blast material is accommodated, and a blast material container 11 Pipes 12a and 12b for supplying the blasting material to the blast injection nozzle 13, an observation device 5 for illuminating and imaging the object to be decontaminated, a self-propelled carriage 8b equipped with them, compressed air and control And a self-propelled carriage 8c on which a compressor 17 for sending a signal to the blasting material container 11 via a pipe 18 and a signal cable 19 is mounted.

The suction collection device 30 sucks and collects contaminants and the like that have been peeled and scattered from the object to be decontaminated during the decontamination work.
As shown in FIG. 3, the suction recovery device 30 includes a self-propelled carriage 8d, a multi-joint multi-joint arm 7c having a suction hood 28 attached to the tip, and a contaminant collected by suction through a pipe 21. And a collection unit 27 for collection and an observation device 5 for illuminating and imaging a decontamination target. The collection unit 27 includes, for example, a cyclone suction unit 22, a collection container 23, a filter 24 including a HEPA filter (High Efficiency Particulate Air Filter), and a fan 25 driven by a small motor.

(Function)
In the remote decontamination apparatus configured as described above, first, the remote spray apparatus 10, the blast decontamination apparatus 20, and the suction recovery apparatus 30 are driven by the self-propelled carriages 8a to 8d to be targeted in the nuclear power plant. Stop moving to the decontamination target location.
The traveling control of these carts is controlled by a remote control system arranged in a central control room, which will be described later, on the basis of images taken by observation devices mounted on the carts.

  Next, by operating the articulated arm 7a of the remote spraying device 10, the spray nozzle 3 is arranged at a position separated from the object to be decontaminated by a predetermined distance. Then, by spraying the spray liquid from the spray nozzle 3 onto the object to be decontaminated, the surface of the object to be decontaminated is uniformly wetted with the spray liquid. At that time, the spray pressure is adjusted so that floating contaminants existing on the surface of the decontamination target do not rise due to the spray pressure of the spray nozzle 3, and the spray nozzle 3 is set at an appropriate distance from the decontamination target. It is desirable to arrange them apart. Thereby, the floating contaminant which exists in the surface of a decontamination target object is reliably taken in into the spray liquid which covers the surface of a decontamination target object.

  Next, a blast material made of dry ice is sprayed from the blast spray nozzle 13 of the blast decontamination device 20 to perform blast decontamination. At that time, since the surface of the object to be decontaminated is wet with the spray liquid, it is possible to minimize the amount of floating contaminants that rise from the surface. Thereby, the quantity of the space dust which scatters from a decontamination target object during a decontamination operation | work can be suppressed to the minimum.

  Moreover, it is preferable to arrange | position the blast injection nozzle 13 100 mm-500 mm apart with respect to a decontamination target, and also to arrange | position with a predetermined angle inclination with respect to a perpendicular direction.

  While the blast decontamination is performed by the blast decontamination device 20, the suction collection device 30 performs the suction collection of the scattered matter. At that time, it is preferable that the suction hood 28 of the suction recovery apparatus 30 is disposed to be inclined at a predetermined angle on the side opposite to the position where the blast injection nozzle 13 is disposed with respect to the vertical direction of the decontamination target. The spray liquid containing floating contaminants and debris generated during the blast decontamination process and contaminants on the surface of the decontamination target is passed through the suction hood 28, the pipe 21, the suction unit 22 or the fan 25. Then, it is recovered in the recovery container 23 or the filter 24. That is, solid scattered matter is collected in the collection container 23, micron-sized minute contaminants and mist-like liquid are collected by the filter 24 such as a HEPA filter, and carbon dioxide gas is released into the air. .

  The remote decontamination work consisting of the spraying process, the blast decontamination process, and the suction recovery process described above is carried out by appropriately controlling the articulated arms 7a to 7c and the carts 8a to 8d, so that necessary decontamination sites in the nuclear power plant It is carried out against.

(effect)
As described above, according to the present embodiment, by spraying the spray liquid on the surface of the decontamination target before the blast decontamination of the decontamination target, airborne dust composed of airborne contaminants, etc. The generation amount can be reduced to the minimum. Thereby, the remote decontamination work in a nuclear power plant can be implemented more safely and efficiently.

[Second Embodiment]
A remote decontamination method and a remote decontamination apparatus according to the second embodiment will be described with reference to FIG.

(Constitution)
In the present embodiment, the spray nozzle 31 and the blast spray nozzle 32 are mounted on the tip of one articulated arm 7d.

  In this case, as shown in FIG. 4, the spray nozzle 31 is arranged in front of the blast spray nozzle 32 in the decontamination direction, and sprays the spray liquid on the decontamination target prior to the blast decontamination.

  Moreover, in this embodiment, since the self-propelled carts 8a and 8b according to the first embodiment can be integrated into one cart, the entire remote decontamination apparatus is reduced in size and the efficiency of the decontamination work is increased. Can be achieved.

  Attached devices such as the spray liquid container 1, the pump 2, and the blasting material container 11 in which the spray liquid is accommodated are distributed and mounted on one or more carts depending on their size, weight, working space, etc. You may make it do.

(Modification)
In the above-described embodiment, an example in which the spray nozzle 31 and the blast injection nozzle 32 are attached to the tip of one articulated arm 7d has been described, but a suction hood 28 may also be attached (not shown).

  Further, a plurality of articulated arms 7 may be provided in one carriage, and the spray nozzle 31, the blast injection nozzle 32, and / or the suction hood 28 may be appropriately combined to be appropriately attached to the tips of the plurality of articulated arms. . Thereby, further miniaturization of the entire remote decontamination device and efficiency of the decontamination work can be achieved.

(Function)
When decontaminating the object to be decontaminated by the remote decontamination apparatus configured as described above, as shown in FIG. 4, the articulated arm 7d equipped with the spray nozzle 31 and the blast injection nozzle 32 is decontaminated. First, spray liquid is sprayed by the spray nozzle 31 on the surface of the object to be decontaminated, and blast decontamination is performed by the blast spray nozzle 32 immediately after that.
In addition, the suction hood 28 attached to the same multi-joint arm 7d or another multi-joint arm collects flying contaminants such as floating contaminants or decontaminated substances.

(effect)
According to the present embodiment, at least the spray nozzle 31 and the blast injection nozzle 32 are attached to one articulated arm, thereby reducing the size of the remote decontamination apparatus, increasing the efficiency of the decontamination work, and shortening the work time. be able to.
Moreover, since the number of self-propelled carriages can be reduced, the remote decontamination apparatus can be further reduced in size, the efficiency of decontamination work, and the number of parts can be reduced.

[Third Embodiment]
Examples 1 to 6 of the remote decontamination method and remote decontamination apparatus according to the third embodiment will be described with reference to FIGS.
The present embodiment is characterized in that a plurality of spray nozzles are used or the spray nozzles are configured to be rotatable.

(Example 1)
In the first embodiment, as shown in FIGS. 5A and 5B, a plurality of spray nozzles 34 are arranged in a row on one side of the blast injection nozzle 32.

  Thereby, the spray area | region of a spray liquid expands and it becomes possible to wet the surface of the decontamination target object with a spray liquid efficiently over a wide range. Further, by performing the spraying process and the blast decontamination process in parallel, the efficiency of the decontamination work and the shortening of the work time can be achieved.

(Example 2)
In the second embodiment, as shown in FIGS. 6A and 6B, a plurality of spray nozzles 36 are arranged in an annular shape around the blast injection nozzle 37.
As a result, as in the first embodiment, the spray region of the spray liquid is expanded, and the surface of the decontamination target can be efficiently wetted with the spray solution over a wide range.

  Further, even during the blast decontamination operation, the spray liquid is sprayed from the plurality of annular spray nozzles 36 to form a spray liquid curtain with the spray liquid in the upper space of the decontamination target. The exfoliation can be trapped in the spray liquid curtain. Thereby, while being able to collect | recover contaminants efficiently, generation | occurrence | production of aerial dust can be reduced significantly.

(Examples 3 and 4)
In the third and fourth embodiments, as shown in FIGS. 7 and 8, the spray nozzle 36 arranged in the annular shape of the second embodiment is configured to be rotated hydraulically or electrically.

Among these, in the example of FIGS. 7A and 7B according to the third embodiment, a plurality of spray nozzles 44 are provided in the rotation direction, and the plurality of spray nozzles 36 are placed around the blast spray nozzle 37 by the spray pressure. It is configured to rotate in a predetermined direction around the provided rotation shaft 42.
Further, in the example of FIGS. 8A and 8B according to the fourth embodiment, the plurality of spray nozzles 36 are rotated by the motor 45 including an electric motor or a hydraulic motor.

  This expands the spray area of the spray liquid and allows the surface of the decontamination object to be more uniformly wetted with the spray liquid over a wide range, greatly reducing the generation of airborne contaminants and airborne dust. be able to.

(Example 5 and Example 6)
As shown in FIGS. 9A and 9B, the spray nozzle 40 according to the fifth and sixth embodiments is configured to be rotatable with respect to the decontamination target.
Among these, in the example of FIG. 9A according to the fifth embodiment, the spray nozzle 40 is rotated by the electric motor 38 and the transmission mechanism 39.

In the example of FIG. 9B according to the sixth embodiment, the spray nozzle 40 is rotated by the hydraulic motor 41 using the spray pressure and the transmission mechanism 39 without using external power.
Thereby, even if there is only one spray nozzle, by rotating the spray nozzle 40, the spray area is expanded and the surface of the object to be decontaminated can be wetted with the spray liquid over a wide range. Generation of toxic contaminants and airborne dust can be greatly reduced.

[Fourth Embodiment]
A remote decontamination method and a remote decontamination apparatus according to the fourth embodiment will be described with reference to FIG.
The present embodiment relates to a remote operation system for remotely controlling a plurality of self-propelled carts and articulated arms.

  As shown in FIG. 10, this remote control system is connected to the trolley side system 50 via, for example, a trolley side system 50 mounted on the trolleys 8b and 8c of the blast decontamination apparatus 20, a composite cable 56 and a branch board 57. And an operation room side system 60.

The cart side system 50 includes a monitoring camera 5a, a lighting device 5b, a cable winding device 52, power units 53a and 53b, a control CPU 54, a LAN communication system 55, and the like, and is appropriately disposed on the carts 8b and 8c. The
A similar cart side system can also be installed in the carts 8a and 8d.

  The operation room side system 60 in the operation room provided at a place away from the decontamination work site is configured by a LAN communication system 55, a generator unit 58, a monitor, various input display devices, and the like.

  The composite cable 56 drawn out from the cable winding device 52 of the cart side system 50 is connected to a branch board 57 and supplied with electric power from a generator unit 58 composed of, for example, a diesel generator provided in the operation room side system 60. The Further, the LAN communication systems 42 and 55 make a communication connection between the cart side system 50 and the operation room side system 60 using a LAN line or the like in the facility.

  According to this embodiment, the worker can perform drive control of a plurality of self-propelled carriages and remote operation of a plurality of multi-joint arms from a location far away from the work site. This remote control system can reduce the radiation exposure of workers during the decontamination work.

[Fifth Embodiment]
A remote decontamination method and a remote decontamination apparatus according to a fifth embodiment will be described.
In the present embodiment, a spray liquid mixed with a surfactant is used.
By mixing the surfactant into the spray liquid, the wettability is improved, so that even with a small amount of the spray liquid, the spray liquid can be distributed over the entire surface of the object to be decontaminated without gaps.

  Moreover, the spray solution mixed with the surfactant also exhibits a decontamination effect as a detergent. That is, the surfactant has an effect that the floating contaminants are peeled off from the adhesion surface and are easily taken into the spray liquid. Furthermore, the surfactant has moisture retention, and by absorbing moisture around it, it is difficult to dry naturally and it is possible to maintain a wet state for a long time with a small amount of spray.

  Further, the surfactant generates a large amount of foam and can maintain the foam state for a long period of time. Therefore, since the contaminants peeled off during the blast decontamination process can be taken in by the large amount of bubbles generated on the surface of the decontamination target, the amount of floating contaminants generated can be greatly reduced.

[Sixth Embodiment]
A remote decontamination method and a remote decontamination apparatus according to a sixth embodiment will be described with reference to FIGS.
11 to 13 illustrate the steps of the remote decontamination method described in the above embodiment.

(Process diagram 1)
As shown in FIG. 11, the process diagram 1 is a method of spraying a spray liquid of a predetermined pressure from a spray nozzle 3 that is spaced at an appropriate distance. Wet the surface with spray solution (spraying process). As a result, floating contaminants are taken into the spray liquid, and floating contaminants are prevented from floating in the air by the injection pressure.

Next, in that state, a blast material made of dry ice or the like is sprayed onto the object to be decontaminated (blast decontamination step). At that time, the spray liquid distributed on the surface of the object to be decontaminated can greatly reduce the risk that airborne contaminants and exfoliated materials are scattered during blast injection.
In parallel with the blast decontamination process, the contaminants are sucked and collected by a suction hood (collection process). Thereby, it is possible to collect the contaminants without being scattered around.

(Process diagram 2)
As shown in FIG. 12, the process diagram 2 is configured to add a process (a spray liquid suction and recovery process) of recovering the extra sprayed liquid by the suction and recovery device immediately after the spraying process in the process chart 1.

  That is, in the blast decontamination step, the spray liquid distributed on the surface of the object to be decontaminated may be solidified and pulverized and scattered by blasting. Since the blast material is consumed by the action of removing the spray liquid, the decontamination speed and decontamination efficiency may be reduced.

Therefore, it is desirable to minimize the spray liquid distributed on the surface of the object to be decontaminated. Therefore, in FIG. 2, by adding the spray liquid suction and recovery process, the excess spray liquid is immediately after the spray process, that is, Collect from the surface of the object to be decontaminated before the blast decontamination process.
Thereby, a decontamination speed and decontamination efficiency can further be improved.

(Process diagram 3)
In the above-described process diagrams 1 and 2, as shown in FIG. 13, the spraying process and the blast decontamination process are sequentially performed. In this process diagram 3, these two processes are simultaneously performed by one articulated arm. .
Thereby, shortening of working time and efficiency improvement of decontamination work can be further improved.

In addition, airborne dust such as floating contaminants and exfoliated materials that are separated from the object to be decontaminated during the blast decontamination process can be confined in the space surrounded by the spray liquid curtain.
As a result, it is possible to minimize the scattering of contaminants and exfoliated materials into the air, so it is possible to reliably collect and collect contaminants and exfoliated materials, reducing the occurrence of secondary contamination and ensuring safety. Highly decontamination work can be performed.

  As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. The novel embodiment can be implemented in various other forms, and various omissions, combinations, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Spray liquid container, 2 ... Pump 3, 31, 34, 36, 40 ... Spray nozzle, 4a, 4b ... Piping, 5 ... Observation apparatus, 7a-7d ... Articulated arm, 8a-8d ... Carriage, 10 ... Remote spray device, 11 ... Blast material container, 12a, 12b ... Pipe, 13, 32, 37 ... Blast injection nozzle, 17 ... Compressor, 20 ... Blast decontamination device, 21 ... Pipe, 22 ... Suction part, 23 ... Recovery container , 24 ... Filter, 25 ... Fan, 27 ... Recovery part, 28 ... Suction hood, 30 ... Suction recovery device, 38 ... Electric motor, 39 ... Transmission mechanism, 41 ... Hydraulic motor, 45 ... Motor, 50 ... Dolly side system , 60 ... Operation room side system.

Claims (7)

  A spraying process for spraying a spray liquid onto the surface of a decontamination target contaminated with a radioactive substance, a blast decontamination process for injecting a blast material onto the decontamination target covered with the spray liquid, and the blast decontamination process And a suction collection step of sucking and collecting the scattered matter scattered in the air.   The remote decontamination method according to claim 1, wherein the blast decontamination step and the suction collection step are performed simultaneously.   3. A spray liquid suction / recovery process for sucking / recovering excess spray liquid from the spray liquid sprayed in the spray process is added between the spray process and the blast decontamination process. Remote decontamination method.   The spraying step and the blast decontamination step are performed simultaneously, and the excess spray liquid is sucked and collected from the scattered matter scattered in the air in the blast decontamination step and the spray liquid sprayed in the spraying step in the suction recovery step. The remote decontamination method according to claim 1.   The spraying liquid is sprayed in an annular shape on the object to be decontaminated in the spraying step, and an annular spray liquid curtain is formed in the front space of the object to be decontaminated. The remote decontamination method according to item 1.   The remote decontamination method according to any one of claims 1 to 5, wherein a surfactant is contained in the spray liquid. A remote spray device composed of an articulated arm with a spray nozzle attached to the tip, a spray liquid container, a pump for supplying the spray liquid to the spray nozzle, and a self-propelled carriage equipped with them;
It is composed of an articulated arm with a blast injection nozzle attached to the tip, a blast material container, a compressor for supplying the blast material to the blast injection nozzle, and at least one self-propelled carriage equipped with them. Blast decontamination equipment,
Consists of an articulated arm with a suction hood attached to the tip, a collection part that sucks and collects scattered matter generated by blast decontamination via the suction hood, and a self-propelled carriage equipped with them A suction recovery device;
A remote decontamination apparatus comprising:

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