JPH10123285A - Removal and collection device of in-reactor deposit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve removal working efficiency and reduce labor of workers by integrating a suction means for deposit and an underwater TV camera, and sucking the deposit as recognition of its presence is made. SOLUTION: An in-reactor deposit removal device 12 is constituted of a suction means of deposit and the like composed of e.g. a suction opening 13, a filter 14 and a suction pump 15, and a water jetting means 17 provided with an underwater TV camera 3 and a water jetting opening as an integrate unit. A support handle capable of grasping by the main mast of a refueling machine on the upper end of the pump is provided. The suction opening 13 for sucking deposit together with water is protruded, e.g. a suction direction modification means for making a suction object of deposit and the like of a reactor core fuel upper part is provided, and vertically moved by providing a lift mechanism. If constitution for housing electric equipment and the like in a watertight waterproof chamber is performed, their equipment can be made to ordinary specifications, and maintenance and inspection services can be also simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to underwater purification in a nuclear reactor of a nuclear power plant, and more particularly to an apparatus for removing deposits and the like in a nuclear reactor for removing suspended matters and cladding deposited on an upper part of a core fuel.

[0002]

2. Description of the Related Art In a nuclear power plant, a reactor pressure vessel is opened at the time of a periodic inspection or at the time of replacement work of in-furnace equipment and the like, thereby reducing the exposure of workers and maintaining the integrity of the in-furnace equipment. For this purpose, it is necessary to decontaminate necessary parts in the reactor pressure vessel and to remove suspended matter such as underwater cladding.

[0003] This operation is also performed on the upper part of the fuel in the nuclear reactor.
In addition, the sediment, the clad, etc. (hereinafter collectively referred to as sediment, etc.) are removed, and it is confirmed that the sediment has been surely removed each time. For the removal and collection of the deposits and the like, a suction tool such as an underwater vacuum cleaner is used. Was used.

FIG. 4 is a front view schematically showing an underwater cleaner as a typical suction device. This “underwater vacuum cleaner” is disclosed in Japanese Patent No. 1601314 (Japanese Patent Publication No. 2-17000).
Are already known.

When the underwater cleaner 1 removes deposits, for example, on the upper portion of the fuel, an operator attaches the underwater television camera 3 to the tip of the extension operation rod 2 suspended by an auxiliary hoist (not shown) in advance. Then, the underwater television camera 3 is lowered from above the water surface 4 into the water for shielding radiation in an open reactor pressure vessel (not shown) to check the state of floating substances in the water and deposits on the upper part of the fuel (not shown).

[0006] When a deposit or the like is found above the fuel in the inspection by the underwater television camera 3, an operator once pulls up the underwater television camera 3, removes the underwater television camera 3 from the tip of the extension operation rod 2, and removes the underwater television camera 3. Instead, the suction jig 5 is attached, and the suction jig 5 is again brought close to the upper part of the fuel in the reactor pressure vessel.

[0007] A collecting tank 7, a cyclone separator 8 and a submersible pump 9 are attached from below to a gantry 6 suspended from the water surface 4 with a rope or the like. A bag filter 10 is provided. The inlet side of the cyclone separator 8 is connected to the suction jig 5 via a flexible suction hose 11.

[0008] Here, when the submersible pump 9 is operated, water is sucked from the suction jig 5.
In the vicinity of the suction jig 5, the sediment in the upper part of the fuel is sucked together, and the cyclone separator 8 is sucked through the suction hose 11.
Flows into.

In the cyclone separator 8, the sucked water and the sediment are swirled to separate them according to their specific gravities, and the sediment having a large specific gravity is collected in the collection tank 7, while the sediment having a small specific gravity is collected. Are sucked into the submersible pump 9 together with the water. The sediment and the like having a low specific gravity and the water sucked into the submersible pump 9 are collected and collected by the bag filter 10, and the water is filtered and returned to the reactor pressure vessel again.

The result of the work of removing deposits and the like at the upper part of the fuel performed by approaching the suction jig 5 is based on the fact that the underwater television camera 3 is attached again to the tip of the extension operation rod 2 and the upper part of the fuel is removed. Check it down. This allows
If the result of the removal operation is good, the underwater television camera 3 is moved to the next operation target position, and the removal operation is performed in the same procedure as described above.

[0011]

In the conventional work of removing deposits and the like by the underwater cleaner 1 in the reactor pressure vessel, first, the work to be performed by the underwater television camera 3 is checked, and then the work is performed by the underwater cleaner 1. Removal work was performed, and the underwater television camera 3 was used to confirm the work result again. Accordingly, each time the replacement of the underwater television camera 3 and the suction jig 5 is performed at the tip of the extension operation rod 2, the replacement requires a lot of time.
There was an obstacle that put a heavy burden on the workers.

Further, even if the presence of deposits and the like in the reactor pressure vessel is confirmed by the underwater television camera 3, the target deposits and the like are not obtained when the suction jig 5 is disposed at the position and the suction operation is performed. There is a case where it is difficult to move and securely capture, and there is a problem that the efficiency of the removing operation is low.

In order to eliminate the replacement of the underwater television camera 3 and the suction jig 5 in the extension operation rod 2, the extension operation rod 2 dedicated to the underwater television camera 3 and the suction jig 5 may be used. There are drawbacks that the two extension operation rods 2 radiate and that a dedicated operator is required for each of the extension operation rods 2.

An object of the present invention is to provide a suction means for sucking sediments together with water in a reactor pressure vessel to separate and collect the sediments, a fountain means for moving the sediments, etc. An object of the present invention is to provide an apparatus for removing deposits and the like in a nuclear reactor, which integrates a means and an underwater television camera or the like for photographing an operation target portion.

[0015]

According to a first aspect of the present invention, there is provided an apparatus for removing and recovering deposits and the like in a nuclear reactor according to the first aspect of the present invention. A suction port for sucking, a suction means such as a filter for capturing sediment etc. from the sucked water and a suction pump, and an underwater television camera that captures the work target unit are integrated with a support handle at the top. It is characterized by having.

The device for removing and collecting deposits and the like in the reactor is suspended in the water of the reactor via the support handle, and the underwater television camera is used to photograph the work target portion to check for the presence of the deposits and the like.
When the presence of the sediment or the like is confirmed, the sediment or the like is sucked together with the water at the suction port while monitoring with an underwater television camera, and the sediment or the like is captured and collected from the water with a filter or the like.

According to a second aspect of the present invention, there is provided an apparatus for removing and recovering deposits and the like in a nuclear reactor, wherein a fountain means for moving deposits and the like in water is provided. Deposits in places where suction is difficult even if the removal and recovery device of the deposits in the reactor is moved or the direction of the suction port is changed by operating the suction direction changing means,
A fountain is sprayed from fountain means to a sediment having a strong adhesive force. As a result, the sediment or the like is separated and moved, and the moved sediment or the like is sucked at the suction port.

The apparatus for removing and recovering deposits and the like in a nuclear reactor according to the present invention is characterized in that the support handle provided on the upper part can be gripped by the main mast of the refueling machine. At the time of transporting the sediment removal / recovery device inside the reactor, it can be freely performed by suspending the support handle with a handling device such as an overhead crane. Thereby, the movement to the predetermined position can be efficiently performed.

According to a fourth aspect of the present invention, there is provided an apparatus for removing and collecting deposits and the like in a nuclear reactor, wherein a suction direction changing means for changing a direction of a suction port of the suction means for deposits and the like is provided. The suction port can be changed in direction by the suction direction changing means without moving the main body of the device for removing and collecting deposits in the reactor, and the suction port can be arranged at an appropriate position for the deposits to be removed.

According to a fifth aspect of the present invention, there is provided an apparatus for removing and collecting deposits and the like in a nuclear reactor, wherein a suction port elevating means for vertically moving a suction port of the suction means for deposits and the like is provided. The suction port can be moved up and down by the suction port elevating means without moving the main body of the apparatus for removing and collecting deposits in a nuclear reactor, and can be disposed at a position suitable for suction with respect to the deposits to be removed.

According to a sixth aspect of the present invention, there is provided an apparatus for removing and collecting deposits in a nuclear reactor, wherein equipment such as a deposit suction means, a fountain pump and a suction port elevating means are housed in a waterproof room. And Since the components are housed in a waterproof room in a watertight manner, there is no need to provide a waterproof structure to each device, and maintenance can be performed easily.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. The same components as those of the above-described conventional technology are denoted by the same reference numerals, and detailed description thereof will be omitted. The first embodiment relates to claims 1 to 4,
As shown in the front view of FIG. 1, the apparatus 12 for removing and collecting deposits and the like in the reactor includes a suction means for deposits such as a suction port 13, a filter 14 and a suction pump 15, an underwater television camera 3 and a fountain port.
The fountain means 17 provided with 16 are integrally formed (claims 1 and 2).

At the upper end of the suction pump 15, there is provided a support handle 18 which can be gripped by a main mast of a fuel exchanger (not shown). Further, as shown in the main part enlarged front view of FIG. 2, the suction port 13 for sucking the sediment and the like in the reactor pressure vessel together with water is protruded, and for example, for the sediment and the like to be sucked in the upper part of the core fuel. Thus, a suction direction changing means 19 for directing the suction port 13 in an arbitrary direction is provided (claim 4).

The filter 14 includes a filter casing 20
And a filter package 21. The cover 20a of the filter casing 20 is opened and closed, and the filter package 21 is
Can be loaded and unloaded. Note that the filter package 21 is formed by combining a filter or a strainer, or a filter and a strainer, in order to separate and collect sediment from water.

The underwater television camera 3 provides a photographed image to a worker on a water surface 4 by a monitor (not shown), and also has a lighting device (not shown) so that the underwater television camera 3 can clearly photograph the work area. Support.

The fountain means 17 is composed of, for example, a water piston driven by an air cylinder or the like. Also,
The suction direction changing means 19 is composed of an air cylinder or the like, and is configured so that the direction of the suction port 13 can be arbitrarily changed by a remote operation of an operator.

Next, the operation of the above configuration will be described. In the reactor pressure vessel, for example, in the upper part of the core fuel which is an operation target portion, floating substances or cladding in water may adhere or accumulate to form deposits.

First, the support handle 18 of the device 12 for removing and collecting deposits and the like in the reactor is gripped by the main mast of a fuel exchanger (not shown) and lowered below the water surface 4 in the reactor pressure vessel. Stop close to the top of the fuel. The transportation and movement of the device 12 for removing and collecting deposits in the reactor are
This can be done freely by hanging the support handle 18 with a handling device such as an overhead crane (not shown).

However, as described above, the main mast of the refueling machine which can semi-automatically refuel a fixed position in the core,
By suspending the apparatus for removing and collecting sediment in the reactor via the support handle 18 instead of the fuel, the operator can efficiently and automatically move to a predetermined position in the reactor remotely or automatically. Thereby, the worker can see from the image of the upper part of the core fuel sent by the underwater television camera 3 on the monitor,
The situation of the deposit and the like can be checked in detail.

After confirming the presence of deposits and the like in the upper part of the core fuel, the suction direction changing means 19 is operated and the suction port 13 is moved to the suction target deposit while checking the condition of the deposits and the like by the underwater television camera 3. Suction pump 15
To drive. As a result, the deposits and the like are sucked into the suction port 13 together with the surrounding water, and are collected in the filter package 21 of the filter 14.

The water that has passed through the filter 14 and has been purified by removing deposits and the like returns to the reactor pressure vessel via the suction pump 15 again. The operation of removing the deposits and the like can be continuously monitored by the underwater television camera 3 and the monitor. The position of the sediment or the like to be removed, the presence of which has been confirmed by the underwater television camera 3, changes the direction of the suction port 13 due to the movement of the removal / recovery device 12 for the sediment in the reactor and the operation of the suction direction changing means 19. There may be places where suction is difficult even after replacement.

Further, the adhesion is so strong that the sediment or the like is removed by the suction port 13.
May not be peeled off by suction alone, and may not be easily sucked into the suction port 13. At this time, the operator operates the fountain means 17 to urge water with a water piston or the like, and sprays the fountain from the fountain port 16 to the target sediment or the like.

By sucking the sediment and the like that have been separated and floated by the fountain and moved by the suction port 13, the sediment and the like in a state where it is difficult to collect by the simple suction with the suction port 13 can be easily removed. Can be.

The sediment or the like collected in the filter 14 is opened by opening the lid 20a of the filter casing 20 and taking out the filter package 21 therein, thereby changing the position of the sediment and the like removing and collecting device 12 in the reactor. It can be done easily without any. In addition, by loading the new filter package 21 instead, the work of removing deposits and the like can be performed continuously.

The second embodiment is a modification of the first embodiment according to claims 1 to 6. Therefore, description of the same configuration and operation as in the first embodiment is omitted,
The differences will be mainly described. The schematic configuration diagram of FIG. 3 emphasizes the function of each part. The apparatus 22 for removing and collecting deposits in the reactor includes a lifting motor 23a for vertically moving the suction port 13 of the suction means for deposits and a lifting mechanism. 23b is provided.

Further, a pump 24 commonly used as a means for sucking deposits and the like and a fountain means, and a switching valve 25 are provided, and the elevating motor 23a, the pump 24 and the switching valve 25 are made dry, and the watertight waterproof chamber 26 is provided. It is configured to be accommodated (claims 5 and 6). In addition, the suction direction changing means 19 of the suction means such as sediment, the underwater television camera 3, the fountain port 16 and the support handle 18 are integrally provided, and the filter 14 is attached to a position where it can be easily replaced outside. ing.

Further, on the upper part of the outer periphery, there is provided a check for the sediment removal / recovery device 22 in the nuclear reactor, a temporary placement when the suspension is changed from a ceiling crane or the like to the refueling machine, or a temporary fixing at the time of the check. An installation leg 28 is provided to be mounted on a temporary gantry 27 installed at an edge of a reactor pressure vessel or a reactor well (not shown).

The operation of the above configuration is as follows. An apparatus for removing and recovering deposits and the like in the reactor suspended from the support handle 18 by an overhead crane or the like is once mounted on the upper part of the reactor pressure vessel via the installation legs 28. It is mounted on a temporary mount 27 provided at the edge of an open reactor well (not shown).

At this point, the device 22 for removing and collecting deposits in the reactor
After the inspection is performed, the support handle 18 is gripped by the main mast of the refueling machine and lowered below the water surface 4 in the reactor pressure vessel. Thereby, the worker can see from the image of the upper part of the core fuel sent by the underwater television camera 3 on the monitor,
The situation of the deposit and the like can be checked in detail.

At this time, the suction port 13 can be directed to the direction of the suction target sediment or the like by the operation of the suction direction changing means 19 by the operator. In addition, without moving the main body of the device 22 for removing and collecting deposits in the reactor, by operating the lifting / lowering motor 23a by operating the suction port lifting / lowering means 23 in the normal / reverse direction,
It can be moved up and down via the lifting mechanism 23b.

This avoids interference with surrounding reactor internal structures caused by raising and lowering the main body of the reactor internal sediment removal / recovery device 22, and also provides a suction port 13 at a position suitable for sucking the sediment. Can be easily arranged, so that the safety and operability of the work of removing and collecting deposits and the like are improved.

The suction port lifting / lowering means 23 is
Not only for the suction port 13 but also for the fountain port 16, the fountain port 16 is locked to the suction port 13 so as to be integrated, so that the suction port lifting / lowering means is provided.
By moving the fountain port 16 up and down together with the suction port 13 by the operation of 23 to eject a strong fountain from a short distance to the sediment or the like, the sediment or the like can be more easily moved.

The fountain port 16 can also be provided with a dedicated elevating means and a direction changing means, and the function and effect of the fountain port 16 are similar to the case of the suction port 13 in that it removes and collects deposits in the reactor. The fountain can be spouted at an appropriate position with respect to the sediment or the like without moving the main body of the device 22 up and down, or back and forth and left and right each time.

When the pump 24 is operated by switching the switching valve 25 to the suction side to suck the deposits, the deposits are sucked into the suction port 13 together with the surrounding water, and are filtered by the filter 14 disposed outside. Collected.

The filter 14 has a filter package.
The filter package 21 is easily exchanged because the filter 14 is arranged outside. Further, the purified water is returned again into the reactor pressure vessel via the pump 24 and the switching valve 25.

After the fountain port 16 is set at a predetermined position, the switching valve 25 is switched to the fountain side, and the pump 24 is moved.
When operated, the filter is sucked from the suction port 13 and
The water purified in 14 is injected from a fountain port 16 toward sediments and the like. The sediment and the like that have been separated and floated by the fountain are sucked at the suction port 13 by switching the switching valve 25 to the suction side again. Objects and the like can be easily removed.

By switching the switching valve 25 to the fountain side at any time during the work of sucking the sediment, etc.
The fountain is sprayed toward sediments from 16. At this time, suction of water and sediment at the suction port 13 is temporarily stopped,
For the separation movement of deposits etc. attached to the surface of the furnace internals,
The intermittent jetting of the fountain and the suction between the jets cause the sediment and the like to oscillate, so that it works effectively as a separating action. Therefore, the effect of removing and collecting deposits due to the peeling movement is improved.

In the apparatus 22 for removing and recovering deposits and the like in the nuclear reactor, the lift motor 23a and the pump 24 and the switching valve 25, such as electric equipment, are connected to the watertight waterproof chamber 26 by the main mechanism.
Since each device is housed in a watertight structure, each device does not need to have a waterproof structure, and a device with a normal specification can be used, and inspection can be easily performed by opening the waterproof room 26 during maintenance.

Further, the above-mentioned temporary gantry 27 is provided at a place where a worker's scaffold is safe and easy to work, such as an edge of a reactor well, at the time of maintenance and inspection of the reactor sediment removal / recovery device 22, By temporarily fixing the sediment removal / recovery device 22 in the reactor with bolts or the like, the operation can be performed safely compared to a simple mounting.

[0050]

As described above, according to the present invention, it is easy to hold the reactor sediment removal / recovery device by the fuel exchanger and place it at a predetermined position. Can be inspected by underwater television camera.

At the predetermined position, the main body of the apparatus for removing and collecting deposits in the reactor is not moved, and there is no need to replace the underwater television camera and the suction jig. Since the collection and removal of the movement can be performed simultaneously while monitoring with the underwater television camera,
The work efficiency of removing deposits and the like is improved, and the burden on the operator is reduced.

[Brief description of the drawings]

FIG. 1 is a front view of an apparatus for removing and collecting deposits in a nuclear reactor according to a first embodiment of the present invention.

FIG. 2 is an enlarged front view of a main part of the first embodiment according to the present invention.

FIG. 3 is a schematic configuration diagram of an apparatus for removing and collecting deposits in a nuclear reactor according to a second embodiment of the present invention.

FIG. 4 is a front view of a conventional underwater cleaner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Underwater cleaner, 2 ... Extension operation stick, 3 ... Underwater television camera, 4 ... Water surface, 5 ... Suction jig, 6 ... Stand, 7 ... Collection tank,
8: cyclone separator, 9: submersible pump, 10: bag filter, 11: suction hose, 12, 22: device for removing and collecting deposits etc. in the reactor, 13: suction port, 14: filter, 15: suction pump, 16 ... Fountain opening, 17: fountain means, 18: support handle, 19: suction direction changing means, 20: filter casing,
20a: lid, 21: filter package, 23: suction port lifting / lowering means, 23a: lifting / lowering motor, 23b: lifting / lowering mechanism, 24: pump, 25: switching valve, 26: waterproof room, 27: temporary mounting stand, 28: installation leg .

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI G21F 9/28 522 G21F 9/28 522H (72) Inventor Shigehiro Oka 66-2 Horikawa-cho, Sai-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Engineering Corporation

Claims (6)

[Claims] 1. A suction port for sucking sediments, suspended solids, and attached matter in a nuclear reactor together with water, a filter for trapping sediments, etc. from the sucked water, and a suction pump including a suction pump. A device for removing and collecting deposits and the like in a nuclear reactor, wherein a support handle is provided on an upper part integrally with the means and an underwater television camera for photographing a work target portion. 2. The apparatus for removing and collecting sediments in a nuclear reactor according to claim 1, wherein said apparatus for removing and collecting sediments in a nuclear reactor includes fountain means for moving sediments in water. 3. The reactor according to claim 1, wherein the support handle is capable of being gripped by a main mast of a refueling machine in the apparatus for removing and collecting deposits in a nuclear reactor. Internal sediment removal and recovery equipment. 4. The reactor internal deposit according to claim 1, further comprising a suction direction changing means for changing a direction of the suction port in the apparatus for removing and recovering internal deposits and the like. Etc. removal and recovery equipment. 5. The reactor sediment according to claim 1, further comprising a suction port elevating means for vertically moving the suction port in the reactor sediment removal / recovery apparatus. Etc. removal and recovery equipment. 6. The apparatus for removing and recovering deposits and the like in a nuclear reactor, wherein equipment such as a suction means for the deposits and a pump of a fountain means and a suction port raising / lowering means are housed in a waterproof room. The apparatus for removing and collecting deposits in a nuclear reactor according to any one of claims 1 to 5.