JPH07120585A - Handling tool for diffuser wear ring - Google Patents

Abstract

PURPOSE:To conduct maintenance and inspection work for an internal pump safely for a short time and reduce the radiation exposure dose of workers. CONSTITUTION:A side-face concavity 35 is formed on the upper outer peripheral surface of a diffuser wear ring 32, and a hook 37 is held in the side-face concavity 35. The hook 37 is installed on a base plate 80 by a guide block 78, which is moved to the right and left by an arm 48. The arm 48 is connected with a lower joint 76, which is installed on the base plate 80. The upper part of the lower joint 76 is connected with a joint rod 75 and an air cylinder 44, and the top of a piston rod 45 is connected with a disk 46, which is locked and unlocked by a locking mechanism consisting of a lever 42 and a pin 41. Above the locking mechanism, a cable box 69, a stand pipe 88, an upper joint 60, a suspending rope 16 and a suspension 58 are sequentially connected with each other one by one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a built-in-reactor pump installed in an improved boiling water reactor (ABWR)
An internal pump) and a handling tool for a diffuser wear ring for an internal pump used for installation and removal work.

[0002]

2. Description of the Related Art Generally, a conventional boiling water reactor (BW) is used.
R) sends the coolant to the core by forcibly circulating the coolant between a recirculation pump provided outside the reactor pressure vessel and a jet pump provided inside the reactor pressure vessel as is well known. I'm out.

Such an external recirculation system not only has a complicated structure, but the recirculation pipe connecting between the reactor pressure vessel and the recirculation pump serves as a boundary of the coolant, so that it may be regenerated by some accident. If the circulation pipe breaks,
Possible loss of coolant.

Therefore, in order to prevent such a loss of coolant accident, an improved boiling water reactor (ABWR) has been developed in which the coolant is forcedly circulated in the reactor pressure vessel.

The improved boiling water reactor is constructed as shown in FIG. That is, a spent fuel pool 3 and an equipment storage pool 4 are arranged on an operating floor 2 attached above the reactor pressure vessel 1, and a circular reactor well 5 is installed between these pools 3 and 4. Has been done.

A reactor pressure vessel 1 is supported in the reactor well 5 by a support 6. A cylindrical shroud 7 is provided in the reactor pressure vessel 1, and a shroud head 8, a steam separator 9 and a steam dryer 10 are sequentially provided above the shroud 7 so as to face upward.
Further, a plurality of internal pumps 11 are provided vertically through the bottom of the reactor pressure vessel 1, and the heads thereof are inserted into the reactor pressure vessel 1.

These internal pumps 11 are arranged in an annular space 12 formed by the outer peripheral surface of the shroud 7 and the inner peripheral surface of the reactor pressure vessel 1, for example, ten pumps are arranged in an annular shape at an equal pitch in the circumferential direction. The reactor water is forcedly circulated in the lower part of the reactor pressure vessel 1.

Further, a guide rail 13 is attached to the outer peripheral surface of the shroud 7 on the installation position of each internal pump 11, while a platform 14 is provided on the operating floor 2 at the peripheral edge of the upper end of the reactor well 5. It is arranged so that it can travel. In FIG. 3, 15 is a trolley, 16 is a lifting rope, and 17 is a hoist.

FIG. 4 shows a state in which the reactor shown in FIG. 3 is inspected. The reactor pressure vessel head 18 and the containment vessel head are shown.
19 is removed, and the equipment above the shroud head 8 in the reactor pressure vessel 1 is removed.

The internal pump 11 installed in such a nuclear reactor is usually mainly composed of a pump section P and a motor section M as shown in FIG. That is, the motor case 20 of the motor unit M is inserted into the opening sleeve 1a at the bottom of the reactor pressure vessel 1, and the upper end thereof is the opening sleeve 1a.
The lower half of the motor case 20 is hung outside the reactor pressure vessel 1 by being welded to the.

In the motor case 20, a motor shaft 21 keyed so as to be freely separated downward is rotatably and coaxially housed. A rotor is integrally fixed to the outer circumference of the motor shaft 21, and a stator 24 is arranged on the outer circumference of the rotor 23 with a predetermined gap.

The pump portion P includes a pump shaft 22 and
The pump shaft 22 includes an impeller 26 screwed to the upper end of the pump shaft 22 with a grip bolt 25. This impeller
A diffuser 27 is provided on the outer periphery of 26.

The lower end of the diffuser 27 engages with the upper end of the stretch tube 28, and the stretch tube 28 is connected to the stretch tube nut 29. As a result, the diffuser 27 is fixed on the opening sleeve 1a. The diffuser 27 and the stretch tube 28 are keyed to the opening sleeve 1a to prevent them from rotating. In the figure, reference numeral 30 is a closing cover that closes the lower end of the motor case 20, 31 is a secondary seal, and 32 is a diffuser wear ring.

Internal pump configured in this way
When inspecting 11 after the start of plant operation, each component of the internal pump 11 must be disassembled remotely and reassembled after the inspection.

In the operation, first, the containment vessel head 19, the reactor pressure vessel head 18 and the steam dryer 10 shown in FIG. 3 are sequentially removed, and then the upper portion of the reactor well 5 is filled with water as shown in FIG. Then, the radiation is shielded and the steam separator 9 and the shroud head 8 are removed.

Then, the handling tool attached to the end of the suspension rope 16 is positioned by the traveling of the platform 14 and the traverse of the trolley 15, and along with the vertical movement by the hoist 17, the guide is guided along the guide rail 13. The parts of the pump are moved up and down by the handling tool.

In this way, the disassembling work of the internal pump 11 is started, and the inspection pump is assembled again after the inspection. In the disassembling procedure of the internal pump, first, the impeller 26 and the pump shaft 22 of the pump section P shown in FIG. 5 are removed from the inside of the reactor pressure vessel 1 shown in FIG.

Then, after removing the impeller 26, the diffuser wear ring 32 having a structure in which the inner diameter portion of the diffuser 27 and a plurality of fitting portions of different diameters are provided and a tapered guide is provided is inspected and inspected. Be seen.

FIG. 6 shows a state in which the diffuser wear ring 32 is removed from the diffuser 27. The diffuser wear ring 32 is assembled by fitting to the inner surface of the diffuser 27 with a fitting tolerance. The orientation is fixed by the four short pins 33 provided on the upper surface of the diffuser 27 and the holes 34 of the diffuser wear ring 32 which match with each other. The diffuser wear ring 32 is replaced with a cover that prevents the impeller 26 from being scratched.

[0020]

By the way, the work of attaching and detaching the diffuser wear ring 32 of the internal pump 11 as described above is a work of 20 meters or more underwater. For this reason, for example, it is performed remotely from above the reactor pressure vessel 1 using a grip or the like operated by an air cylinder, and it is not possible to confirm the engagement of the grip with the diffuser wear ring 32 of the internal pump 11. It is done visually by a worker from the surface of the water.

However, such a work is a remote work in a narrow place under water or has a tight fitting tolerance, so that the workability is poor and it takes a long time. Moreover, if the engagement state of the portion holding the diffuser wear ring 32 is incomplete, the diffuser wear ring 32 may fall off during the lifting operation and the diffuser wear ring 32 may fall into the reactor pressure vessel.

Further, even if the engaged state is perfect,
When an accidental operation or an accident such as loss of air source occurs, the engaged state may be disengaged, and the diffuser wear ring 32 may fall into the reactor pressure vessel 1 as well, which greatly impedes the operation of the reactor. There are issues such as the possibility of coming.

The present invention has been made to solve the above problems, and the purpose thereof is to allow the diffuser wear ring to be attached and detached safely and surely during the maintenance and inspection work of the internal pump. It is to provide a handling tool for a diffuser wear ring.

[0024]

SUMMARY OF THE INVENTION According to the present invention, a side surface recess is provided on an upper outer peripheral surface of a diffuser wear ring, a base plate seated on an upper surface of the diffuser wear ring is provided, and a hook for holding the side surface recess is provided on the base plate. A lower joint that pivotally supports one end of an arm connected to the guide block is provided on the base plate, a joint rod is connected to the lower joint, and the joint rod is connected to an air cylinder. An air cylinder is fixed to a plate, a cable box is installed above this plate via a rod, an upper lid is installed above this cable box, an upper joint is installed on this upper lid via a pin, and it is suspended on this upper joint. It is characterized in that a hanging device is provided via a rope.

[0025]

[Function] The diffuser wear ring can be installed and removed safely and reliably during maintenance and inspection work of the internal pump. Even if you accidentally operate the operation panel and, for example, release the diffuser wear ring while lifting it, a mechanical interlock mechanism (hereinafter referred to as the lock mechanism) that uses the weight of the diffuser wear ring operates Cylinder piston rod locks.

That is, the operation of the air cylinder is mechanically stopped when the diffuser wear ring of the internal pump is lifted. Further, the limit switch of the interlock mechanism is electrically operated when the handling tool is seated on the upper surface of the diffuser pin. Therefore, there is no concern of hanging the diffuser wear ring, and safe and reliable handling work can be performed.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a handling tool for a diffuser wear ring according to the present invention will be described with reference to FIGS. FIG. 1 shows a side surface recess 35 of the diffuser wear ring 32.
The handling tool 36 for the diffuser wear ring according to the present embodiment
Grip the hooks 37, 37 from both sides and place the diffuser wear ring handling tool 36 on the top surface of the diffuser wear ring 32.
2 is a plan view of FIG. 1 showing a seated state of the base plate 80 of FIG.

Reference numeral 16 in the drawing is a suspension rope suspended from the trolley 15 above the reactor pressure vessel 1 shown in FIGS. 3 and 4, and a diffuser wear ring is attached to the lower portion of the suspension rope 16. The handling tool body 38 of the handling tool 36 is connected. The upper part of the suspension rope 16 is connected to the suspension device 58.

The handling tool main body 38 is composed of a frame 39 that can slide up and down due to the weight during lifting and seating, and a lever 42 that is connected to the frame 39 with pins 40 and 41 on the left and right, and the frame 39 slides up and down. Thus, the lever 42 has a mechanical lock mechanism that opens and closes mechanically. The lock mechanism is composed of a lever 42 and a pin 41.

A grip body 43 is formed below the body 38 of the diffuser wear ring handling tool 36, and an air cylinder 44 is incorporated in the grip body 43. The piston rod 45 of the air cylinder 44 is projected upward, and a disc 46 is fixed to the upper end by a nut 47, and the vertical movement of the disc 46 is limited (controlled) by the opening / closing operation of the lever 42.

A joint rod 75 is connected to the lower side of the air cylinder 44, and an arm 48 for opening and closing the hook 37 is connected through a joint 76. The arm 48 interlocks with the operation of the arm 48.
Open and close 37. A plurality of seating detection mechanisms for the grip body 43 are provided inside the grip body 43.

A lever 50 is incorporated inside the seating detection mechanism, and when the base plate 80 of the handling tool 36 of the diffuser wear ring is seated on the upper surface of the diffuser 27, the pin 51 is inserted.
Is pushed up to operate the lever 50, thereby operating the underwater limit switch 53 incorporated in the grip body 43, thereby forming an electrical interlock mechanism. Further, a block 49 is provided integrally with the hook 37 to detect the closing motion (grasping motion) of the hook 37, and the block 49 moves in conjunction with the motion of the hook 37 to operate an underwater limit switch 52. It has a lock mechanism.

That is, the grip body 43 is the diffuser 27.
When it is seated on the upper surface of the air cylinder 44, air (air) can be supplied to the air cylinder 44, and the side surface recess 35 of the diffuser wear ring 32 can be grasped and released by the hook 37 to serve as an electrical interlock mechanism. ing.

When the grip body 43 is seated at the correct position on the diffuser 27, the tip of the pin 51 incorporated in the grip body 43 contacts the pin head of the diffuser 27 to activate the underwater limit switch 53. Also, air can be supplied to the air cylinder 44 in this state, and the hook
Block 37 integrated with hook 37 when 37 moves to the grip side 49
Moves and activates the underwater limit switch 52.

As a result, the operation is displayed (lighted) from the grip body 43 to the control panel on the trolley (reference numeral 15 in FIG. 3).
The operator on the trolley 15 is informed that the diffuser wear ring handler 36 is seated in the correct position on the diffuser 27.

Next, in this state, the operation switch of the control panel on the trolley is operated to supply air into the air cylinder 44,
Push the piston rod 45 upward. This allows arm 48
Moves upward and the side surface recess 35 of the diffuser wear ring 32 can be gripped by the hook 37.

When the handling tool 36 of the diffuser wear ring is lifted up by the hanging rope 16, the frame 39 is first moved upward and the lever 42 is changed from the opening operation to the closing operation (horizontal). By making contact with the disk 46 from above, the operation (release operation) of the air cylinder 44 can be mechanically locked.

Further, a plurality of positioning pins 56 (2 in FIG. 2 are provided on the lower surface of the diffuser wear ring grip body 43 at positions corresponding to the guide holes formed in the diffuser 27.
Orientation can be aligned when the diffuser wear ring grip body 43 is engaged with the internal pump body (diffuser wear ring 32).

Further, guide rollers 54 and 56 which are opened and closed by the operation of the air cylinder 44 are provided inside the main body 43 of the diffuser wear ring gripping tool and vertically moved along a guide rail 13 provided on the outer wall of the shroud 7. And can be aligned with the internal pump body (diffuser wear ring 32). An absorber (spring 57) is incorporated in the guide roller 54 that extends toward the inner wall side of the reactor pressure vessel 1 and can contract, so as to absorb irregularities on the inner wall of the reactor pressure vessel 1.

A plurality of large and small cylinders are used for the opening and closing operations of the guide rollers 54 and 55, and a large cylinder (not shown) and a large-diameter joint are assembled on the guide rail 55 side of the guide rail side to form a guide roller. The opening / closing operation of 55 can be performed first from the guide roller 54, and the engagement with the guide rail 13 can be easily performed.

The suspending device 58 is a device for suspending the diffuser wear ring handling tool 36 with the two suspending ropes 16, and has the function of a balance for absorbing the deviation of the two lengths. In the figure, reference numeral 59 is a swing bolt, which is a fastener for attaching the cover to the suspension device 58. The suspension device 58 and the handling tool 36 are connected by an upper joint 60. The upper joint 60 is connected by a first pin 61 and a second pin 62, the first pin 61 is rotatable, and the second pin 62 is rotatable until it is assembled in a direction perpendicular to the first pin 61. .

The swing bolt 59 is assembled to the plate 89, and the plate 89 is attached to the stand pipe 88.
The stand pipe 88 is fixed to the upper surface of the upper lid 63. Top cover 63
Is a component for forming the upper part of the grip 38.

A first rod 64 is coupled to the upper lid 63, and a lower portion of the first rod 64 is connected to the frame 39. A second rod 65 is a component that connects the guide roller 54 and the grip 38. A cable box 69 is provided below the upper lid 63, and the cable box 69 connects a plurality of cables 67 and a cable bundle 68 in which these cables 67 are combined.

The upper end of the cable box 69 is the box lid 66.
Is blocked by. Cable 67 is an underwater limit switch
It is connected to 52, 53. A plurality of cables 67 penetrate the cable box bottom plate 70 and are sealed. The upper part of the rod 71 is connected to the cable box bottom plate 70, and the lower part of the rod 71 is connected to the plate 72.

The rod 71 serves as a guide for moving the frame 39 up and down. The plate 72 is a component for assembling internal parts, and is placed on the upper end surface of a cylinder 73 that serves as a cover for the grip 38. A cylinder head 74, which is a component of the air cylinder 44, is provided in the cylinder 73.
On the lower surface of 74, a joint rod 75, which is a component of the air cylinder 44,
Is installed.

The joint rod 75 is connected to the lower joint 76,
Arm 48 is connected to 76. A cover 77 is provided at the lower end of the cylinder 73 to cover the upper part of the arm 48 and protect each component. Each part is mounted on the base plate 80, and the guide block 78 and the base block are mounted on the base plate 80.
79 is placed, and the base block 79 is a member that holds a column that guides the joint 76.

The guide block 78 guides the movement of the hook 37. Guides on the bottom of the base plate 80
81 is provided and this guide 81 is for inserting the handling tool 36 into the diffuser wear ring 32.

In FIG. 2, reference numeral 82 indicates an air joint,
The air joints 82 are connected to air hoses (not shown) for supplying air to the air cylinders 44, and are provided at four locations. This is a total of four locations for the insertion and extraction of the air cylinder 44 and the expansion and contraction of the guide rollers 54, 54. Sign
Reference numeral 83 is a connecting rod, which serves as a shaft of the guide roller 55.

Reference numeral 84 is a member for holding the connecting rod 83 by a support, 85 is a member for attaching the support 84, 86 is a stopper, and a mechanical stopper when the hook 37 is retracted. is there. 87 is the first block,
The second block 90 is a component for assembling the underwater limit switch 53 and the lever 50, and is a component necessary for assembling the guide roller 54.

Next, the operation of the present apparatus configured as described above will be described. First, the trolley 15 above the reactor pressure vessel 1
The diffuser wear ring gripper 36 is suspended from the reactor pressure vessel 1 using the suspension rope 16 from the above.

The diffuser wear ring grip 36 suspended in the reactor pressure vessel 1 is guided by the guide rail 13 provided on the outer wall of the shroud 7 to guide the internal pump.
It is hung just above 11. And internal pump
Positioning pins 56, 56 of the present device are engaged with guide holes provided on the upper surface of the diffuser wear ring 32 of 11, and the limit switch 53 is operated, which is displayed on the operation panel on the trolley 15.

At this time, the hook 37 of the handling tool 36 for the diffuser wear ring is in the open state and is located on the upper side surface of the diffuser wear ring 32. In this state, the air cylinder 44 is driven to pull up the piston rod 45, so that the arm 48 is pulled up and the hook 37 engages with the groove portion of the diffuser wear ring 32.

When the hoisting rope 16 is hoisted by the hoisting machine 17 in this state, the frame 39 first moves upward and the lever 42 changes from the opening operation to the closing operation (horizontal), and the upper portion of the piston rod 45 is moved. The disc diffuser wear ring 32 is removed from the internal pump 11 by contacting it from above the circular plate 46 and pulling up the operation (release operation) of the air cylinder 44 from the inside of the reactor pressure vessel 1 in a mechanically locked state. Removed.

In the above embodiment, by providing the indicator light for indicating the engagement state of the grip portion on the trolley 15 connected to the diffuser wear ring gripping tool 36 by the cable, the engagement state can be easily confirmed from above. be able to.

Further, by providing a lock mechanism for mechanically locking the piston rod (rod) 45 of the air cylinder 44 in accordance with the lifting load of the grip body 43, even if an accidental operation or loss of the air source occurs, The diffuser wear ring can be reliably lifted without being released during lifting.

In addition to the above-described embodiment, the present invention uses a plurality of underwater limit switches to be seated on the upper surface of the diffuser when the diffuser wear ring is gripped by the body of the handling tool for the internal pump. An electric interlock mechanism capable of detecting a state is incorporated, and a mechanism for controlling the air supply to the air cylinder portion according to the detected state is provided.

[0057]

As described above, according to the present invention, it is possible to safely and reliably perform the work of mounting and removing the internal pump in the maintenance and inspection work of the internal pump in a short time.

[Brief description of drawings]

FIG. 1 is an elevational view showing an embodiment of a handling tool for a diffuser wear ring according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a longitudinal sectional view schematically showing a boiling water reactor.

FIG. 4 is a vertical cross-sectional view showing a state at the time of periodic inspection of the nuclear reactor in FIG.

5 is a vertical cross-sectional view showing an internal pump installed in the nuclear reactor of FIG.

FIG. 6 is a perspective view showing a relationship between the diffuser and the diffuser wear ring in FIG.

[Explanation of symbols]

1 ... Reactor pressure vessel, 1a ... Opening sleeve, 2 ... Operating floor, 3 ... Spent fuel pool, 4 ... Equipment storage pool, 5 ... Reactor well, 6 ... Support, 7 ... Shroud, 8 ... Shroud head, 9 … Air-water separator, 10…
Steam dryer, 11… Internal pump, 12 Annular space, 13
… Guide rails, 14… Platforms, 15… Trolleys,
16 ... Suspension rope, 17 ... Hoisting machine, 18 Reactor pressure vessel head, 19 ... Containment vessel head, 20 Motor case, 21 ... Motor shaft, 22 ... Pump shaft, 23 ... Rotor, 24 ... Stator, 25 ... Grip bolt , 26 ... Impeller, 27 ... Diffuser, 28 ... Stretch tube, 29 ... Stretch tube nut, 30 ... Closing cover, 31 ... Secondary seal, M ... Motor part, P ... Pump part, 32 ... Diffuser wear ring,
33 ... Short pin, 34 ... Hole, 35 ... Side recessed part, 36 ... Diffuser wear ring handling tool, 37 ... Hook, 38 ... Handling tool body, 39 ... Frame, 40, 41 ... Pin, 42 ... Lever, 43 ... Grip Tool body, 44 ... Air cylinder, 45 ... Piston rod, 46 ...
Disc, 47 ... Nut, 48 ... Arm, 49 ... Block, 50 ... Lever, 51 ... Pin, 52, 53 ... Underwater limit switch, 54,
55 ... Guide roller, 56 ... Positioning pin, 57 ... Spring, 58 ... Suspension device, 59 ... Swing bolt, 60 ... Upper joint, 61 ... First pin, 62 ... Second pin, 63 ... Upper lid, 64 ...
First rod, 65 ... Second rod, 66 ... Box lid, 67
… Cables, 68… Cable bundles, 69… Cable boxes,
70 ... Cable box bottom plate, 71 ... Rod, 72 ... Plate, 73 ... Tube, 74 ... Cylinder head, 75 ... Joint rod, 76 ... Lower joint, 77 ... Cover, 78 ... Guide block, 79 ... Base block, 80 ... Base plate (Bottom plate), 81 ... guide,
82 ... Air fitting, 83 ... Connecting rod, 84 ... Support, 85 ... Plate, 86 ... Stopper, 87 ... First block, 88 ... Stand pipe, 89 ... Plate, 90 ... Second block.

Claims (4)

[Claims] 1. A side surface recessed portion is provided on an upper outer peripheral surface of a diffuser wear ring, a base plate seated on an upper surface of the diffuser wear ring is provided, and a hook for gripping the side surface recessed portion is provided on the base plate via a guide block. A lower joint that pivotally supports one end of an arm connected to the guide block is provided on the base plate, a joint rod is connected to the lower joint, the joint rod is connected to an air cylinder, and the air cylinder is fixed to the plate. , A cable box is provided above the plate via a rod, an upper lid is provided above the cable box, an upper joint is provided on the upper lid via a pin, and a lifting device is attached to the upper joint via a suspension rope. A diffuser wear ring handling tool characterized by being provided. 2. A disk is provided at an upper end portion of a piston rod of the air cylinder, and a locking mechanism is provided which is coupled with a lever and a pin which engages and disengages with the disc by the operation of the piston rod. The handling tool for the diffuser wear ring according to claim 1. 3. The handling tool for a diffuser wear ring according to claim 1, wherein a guide for guiding along an inner surface of the diffuser wear ring is provided on a lower surface of the base plate. 4. A handling tool for a diffuser wear ring according to claim 1, wherein a guide roller that opens and closes by the operation of the air cylinder is provided, and a plurality of large and small cylinders are provided in an opening and closing operation mechanism of the guide roller. .