JPH1184066A - Channel bolt wrench - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a channel bolt wrench which can improve the workability of fuel assembly installing and housing work, because the wrench can easily and stably attach and detach a channel fastener to and from a fuel assembly by remote control. SOLUTION: A channel bolt wrench 28 is provided with a long main body 50 which can transmit rotationally operating forces, a wrench section 53 provided at the front end of the main body 50, a wrench operating section 54 which attaches/detaches the wrench section 53 to and from the channel fastener of a fuel assembly, a wrench guide section 55 which guides the wrench section 53 onto the channel fastener, and a rotationally operating section 51 which rotationally operates the wrench section 53. The wrench guide section 55 has a guide face which is engaged at least with the handle of the fuel assembly or the internal surface of an angular pipe-like fuel channel. The section 55 guides and positions the wrench section 53 to the cap screw of the channel fastener when the section 55 is engaged at least with the handle of the fuel assembly or the internal surface of the fuel channel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel bolt wrench for attaching and detaching a channel fastener of a fuel assembly, and more particularly to a long fuel channel bolt suitable for attaching and detaching a channel fastener attached to the fuel assembly in a boiling water reactor. About a wrench.

[0002]

2. Description of the Related Art Generally, in a boiling water reactor, a core portion is formed in a reactor pressure vessel, and a number of fuel assemblies are mounted on the core portion. Four fuel assemblies form a set, and control rods having a cross-shaped cross section are put in and out between the fuel assemblies in each set. In the fuel assembly, a fuel bundle in which a large number of fuel rods are bundled is accommodated in a rectangular tubular fuel channel, and the fuel bundle and the fuel channel are connected by a channel fastener.

[0003] A channel fastener is attached to an upper corner of each fuel assembly, and fastens a fuel bundle to a fuel channel. Also, the channel fastener is 4
Each set of fuel assemblies is separated from each other by a predetermined distance so that control rods can be inserted or withdrawn between each set of four fuel assemblies.

[0004] On the other hand, at the time of refueling or inspection, it is necessary to remove the fuel channel and the fuel bundle. Therefore, the channel fastener is configured to be attached to and detached from the fuel assembly.

[0005]

Although a channel fastener is removably attached to the fuel assembly, the cap screw cannot be made large due to restrictions on the mounting position of the channel fastener. When the fuel assembly is in relatively deep water due to the small shape of the cap screw, the conventional channel bolt wrench has a short length in the longitudinal direction, making it difficult to remotely attach and detach the channel fastener. Was.

The channel fastener is composed of a cap screw and a fuel spring, and a side surface of the fuel spring also serves as a guide for positioning a channel bolt wrench. However, when the fuel assembly is stored in a fuel rack or the like, the channel fastener is not exposed to the outside,
Since the side surface of the fuel spring cannot perform the guiding function, the channel fastener cannot be detached.

The present invention has been made in view of the above-described circumstances, and has an improved workability by easily and stably attaching and detaching a channel fastener regardless of the installation or accommodation of a fuel assembly. The purpose is to provide a wrench.

Another object of the present invention is to provide remote control by remote control when the fuel assembly is located in relatively deep water and when the channel bolt wrench cannot be guided outside the fuel assembly including the fuel spring. An object of the present invention is to provide a channel bolt wrench that can efficiently perform attachment and detachment work of a channel fastener in a short time.

[0009]

SUMMARY OF THE INVENTION A channel bolt wrench according to the present invention has a long channel bolt wrench body capable of transmitting a turning operation force as described in claim 1 in order to solve the above-mentioned problems. A wrench provided at the tip of the channel bolt wrench main body, a wrench operating unit for attaching and detaching the wrench to and from the channel fastener of the fuel assembly, and a wrench guide for guiding the wrench to the channel fastener. A swivel operation unit for performing a swivel operation of the wrench unit, wherein the wrench guide unit engages at least one of the handle of the fuel assembly and the inner surface of the rectangular tubular fuel channel to guide the wrench unit, The wrench can be positioned and installed on the cap screw of the channel fastener.

According to a second aspect of the present invention, there is provided a channel bolt wrench having a wrench guide provided on an outer side of a wrench and an inner surface of a fuel channel. A wrench guide is engaged with the corner to guide the wrench.

Further, in order to solve the above-mentioned problems,
In the channel bolt wrench according to the present invention, as described in claim 3, the channel bolt wrench main body is configured such that a plurality of rod-shaped or pipe-shaped connecting members are detachably connected in the axial direction to be integrally rotatable. is there.

Furthermore, in order to solve the above-mentioned problems, a channel bolt wrench according to the present invention is provided in claim 4.
As described in the wrench portion, the outer pipe and the inner pipe that are relatively slidable in the axial direction are provided in a double pipe structure, and the lower end of the outer pipe has a circumferential groove of a cap screw of the channel fastener. While a gripping means capable of being gripped is provided, a socket means capable of engaging with the vertical groove of the cap screw is provided at a lower end portion of the inner pipe, and the cap screw can be turned through the socket means. .

Still further, in order to solve the above-mentioned problem, a channel bolt wrench according to the present invention is described in claim 5.
As described above, the wrench is a cylinder provided above the wrench, and the cylinder is operated by remote control to drive the wrench.

On the other hand, in order to solve the above-mentioned problem, a channel bolt wrench according to the present invention is characterized in that the wrench guide part is fixed to a guide holder fixed to the outside of the wrench part. A guide member fixed to a guide holder, the guide member including at least one of a channel guide surface engageable with an inner surface of the fuel channel and a handle guide surface engageable with a handle of the fuel assembly. It is a thing.

On the other hand, in order to solve the above-mentioned problem, in the channel bolt wrench according to the present invention, as described in claim 7, the wrench portion has a detection member therein so as to be relatively slidable in the axial direction. The detecting member is linked to a switch means electrically connected to the display means so that the display means can confirm the positioning to the channel fastener.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a channel bolt wrench according to the present invention will be described below with reference to the accompanying drawings.

The channel bolt wrench according to the present invention comprises:
Used to remove channel fasteners attached to fuel assemblies. As shown in FIGS. 1 and 2, the fuel assembly 10 includes a core 12 of a reactor pressure vessel 11.
Are mounted in pairs. In the core 12,
Core support plate 14 and upper lattice plate 1 in core shroud 13
5 are laid horizontally to form a furnace internal structure. On the lower side of the core support plate 14, the mechanical and physical strength is reinforced by a reinforcing beam 16, while a fuel support bracket 17 is installed on the core support plate 14. The lower portion of a set of four fuel assemblies 10 is mounted on the fuel support bracket 17, and the upper portion of the fuel assembly 10 is supported by an upper grid plate 15.

A channel fastener 20 is provided at the top corner of a set of four fuel assemblies 10, and the space between the fuel assemblies 10 is assisted by the channel fastener 20 as shown in FIG. Received and held. A control rod 22 having a cross-shaped cross section is guided between the four fuel assemblies 10 so as to be able to enter and exit. The control rod 22 is driven by the control rod drive mechanism 23, passes through the control rod guide tube 24, passes through a cross-shaped slit in the fuel support bracket 17, and moves between the four fuel assemblies 10 between the insertion position and the withdrawal position. You will be guided.

The fuel assembly 10 mounted on the core 12
The fuel is transferred from the reactor pressure vessel 11 to the fuel storage pool 25 shown in FIG. 4 at the time of refueling, inspection, or the like, and is carried in the storage pool 25 while being filled with water. Will be kept. The channel fastener 20 is attached to and detached from the fuel assembly 10 stored in the fuel storage rack 26 using a long channel bolt wrench 28 at the time of refueling and inspection. Reference numeral 29 denotes a work bench attached to the fuel storage pool 25.

As shown in FIGS. 2 and 3, the fuel assembly 10 is configured by storing a fuel bundle 31 in which a large number of fuel rods are bundled in a fuel channel 30 which is a rectangular tubular channel box. The fuel bundle 31 and the fuel channel 30 are fastened by the channel fastener 20 attached to the upper corner of the fuel assembly 10 and are assembled together.

As shown in FIGS. 2 and 3, the fuel bundle 31 has a large number of fuel rods held between a lower tie plate 33 and an upper tie plate 34, and the middle of the fuel bundle 31 is held by a plurality of fuel spacers (not shown). You. The upper tie plate 34 is integrally provided with a handle 35 used when the fuel assembly 10 is moved, while a boss portion 36 rises at a corner of the upper tie plate 34 as shown in FIG.
The channel fastener 20 is fixed to the boss portion 36.

The channel fastener 20 is constructed by assembling a cap screw 38 and a plate-shaped fuel spring 39, and the cap screw 38 is screwed to the boss portion 36 of the upper tie plate 34 so that the channel fastener 20 is connected to the fuel assembly. It is detachably fixed to 10. The cap screw 38 has a fuel spring 39
Are fastened to the fuel channel 39 and the upper tie plate 34 together. The channel fasteners 20 are provided at upper corner portions of the four fuel assemblies 10 facing each other, respectively, so as to keep the intervals between the four fuel assemblies 10 uniform.

The cap screw 38 has a lower corner portion 43 and an upper head portion 44.
A ring-shaped outer peripheral groove 45 is formed on the outer peripheral groove 45, and a plurality of, for example, six vertical grooves or slits 46 are formed above the outer peripheral groove 45.
Are provided at equal intervals in the circumferential direction. A channel bolt wrench 2 is provided in the outer circumferential groove 45 of the cap screw 38.
Eight gripping means 47 are detachably engaged. The gripping means 47 may be a ball lock type gripping mechanism, a leaf spring type gripping mechanism, or another gripping mechanism.

FIG. 6 is an overall structural view showing a schematic configuration of the channel bolt wrench 28, and FIG. 7 is an enlarged longitudinal sectional view showing a portion A of the channel bolt wrench 28 of FIG.

The channel bolt wrench 28 has a long shape. The channel bolt wrench 28 is an elongated and long channel bolt wrench main body 5 that constitutes an operation force transmitting unit.
0, a swiveling operation part 51 formed on the upper part of the channel bolt wrench main body 50, a hanging part 52 provided to be rotatable above the turning operation part 51, and a lower end of the channel bolt wrench main body 50. Formed wrench part 53
A wrench operating section 54 for attaching and detaching the wrench 53 to the cap screw 38 of the channel fastener 20; and a wrench guide 55 for guiding the wrench 53 to the cap screw 38 of the channel fastener 20.

The channel bolt wrench main body 50 is formed by connecting a plurality of connecting members 56 such as connecting rods and connecting pipes in the axial direction, and assembling them into a long shape and integrally rotating them. ing. A turning handle 57 is provided at the upper end of the channel bolt wrench body 50,
The turning operation unit 51 is configured. An indicator light 58 is provided in the vicinity of the turning handle 57 as display means.

Above the turning handle 57, a suspension portion 52 such as an eyebolt 60 is formed via a rotatable turning joint 59. The eyebolt 60 can easily lift and lower the long channel bolt wrench 28. Also, the turning handle 57
The air hose (not shown) connected to the swivel joint 59 has a structure that does not twist even when the swivel operation is performed, and this air hose is connected to the air supply port 61 on the side surface of the swivel joint 59.

The wrench portion 53 of the channel bolt wrench 28 is formed at the lower end of the channel bolt wrench main body 50, and as shown in FIG.
3 and an inner pipe (inner pipe) 64. The outer pipe 63 and the inner pipe 64 are integrally rotatable and relatively slidable in the axial direction.

At the lower part of the outer pipe 63, a fastening means such as a ball lock or a holding means 47 for detachably holding the outer peripheral groove 45 of the cap screw 38 is provided integrally. The ball lock includes a plurality of balls that can be engaged with the outer peripheral groove 45. Further, a socket means 65 which can be engaged with the slit 46 of the cap screw 38 is provided integrally with a lower portion of the inner pipe 46, and a turning operation force is transmitted to the cap screw 38 via the socket means 65,
The cap screw 38 can be attached and detached.

The socket means 65 includes the cap screw 3
8 has a plurality of claw bodies engaging with the top slit 46 so as to be able to advance and retreat.
A tapered surface to be pushed out by the relative displacement in the axial direction of 4 is provided on the inner peripheral surface of the outer pipe 63.

A detection member 67, such as a round bar, is slidably incorporated in the inner pipe 64 of the wrench 53. When this detecting member 67 comes into contact with the upper surface of the channel fastener 20, it relatively slides in the inner pipe 64 to operate a limit switch 68 (see FIG. 6) as a switch means, and is incorporated into the upper portion of the channel bolt wrench 28. The indicator light 58 is turned on.

Above the outer pipe 63 constituting the wrench 53 of the channel bolt wrench 28, a cylinder 70 constituting the wrench operating part 54 is incorporated, and this cylinder 70 is remotely operated underwater. The outer pipe 63 is driven relative to the inner pipe 64 in the axial direction by this cylinder operation. The gripping means 47 is moved by the axial movement of the outer pipe 64.
Are moved up and down in conjunction with each other to be operated to the release side. Thereby, the channel fastener 20
Of the cap screw 38 is carried out.

An operation spring 71 is incorporated below the cylinder 70, and the holding means 47 of the ball lock operates the cap screw 38 of the channel fastener 20 to the holding side by the spring force of the operation spring 71. The operation spring 71 is attached to the cylinder 70.
By supplying air overcoming the spring force of the above and operating the cylinder, the ball lock releases the gripping operation and performs the releasing operation.

An air supply port 72 is formed in the upper part of the cylinder 70, and air pressure is supplied from the air supply port 72 into the cylinder 70. This air supply port 7
2, the pressurized air supplied from the upper air supply port 61 of the channel bolt wrench 28 passes through the turning operation section 51 in the axial direction, and flows from the upper air supply port 73 to the lower air via an air hose (not shown). It is sent to the supply port 72 and is supplied into the cylinder 70.

Further, a wrench guide 55 is formed on one side of the wrench 53 of the channel bolt wrench 28. The wrench guide part 55 is the outer pipe 6 of the wrench part 53.
A guide member 76 such as a guide plate is fixed to a guide holder 75 fixed to the outside of the third member 3 by fixing means such as a tightening bolt. As shown in FIG. 8, the guide member 76 engages with a corner on the inner surface of the top of the fuel channel 30 so that the wrench 50 can be positioned. Specifically, the guide member 76 is guided by the handle 35 of the fuel assembly 10 and engages with the inner surface of the fuel channel 30, and the channel fastener provided at the top corner (corner) of the fuel assembly 10. 20 cap screws 38
The wrench 53 is guided so as to be able to engage with the wrench 53.

In this embodiment, an example is shown in which the guide member 76 of the wrench guide portion 55 has a channel guide surface and a handle guide surface that engage with both the inner surface of the fuel channel 30 and the handle 35 of the fuel assembly 10. However, the guide member may be formed with at least one of a channel guide surface and a handle guide surface. The guide member 76 of the wrench guide portion 55 is seated on and engaged with the fuel channel 30 or the handle 35 of the fuel assembly 10 to position the channel bolt wrench 28 in the height direction with respect to the fuel assembly 10. be able to.

Next, an operation of removing the channel fastener of the fuel assembly stored in the fuel storage pool using the channel bolt wrench 28 will be described.

FIGS. 4 and 9A and 9B show long channel bolts for detaching the channel fastener 20 from the fuel assembly 10 installed in the fuel storage rack 26 of the fuel storage pool 25. FIG. 4 shows a handling state diagram in which a wrench 28 is handled.

A workbench 29 or a refueling machine 78 is provided on the fuel storage pool 25. The work of handling the long fuel channel bolt wrench 28 is performed from the workbench 29 or the refueling machine 78. The axial length of the channel bolt wrench 28 can be freely adjusted by changing the number of the connecting members 56 according to the height of the work table 29. The long channel bolt wrench 28 is suspended and supported by a crane (not shown) via a suspension rope.

To remove the channel fastener 20 attached to the fuel assembly 10, a long channel bolt wrench 28 is hung to the fuel assembly 10 storage position, and an object stored in the fuel storage rack 26 is used. The fuel assembly 10 is suspended to a storage position.

Subsequently, when the wrench 53 of the channel bolt wrench 28 is positioned on the target fuel assembly 10, the cylinder 70 is operated by supplying pressurized air to the cylinder 70. Since the ball lock as the gripping means 47 is released by this cylinder operation, the wrench 53 is set on the cap screw 38 of the channel fastener 20 while maintaining this state.

After being set on the cap screw 38 of the channel fastener 20, the supply of pressurized air is stopped, and the cap screw 38 is gripped by the ball lock with the spring force of the operation spring 71 to perform a gripping operation.

At this time, the wrench 53 of the channel bolt wrench 28 is guided by the wrench guide 55 engaging the handle 35 of the fuel assembly 10 and the inner surface of the fuel channel 30, and is positioned on the channel fastener 20. Can be easily performed in a short time.

Next, by gripping and turning the turning handle 57 of the channel bolt wrench 28, the turning operation force is transmitted to the cap screw 38 of the channel fastener 20, and the cap screw 38 can be loosened and removed. By removing the cap screw 38, the channel fastener 20 can be removed.

Channel fastener 2 to fuel assembly 10
The mounting of 0 is performed in a procedure reverse to the removal operation.

In the channel bolt wrench 28, the wrench guide 55 is engaged with the inside of the fuel channel 30 to guide the wrench 53, so that the fuel assembly 10 accommodated in the fuel storage rack 26 is moved. In addition, the attachment and detachment of the channel fastener 20 can be easily performed in a short time, and the radiation exposure of the worker can be reduced.

In the channel bolt wrench shown in this embodiment, an example of the operation of attaching and detaching the channel fastener from the fuel assembly stored in the fuel storage rack of the fuel storage pool has been described. The channel fastener can be replaced with a channel bolt wrench from the fuel assembly mounted on the vehicle.

[0048]

As described above, in the channel bolt wrench according to the present invention, the fuel assembly stored in the fuel storage rack of the fuel storage pool and mounted on the core of the reactor pressure vessel is used. In addition, the channel fasteners can be securely attached and detached in a short period of time without being removed, improving workability and reducing the radiation exposure of workers. The operation rate can be improved.

In the invention according to claim 1, the wrench guide portion engages with at least one of the handle of the fuel assembly and the inner surface of the rectangular tubular fuel channel to guide the wrench portion, and the wrench portion of the channel fastener is formed. Since it can be positioned and installed on the cap screw, with the fuel assembly stored in the storage rack of the fuel storage pool,
The work of attaching and detaching the channel fastener can be efficiently performed by remote control while being mounted on the core portion of the reactor pressure vessel, and the workability is improved.

In the invention according to claim 2, the wrench is guided by engaging the wrench guide with the inner surface corner of the fuel channel, so that the wrench guide is stably engaged with the corner of the fuel channel. In addition, the reliability of the guide of the wrench can be improved.

In the invention according to claim 3, by selecting the number of connecting members and integrally connecting them in the axial direction,
The axial length of the channel bolt wrench can be easily and easily adjusted.

In the invention according to claim 4, the wrench has a double pipe structure which can be slid relative to the outer pipe and the inner pipe in the axial direction, and the outer pipe is provided with gripping means and the inner pipe is provided with socket means. Therefore, the wrench part can be attached to and detached from the cap screw of the channel fastener of the fuel assembly by remote control, and the work of tightening and removing the cap screw can be easily performed.

According to the fifth aspect of the present invention, the cap screw of the channel fastener can be automatically attached and detached by driving the wrench by a cylinder provided above the wrench, and the channel can be remotely operated underwater. Fastener attachment / detachment work can be performed.

In the invention according to claim 6, the wrench guide portion has at least one of a channel guide surface engageable with the inner surface of the fuel channel and a handle guide surface engageable with the handle of the fuel assembly. Since the wrench portion guides the wrench portion, the upper lattice plate of the fuel storage rack and the core portion does not hinder the wrench guide portion, and the wrench portion can be guided within the projected area of the fuel channel.

In the invention according to claim 7, it can be confirmed by the display means that the wrench portion has contacted the channel fastener, and the reliability and reliability of the work of attaching and detaching the channel fastener can be further improved. .

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a mounted state of a fuel assembly mounted on a core portion in a reactor pressure vessel.

FIG. 2 is a partial cross-sectional view showing a mounted state of a fuel assembly mounted on a core in a reactor pressure vessel.

FIG. 3 is a plan view showing a set of four fuel assemblies mounted on a core in a reactor pressure vessel.

FIG. 4 is a diagram showing a state in which the channel bolt wrench according to the present invention is used in a fuel storage pool.

FIG. 5 is a diagram showing an attached state of a channel fastener attached to the fuel assembly.

FIG. 6 is an overall structural view showing one embodiment of a channel bolt wrench according to the present invention.

FIG. 7 is an enlarged view of a portion A in FIG. 6;

FIG. 8 is a plan sectional view taken along the line VIII-VIII in FIG. 7;

FIGS. 9A and 9B are diagrams showing a use state of a channel bolt wrench in a fuel storage pool, respectively.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 fuel assembly 11 reactor pressure vessel 12 core 13 core shroud 14 core support plate 15 upper lattice plate 16 reinforcing beam 17 fuel support bracket 20 channel fastener 21 spacing spacer 22 control rod 23 control rod drive mechanism 25 fuel storage pool 26 Fuel storage rack 28 Channel bolt wrench 29 Workbench 30 Fuel channel (channel box) 31 Fuel bundle 33 Lower tie plate 34 Upper tie plate 35 Handle 36 Boss 38 Cap screw 39 Fuel spring 43 Screw 44 Head 45 Outer groove 46 Vertical Groove (slit) 47 Gripping means 50 Channel bolt wrench main body 51 Rotating operation part 52 Suspension part 53 Wrench part 54 Wrench operation part 55 Wrench guide part 56 Connecting member 57 Turning handle 5 Indicator light (display means) 59 Swivel joint 60 Eye bolt 61 Air supply port 63 Outer pipe (outer pipe) 64 Inner pipe (inner pipe) 65 Socket means 67 Detecting member 68 Limit switch (switch means) 70 Cylinder 71 Operating spring 72, 73 Air supply port 75 Guide holder 76 Guide member

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsuyoshi Maehara 2-4 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Keihin Works Co., Ltd.

Claims (7)

[Claims] 1. A long channel bolt wrench main body capable of transmitting a turning operation force, a wrench provided at an end of the channel bolt wrench main body, and the wrench mounted on and removed from a channel fastener of a fuel assembly. A wrench operating portion, a wrench guide portion for guiding the wrench portion on the channel fastener, and a turning operation portion for turning the wrench portion, wherein the wrench guide portion has a handle and a square tubular shape of a fuel assembly. A channel bolt wrench characterized in that the wrench is guided by engaging at least one of the inner surfaces of the fuel channel, and the wrench can be positioned and installed on a cap screw of the channel fastener. 2. The channel bolt wrench according to claim 1, wherein the wrench guide is provided outside the wrench, and the wrench is guided by engaging the wrench guide with an inner surface corner of the fuel channel. 3. The channel bolt wrench according to claim 1, wherein the channel bolt wrench main body is constituted by a plurality of rod-shaped or pipe-shaped connecting members that are detachably connected in the axial direction and are integrally rotated. 4. The wrench portion has an outer pipe and an inner pipe slidable in the axial direction relatively in a double pipe structure,
The lower end of the outer pipe is provided with gripping means capable of gripping the circumferential groove of the cap screw of the channel fastener, while the lower end of the inner pipe is provided with socket means engageable with the vertical groove of the cap screw. 2. The channel bolt wrench according to claim 1, wherein the cap screw can be turned through the means. 5. The channel bolt wrench according to claim 1, wherein the wrench is a cylinder provided above the wrench, and the wrench is driven by remotely operating the cylinder. 6. The wrench guide has a guide holder fixed to the outside of the wrench and a guide member fixed to the guide holder, the guide member being engageable with the inner surface of the fuel channel. The channel bolt wrench according to claim 1, further comprising at least one of a channel guide surface and a handle guide surface engageable with a handle of the fuel assembly. 7. A wrench part has a detection member provided therein so as to be relatively slidable in the axial direction. The detection member is interlocked with a switch means electrically connected to the display means. The channel bolt wrench according to claim 1, wherein the positioning of the channel bolt wrench can be confirmed.