JPS64640Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a fuel channel attaching/detaching device for removing a channel from a fuel assembly (hereinafter referred to as a fuel bundle) or inserting it into the channel.

[Technical background of the invention]

In general, in a boiling water reactor, spent fuel assemblies are taken out of the core by fuel grips attached to a fuel exchange platform and transferred to a fuel pool, and then stored in a spent fuel storage rack installed in the fuel pool. will be temporarily stored. Then, in order to clean the fuel assembly or reuse the fuel assembly channel, the fuel channel attaching/detaching device removes the channel. Further, after cleaning, the fuel bundle may be reinserted into the channel.

A conventional fuel channel attaching/detaching device will be explained with reference to FIG. FIG. 1 is a front view of the fuel channel attachment/detachment device. 1 in the figure indicates a fuel pool. A guide rail 3 is vertically attached to the inner wall 2 of the fuel pool 1. A support stand 4 is attached to the guide rail 3 so as to be movable in the vertical direction along the guide rail 3.
This support stand 4 is constructed by integrally connecting upper and lower support parts 4A and 4B, which support the upper and lower ends of the fuel assembly 5 or the fuel bundle 5B, by a connecting member 4C. The support stand 4 is driven by a motor 6 through gears 7, 8 and a screw shaft 9 to move vertically along the guide rail 3. Further, numeral 10 in the figure indicates a crane for hoisting the channel 5A. Note that the channel 5A has a rectangular tube shape.

According to the fuel channel attachment/detachment device configured as described above, first, the fuel assembly 5 temporarily stored in the spent fuel storage rack (not shown) in the fuel pool 1 is held on the support stand 4. Next, the motor 6 is driven to raise the support stand 4 vertically upward. Then, the channel 5A is raised to a position where bolts (not shown) etc. fixing it to the fuel bundle 5B can be removed, and the motor 6 is stopped. Then remove the bolt above and channel 5.
When A is lifted by the crane 10, the motor 6
is driven to lower the support stand 4. This makes it possible to separate the channel from the fuel assembly 5. Conversely, when attaching the channel 5A to the fuel bundle 5B, the fuel bundle 5B is first held on the support stand 4, and the channel 5A is lifted by the crane 10. Then, after the worker visually guides the crane 10 so that the channel 5A is located directly above the fuel bundle 5B, the worker gradually guides the fuel bundle 5B to the fuel bundle 5B while visually aligning the insertion position of the fuel bundle 5B into the channel 5A.
It is then raised and inserted into the channel 5A.

[Problems with background technology]

According to the fuel channel attachment/detachment device with the above configuration,
Even though the attachment/detachment work is carried out underwater in the fuel pool 1, the positioning of the fuel bundle 5B with respect to the channel 5A must be visually performed by the operator, especially during the insertion work. Therefore, the work required a high degree of skill, and there were problems such as poor workability and efficiency, and an increase in the radiation exposure of the workers. There was also a risk of damaging the fuel bundle 5B and the fuel channel 5A during attachment and detachment.

[Purpose of invention]

The purpose of this invention is to improve work efficiency and work efficiency by automatically determining the insertion position of the fuel bundle into the channel without relying on the operator's visual inspection. It is an object of the present invention to provide a fuel channel attachment/detachment device that reduces the radiation exposure dose and does not damage the fuel bundle and the channel during attachment/detachment.

[Summary of the idea]

The fuel channel attaching/detaching device according to the present invention includes a support base that is provided in a fuel pool so as to be able to move up and down and vertically supports a fuel bundle, and a pair of support bases that are disposed facing each other on this support base and are movable in directions toward and away from each other. The present invention is characterized in that it includes a movable arm and a Y-shaped clamping part that clamps the corners of the fuel bundle and channel provided above and below the movable arm via rollers.

Therefore, it is possible to improve work efficiency and work efficiency, and it is possible to shorten working time, so it is possible to reduce the radiation exposure dose of workers.
Also, the fuel bundle and channel will not be damaged during attachment and detachment.

[Example of idea]

An embodiment of the present invention will be described with reference to FIGS. 2 to 7. FIG. 2 is a front view of the fuel channel attachment/detachment device. In the figure, 51 indicates a fuel pool.
A guide rail 53 is attached to the inner wall 52 of this fuel pool 51 in the vertical direction. A support stand 54 is attached to the guide rail 53 so as to be movable in the vertical direction along the guide rail 53. This support stand 54 is a fuel assembly 55
Alternatively, the upper and lower support parts 54A and 54B that support the upper and lower ends of the fuel bundle 55B are integrally connected by a connecting member 54C or the like. The support stand 54 is driven by a support movement mechanism 59 consisting of gears 57A, 57B and a screw shaft 58 by a motor 56, and is configured to be movable vertically along the guide rail 53 as described above.
In the figure, 60 indicates a crane for hoisting the channel 55A. Furthermore, the support stand 54
A positioning mechanism 61 is provided on the upper support portion 54A.

3 and 4 show the positioning mechanism 61. As shown in FIG. As shown in FIG.
A pair of support frames 62 and 63 are installed on the 4A, and each support frame 62 and 63 has a drive mechanism 64,
65 are arranged opposite to each other. Each drive mechanism 6
4 and 65 respectively support movable arms 66 and 67, and these movable arms 66 and 67 can be horizontally moved toward or away from each other by the drive mechanisms 64 and 65. Further, as shown in FIGS. 3 and 4, the movable arms 66 and 67 have Y-shaped channel clamping parts 68 and 69 at the upper part that clamp the corner of the channel 55A, and also have Y-shaped channel clamping parts 68 and 69 at the lower part that clamp the corner of the fuel side 55B. Y to hold the part
It has letter-shaped fuel bundle holding parts 70 and 71. The channel clamping parts 68, 69 and the fuel bundle clamping parts 70, 71 each have two auxiliary arms 68A, 68B, 69A, which are opened by 45 degrees to the left and right, respectively.
It is composed of Y-shaped arm portions consisting of 69B, 70A, 70B, 71A, and 71B. And these auxiliary arms 68A, 68B, 69A, 6
9B, 70A, 70B, 71A, 71B have rotating rollers 72, 73, 74, 75, 7, respectively.
6, 77, 78, and 79 are provided. That is, the movable arms 66, 67 are driven by the drive mechanisms 64, 65 and approach each other, and the four rotating rollers 72, 73, 7 of the channel holding parts 68, 69
4, 75 around the outer periphery of the channel 55A, and the four rotating rollers 76, 7 of the fuel bundle holding parts 70, 71.
7, 78, and 79 simultaneously hold the outer periphery of the fuel bundle 55B, respectively, and determine the horizontal position of the fuel bundle 55B with respect to the channel 55A. The channel 5A is connected to the channel holding parts 68 and 69 and the fuel bundle holding parts 70 and 71, respectively.
and the support stand 5 with the fuel bundle 55B sandwiched between them.
4 is moved up and down, the rollers 72, 73,
Since 74, 75, 76, 77, 78, and 79 roll on the outer surface, the support base 54 can be moved up and down without changing the insertion position.

When removing a channel using the fuel channel attaching/detaching device configured as described above, first, the fuel assembly 55 is attached to and supported by the support base 54. After the support base 54 is raised to a predetermined height in the water by the support base moving mechanism 59, the channel 5 is attached to a hook suspended from the crane 60.
Hook 5A. Then, after removing bolts (not shown) etc. fixing the channel 55A to the fuel bundle 55B, the support stand 54 is lowered, and the work of removing the channel 55A is completed.

Next, the operation of inserting the fuel bundle 55B into the channel 55A will be explained. The fuel bundle 55B is held on the support stand 54, and the channel 55A is lifted above the fuel bundle 55B by a crane 60. Next, the crane 60 is operated to lower the channel 55A to near the fuel bundle 55B as shown in FIG. Then, the movable arms 66 and 67 are brought close to each other by the drive mechanisms 64 and 65, and the corners of the fuel bundle 55B and the channel 55A are held between Y-shaped holding parts 68-71 via rollers 72-79. As a result, the lower end opening of the channel 55A is positioned directly above the fuel bundle 55B, and when the hook suspended from the crane 60 via the wire rope is lowered in this state, the channel 55A is opened under its own weight as shown in FIG. The lower end of the channel 55A comes into contact with the lower rotating rollers 76 to 79. Therefore, in this state, the movable arm 66,
67 from the channel 55A and the fuel bundle 55B to loosen the clamping state, the rotating rollers 76 to 7
9 is rotated by the weight of the channel 55A, and the lower end of the channel 55A is inserted between the rotating rollers 76 to 79 and the fuel bundle 55B. Then the seventh
As shown in the figure, the support table 54 is moved by a support table moving mechanism 59.
When the fuel bundle 55B is vertically supported by the support stand 54, it is inserted into the channel 54A. When the fuel bundle 55B is completely inserted, the channel 55A is fixed to the fuel bundle 55B with bolts or the like, and the insertion work is completed.

As described above, according to this fuel channel attachment/detachment device, the positioning mechanism 61 allows the channel 5
Since the horizontal positioning of the fuel bundle 55B with respect to the fuel bundle 55A can be automatically performed, the insertion work does not require skill as in the conventional case, and workability and efficiency can be significantly improved.
As a result, the work time can be shortened, which reduces the radiation exposure of the workers.
Furthermore, when attaching and detaching, the fuel bundle 55B and channel 5
There is no risk of damaging 5A.

[Effect of idea]

As explained above, according to the present invention, the lower end opening of the channel can be positioned directly above the fuel bundle, and when the movable arms are moved away from each other to loosen the grip on the fuel bundle, the lower end of the channel can be positioned directly above the fuel bundle. Since it is inserted between the roller and the fuel bundle, it can prevent the upper tie plate of the fuel bundle from coming into contact with the lower end of the channel when inserting the fuel bundle into the channel, thereby preventing the fuel bundle from being inserted into the channel. It can be done smoothly. Therefore,
It is possible to improve the workability and efficiency in the work of attaching and detaching the channel to and from the fuel bundle.

[Brief explanation of drawings]

Figure 1 is a front view of a conventional fuel channel attachment/detaching device, Figures 2 to 7 show an embodiment of the present invention, Figure 2 is a front view of the fuel channel attachment/detachment device, and Figure 3 is a positioning diagram. FIG. 4 is a front view of the mechanism, FIG. 4 is a view taken in the direction of the − arrow in FIG. 3, FIGS. 5 and 6 are partially cutaway front views showing the operating state of the positioning mechanism, and FIG. It is a front view. 51...Fuel pool, 54...Support stand, 55...
...Fuel assembly, 55A...Channel, 55B...
...Fuel bundle, 59... Support table moving mechanism, 61... Positioning mechanism.

Claims (1)

[Scope of utility model registration request] A support stand that is provided in the fuel pool so as to be able to rise and fall and vertically support the fuel bundle; a pair of movable arms that are placed facing each other on this support stand and are movable toward and away from each other; 1. A fuel channel attaching/detaching device comprising: a Y-shaped holding portion that is provided to hold the fuel bundle and the corners of the channel via rollers.