JPH0582914B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a fuel canning device for storing spent fuel bodies carried out from a nuclear reactor together with a cooling medium in a can, and particularly to the structure of the can support mechanism.

[Prior art and its problems]

As is well known, spent fuel taken out from inside a nuclear reactor is cleaned and then stored in cans together with highly heat-conductive cooling media such as water and helium gas.
The fuel assembly is immersed in a fuel storage pool for long-term cooling storage until the decay heat level of the fuel assembly falls to a safe level for handling. For this purpose, a fuel canning device is installed in the reactor facility, where empty cans brought in from the storage standby area are stored with spent fuel bodies taken out from the reactor, and the cans are sealed. Operations are performed by remote control. The general structure of the above canned food is shown in FIG. 4. That is, the can 1 is composed of a can body 1a as a bottomed container, a can lid 1b for sealing the can body, a sealing material 1c interposed between the flange of the can body and the can lid, a fastening bolt 1d, etc. , can body 1a
After accommodating the spent fuel body 2 and the cooling medium 3 inside, the can lid 1b is attached, and the fastening bolt 1d is further tightened to seal the can. Note that 1e is a handling head formed on the can lid 1b. On the other hand, for such a can 1, a spent fuel body 2
The device shown in FIG. 3 has already been put to practical use and is well known as a fuel canning device for carrying out the canning operation. That is, the canning device includes a canning support mechanism 4 for receiving and supporting canning cans in a predetermined position, an operation head 5 located above the canning mechanism 4 for attaching and detaching the lid of the canning can, and operating bolts.
and a drive system for these. Here, the canned can support mechanism 4 has a rotary pedestal 4a having a hole in the center for inserting a canned can in a vertical position, and a parallel movable pedestal 4a installed on the rotary pedestal to grip the canned can from both sides. The rotating pedestal 4a has a gear 6a and a drive shaft 6b.
It is connected to an operation handle 6 for rotating the canned food via the handle. On the other hand, the can fixing mechanism 4b is
A pair of front and rear gripping pieces are connected via screw shafts 4c disposed on the left and right, and the screw shaft 4c is connected to a drive shaft 7a of a can fixing operation handle 7 through a gear 4d and a clutch 4e. Note that 7b is a switching lever for the clutch 4e. On the other hand, the operation head 5 is equipped with a glove 5a for attaching and detaching a can lid and a spanner 5b for operating a bolt at its tip, and is supported so as to be able to move laterally along a ball screw 8a. It is connected to an operating handle 8 for moving the head via a shaft 8c. In addition, a glove 5a for attaching and removing a can lid and a spanner 5b for operating a bolt in the operating head 5 are connected to a trapezoidal screw 5c inside the operating head 5, and are connected to a lifting operating handle 9 and a rotating operating handle through splines, gears, and a drive shaft. connected to 10. The operation of such a canner is carried out as follows. First, when an empty canned can is carried in, the canned can is inserted into the center hole of the rotating pedestal 4a of the canned can support mechanism 4 described above, and then the fixing mechanism 4b is moved by operating the handle 7 with the clutch 4e engaged. After operating the gripping piece to bring it to the center and clamping and fixing the canned food in that position, in this state, the lever 7b is operated to once release the clutch 4e. Next, by operating the handle 8, the operating head 5 is moved horizontally to a position directly above the canned food, and further by operating the handle 6, the rotating cradle 4a is moved.
At the same time, the can can is rotated to align the spanner 5b with the fastening bolts of the can, and in this state, the handles 9 and 10 are operated to loosen the fastening bolts one by one. After loosening all the fastening bolts in this way, align the grab 5a with the handling head of the can lid, then move the grab up and down to lift the can lid upwards, and then move the operating head 5 onto the can body. Move backward to the side. In this state, the spent fuel body carried out from the reactor side is then lowered into the can body from above and accommodated, and a cooling medium is further injected into the can body. After this operation is completed, the can lid is lowered onto the can body in the reverse order of the can lid removal operation described above, and then each fastening bolt is tightened. Next, the handle 6 is operated to return the rotating pedestal 4a to its original position, and then the clutch 4e is engaged, and the handle 7 is operated to loosen the fixing mechanism 4b to release the fixed can. Thereafter, the canned food is pulled out from the support mechanism 4, mounted on an underwater truck, and transported into the fuel storage pool. However, the above-mentioned conventional fuel canning apparatus, particularly the structure of its canning support mechanism, has the following drawbacks in terms of operation and reliability. That is, (1) After the canned food is fixed, since the threaded shaft 4c of the fixing mechanism 4a and the drive shaft 7a of the operating handle 7 are separated, the canned food must be rotated together with the fixed pedestal 4a to operate the bolt. During this process, the fixing mechanism 4b may loosen due to external force applied to the can, making the fixing of the can unstable, which may impede bolt operation. (2) When operating the handle of the fixing mechanism 4b, it is necessary to position and stop the rotary pedestal 4a correctly so that it faces the front so that the clutch 4e can be engaged. A stopper is installed to stop the machine at a fixed position, but
This stopper restricts the rotation angle of the rotary pedestal to within one rotation, which causes inconvenience in rotational movement operations. (3) The can support mechanism requires two independent drive systems for fixing and rotating the can, which complicates the drive system and its operation.

[Purpose of the invention]

This invention has been made in consideration of the above points, and provides operability that prevents the fixing of the canned can from loosening during the process of canning operation, and allows the fixing and rotation of the canned can to be performed using a common drive system. An object of the present invention is to provide a can support mechanism for a fuel canning device with excellent reliability.

[Key points of the invention]

In order to achieve the above object, the present invention includes a ring-shaped rotating pedestal for receiving and holding canned cans carried into a canning machine in a vertical position, and a ring-shaped rotating pedestal that can be slid in the radial direction in line with the periphery of the rotating pedestal. A claw comprising a plurality of guide-supported can fixing claws, a tooth row formed on the plate surface of the claw, and a spiral groove that engages with the tooth row, and which moves the claws forward and backward in the radial direction by rotation. A drive ring and a drive system that rotates the pawl drive ring independently and in synchronization with the rotary cradle based on a command, and when fixing cans, the rotary cradle is used. By driving only the pawl drive ring while the can is stopped, the pawl is slid in the radial direction to fix the can, and when rotating the can, the pawl drive ring is moved along with the rotating pedestal using the same drive system. By rotating the cans at the same speed, the cans can be rotated together with the rotary pedestal to a designated position while reliably maintaining the fixed state of the cans.

[Embodiments of the invention]

1 and 2 show the structure of a can support mechanism of a fuel canning apparatus according to an embodiment of the present invention. That is, according to the present invention, the can support mechanism can be roughly divided into a rotary pedestal 11 that receives and holds the can 1 in a vertical position, and a plurality of cans that are arranged and guided and supported around the upper surface of the rotary pedestal 11 so as to be slidable in the radial direction. A can fixing claw 12, a claw driving ring 13 for moving the claw 12 forward and backward in the radial direction;
It consists of a combination of the rotary pedestal 11 and a drive system 14 that rotates the pawl drive ring 13. Here, the rotary pedestal 11 has a canned food 1 at its center.
The gear 16 is formed as a ring body with an insertion hole for receiving and holding the gear in a vertical position, and the gear 16 is supported by a bearing 15.
is combined with In addition, for example, three can fixing claws 12 are disposed so as to be slidable in the radial direction on the circumferential area of the upper surface of the rotary pedestal 11 via guide rails 17. A tooth row 18 arranged in the direction is formed. On the other hand, a claw driving ring 13 having a spiral groove 19 that engages with the tooth row 18 is located on the upper surface of the fixed claw 12, and is connected to a gear 21 supported by a bearing 20. Therefore, with this configuration, by rotating the pawl driving ring 13 in the direction of arrow P as shown in FIG. 2, the fixed pawl 12 that engages with the spiral groove 19 is screwed forward in the radial direction of arrow Q.
It will move backwards. On the other hand, the gears 21 and 16 described above include the gear 22,
Drive shafts 24 and 25 having an inner and outer double structure are connected via a gear 23, and the other end of each drive shaft 24 and 25 is transmission coupled to an output shaft of a drive motor 30 via gears 27 to 29, respectively. Also, the drive motor 3
An electromagnetic clutch 31 is provided between the gears 27 and 29 on the output shaft of the motor 0, and an electromagnetic brake 32 is provided on the shaft on the gear 29 side, and these parts constitute the drive system 14. . Note that this drive system 14
, from the drive motor 30 to the gears 29-28-
23-16 to the rotary pedestal 11, and the gear reduction ratio from the drive motor 30 to the gear 27.
-26-22-21 and the gear reduction ratio of the power transmission path leading to the pawl drive ring 13 is set to be the same. Next, the operation of the can support mechanism having the above structure will be explained. First, an empty can 1 carried into the canning machine is lowered from above by the operation of a handling machine (not shown), and is inserted into the insertion hole of the rotary pedestal 11 to be received and held in a vertical position. Next, the clutch 31 of the drive system 14 is disengaged, and the brake 3
2 is activated, the drive motor 30 is started.
As a result, gears 27, 26 - inner shaft 24 - gear 2
2 and 21, the pawl driving ring 13 rotates, and as described in FIG.
is interlocked and moves forward toward the center, hits the side of the can 1, and fixes the can at this position.
Once the can 1 is fixed to the support mechanism in this manner, the process of loosening the bolts of the can and removing the lid of the can then proceeds as described in FIG. In this process, the clutch 31 is used to rotate the can 1.
is coupled, the brake 32 is released, and the drive motor 30 is restarted in this state. As a result, the inner and outer drive shafts 24 and 25 of the drive system 14 are synchronously interlocked and rotated at the same speed, driving the rotary pedestal 11 and the pawl drive ring 13 to rotate in the same direction. Therefore, the can 1 remains in the fixed state held by the fixing claws 12 and rotates to the designated position. Moreover, in the process of this rotation operation, there is no relative movement between the rotating pedestal 11 and the claw driving ring 13, and the driving force is acting on the fixed claw 12 in the direction of gripping the can 1. The fixed state of the canned food will not loosen, and the rotation angle and stop position can be freely determined. When the spent fuel and cooling medium have been accommodated and the can body and can lid have been fastened together, the clutch 31 is disengaged again and the brake 32 is applied to restrain the rotary pedestal 11 in a stopped state. In this state, the drive motor 30 is rotated in the opposite direction to the above operation. As a result, the rotary claw 12 moves backward to release the canned food 1 from its restraint. The cans 1 can therefore be freely withdrawn from the canner by the handling machine and transferred to the fuel storage pool.

【Effect of the invention】

As described above, according to the present invention, there is a ring-shaped rotating pedestal that receives and holds canned cans carried into a canning machine in a vertical position, and a ring-shaped rotating pedestal that can be arranged around the periphery of the rotating pedestal and slidable in the radial direction. A claw comprising a plurality of guide-supported can fixing claws, a tooth row formed on the plate surface of the claw, and a spiral groove that engages with the tooth row, and which moves the claws forward and backward in the radial direction by rotation. By configuring the can support mechanism by comprising a drive ring, a drive system that rotates the pawl drive ring independently based on a command, and a drive system that rotates in synchronization with the rotating pedestal, the same drive system can be used. The canner can be fixed and rotated with the canner, and the canner can be reliably prevented from loosening during this rotational operation. The reliability of fixed support for cans can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the configuration of a can support mechanism according to an embodiment of the present invention, FIG. 2 is a plan view of the main parts in FIG. 1, FIG. 3 is a schematic configuration diagram of the entire conventional fuel canning device, and FIG. The figure is a cross-sectional view of the structure of a typical canned food. In each figure, 1...canned food, 2...
...Spent fuel body, 11...Rotating pedestal, 12...Can fixing claw, 13...Claw driving ring, 14...
Drive system for rotating pedestal and pawl driving ring, 15.
20...Bearing, 16, 21, 22, 23, 26~
29...Gear, 18...Tooth row, 19...Spiral groove,
24, 25... Drive shaft with dual structure inside and outside, 30...
Drive motor, 31... clutch, 32... brake.

Claims (1)

[Scope of Claims] 1. In a nuclear reactor fuel canning device for storing spent fuel bodies carried out from a nuclear reactor into a can by remote control, a ring that receives and holds canned cans carried into the canning device in a vertical position. a rotating pedestal having a shape, a plurality of can fixing claws that are arranged in a peripheral area on the rotating pedestal and guided and supported so as to be slidable in the radial direction; a row of teeth formed on a plate surface of the claw; a pawl driving ring that is provided with a spiral groove that engages with the row and that moves the pawl forward and backward in the radial direction by rotation; and a pawl driving ring that rotates independently and in synchronization with the rotating pedestal based on a command; What is claimed is: 1. A can support mechanism for a nuclear reactor fuel canning device, characterized by comprising a drive system for driving the can. 2. In the can support mechanism according to claim 1, the drive system includes an inner and outer dual-structure drive shaft connected to the rotary pedestal and the pawl drive ring via gears, and to the inner and outer drive shafts. 1. A can support mechanism for a nuclear reactor fuel canning device, comprising a gear and a drive motor transmission-coupled via a clutch. 3. The can support mechanism according to claim 2, characterized in that the gear reduction ratios of the power transmission path on the rotary pedestal side and the power transmission path on the pawl drive ring side of the drive system are set to be the same. A can support mechanism for a nuclear reactor fuel canning device.