JPH05264783A - Equipment for automatic removal of key member in support lattice - Google Patents

Abstract

PURPOSE:To attain efficiency and manpower-saving, to reduce exposure of an operator and thereby to cope also with assembling of MOX fuel in the future by automating removal of a number of key members by machines, in regard to the key members which are inserted into a support lattice in two directions in a crossing manner when fuel rods are inserted into the support lattice in assembling PWR fuel assembly. CONSTITUTION:An assembling drum 3 holding a necessary number of support lattices S at prescribed intervals and a rotary support mechanism 4 supporting rotatably this assembling drum 3 provided transversely are provided. Moreover, a key member extracting mechanism 6 for which at least a pair of chucks 5 gripping the opposite ends of key members K inserted into the support lattices S are provided so that they can be moved back and forth and rotated, and a vertical movement mechanism 7 and a horizontal movement mechanism 8 which move this extracting mechanism 6 vertically and horizontally, are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for automatically removing a key member in a support grid, which is suitable for extracting a key member used when inserting a fuel rod or the like into a support grid of a PWR fuel assembly. Is.

[0002]

2. Description of the Related Art As shown in FIG. 7, a nuclear fuel assembly (2
In 5), a large number of fuel rods (26) are securely held between the upper nozzle (27) and the lower nozzle (28) at a predetermined interval, and sufficient performance is achieved without any trouble during the reactor operation. A plurality of support grids (S) ... (S) are provided in the longitudinal direction of the fuel rod so that they can be exhibited. In order to remove heat from the surface of the fuel rods that generate heat, the support lattices usually have a large number of fuel rods and control rod guide thimble tubes aligned in parallel in a large number of cells partitioned by the lattices. It serves to maintain the necessary gap between the fuel rods and to ensure the flow of the coolant, and in general, a thin plate of iron-chromium-nickel superalloy Inconel is pressed into a predetermined shape and 5 (A) and 5 (B), a grid with slits provided with elastic protrusions (30) and fixing protrusions (31) for elastically holding fuel rods (not shown) in the cells (29) It is manufactured by assembling the plates in a vertical-horizontal lattice shape and connecting and integrating the intersecting portions with various metallurgical joining means such as welding or brazing.

On the other hand, the large number of fuel rods are elastically held by the elastic protrusions and the fixed protrusions in each cell of the support grid as described above. It is desirable to retract the elastic protrusion so that the fuel rod is not damaged by both protrusions. Therefore, conventionally, Japanese Patent Publication No. 54-44
As described in Japanese Unexamined Patent Publication No. 360-360, when the fuel rod is inserted into or removed from the support grid, as shown in FIGS. 6 (A) and 6 (B), slit holes (S ₁ ) ... ( a plurality of protrusions fit to the spacing S ₁₎ (3
2) After inserting the key member (K) provided with (32) into the slit holes (S ₁ ), ... (S ₁ ) with the protruding portion vertically, the key member is rotated by 90 degrees and the protruding portion ( 32) ... (3
2) is pressed against the groove edges (33) ... (33) as shown in the figure, so that the elastic projections (3
0) ... (30) were pressed to form a space in the cell (29) into which the fuel rod entered in a non-contact state.

[0004]

By the way, the key members pass through the cells formed in a square matrix and penetrate the supporting grid in two directions orthogonal to each other, and are inserted by the number of the matrix. Then, when the key member is rotated, one worker must stand on each side of the key member so as not to break the key member and rotate the key member from both ends. That is, when the key member is inserted, the support grids are not fixed individually, so even if the above-mentioned rotation work can be performed, the support grids are fixed by the assembly fixing jig for inserting the fuel rods when the key members are removed. Therefore, even if the key member inserted in the horizontal direction can be removed by rotating it from both sides, the above-mentioned fixing jig interferes with the removal of the key member in the vertical direction, and the rotation work from both sides cannot be performed. Therefore, it has a problem that it is very difficult to remove.
Further, the key members are usually inserted in an amount of 26 to 34 per support grid, but for a fuel assembly in which 7 to 9 support grids are used per body, as described above, the key members are manually inserted. Not only is it very time-consuming to carry out the removal work, but the work time is long and the work is done in the immediate vicinity of the fuel assembly, so the exposure dose is large and a major problem in the future assembly of MOX fuel. Has become.

The present invention copes with the actual situation as described above and develops an automatic device for removing the key member in the support grid, thereby automating and increasing the efficiency of the key member extracting work and reducing the exposure of the worker. At the very least, it is intended to support future MOX fuel assembly.

[0006]

However, the feature of the automatic key member removing device of the present invention that meets the above object is that the outer peripheral surface of the fuel assembly support lattice is exposed in the slit hole. Multiple drums that can be detachably attached,
If the support grid held by each drum is connected by a support rod so that the support grid is located at a specified position of the fuel assembly, and the assembly drum is installed horizontally, if the assembly grid is rotatable about the direction in which the support grids are arranged. A key that is capable of advancing / retreating in a mutually opposing direction and pivoting around the gripped key member and a pair of chucks for gripping both ends of the key member penetrating the support grid It is provided with a member extracting mechanism, a vertical moving mechanism for moving the extracting mechanism up and down, and a horizontal moving mechanism for moving the vertical moving mechanism and the extracting mechanism in the arrangement direction of the support grid along the assembly drum.

[0007]

The method of using the device of the present invention having the above-described structure will be described. First, the required number of support grids in which the key members are inserted as described above and the elastic projections are pressed are first held by the respective drums, and then the respective supporting grids are held. The rotation support mechanism is operated so that one of the key members orthogonal to the two directions in the support grid becomes horizontal.
Then, by using one or more pairs of chucks of the key member extracting mechanism, for example, both ends of the lower one of the above-mentioned horizontal key member of the support grid on the end side are grasped and are rotated to form elastic protrusions. , Then the gripping force of one of the chucks is released and the other is retracted to pull the key member out of the support grid. The extracted key member is dropped into a container installed below by freeing the chuck on the extraction side.

Thus, the operation of the key member withdrawing mechanism is sequentially performed on the upper key members by moving the withdrawing mechanism by the moving mechanism,
Hereinafter, while moving the extracting mechanism and the vertical moving mechanism by the horizontal moving mechanism, this is similarly repeated for the adjacent support grids. When the horizontal key members have been extracted from all the support grids, the assembly drum is rotated by 90 ° by the rotation support mechanism to make the remaining key members horizontal, and the above-described extraction is performed again. The order of extracting the key members is not limited to this, and it is also possible to remove all the key members for one support grid and then move to the next support grid.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front view showing an automatic key member removing device according to an embodiment of the present invention, and FIG. 2 is a partial side view of the device.
FIG. 3 is a perspective view showing an assembly drum and a rotation support mechanism of the same apparatus, and FIG. 4 is an enlarged perspective view of the drum. The above-mentioned key member is already attached to the drum in each drawing.

As shown in FIG. 3, the apparatus according to the embodiment of the present invention detachably holds the outer peripheral surface of the support grid (S) of the fuel assembly by exposing a number of slit holes (S ₁ ). Four
, A plurality of drums (1), each drum (1) ...
The supporting drums (S) ... (S) held by (1) are connected by three supporting rods (2) ... (2) so that the supporting drums (S) ... (S) are located at the prescribed positions of the fuel assembly as shown in FIG. 3) and
This assembly drum (3) installed horizontally is used as a support grid (S) ...
(S) is provided with a rotation support mechanism (4) for rotatably supporting the axis of alignment. In addition to the above-mentioned configuration, the device of the embodiment of the present invention includes a pair of chucks (5), (5) for holding both ends of the key member (K) penetrating the support grid (S) with each other. A key member withdrawing mechanism (6) for advancing and retracting in the opposite direction and allowing the gripped key member (K) to rotate about an axis, and the withdrawing mechanism (6).
A vertical moving mechanism (7) for vertically moving, and a horizontal mechanism for moving the extracting mechanism (6) and the vertical moving mechanism (7) along the assembling drum (3) in the arrangement direction of the support grids (S) ... (S). And a moving mechanism (8) (a plurality of pairs of the chucks may be provided).

As shown in FIG. 4, the drum (1) is formed in a disk shape having a fitting opening (1d) for fitting the support lattice (S) in the center thereof, and a part (1a) thereof is supported. Bolts (1) so that the grid (S) can be inserted or pulled out
It is detachably divided by b). As described above fitting opening (1d) is described above, as a large number of slits provided in the outer peripheral surface of the support grid _{(S) (S 1) ...} (S 1) is exposed, the support grating (S) It is formed to hold shallow.

On the other hand, usually 7 to 9 support grids (S) ... (S) are used in the fuel assembly, but the dimensions between these support grids are very strictly protected for various reasons. There is a need. Therefore, in the drum (1) ... (1), the above-mentioned three support rods (2) ... (2) are provided in the support rod holes (1c) ... (1c) of the drum (1) shown in FIG. Assembly drums (3) that are fixed by being inserted through each and have rigidity as a whole
Is formed. It is preferable that the number of the support rods is two or more because it is easy to maintain the rigidity of the assembly drum (3) and the spacing between the support grids (S) ... (S) is accurately maintained. Further, it is desirable that the drum (1) is provided by the number of supporting grids (S) required.

On the other hand, as shown in FIG. 3, the rotation support mechanism (4) includes a disc-shaped drum (1) ... Of the assembly drum (3).
It is composed of two rollers (9) and (9) that support the lower part of (1) and that are provided parallel to the axis of the drum (1),
The rollers (9), (9) are rotatably provided on the base (10) via bearings (B) ... (B). That is, the assembly drum (3) is centered on the line connecting the centers of the support grids (S) to (S) by rotating the rollers (9) and (9) by a servomotor with a brake or the like. It can be rotated and fixed at any position. Further, the key member extracting mechanism (6)
Has a structure in which the chucks (5), (5) are provided so as to be capable of advancing and retracting and rotating in opposite directions as described above. The chuck is rotated by the rotation motor (11) shown in FIG. (1
1), the advance / retreat is performed by the LM guide (12), (1
Along with 2), the extraction motors (13) and (13) are used. And opening and closing of the chucks (5), (5)
It is performed by air pressure, a motor or an actuator (not shown). In this case, the end of the key member (K) on the pull-out side may be made flat and uneven so that it can be easily gripped by the chuck (5).

Further, the vertical movement mechanism (7) moves the extraction mechanism (6) up and down along the guide rods (G) ... (G) by the vertical drive motor (14), and the horizontal movement mechanism (8). ) Is a longitudinal drive motor (15)
Withdrawal mechanism (6) and vertical movement mechanism (7)
It is possible to move along the linear guide (16) through the linear ball bearing (17) in the direction in which the supporting grids are arranged as shown in FIG. In addition, (1
Reference numeral 8) is a shield that covers the entire apparatus, and windows (19) and (19) are hermetically provided on the side wall of the shield.

By the way, as shown in FIGS. 1 and 2, in the apparatus of the embodiment, the outer peripheral key removing mechanism (20) is provided on the upper portion of the frame (21) extending from the horizontal moving mechanism (8). It is attached. The outer peripheral key is, as described in Japanese Patent Application Laid-Open No. 3-199998 filed by the applicant of the present application, a member for pulling in the elastic protrusion on the outer peripheral surface of the support grid that cannot be pressed by the above-mentioned ordinary key member (K). A contact plate having a U-shaped cross-section that is applied to the outer peripheral surface of the support grid with the concave portion facing inward, and a plurality of outer peripheral keys provided on the corresponding plate and engageable with slit holes of the elastic protrusions on the outer peripheral surface of the support grid. Used in combination. That is, while pressing the outer peripheral surface of the support grid with a backing plate, the outer peripheral key engaged with the slit hole of the elastic projection is pulled and the projection is retracted to the outside. Disengage from engagement with the protrusion.

Then, the outer peripheral key removing mechanism (2
0) is a backing plate chuck (2) slidable up and down by cylinders (22a) (22a) on both sides.
2) and (22) are used to hold or fix both ends of the contact plate, and to be vertically slidable by a central cylinder (23) and rotatable by a motor (not shown) or the like. In 24), the outer peripheral key can be rotated and removed. The chuck (24) for the outer peripheral key is provided with a support grid (S) by a motor or the like.
It is slidable in the left-right direction shown in FIG. 1 along the outer periphery of
The outer peripheral key removing mechanism (20) can be moved by the horizontal moving mechanism (8) through the frame body (21) in the arrangement direction of the support grids (S) ... (S).

Next, a method of using the automatic key member removing device of the embodiment of the present invention having the above structure will be described. First, a required number of supporting grids (S) in which the key members (K) are inserted in two directions orthogonal to each other to press the elastic protrusions in the cells ...
(S) is held on each drum (1) ... (1), and then one of the key members (K) ... (K) orthogonal to the above two directions in each support grid (S) ... (S). The rotation support mechanism (4) is operated so as to be horizontal. Then, by the pair of chucks (5), (5) of the key member extracting mechanism (6), for example, in the lower stage of the horizontal key members (K) ... (K) of the support grid (S) on the end side. Grasp both ends of the object and rotate it to disengage it from the elastic projection, and then release the grip force of one of the chucks (5) and retract the other to remove the key member (K ) From the support grid. The pulled-out key member (K) is dropped into a container installed below by freeing the chuck (5) on the pulling-out side. In this example, the key member is pulled out to the right side of FIG. Then, the operation of the key member extracting mechanism (6) is sequentially performed on the upper key members (K) ... (K) by moving the extracting mechanism (6) by the vertical movement mechanism (7). Hereinafter, while moving the extracting mechanism (6) and the up-and-down moving mechanism (7) by the horizontal moving mechanism (8), this is similarly repeated for the adjacent support grids (S). When the horizontal key members (K) ... (K) have been extracted from all the supporting grids (S) ... (S), the rotary supporting mechanism (4) causes the assembly drum (3).
Is rotated by 90 ° to make the remaining key members (K) ... (K) horizontal, and the above-described extraction is performed again (the extraction of these key members is not limited to this order).

Although the removal of the key member of the support grid in one fuel assembly is completed by the above steps, it is preferable to operate the device by automatic control while paying attention to Table 1 below when performing this work. .. Margin below

[0019]

[Table 1]

The embodiment of the present invention has been described above. The structure of each part mechanism including the rotation support mechanism is as follows.
It goes without saying that the design can be appropriately changed without departing from the scope of the present invention.

[0021]

As described above, in the automatic key member extracting device of the present invention, an assembly drum for holding a required number of support grids at predetermined intervals and a horizontal support of the assembly drum are provided. The rotating support mechanism and the both ends of the key member inserted in the support grid are provided so as to be graspable by one or a plurality of pairs of chucks, and the chucks can be moved back and forth in opposite directions, and the grasped key member can be rotated about an axis. It is provided with a movably provided key member extracting mechanism, a vertical moving mechanism for moving the extracting mechanism vertically and horizontally, and a horizontal moving mechanism, and a large number of keys crossed and inserted in two directions in a support grid. All the members are in a horizontal state, and the key members in each direction can be rotated from both sides to facilitate their removal. It turned into and can be carried out efficiently and labor saving, in which a marked effect with can be sufficiently compatible to the assembly of the future MOX fuel allowed reducing the exposure of workers by mechanized equipment.

[Brief description of drawings]

FIG. 1 is a front view showing an automatic key member removing device according to an embodiment of the present invention.

FIG. 2 is a partial side view of the same device.

FIG. 3 is a perspective view showing an assembly drum and a rotation support mechanism of the apparatus.

FIG. 4 is an enlarged perspective view of a drum of the device.

FIG. 5A is a plan view of a support grid cell. (B) It is the same front view.

FIG. 6A is a plan view showing a usage state of the key member. (B) It is the same front view.

FIG. 7 is a schematic diagram of a fuel assembly.

[Explanation of symbols]

(1) Drum (2) Support rod (3) Assembly drum (4) Rotation support mechanism (5) Chuck (6) Key member extraction mechanism (7) Vertical movement mechanism (8) Horizontal movement mechanism (9) Roller (10) Base (11) Rotation motor (12) LM guide (13) Extraction motor (14) Vertical drive motor (15) Longitudinal drive motor (16) Linear guide (17) Linear ball bearing (18) Shield (19) Window (20) Peripheral key removal mechanism (21) Frame body (22) Cover plate chuck (23) Cylinder (24) Peripheral key chuck (K) Key member (S) Support grid (S ₁ ) Slit hole

Claims (1)

[Claims] 1. A device for removing a key member for pressing an elastic protrusion in a cell, which is inserted by penetrating the support grid into a slit hole provided at a corner portion of each cell of the support grid,
A plurality of drums that hold the outer peripheral surface of the support grid detachably by exposing the slit holes in the outer peripheral surface are connected by a support rod so that the support grid held by each drum is at a specified position of the fuel assembly. A set assembly drum, a rotation support mechanism in which the assembly drum is provided laterally, and is rotatable about the arrangement direction of the support grids, and one or a plurality of pairs of chucks for holding both ends of the key member. A key member withdrawing mechanism that moves the withdrawing mechanism up and down in a direction opposite to each other and is rotatable around a gripped key member, a vertically moving mechanism that vertically moves the withdrawing mechanism, the up and down moving mechanism and the withdrawing mechanism. And a horizontal movement mechanism for moving the assembly in the direction in which the support grids are arranged along the assembly drum.