JPH036476B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel assembly assembly apparatus for assembling a fuel assembly by drawing fuel rods into a skeleton assembly.

[Prior art]

Fuel assemblies are used in pressurized water reactors currently in use. This fuel assembly is the 13th
As shown in the figure, an upper nozzle 1 and a lower nozzle 2 are arranged vertically apart, and a lattice space (called a cell) is arranged between them at a predetermined interval and formed by a strap. A plurality of support grids 3 having a plurality of support grids 3 are inserted into the cells of the support grids 3 at predetermined intervals, and are fixed by fixing parts of the support grids 3, and the upper and lower ends of each are connected to an upper nozzle 1 and a lower nozzle. 2, and a large number of fuel pellets 6 sealed within the cladding tube 5 by welding end plugs 8a to both ends of the cladding tube 5.
The fuel rods 8 are inserted into predetermined cells of the support lattice 3 and elastically supported by the support portions of the support lattice 3.

To assemble a fuel assembly, first, the support grids 3 are arranged in parallel at predetermined intervals, and after inserting a plurality of control rod guide tubes 4 into predetermined cells of the support grids 3, they are controlled by a tube expansion jig. The rod guide tube is expanded and fixed to the support grid 3 to form a skeleton assembly 9. Next, after drawing the fuel rods 8 into predetermined cells of the support grid 3 of the skeleton assembly 9 using the fuel assembly assembly device, the control rod guide tubes 4
The lower nozzle 2 is attached to the lower part, and the upper nozzle 1 is attached to the upper part.

Incidentally, in order to assemble the fuel assembly, it is possible to use the one in U.S. Pat. This will be briefly explained with reference to FIGS. 14 and 15.

In FIG. 14, 10 is a fuel rod magazine that stores fuel rods 8 vertically and horizontally, and 11 is a skeleton assembly 9.
12 is a fuel rod pulling machine. A movable table 14 is disposed on the fuel rod puller 12 and is moved by a drive mechanism 13 in the left-right direction in FIG. A plurality of fuel rod retracting tools 15 are detachably attached to the movable table 14.

The fuel rod retractor 12 includes manual vertical movement of a retraction rod holding pin (not shown) provided on the movable table 14 so as to be movable up and down, and a lock pin (not shown) for locking the retraction rod holding pin in a predetermined position. (not shown), the fuel rod retraction tool 15 is located at a position opposite to the fuel rod 8 that can be retracted into the skeleton assembly 9, and the fuel rod retraction tool 15 is located at a position opposite to the fuel rod 8 that does not need to be retracted. can be selectively fixed to the moving table 14.

[Problem that the invention seeks to solve]

As mentioned above, in the fuel assembly assembly device,
Fuel rods 8 to be drawn into skeleton assembly 9
The selection of the fuel rod retracting tool 15, which is located opposite the fuel rod 8 and the fuel rod 8 that does not need to be retracted, is all done manually. Since manual operations must be performed and it is time-consuming to perform this operation and confirm the selection results of the fuel rod retracting tool 15, these operations must always be carried out in pairs, which reduces the amount of effort required. The time was very difficult.

Therefore, the present invention automates the selection work of the actuation of the fuel rod retracting tool that faces the fuel rods to be retracted into the skeleton assembly and the fuel rods that do not need to be retracted, thereby eliminating the manual selection work. It is an object of the present invention to provide a fuel assembly assembly device that can save labor and time and greatly improve the efficiency of drawing fuel rods into a skeleton assembly.

[Means for solving problems]

A plurality of fuel rods are attached to a movable stage that is movable in the axial direction of the fuel rods to a fuel rod retracting machine. A fuel assembly assembly device in which a rod is pulled out using a rod retracting tool and placed at a predetermined location within a skeleton assembly, includes a tubular pull rod, an inner rod slidably inserted within the pull rod within a predetermined range, and a rod provided at the tip of the pull rod. the fuel rod retracting tool comprising a fuel rod attachment/detachment mechanism; and an engaging body provided on the other side is removably biased into a recess provided on one of the fuel rod retraction tool and the moving base. The movable base and the fuel rod retracting tool are automatically engaged within a predetermined resistance force against the relative movement of the movable base and the fuel rod retracting tool when the movable base and the fuel rod retracting tool are inserted, and when the predetermined resistance force is exceeded. A lock mechanism that automatically releases these engagements, a stopper mechanism provided on the puller and capable of engaging and disengaging from a predetermined inner rod, and a drive mechanism provided on the movable table are used to control the pull rod in the axial direction. A fuel rod attaching/detaching mechanism actuating mechanism which is movably provided to the inner rod and engages and disengages the inner rod to move the inner rod relative to the pull rod, a movable base drive mechanism, a drive mechanism provided on the movable base, a stopper mechanism, etc. A control mechanism is provided.

[Effect]

Remove the stopper from the inner rod inserted into the pull rod located opposite the fuel rod that is to be pulled into the skeleton assembly, and place the stopper onto the inner rod inserted into the pull rod located opposite the fuel rod that does not need to be pulled into the skeleton assembly. When the moving table is moved toward the fuel rod magazine side in the engaged state, the pull rods facing the fuel rods that do not need to be drawn into the skeleton assembly remain stopped, and the engaging bodies are removed from the recesses, and the fuel rods that need to be drawn into the skeleton assembly are removed. Only the pull rod facing the rod passes through the skeleton assembly, and if a pull rod gets caught on the way, the engaging body automatically releases from the recess, leaving that pull rod in place, and the other pull rods are connected to the end plugs of the fuel rods. The fuel rod attachment/detachment mechanism operates to connect the fuel rods and pull rods, and in this state, the moving platform moves from the fuel rod magazine to the fuel rod pulling machine, and the fuel rods in the fuel rod magazine are A predetermined fuel rod is pulled by the pull rod into a predetermined cell of the support grid of the skeleton assembly, the moving table moves to a predetermined position and then stops once, and the fuel rod attachment/detachment mechanism operating mechanism is activated again. The fuel rod pulled into the skeleton assembly is uncoupled from the pull rod, and the movable stage is moved again to a position where the pull rod selection mechanism operates and moves to the next fuel rod retracting position. At this time, the engaging body is fitted into the recess.

〔Effect of the invention〕

It is possible to automate the selection of the actuation of the fuel rod retraction tool for the fuel rods to be retracted into the skeleton assembly and for the fuel rods that do not need to be retracted, thereby saving the effort and time spent on this type of selection operation manually. It is possible to greatly improve the efficiency of drawing fuel rods into the skeleton assembly, thereby saving labor, and the automation can be achieved with a simple structure, making it economical. be.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 12. In this embodiment, the same parts as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted. Reference numeral 21 in FIGS. 1 to 6 is a frame-shaped moving table, and a space 21a is formed within this moving table 21. As shown in FIGS. The movable table 21 has a recess (not shown) formed on its lower surface fitted into two rails (not shown) provided horizontally and parallel to the fuel rod puller 12, as shown in FIG. Arrows A, B
It is said to be able to move freely in any direction. In addition, the moving platform 21
Both ends of wire ropes 22 are attached to both left and right sides in the same figure. This wire rope 22 is wound around a pulley 23 attached to the fuel rod puller 12. Further, a part of the wire rope 22 is connected to a drive mechanism 13, and the drive mechanism 13 allows the movable table 21 to be moved in the left-right direction in FIG. 6 via the wire rope 22. Note that the moving table 21 has a U-shaped bridge 24 provided on its upper surface.

Further, a large number of fuel rod retracting tools 25 are connected to the movable table 21 .

In FIG. 7, the fuel rod retraction tool 25 consists of a pull rod 26 and an inner rod 27. The pull rod 26 consists of a guide tube 28 and a finger 29 detachably connected to the tip (left end in FIG. 7) of the guide tube 28 by screw fitting. finger 29
It is a tubular type with a closed end, and its end side is tapered and the end is shaped like an arrow. The finger 29 is divided into a plurality of sections from the center to the tip side in the circumferential direction (for example, divided into four as shown in Fig. 8b, or into six as shown in Fig. 9b).
) and becomes a leaf spring part, the tip of which is the outer claw 3.
0 is formed.

The guide tube 28 has a connecting member 31 provided at the upper rear end thereof. This connecting member 31
consists of a connecting rod 33 that is integrally connected to the guide tube 28 in parallel through a connecting plate 32. A concave portion 34 having an arcuate surface is formed on the upper surface of the distal end side of the connecting rod 33, and a flange 35 is formed at the rear end of the connecting rod 33.

An inner rod 27 is inserted into the pull rod 26. This inner rod 27 consists of an intermediate rod 36, a lock rod 37 screwed and connected to the tip of the intermediate rod 36, and a lock rod flag 38 screwed and connected to the rear end of the intermediate rod 36. . This lock bar flag 38 is
A rod-shaped portion 9 is screwed onto the intermediate rod 36 and has a conical rear end and a rounded tip, and a through-hole 40 whose lower surface is integrally fixed to the upper surface of the rod-shaped portion 39 is parallel to the guide tube 28. It consists of a plate-like part 41 formed in. A recess 43 having a slope 42 and a protrusion 44 located at the rear of the recess 43 are formed on the upper surface of the plate-like portion 41 . The connecting rod 33 of the pull rod 26 is loosely fitted into the through hole 40, and its flange 35 is capable of being engaged with and detached from the rear surface of the plate-shaped portion 41. The lock rod 37 has a smaller diameter than the intermediate rod 36 except for the head 45, and the head 45 has a slightly smaller diameter than the inner diameter of the base of the finger 29. Therefore, when the head 45 is moved toward the distal end of the finger 29 with respect to the finger 29, each external pawl 30 of the finger 29 is expanded.

Furthermore, a lock mechanism 46 is provided between the movable table 21 and the fuel rod retracting tools 25 so as to face each fuel rod retracting tool 25. This lock mechanism 46
It consists of an engaging body (lock pin) 47, a ring plate 48, and a spring (biasing member) 49. The lock pin 47 has a flange 50 at the bottom and is rounded at both ends, and the lower end is removably fitted into the recess 43 of the pull rod 26. The length of the lock pin 47 is such that its lower end comes into contact with the bottom of the recess 34 when its upper end is pressed by the lower surface of a slide base 55, which will be described later. The ring plate 48 is loosely fitted to the pin 47 and the flange 5
0 and is attached to the moving table 21. A spring 49 is enclosed between the flange 50 and the ring plate 48, and biases the lock pin 47 toward the connecting member 31. Note that a stepped portion 51 is formed at the lower right portion of the moving table 21 in FIG.
The vertical surface 52 constituting the pull rod 26 can be engaged with and detached from the connecting member 31 of the pull rod 26.

Further, a cylinder mechanism 53 is provided on the mounting plate 21b of the moving table 21 in parallel with the pull rod 26. The piston rod 54 of this cylinder mechanism 53
passes through the mounting plate 21b, and a frame-shaped slide base 55 is attached to the tip thereof. A space 56 is formed within this slide bed 55. The slide base 55 is slidably provided on the movable table 21. Cutouts 57 and 58 are formed in the upper and lower parts of the slide base 55 on the side opposite to the cylinder mechanism 53, respectively. A hook-shaped lever 59 is disposed in the notch 57 above each fuel rod retracting tool 25 . The base end of the lever 59 is rotatably fitted onto a shaft 60 attached to the slide base 55. lever 59
The tip of the protrusion 44 can be engaged with and detached from the rear surface (the right side surface in FIG. 1). Also, lever 5
9. A spring 61 is provided in each spring seat formed on the slide base 55 so as to bias the lever 59 in the direction of arrow C in FIG.
The vertical surface 58a of the notch 58 can be engaged with and detached from the front surface (the left side in FIG. 1) of the plate-like section 41.

Further, a cylinder mechanism 62 and a horizontal shaft 63 are attached to predetermined locations of the fuel rod retractor 12, and a hook-shaped lever 64 is rotatably attached to the shaft 63. The rear end of this lever 64 is rotatably attached to the piston rod of the cylinder mechanism 62, and the tip of the lever 64 is attached to the inner rod 2.
The lock bar flag 38 of No. 7 can be fitted into and removed from the recess 43 of the lock bar flag 38 and engaged with and removed from the protrusion 44.

In addition, the drive mechanism 13, cylinder mechanisms 53, 62
etc. are connected to a control device (such as a microcomputer), not shown, and are automatically controlled by this control device.

Next, the operation of the fuel assembly assembly apparatus configured as described above will be explained.

(1) Selection of fuel rod retracting tool 25 For the fuel rod retracting tool 25 located in the fuel rod magazine 10 and facing the fuel rod 8 to be retracted into the skeleton assembly 9, select the cylinder mechanism 6.
2 (input a command signal to the control device)
to remove the lever 64 from the protrusion 44, and actuate the cylinder mechanism 62 for the fuel rod retraction tool 25 facing the fuel rod 8 that does not need to be retracted into the skeleton assembly 9 (input a command signal to the control device). Then hook the tip of the lever 64 onto the protrusion 44. At this time, the engagement between the lever 59 and the protrusion 44 is released. Also, at this time, the lock pin 47 fits into the recess 34 and the pull rod 26
and the moving table 21 are engaged with each other.

(2) Inserting the pull rod 26 into the skeleton assembly 9 Next, the drive mechanism 13 is activated, thereby moving the movable table 21 in the direction of arrow B in FIG.
Then, the fuel rod retraction tool 2 is placed opposite the fuel rod 8 that does not need to be retracted into the skeleton assembly 9.
5 remains in place since it is engaged with the lever 64, and the lock pin 47 is automatically removed from the recess 34 of the fuel rod retracting tool 25. The fuel rod retracting tool 25 facing the fuel rod 8 to be retracted into the skeleton assembly 9 has a resistance force acting between the recess 34 and the lock pin 47 that does not allow relative movement between the movable table 21 and the fuel rod retracting tool 25. The movable table 21 passes through the skeleton assembly 9 and is automatically and temporarily stopped at a position where the outer claw 30 comes into contact with the end plug 8a of the fuel rod 8 in the fuel rod magazine 10.

(3) Connection of the end plug 8a and the outer claw 30 Next, the cylinder mechanism 53 is operated to contract. Then, the lever 59 is pushed downward by the bridge 24, and the tip of the lever 59 catches on the rear surface of the protrusion 44 of the lock rod flag 38, and is further pushed onto the lock rod 37 via the lock rod flag 38, inner rod 27, and intermediate rod 36. moves toward the outer claws 30 with respect to the fingers 29, and each outer claw 30 is expanded by the head 45. As a result, each of the outer claws 30 hooks onto the inner flange 8c in the recess 8b of the end plug 8a of the fuel rod 8 shown in FIG. 10, and the fuel rod 8 and the fuel rod retracting tool 25 are coupled together.

(4) Retraction of fuel rods Next, in this state, the moving table 21 moves a predetermined amount in the direction of arrow A in FIG.
A predetermined fuel rod 8 that is located inside the skeleton assembly 9 and is to be drawn into the skeleton assembly 9 is pulled by the pull rod 26 into a predetermined cell of the support grid 3 of the skeleton assembly 9, and the predetermined fuel rod 8 is drawn into the cell. When the retraction to the position is completed, the moving table 21 temporarily stops. At this time, the lock pin 47 is still fitted into the recess 34.

(5) Disengagement of the outer claw 30 from the end plug of the fuel rod 8 Next, the cylinder mechanism 53 is operated to extend. Then, the lock bar flag 38 is pushed by the slide base 55 and moves in the direction of arrow A in FIG.
Accordingly, the head 45 moves in the direction of arrow A in FIG. 1 with respect to the finger 29, and as a result, each external claw 30 moves inward and narrows. Therefore, the outer claw 30 comes off and separates from the end plug 8a. Further, the engagement between the bridge 24 and the lever 59 is released, and the spring 6
The lever 59 is raised by a force of 1. At this time, the lock pin 47 is fitted into the recess 34.
After this, the movable table 21 is moved again to the arrow A in FIG.
direction, return to the original state, and proceed from (1) to (5) above.
The action is repeated.

Note that the above operations are automatically performed by the action of the control device.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional side view of the main part showing an embodiment of the present invention, Fig. 2 is an enlarged detailed sectional view of the circular part in Fig. 1, Fig. 3 is a plan view of the main part, and Fig. 4 is Fig. 5 is a plan view of the fuel rod, Fig. 6 is a schematic side view of its main parts, Fig. 7 is a vertical side view of the fuel rod pulling tool, and Fig. 8a is a cross section of the tip of the pull rod. Figure 8b is a view taken in the direction of the arrow in Figure 8a, Figure 9a is a sectional view of the main parts of the fuel rod retracting tool with different numbers of divisions of the outer claw of the pull rod, and Figure 9b is the 9th arrow view of Figure 8a.
Fig. 10 is a cross-sectional view of the end plug portion of the fuel rod, Fig. 11 is a cross-sectional view showing the state in which the external claws of the fuel rod retracting tool of the present invention are depressed, Fig. 12
The figure is a sectional view showing a state in which the outer claws of the fuel rod retracting tool of the present invention are expanded and connected to the end plugs of the fuel rods, FIG. 13 is a side view showing an example of a fuel assembly, and FIG.
The figure is a side view of a conventional fuel assembly assembly device, No. 15.
The figure is a plan view of a conventional fuel assembly assembly device. 8... Fuel rod, 9... Skeleton assembly,
DESCRIPTION OF SYMBOLS 10... Fuel rod magazine, 12... Fuel rod retracting machine, 21... Moving table, 25... Fuel rod retracting tool, 26... Pull rod, 27... Inner rod, 31... Connection member, 34... Recessed part, 37...
Lock rod, 43... recess, 46... lock mechanism,
47... Engaging body (lock pin), 49... Spring (biasing member), 53... Cylinder mechanism (drive mechanism),
55...Slide base, 59, 64...Lever, 62...Cylinder mechanism.

Claims (1)

[Claims] 1. A plurality of fuel rods are moved from a fuel rod magazine in which a plurality of fuel rods are housed at predetermined intervals to a fuel rod retractor using a plurality of movable bases attached to a movable stage movable in the axial direction of the fuel rods. In a fuel assembly assembly device in which fuel rods are pulled out using a fuel rod pulling tool and placed at a predetermined location within a skeleton assembly,
The fuel rod retracting tool comprises a tubular pull rod and an inner rod slidably inserted within a predetermined range within the pull rod, and a fuel rod attachment/detachment mechanism is provided at the tip of the pull rod, and a connecting member provided on the pull rod. An engaging body provided on the other side of the connecting member and the moving table is removably urged by a biasing member to fit into a recess provided on one side of the connecting member and the moving table, and is pulled into the skeleton assembly. For a fuel rod retracting tool facing a fuel rod to be removed, the recess and the engaging body are engaged with each other when the movable base is moved toward the fuel rod magazine side, so that the movable base and the fuel rod retracting tool are connected to each other. For a fuel rod retracting tool that is opposed to a fuel rod that does not need to be pulled into the skeleton assembly, the recess and the engaging body are The engagement is broken,
A lock mechanism that allows relative movement between the movable base and the fuel rod retracting tool, a stopper mechanism provided on the retractor and capable of engaging and disengaging from a predetermined inner rod, and a drive provided on the movable base. a fuel rod attaching/detaching mechanism operating mechanism provided movably in the axial direction of the pull rod by a mechanism and configured to engage and disengage from the inner rod to move the inner rod relative to the pull rod; a drive mechanism for moving the movable base; a drive mechanism provided on the movable base; 1. A fuel assembly assembly device comprising a drive mechanism for controlling a stopper mechanism, a control mechanism for controlling a drive mechanism for a stopper mechanism, etc.