JPH0247591A - Fuel rod pulling-in force measuring device - Google Patents

Abstract

PURPOSE:To measure holding force every cell by mounting a pulling-in force measuring device on a pulling-in rod in a fuel assembly assembling device for pulling in fuel rods in a skeleton assembly and assembling a fuel assembly. CONSTITUTION:A fuel rod pulling-in machine shop tool 31 composed of a pulling-in rod 32 and a closing rod 31 is connected to a movable carriage 30. A recess part 36 for mounting a pulling-in force measuring device 37 is formed between two tube parts 32a, 32b of the pulling-in rod 32. A lead wire 40 of the pulling-in force measuring device 37 is backward introduced through the inside of a lead wire protecting cover 39 and a closing rod 33. When a fuel rod 8 is pulled in the fixed cell of a support lattice of a skeleton assembly 9 by the use of the pulling-in rod 32, the restraint loaded on the fuel rod 8 is continuously measured by the pulling-in force measuring device 37 to record, so that the holding force of the fuel rod 8 can be grasped by each support lattice.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention is a fuel rod retraction force measuring device that determines the retraction force of a fuel rod when assembling a fuel assembly by retracting a fuel rod into a skeleton assembly. Regarding.

“Prior Art” Generally, as shown in FIG. 6, a fuel assembly consists of an upper nozzle 1 and a lower nozzle 2 that are vertically spaced apart, and a predetermined space between them. a plurality of support grids 3 having grid spaces (cells) formed by straps, which are inserted into the cells of the support grid 3 at predetermined intervals and fixed to the support grid 3; A control rod guide tube 4 whose lower end is connected to the upper nozzle l and the lower end/zzle 2, and a large number of pellets 6 sealed in the cladding tube 5 with end plugs 8a welded to both ends of the cladding tube 5. The fuel rod 8 has a pressing spring 7 and a large number of fuel rods 8 which are inserted into predetermined cells of the support grid 3 and elastically supported by the support grid 3.

To assemble this 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, a pipe expansion jig is used to assemble the fuel assembly. The control rod guide tube 4 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 lower nozzle 2 is inserted into the lower part of the control rod guide tube 1, and the upper nozzle is inserted into the upper part of the control rod guide tube 1. nozzle l
Install each.

By the way, as a device for assembling the fuel assembly, it is possible to use the fuel assembly assembly device disclosed in Japanese Patent Application No. 5,923,7188, which was previously filed by the present applicant. An outline will be explained with reference to FIGS. 7 and 8.

In the figure, IO is a fuel rod magazine that stores fuel rods 8 vertically and horizontally, 1 is an assembly stand that holds a skeleton assembly 9,
12 is a fuel rod retractor. This fuel rod retractor 12
A movable table 14 that moves in the left-right direction in FIG. 7 by a drive mechanism 13 is disposed. A plurality of fuel rod retracting tools 15 are detachably attached to the movable table 14.

As shown in FIG. 9, the fuel rod retractor 12 includes a tubular pull rod 16, an inner rod 17 slidably inserted into the pull rod 16 within a predetermined range, and a fuel rod retractor 17 provided at the tip of the pull rod 16. The fuel rod retracting tool 15 includes a rod attaching/detaching mechanism 18, and the fuel rod retracting tool 1
5 and the movable table 14, an engaging body provided on the other side is removably biased and fitted into the concave portion provided on one side of the movable table 14, and relative movement between the movable table 14 and the fuel rod retracting tool 15 is achieved. a locking mechanism 19 that automatically engages the movable table 14 and the fuel rod retracting tool 15 when the resistance force is within a predetermined resistance against the fuel rod, and automatically releases the engagement when the resistance exceeds the predetermined resistance force; It is movable in the axial direction of the pull rod (6) by a stopper mechanism 20 that is detachably attached to the inner rod 17 and a drive mechanism 21 that is attached to the movable table 14, and is attached to the inner port and door 17. The fuel rod attachment/detachment mechanism operating mechanism 22 is configured to remove the inner port and move the inner port 17 relative to the pull rod 16.

Then, the stopper mechanism 20 is removed from the inner rod 17 inserted into the pull rod 16 at a position opposite to the fuel rod 8 to be pulled into the skeleton assembly 9, and the fuel rod 8 that does not need to be pulled into the skeleton assembly 9 is removed. When the movable table 14 is moved toward the fuel rod magazine 10 side using a stopper mechanism 20 that engages the inner rod 17 inserted in the pull port located in the pull port 16, it is necessary to pull it into the skeleton assembly 9. The pull rod 16 facing the fuel rod 8 without the
Only the pull rod 16 facing the fuel rod 8 to be pulled into the skeleton assembly 9 passes through the skeleton assembly 9, comes into contact with the end plug 8a of the fuel rod 8, and stops temporarily, and the fuel rod attachment/detachment mechanism operating mechanism 22 is activated. In this state, the moving table 14 moves from the fuel rod magazine 10 to the fuel rod pulling machine 12 side, and pulls a predetermined fuel rod 8 in the fuel rod magazine 10, pull port, or pull rod 16 together. 16 into a predetermined cell of the support grid 3 of the skeleton assembly 9, the moving table 14 moves to a predetermined position and then stops once, and the fuel rod attachment/detachment mechanism operating mechanism 22 works again to remove the skeleton. The fuel rod 8 drawn into the assembly 9 is disconnected from the pull port 16, and the movable table 14 returns to its original position.

In this manner, in the conventional fuel assembly assembly device described above, the operation of the fuel rod retracting tool 15 that faces the fuel rods 8 that should be retracted into the skeleton assembly 9 and the fuel rods 8 that do not need to be retracted is selected. The selection of fuel rods 8 into the skeleton assembly 9 can be automated, saving the effort and time spent on manual selection operations of this type.
The efficiency of retracting work can be greatly improved.

"Problem to be Solved by the Invention" By the way, as described above, the skeleton assembly 9
For the fuel rods 8 inserted into the skeleton assembly 9, it is necessary to confirm that the holding force of the support grid 3 holding the fuel rods 8 is greater than a predetermined level. It was measured after being For this reason, it was only possible to know the holding force as a whole, but it was not possible to grasp the holding force of each individual cell.

The present invention has been made in view of the above circumstances, and its purpose is to be able to smoothly and reliably measure the holding force of each cell of the support grid at the same time when drawing the fuel rod into the skeleton assembly. An object of the present invention is to provide a fuel rod retraction force measuring device that can confirm holding force and improve reliability.

"Means for Solving the Problem" In order to achieve the above-mentioned object, the first invention provides a measuring instrument mounting part on the fuel rod which grips and draws the fuel rod into the skeleton assembly, and a measuring instrument mounting part on the bracket. It is equipped with a retraction force measuring device.

Further, the second invention provides a pull-in rod with a pulling force measuring device, and the lead wires of these pulling force measuring devices are connected to a movable boolean of a lead wire processing mechanism whose stroke changes according to the tension of each lead wire. This is what we are running around with.

"Operation" In the fuel rod retraction force measuring device of the present invention, the bowing force when pulling the fuel rod into the skeleton assembly is measured by the retraction force measuring device provided at the pull-in port. At this time, the lead wire from the retracting force measuring device is looped around the movable pulley of the lead wire processing mechanism to prevent the lead wire from slacking and to perform the retracting work smoothly.

"Embodiment" An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

1 to 5 show an embodiment of the present invention,
Fig. 1 is a sectional view of the retraction force measuring device, Fig. 2 is a sectional view of the fuel rod retraction tool, Fig. 3 is a sectional view of the main parts of the fuel rod retraction machine, and Fig. 4 is the lead wire processing mechanism. FIG. 5 is a perspective view showing the overall configuration. In these figures, reference numeral 30 denotes a movable table, and this movable table 30 is adapted to be moved in the left-right direction in FIG. 3 by a drive mechanism (not shown).

A large number of fuel rod retracting tools 31 are connected to the movable table 30, and the fuel rod retracting tools 31 are composed of a full-in rod 32 and an opening/closing rod 33. This pull-in rod 32 has a tapered shape on the distal end side, and the distal end is formed into an arrow shape, and the distal end is divided into a plurality of parts in the circumferential direction to form a leaf spring part, and an external claw 34 is attached to the distal end. It is formed. And the above pull-in rod 3
The proximal end of 2 is divided into two tube parts 32a and 32b, and a measurement tube 35 is inserted between these tube parts 32a and 32b.
is screwed on.

The outer periphery of the measuring tube 35 has a recess (1l) for mounting a measuring device.
A tension measuring device (tension type load cell) is formed in the recess 36 of the bracket for mounting a measuring device.
37 is installed. Then, the retraction force measuring device 37
A protective cover 38 is placed over the outer periphery of the measuring device, and a lead wire protective cover 39 is placed in a small hole formed at the proximal end of the measuring device mounting recess 36. Also,
An opening/closing rod 33 is movably inserted into the pull-in rod 32 , and the tip head 3 of this opening/closing rod 33 is inserted into the pull-in rod 32 .
3a, the tip of the pull-in rod 32 is pushed open, and each external claw 34 is expanded outward. moreover,
A recess 33b is formed at a position of the opening/closing rod 33 facing the lead wire protection cover 39 so as not to come into contact with the lead wire protection cover 39 as the opening/closing rod 33 moves relative to the pull-in rod 32. The lead wire 4o of the retraction force measuring device 37 passes through the inside of the lead wire protection cover 39, the recess 33b of the opening/closing rod 33, and the inside of the opening/closing rod 33, and is led out rearward.

Further, a connecting member 41 is provided at the base end of the pull-in rod 32.
A mounting member 42 is fixed to the sheath portion 33c which is screwed to the proximal end of the door 33. A connecting rod 43 is attached to the mounting member 42.
is slidably fitted into the connecting rod 43, and the tip of the connecting rod 43 is fixed to the connecting member 41. Further, the connecting member 41 is fitted into the movable table 30. and,
The mounting member 42 includes a strut at the proximal end of the connecting rod 43;
It is configured to be movable between the pad 43C and the connecting member 41.

A printer 44 is attached to the tip of the moving table 30 via a bracket 45.
A movable member 46 is attached to the tip of the piston rod. A locking mechanism 4 is provided on the upper protrusion 30a of the movable table 30 opposite to the lower surface of the movable member 46.
7 is provided. This locking mechanism 47 has a brim portion 48a in the middle portion of the through hole formed in the protrusion portion 30a.
A p-tuck pin 48 is fitted into the opening and retracted from the lower part of the opening/tight pin 48 or from the above-mentioned through hole to engage and disengage from the recess 41a of the connection member 41, and a hollow tightening nut 49 is inserted into the through-hole. On the other hand, a spring 50 is installed around the lock pin 48 between the flange 48a of the lock pin 48 and the flange 49 to be tightened. A presser 51 for preventing the upper part from protruding from the through hole is provided on the movable member 46, and in FIG.
8, the lock pin 48 is configured such that it cannot protrude upward from the protrusion 30a of the movable table 30.

Further, a hook 52 is provided at the tip of the movable member 46 so as to be rotatable in the vertical direction about a pin 53, and this hook 52 connects to the protrusion 52 on the tip side of the upper surface of the mounting member 42.
2a. A rotary roller 54 is brought into contact with the upper surface of this hook 52, and as shown in FIG.
When the rotating roller 54 presses the upper bent portion 52a of the hook 52, the hook 52 rotates upward to release the engagement with the protrusion 42a of the mounting member 42.

Further, a stop/bar mechanism 55 (corresponding to the stopper mechanism 20 in FIG. 9) is detachably disposed on the protrusion 42b on the base end side of the upper surface of the mounting member 42.

Furthermore, the lead wire 40 led out from the base end of the opening/closing rod 33 is, as shown in FIG.
The first movable Fulie 59 and air/ring supported by 8
The second movable pulley 61 supported by the upper rod 60 of 57
and then around the second fixed pulley 62, and by applying a constant air pressure to the middle part of the air/ring 57, both of the above lead wires 40 are The stroke between the movable boo 'J59.61 is designed to vary. And the above air/
Ring-57, both rods 5860, and each pulley 56, 59
, 61 and 62 constitute a lead wire processing mechanism 63, and each lead wire 40 taken out from the lead wire processing mechanism 63, which corresponds one-to-one to the number of fuel rod pulling tools 31, is connected to a terminal 64. The information is compiled into a book and connected to the control device 65.

Next, a case will be described in which a fuel rod is drawn into a skeleton assembly using a fuel assembly assembly apparatus incorporating a fuel rod drawing-in positioning device configured as described above.

First, the slave mechanism 55 is activated for the fuel rod retracting tool 31 which is in the fuel rod magazine 10 and has been rotated once on the fuel rod 8 to be retracted into the skeleton assembly 9. The fuel rod 8 does not need to be removed from the protrusion g 42b of the mounting member 42 and pulled into the skeleton assembly 9.
The stopper mechanism 55 is operated for the fuel rod retracting tool 31 facing the fuel rod retracting tool 31 to engage with the protrusion 42b of the mounting member 42.

In this case, the prefectural association moves the movable member 46 to the left in FIG. It is in an unraveled state by rotating upward around the bottle 53.
At this time, the lock pin 48 of the lock mechanism 47 is fitted into the recess 41a of the connecting member 41 due to the urging force of the spring 50, and the movable member 46 and the presser 51 are moved to the left from above the lock bin 48. Because
When the opening and the pin 48 exceed the biasing force of the spring 50 by +10, they protrude upward and the engagement between the movable table 30 and the connecting member 41 can be released.

In this state, when the drive mechanism is activated and the movable table 30 moves to the right in FIG. Since the lock pin 48 remains in place, the lock pin 48 automatically detaches from the recess 41a of the connecting member 41 of the fuel rod retracting tool 31.

Further, the fuel rod retracting tool 31 facing the fuel rod 8 to be retracted into the skeleton assembly 9 has a resistance force between the four parts 41a and the lock pin 48 that does not allow relative movement between the movable table 30 and the fuel rod retracting tool 31. The movement table 3 passes through the skeleton assembly 9 and reaches the position where the outer claw 34 comes into contact with the end plug 8a of the fuel rod 8 in the fuel rod magazine IO.
0 stops by automatically pausing.

Next, when the piston rod of the /linder 44 is retreated, the hook 52, which had been retracted upward until now, moves to the right in FIG. As a result, the hook 52 rotates downward about the bottle 53 and engages with the protrusion 42a on the distal end side of the attachment member 42. and,
Further, as the piston rod of the cylinder 44 moves backward, the movable member 46 and the hook 52 as well as the mounting member 42 engaged with the hook 52 are moved to the connecting rod 43.
approaches the connecting member 41 side along .

As a result, the opening/closing rod 33 fixed to the mounting member 42
The opening/closing rod 3 moves forward inside the pull-in rod 32.
The tip head 33a of the pull-in rod 32 contacts the tip of the pull-in rod 32 and expands each external claw 34.

As a result, each external pawl 34 engages with the recessed portion of the end plug 8a of the fuel rod 8, and the fuel rod 8 and the fuel rod retracting tool 31 are connected.

Next, in this state, when the moving table 30 is moved a predetermined amount to the left in FIG.
The movable table 30 is pulled into a predetermined cell of the support grid 3 of the skeleton assembly 9 by the pull-in slot 32, and once the fuel rod 8 has been drawn into the cell to a predetermined position, the movable table 30 temporarily stops. In this case, as the fuel rod 8 is drawn into each support grid 3 of the skeleton assembly 9, the restraining force applied to the fuel rod 8 increases;
Since this force is continuously measured by a pulling force measuring device 37 installed on the pull-in rod 32, the measurement data of this pulling force measuring device 37 is input to the control device 65 and recorded, so that each support grid can be The holding force of the fuel rods 8 by each of the fuel rods 8 can be accurately grasped individually.

Furthermore, when the piston rod of the Schilling-44 is advanced, the movable member 46 moves to the left in FIG. The member 42 is a connecting rod 43
Along with this, pull-in rod 3 moves to the left.
The four internal opening/closing throats 33 move to the left, and as a result, each outer claw 34 moves inward and narrows. Therefore, the outer claw 34 comes off and separates from the end plug 8a. Further, since the hook 52 rotates upward around the bottle 53, the engagement between the hook 52 and the mounting member 42 is released.

Thereafter, the movable table 30 moves to the left in FIG. 3 again, returns to its original state, and prepares for the next retracting operation. In this way, the retraction operation of the fuel rods 8 into the skeleton assembly 9 is performed smoothly.

At this time, the pull-in rod 32 reciprocates between the fuel rod puller 12 and the fuel rod magazine 10, and as a result, the lead wire 40 led out to the rear of the pull-in rod 32 is pulled out to the fuel rod magazine 10 side. Alternatively, the lead wires 40 are returned to the fuel rod drawing machine 12 side, but in this case, since a predetermined air pressure is applied to the intermediate portion of the air/linter 57 of the lead wire processing mechanism 63, the lead wires 40 are When the fuel rod magazine is pulled out to the IO side, the distance (stroke) between both rotating pulleys 59 and 61 becomes narrower, and
When the pull-in rod 32 returns to the fuel rod puller 12 side,
By widening the distance between both rotating pulleys 59 and 61, the lead wire 40 is always stretched with a constant tension without sagging.

"Effects of the Invention" As explained above, the first aspect of the present invention is to provide a measuring device mounting part on the pull-in rod that grips the fuel rod and pulls it into the skeleton assembly, and to measure the force applied to this 1llllllll meter mounting force. By measuring the retraction force when the fuel rod is retracted into the skeleton assembly using the retraction force measuring device, the retention force of the fuel rod by each support grid of the skeleton assembly can be individually ensured. Moreover, it can be measured smoothly, and it is possible to confirm the holding force and improve reliability.

Further, the second aspect of the present invention is to provide a pull-in rod with a retracting force measuring device, and to connect the lead wires of these retracting force measuring devices to a lead wire processing mechanism whose stroke changes depending on the tension of each lead wire. Since it is hung around a movable pulley, by moving the movable pulley according to the tension of the lead wire, in addition to the above effect, the lead wire is tensioned at a predetermined tension and prevented from sagging, and the fuel rod is pulled in. Work can be done smoothly.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention,
Figure 1 is a cross-sectional view of the retraction force measurement unit, Figure 2 is a cross-sectional view of the fuel rod retraction tool, Figure 3 is a cross-section of the main parts of the fuel rod retraction machine, and Figure 4 is the lead wire processing mechanism. 5 is a perspective view showing the overall configuration, FIG. 6 is a side view showing an example of a fuel assembly, and FIGS. 7 to 9 show a conventional fuel assembly assembly apparatus. The figure is a side view, FIG. 8 is a plan view, and FIG. 9 is a sectional view of the main parts of the fuel rod puller. 8...ill, 9...skeleton assembly,
IO...Fuel rod magazine, 12...Fuel rod retracting machine, 30...Moving table, 31-...Fuel rod retracting tool, 32...Pull-in rod, 36...Measurement Recess for instrument mounting (measuring instrument mounting part), 37... Retraction force measuring instrument (tension type load cell), 40... Lead wire, 59 First movable pulley, 61... Second movable pulley, 63 lead line processing mechanism. Figure 6 Applicant: Mitsubishi Nuclear Fuel Co., Ltd.

Claims (1)

[Scope of Claims] 1) A fuel rod retractor is provided to move the fuel rods from a fuel rod magazine in which a plurality of fuel rods are housed at predetermined intervals in the axial direction of the fuel rods. In a fuel assembly assembly device in which a plurality of fuel rods are pulled out by a pull-in rod of a pull-in tool attached to a stand and placed at a predetermined location in a skeleton assembly, the pull-in rod is provided with a measuring device mounting part, and the measuring device is mounted on the pull-in rod. A fuel rod retraction force measurement device, characterized in that a retraction force measurement device is provided in the fuel rod retraction force measurement device. 2) A plurality of fuel rods are attached to a movable stand provided in a fuel rod retracting machine so as to be movable in the axial direction of the fuel rods, from a fuel rod magazine in which a plurality of fuel rods are housed at predetermined intervals. In a fuel assembly assembly device in which a fuel rod is pulled out using a pull-in rod of a fuel rod retraction tool and placed at a predetermined location in a skeleton assembly, the pull-in rod is provided with a retraction force measuring device, and the lead wires of these retraction force measuring devices are connected to the pull-in rod. A fuel rod retraction force measuring device, characterized in that the fuel rod retraction force measuring device is hung around a movable pulley of a lead wire processing mechanism whose stroke changes depending on the tension of each lead wire.