JPS6312560B2 - - Google Patents

Description

[Detailed description of the invention] This invention removes a damaged fuel rod from a fuel assembly used in a nuclear reactor, inserts a dummy rod,
The present invention relates to a rod extracting/inserting device for a fuel assembly that makes an unusable fuel assembly reusable.

Fuel assemblies are used in pressurized water reactors currently in use. As shown in Fig. 1, this fuel assembly consists of an upper nozzle 1 and a lower nozzle 2 arranged vertically apart, and a lattice formed by straps arranged at a predetermined interval between them. A plurality of support grids 3 having spaces are inserted into the grid spaces 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 are connected to the upper nozzle 1 and the lower part, respectively. It has a control rod guide tube 4 connected to a knob 2, a large number of fuel pellets 6 sealed in a cladding tube 5, and a pressing spring 7. The fuel rods 8 are elastically supported by 3 supporting parts. Such fuel assemblies are removed from the reactor core after burning for a certain period of time, and after undergoing various inspections, only those that are found to be in good condition are reloaded into the reactor core.

However, conventionally, among the fuel assemblies, the number of damaged fuel rods in the fuel assemblies in which damaged fuel rods were detected in the various inspections was at most 1 to 2 per fuel assembly. If even one fuel rod is damaged, the reactor core cannot be reloaded for use, and the fuel assembly must be stored in a spent fuel tank, which is extremely uneconomical.

Therefore, it was considered to pull out the damaged fuel rod from the fuel assembly, but in this case, since the fuel assembly containing the damaged fuel rod has radiation, it should be located 3 m or less above the water surface in order to shield this radiation. There must be.

In addition, the upper end of each control rod guide tube 4 is welded all around to the upper nozzle, and it is possible to remove the upper nozzle from the fuel assembly, pull out the damaged fuel rod, and reuse the fuel assembly. Control rod guide tube 4
Weld the entire circumference of the weld, remove the upper nozzle from the fuel assembly, and pull out the damaged fuel rod.
Instead, a dummy rod must be inserted and the upper nozzle must be welded underwater to the upper end of each control rod guide tube 4 again, so that the control rod guide tube 4 can be welded to the upper nozzle without cutting. Not only could it not be removed from the tank, but it was also impossible to weld the control rod guide tube 4 to the upper nozzle underwater, since this welding had to be done by operation at the top of the tank.

By the way, the lower nozzle 2 is screwed to the control rod guide tube 4 with a thimble screw, and only both ends of the detent pin fitted to the thimble screw are welded to the lower nozzle, so remove this welded part. If so, it is possible to remove the lower nozzle from the fuel assembly without damaging the control rod guide tube 4, and the attachment of the lower nozzle to the fuel assembly after pulling out the damaged fuel rod can be done using other types of lower nozzles. It turns out that this is possible by attaching the .

As described above, in order to pull out the damaged fuel rod from the fuel assembly and make the fuel assembly reusable, the fuel assembly is inverted underwater, the lower nozzle is positioned above the upper nozzle, and the lower nozzle is removed from the fuel assembly. It was found that it was sufficient to remove the nozzle, then pull out the damaged fuel rod, insert a dummy rod to replace it, and then install another type of lower nozzle.

This invention has been made in view of the above-mentioned circumstances, and a tube that is vertically inserted through the guide section of the upper XY table provided at the upper part of the aquarium is connected to the positioning section of the lower XY table connected to the wall of the aquarium. The rod (damaged fuel rod) of the fuel assembly installed in the water tank is grasped and pulled out using a tool attached to the lower part of the tube.
By inserting a rod (dummy rod) between the drive rollers connected to the guide body attached to the XY table and between the guide rollers and inserting it into the fuel assembly by the operation of the drive roller, the underwater fuel assembly is The damaged fuel rod can be pulled out from the body by operating the upper part of the water tank, and a dummy rod can be inserted, thereby making it possible to reuse the fuel assembly containing the damaged fuel rod, which was previously unusable. It is an object of the present invention to provide a rod extraction/insertion device for a fuel assembly which can thereby significantly reduce costs.

An embodiment of the present invention will be described below based on FIGS. 2 to 23. 11 in Figure 2 is the wall 12,1
A fuel transfer canal (water tank) is provided between the fuel transfer canal 11 and an upper fixing plate 13 attached to the walls 12, 12 at a predetermined location above the fuel transfer canal 11. Guide frames 14 and 15 are provided in a hanging manner on the upper fixing plate 13, and lower fixing plates 16 and 15 are provided below the guide frames 14 and 15, respectively.
17 is attached. Lower fixing plate 16,1
7 is fixed to the walls 12, 12 via an overhanging member 18. Can support frames 19 and 20 are provided between the guide frames 14 and 15 to face each other. Can support frame 19, 20
A sheave 21 is attached to the upper part of each of the can support frames 19 and 20, and an electric winch 22 attached to the upper fixed plate 13 is attached to the can support frames 19 and 20.
(FIG. 4), it is suspended vertically movably via a sheep 23, a wire rope 24, and a sheave 21, and is supported by a holding member 25 attached to guide frames 14 and 15. This holding member 25 is rotatably attached to the guide frames 14 and 15, and has a holding lever 25b whose tip can be opened and closed by a cylinder mechanism 25a. A can 26 rotatably attached to the can support frames 19 and 20 is provided between the can support frames 19 and 20, and is fixed by a stopper 27 provided on the can support frames 19 and 20. A fuel assembly 29 including the damaged fuel rod 125 is fitted into the can 26 , and this fuel assembly 29 is held in the can 26 by a holding mechanism 30 . This can 26 includes a worm 31a, a worm wheel 31b, and an operating rod 3.
1c in the water of the fuel transfer canal 11, and the stoppers 27, 3
It is fixed by 2. Therefore, the fuel assembly 29 in the can 26 is fixed with the lower nozzle 33 positioned above the upper nozzle.

On the upper fixing plate 13, there is an upper XY table 35 indicated by arrows A, B; C, D (X axis, Y axis) in FIG.
It is movable in the direction. The upper XY table 35 is fitted into two parallel rails 37 provided on a base 36 on the upper fixed plate 13 so as to be slidable in the directions of arrows A and B (X-axis direction) in FIG. A first table 38 and two parallel rails 39 provided on this first table 38,
In FIG. 6, the second table 40 is fitted to be slidable in the directions of arrows C and D (Y-axis direction). The first table 38 is screwed to a screw rod 41 rotatably attached to the base 36, and is moved in the directions of arrows A and B by the rotation of a motor 42 connected to the screw rod 41. ing. The second table 40 has two parallel T-grooves 43, and is moved in the directions of arrows C and D by the rotation of a motor 45 connected to a screw rod 44 rotatably attached to the first table 38. It is made so that it can be done.

A positioning jig 46 is provided on the second table 40.
It is fitted into the T-slot 43 and attached so that its position can be adjusted freely. The positioning jig 46 is shown in FIGS. 7 and 9.
As shown in the figure, a through hole 47 with a partial notch is formed, and 2
Guide ring members 48a and 48b of a divided guide ring (guide portion) 48 are provided as shown in FIG. 7, and are fixed to the positioning jig 46 with bolts. A tool connecting tube 50 is inserted into the center hole 49 of the guide ring 48 so as to be vertically slidable. A suspender 51 having a hole 51a is connected to the upper end of the tool connecting pipe 50, as shown in FIG. Further, a tool connecting pipe 50a is fitted into the tool connecting pipe 50 so as to be able to move up and down. is connected to. A tool 53 is provided in the tube 50a as shown in FIG. In addition, the tool connection pipe 5
0 is vertically positioned by a positioning fitting (positioning part) 55 shown in FIG.

Regarding the lower XY table 54, as shown in FIGS. 11 to 13, mounting bases 56 are attached to predetermined locations on the guide frames 14 and 15. There are brackets 57 and 58 on the mounting base 56.
is provided. A guide structure 59 is rotatably attached to the bracket 57 via two mounting plates 60 via a tubular shaft 61. As shown in FIG. The guide structure 59 has a pair of frames 62, 62 and four shafts 63, and sliding bodies 64, 64 are slidably attached to these shafts 63, respectively. The sliding bodies 64, 64 are guide bars 65,
65. Guide bar 65,6
A positioning metal fitting 55 is slidably attached to 5. A V-groove 67 is formed in this positioning metal fitting 55. Further, a shaft 68 is rotatably attached to the upper brackets 57, 58 in FIG. 11, and a shaft 69 is rotatably attached to the lower brackets 57, 58 in FIG. axis 68
A worm wheel 70 is attached to one end and a gear 71 is attached to the other end, and the worm wheel 70 is meshed with a worm 72 rotatably attached to the mounting base 56. An operating rod 73 extending above the upper fixing plate 13 is attached to the upper end of the worm 72. The guide structure 59 includes a chain wheel 74 that has a chain wheel 71 connected to one end via a chain 66, and a chain wheel 74 that has a chain wheel 71 connected to one end via a chain 66.
A shaft 76 to which 5 and 5 are respectively attached is rotatably attached. The chain wheel 75 is
It is connected via a chain 78 to a chain wheel 77 rotatably attached to the frame 62. A stopper 79 is attached to the chain 78,
This stopper 79 is attached to the sliding body 64, and when the chain 78 rotates, the positioning metal fitting 55 is moved to the first position via the sliding body 64 and the guide bars 65, 65.
In FIG. 1, it can be moved in the directions of arrows E and F. A bevel gear 81 is attached to the shaft 69 attached to the lower brackets 57, 58 in FIG. Further, a spline shaft 83 is connected to the sliding body 6 in the guide structure 59.
4 and is rotatably attached to the frame 62. A bevel gear 84 meshed with the bevel gear 81 is attached to an end of the spline shaft 83. Furthermore, a chain wheel 85 is attached to a predetermined location of the spline shaft 83, and a chain wheel 86 is attached to a predetermined location on one side of the spline-fitted side to be rotatable by the shaft 82, and the chain wheel 85, 86 is chain 8
They are connected via 7. A stopper 88 is attached to the chain 87, and this stopper 88 is attached to the positioning metal fitting 55 so that the rotation of the chain 87 moves the positioning metal fitting 55 in the directions of arrows G and H in FIG. being done. Further, rotating plates 9 are provided on the shafts 68 and 69, respectively.
1 are fitted and fixedly attached. These rotating plates 91 are each connected to the frame 62 via a cylinder mechanism 92 and to the guide frames 14 and 15 via a cylinder mechanism 93. Note that a worm wheel 94 is attached to the shaft 69, and this worm wheel 9
4 is engaged with a worm 95 rotatably attached to the mounting base 56. An operating rod 96 extending above the upper fixing plate 13 is attached to the upper end of the worm 95.

Tool 53 attached to the tool connection pipe 50
is constructed as shown in FIGS. 14 to 18. That is, the support plate 10 is attached to the first lever 101.
2 and 103 are provided, and a cylinder mechanism 104 is attached to the support plates 102 and 103. At the tip of the piston rod of the cylinder mechanism 104 is an L.
Wire guide roller 1 through the letter-shaped bracket
05 and rollers 106 are attached. A long hole 107 is formed in the first lever 101, and a roller 106 is fitted into the long hole 107 so as to be vertically movable. Further, the first lever 101 has a roller fitting hole 1 formed slightly below the elongated hole 107.
A wire guide roller 109 fitted in 08 is rotatably attached. first lever 10
A circular recess is formed in the vicinity of the lower end of the spring 1, and the spring seat 110 and the spring 1 are inserted into this recess.
11 is inserted. In addition, the first lever 10
There is a bolt 11 slightly below the spring 111 of 1.
2 is implanted. The bolt 112 has a shaft 113
are screwed together. The shaft 113 has links 114, 114 provided on both sides of the first lever 101.
is rotatably attached. Link 11
A second lever 115 is fitted between 4 and 114. The upper end of the second lever 115 has a slope 11
6 is formed. The upper part of the second lever 115 is connected to the elongated hole 107 and the groove 107 of the first lever 101.
A is removably fitted into the hole. An elongated hole 117 into which the wire guide roller 109 can be loosely fitted is formed in the upper part of the second lever 115. The lower part of the second lever 115 is formed in an L shape,
A recess 118 is formed in this lower part. The upper part of the third lever 119 is fitted into this recess 118 . The lower part of the third lever 119 and the lower part of the first lever 101 are overlapped in a crosswise manner and are rotatably connected to each other by a pin 120. Both the lower end of the second lever 115 and the upper part of the third lever 119 are rotatable between the links 114 and 114 via a pin 121 provided only on the second lever 115 and the third lever 119. connected. Further, the lower end of the second lever 115 and the links 114, 114 are rotatably connected via a pin 122. Also, the third lever 1
A circular recess is formed in the upper part of the spring 19, and the spring 111 is fitted into this recess in a compressed state.

The wire guide rollers 105 and 109 include
Wire 12 with one end attached to support plate 103
3 is wound. The other end of this wire 123 is attached to a wire attachment 124 attached to one side of the second lever 115. In addition,
As shown in FIGS. 14 to 16, the lower ends of the first lever 101 and the third lever 119 have circular recesses into which a damaged fuel rod 125 is inserted with their lower ends aligned. 126 is formed. Incidentally, reference numerals 133 and 134 shown in FIG. 4 are fuel rod guides for fitting the pulled out damaged fuel rod 125 and temporarily storing it, and are attached to the guide frame 15. Incidentally, each of the cylinder mechanisms is connected to a pipe, and these pipes are communicated with an operating unit (not shown) provided on the upper fixed plate 13 as appropriate. In addition, a second
As shown in FIG. 4, a television camera 135,
136 are provided. TV camera 135,
A connecting rod extending above the upper fixing plate 13 is attached to 136, and this connecting rod connects the television camera 13.
5,136 can be moved on the upper fixed plate 13.

Therefore, the damaged fuel rod 12 is removed from the fuel assembly 29.
5, the lower nozzle 33 of the fuel assembly 29 is located above the upper nozzle, and the lower nozzle 33 is 3 m above the water surface of the fuel transfer canal 11.
The fuel assembly 29 is fixed in the water of the fuel transfer canal 11 so as to be located at the following location, and the lower nozzle 33 is removed from the fuel assembly 29 using a cutting tool, and connected to the tool connection pipe 50. The suspended fixture 51 is suspended by a pit crane and carried onto the upper XY table 35. Then, the connecting pipe 50 is inserted into the through hole 47 of the positioning jig 46.
into the center hole 49 of the guide ring 48, which is divided into two parts.
Insert the connecting pipe 50 into the guide ring through the through hole 4.
7 and secure with bolts. Then, while observing the position of the tool 53 using the television cameras 135 and 136, the upper XY table 35 is moved to position the tool 53 above the damaged fuel rod 125 to be extracted from the fuel assembly 29.

Next, the tool connecting tube 50 is lowered together with the tool 53, and the lower XY table 54 is moved by turning the operating rods 73 and 96 from the upper fixing plate 13, and the tool connecting tube 50 is placed in the V groove 67 of the positioning metal fitting 55. The tool connecting tube 50 is placed in a vertical position, and the tool 53 is placed directly above the damaged fuel rod 125.

Next, the cylinder mechanism 104 is activated to contract it. Then, the wire 123 is temporarily loosened,
Since the roller 106 presses the slope 116 and the spring 111 presses the lever 119 in FIG.
Rotate in the direction of arrow I in Fig. 15 around ,
Move to the position indicated by the two-dot chain line in the figure. At this time, the link 114 rotates about the shaft 113 in the direction of arrow M in FIG. 15, and reaches the position indicated by the two-dot chain line in the figure, and the pin 122 moves to the position indicated by the symbol A in the figure. . Therefore, the third lever 119 rotates about the pin 120 in the direction of arrow K in the figure. As a result, the first lever 101, the third
The tip of the lever 119 opens.

Next, with the tips of the first and third levers 101, 119 open, the tool connecting pipe 50 is further lowered to position the damaged fuel rod 125 in the recess 126, and then the cylinder mechanism 104 is activated. Stretch this. Then, the wire 123 is pulled upward, which causes the second lever 115 to move to the first position.
5, the second lever 115, third lever 119, and link 114 return to their original positions, and the lower ends of the first lever 115 and third lever 119 close. The upper end of the damaged fuel rod 125 is sandwiched between the lower ends.

Next, the holding levers 25b attached to the guide frames 14 and 15 are opened by operating the cylinder mechanism 25a, and the electric winch 22 is operated to move the can support frame 1 through the wire rope 24.
Lower 9 and 20. As a result, the fuel assembly 29 is lowered together with the can 26, and the first lever 1
15. Pull out the damaged fuel rod 125 held by the third lever 119 from the fuel assembly 29.
The pulling force at this time is transmitted to the load cell 52 via the tool 53 and the pipe 50a, and the load cell 52
2.

The damaged fuel rod 125 that has been pulled out is operated by a pit crane and inserted into the fuel rod guides 133, 134 for temporary storage.

Next, a dummy rod 131 is inserted into the location where the damaged fuel rod 125 was pulled out from the fuel assembly 29. At this time, the guide ring 48 is removed from the positioning jig 46, and the tool guide 141 is attached onto the positioning jig 46 as shown in FIG. This tool guide 141 is constructed as shown in FIGS. 22 and 23. That is, a box (guide main body) 143 is attached to the positioning jig 46, and has a lower plate extended on one side, an open side on the other side, and a recess 142 formed in the lower part. In the box body 143, two guide bodies (guide bodies) 144 having an L-shaped cross section are spaced apart and parallel to each other.
and is attached in a hanging manner. The two guide bodies 144 are a positioning metal fitting 55 provided on the lower XY table 54 and a guide metal fitting 13 of the guide 144.
2 as shown in FIGS. 20 and 21, and are connected at predetermined locations by connecting fittings 145. Box body 143, guide body 144,
The connecting fitting 145 constitutes a guide body. The box body 143 is provided with bosses 146 and 147. A shaft member 148 is movably attached to the boss 146 using a nut 148a, and two supporting plates 150, 150 are attached to the bearing member 148 through a shaft 149 so as to face each other. Between the two support plates 150, 150 there is a drum-shaped 2
Two driving rollers 151, 151 are connected to shafts 152, 15
It is rotatably attached via 3. The two drive rollers 151, 151 are connected to shafts 152, 153.
It is configured to rotate in conjunction with two pulleys 154 attached to one end of the pulley 154 and a belt 155 wound around these pulleys. A pulley 156 is attached to the other end of the shaft 152, and this pulley 156
is connected to a motor (rotary drive machine) 157 attached to the box body 143 via a belt 158 and a pulley 159. Further, a shaft member 160 is movably attached to the boss 147 using a nut 160a. Two supporting plates 162 are attached to the shaft member 160 via a shaft 161 so as to face each other. Two drum-shaped drive rollers 163 are rotatably attached between the two support plates 162 via shafts 164 and 165. Drive roller 15
By moving the shaft members 148, 160, the distance can be adjusted to an appropriate distance between 1,163 and 1,163.
At predetermined locations of the two guide bodies 144, a stand 166,
167 is attached. The stand 166 has a shaft 1
Hinges 170, 170 are rotatably attached via 68, 168, and hourglass-shaped guide rollers 171, 172 are rotatably attached to the hinges 170, 170. Also, the stand 167 has a shaft 17
Hinges 174, 174 are rotatably attached via 3, 173, and hourglass-shaped guide rollers 175, 176 are rotatably attached to the hinges 174, 174. Guide rollers 171, 17
2 are respectively fitted onto the shaft 177 and mounted on the base 166.
A torsion coil spring (biasing member) 178 engaged with the hinge 170 biases the guide rollers 175 and 176 toward the guide rollers 175 and 176. Further, the guide rollers 175 and 176 each have a torsion coil spring (biasing member) 180 fitted to the shaft 179 and engaged with the base 167 and the hinge 174.
The rollers are urged toward the guide rollers 171 and 172 by. Further, guide rollers 127 and 128 are rotatably attached to the support plates 102 and 103. These guide rollers 127 and 128 are fitted into the guide body 144, and the tool 53 is inserted into the guide body 144.
44 so as not to deviate from it.

Therefore, in order to insert the dummy rod 131 into the fuel assembly 29, the lower nozzle 33 of the fuel assembly 29, which has been lowered from a position of 3 m or less below the water surface in order to pull out the damaged fuel rod 125, must be lowered from the original water surface. Operate the electric winch 22 and pull up to a position of 3 m or less.

Next, another tool 53 having the same shape and size as the tool 53
Attach the dummy rod 131 to the tool guide 1 in advance.
41 drive rollers 151 and 163 between the nut 1
48a, 160a are rotated to expand them, and the dummy rod 13 is inserted between these drive rollers 151, 153.
1 and tool 53 are inserted. drive roller 151,
When the tool 53 passes between 153 and 153, the nut 148
a, 160a to rotate the drive rollers 151, 153.
The tool connecting pipe 50 is held between the drive rollers 151 and 153 with a narrowed interval between them.

Next, the motor 157 is activated. Then, the belt 158, pulleys 159, 156, shaft 152,
Drive roller 15 via pulley 154 and shaft 153
1,163 rotates and sends the tool connecting pipe 50 downward. Dummy rod 1 attached to the tip of tool 53
31 passes between guide rollers 171 and 175, spreads out between guide rollers 172 and 176, and passes between them, and the lower end of dummy rod 131 is connected to fuel assembly 2.
It reaches near the top of 9. Here, the rotation of the motor 157 is stopped, and the lowering of the dummy rod 131 is temporarily stopped. Then, while monitoring with television cameras 135 and 136, the upper XY table 35 and lower XY table 54 are moved to position the dummy rod 131 directly above the dummy rod insertion location of the fuel assembly 29.

Next, the motor 157 is operated again and the dummy rod 131 is inserted into the fuel assembly 29. At this time, the tool 53 uses guide rollers 171, 175;
176, and the tool connecting pipe 50 is held between guide rollers 171, 175; 172, 176. Further, the insertion force of the dummy rod 131 is transmitted from the drive rollers 151 and 163 to the upper part of the load cell 52 via the tool connecting tube 50, and from the load cell 52 via the tube 50a and the tool 53 to the dummy rod 131. Therefore, a compressive force is applied to the load cell 52, and this compressive force is measured as the insertion force of the dummy rod 131 by a measuring device (not shown) connected to the load cell.

After inserting the dummy rod 131 into the fuel assembly 29, the cylinder mechanism 104 of the tool 53 is activated to open the lower end of the tool 53, the tool 53 is removed from the dummy rod 131, and the motor 157 is inserted into the dummy rod 13.
The tool connecting tube 50 is rotated in the opposite direction to the insertion time of 1.
The tool 53 is raised and further pulled up by a crane. As described above, the fuel assembly 29
After pulling out the damaged fuel rods 125 and inserting the dummy rods 131 as required, a predetermined lower nozzle suspended by a pit crane is attached to the fuel assembly 29 using a nozzle attachment tool (not shown). This allows the fuel assembly 29 that contained the damaged fuel rod 125 to be reused.

As explained above, according to the present invention, the tube, which is vertically movably inserted through the guide section of the upper XY table provided at the upper part of the aquarium, is guided by the positioning section of the lower XY table connected to the wall of the aquarium. and a tool attached to the bottom of the tube,
between driving rollers connected to a guide body attached to the lower XY table, which pinches and pulls out a damaged fuel rod of a fuel assembly installed in a water tank;
Since the structure is such that a dummy rod is inserted between the guide rollers and inserted into the fuel assembly by the operation of the drive roller, the damaged fuel rod can be pulled out from the submerged fuel assembly by an operation at the top of the water tank, and then inserted into the fuel assembly. Since a replacement dummy rod can be inserted into the fuel assembly, if a predetermined lower nozzle is further attached to this fuel assembly, the fuel assembly that contains the damaged fuel rod and could not be used in the past can be reused. This makes it possible to significantly reduce costs.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted longitudinal cross-sectional view of a fuel assembly loaded in a conventional nuclear reactor, Fig. 2 is a partially omitted front view showing an embodiment of the present invention, and Fig. 3 is its main components. 4 is a partially omitted side view of the section, FIG. 5 is a diagram showing one operating state of the main part, FIG. 6 is a plan view of the section, and FIG. Enlarged view,
Figure 8 is a side view of the main parts, Figure 9 is a diagram showing the positional relationship of the positioning jig, guide ring, and tool connection pipe, and Figure 10 is a partially cutaway diagram showing the relationship between the hanging tool and the load cell. A sectional view, Figure 11 is a plan view of the lower XY table, and Figure 12 is a diagram of Figure 11.
13 is a sectional view taken along line -XII in Fig. 12, Fig. 14 is a front view of the tool, Fig. 15 is a side view of the tool, and Fig. 16 is a sectional view taken along line - in Fig. 12. Fig. 17 is a partially omitted side view of the tool, Fig. 18 is a sectional view taken along line - in Fig. 15, Fig. 19 is a front view of the main parts, and Fig. 20 is the guide body. 21 is a view taken in the direction of the XI arrow in FIG. 20,
Figure 22 is an enlarged partially cutaway longitudinal sectional front view of the main part;
FIG. 23 is an enlarged longitudinal sectional side view of the main part taken along line -. 11...Fuel transfer canal (water tank), 13...
Upper fixing plate, 16, 17...Lower fixing plate, 19,
20... Can support frame, 22... Electric winch, 26... Can, 27... Stopper,
29...Fuel assembly, 33...Lower nozzle, 35
... Upper XY table, 46 ... Positioning jig,
48... Guide ring (guide portion), 50... Tool connection pipe, 50a... Pipe, 51... Hanging tool, 52
...Load cell, 53...Tool, 54...Lower part
XY table, 55... Positioning fitting (positioning part), 101... First lever, 104... Cylinder mechanism, 105, 109... Wire guide roller, 114... Link, 115... Second lever, 119 ...Third lever, 123...Wire, 125...Damaged fuel rod (rod), 131...
...Dummy rod (rod), 132...Guide metal fittings,
135, 136... Television camera, 143... Box body (guide body), 144... Guide body (guide body), 151, 163... Drive roller, 157
...Motor (rotary drive machine), 171, 172, 1
75,176...Guide roller, 178,180
...Torsion coil spring (biasing member).

Claims (1)

[Claims] 1. An upper part provided at the upper part of the aquarium and having a guide part that is movable back and forth and left and right in a horizontal plane.
an XY table, a lower XY table connected to the wall of the aquarium and provided underwater and having a positioning part movable back and forth and left and right in a horizontal plane; A tube guided by a positioning section, a tool attached to the tube and having a clamping section at its tip that can be opened and closed, a means for opening and closing the clamping section provided on the tool, and a positioning section of the lower XY table. A guide body attached to the guide body is connected to drive rollers whose mutual spacing is adjustable and rotatable in a vertical plane with their outer peripheries facing each other, and a drive roller on either side of the drive rollers. is,
a rotary drive machine that rotates the drive roller; a guide roller that is positioned below the drive roller, has outer peripheries facing each other so as to be close to each other, and is rotatably connected to the guide body in a vertical plane; a biasing member provided to bias at least one of the guide rollers toward the other guide roller, and between the drive rollers and between the guide rollers with respect to the fuel assembly provided in the water tank. A rod extracting/inserting device for a fuel assembly, characterized in that a rod is inserted into the rod, and then the rod is extracted and inserted. 2. A hanger connected to the upper part of the tube that is inserted through the guide section of the upper XY table and guided by the positioning section of the lower XY table, a hole formed in the hanger, and a hanger that fits into the hole. A load cell whose upper part is connected to the hanging tool, a tube which is connected to the lower part of the load cell and fitted into the tool connecting pipe so as to be vertically movable, and the tool is attached to the lower part of the tube. A rod extraction and insertion device for the fuel assembly according to item 1.