JP4000806B2 - Refueling equipment for nuclear facilities - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel exchange device used for loading and unloading fuel assemblies into and out of a nuclear reactor facility.
[0002]
[Prior art]
FIG. 12 is a perspective view showing a general appearance of the fuel changer. In FIG. 12, the fuel changer installed at the upper part of the core includes a traveling carriage 1 that travels in the direction of arrow A in a horizontal plane, a transverse carriage 2 that traverses in the direction of arrow B, and an elevation that moves up and down in the direction of arrow C (vertical) The fuel assembly 4 having a mechanism 3 and suspended from the tip of the elevating mechanism 3 is transported between a reactor core (not shown) and a fuel storage rack or a fuel transfer cask to a fuel storage space partitioned by a grid. Put in and out.
[0003]
FIG. 13 is a longitudinal sectional view showing in principle the conventional lifting mechanism 3 in FIG. In FIG. 13, the illustrated lifting mechanism 3 having a telescopic structure called a mast is composed of a plurality of tubes assembled in a telescopic manner, and has a grip portion 5 called a grapple at the tip. The grip 5 is provided with a hook 5a, and the fuel assembly 4 is suspended by an upper suspension handle 4a hung on the hook 5a. When the fuel is transferred, the elevating mechanism 3 is wound up by a wire rope 7 wound around the drum 6 as shown in the drawing. When the wire rope 7 reaches the designated position and is unwound, the elevating mechanism 3 is extended by its own weight and the grip portion 5 is lowered. .
[0004]
FIG. 14 is a longitudinal sectional view showing the BWR fuel assembly 4. In FIG. 14, as is well known, the fuel assembly 4 includes a number of fuel rods 4b each having a length of about 4 m in which fuel pellets are loaded into a rod-shaped cladding tube. Ten pieces are housed in a channel box 4c formed of a square cylinder having a side of about 150 mm, and upper and lower ends are held by tie plates 4d and 4e. A U-shaped suspension handle 4a is attached to the upper tie plate 4d diagonally. FIG. 15 is a perspective view showing an appearance of a control rod inserted between the fuel assemblies 4 as will be described later. The control rod 8 has a cross-shaped cross section as shown in the figure, and a U-shaped handle 8a is provided at the upper end.
[0005]
16 is a longitudinal sectional view showing a part of the core in which the fuel assembly 4 and the control rod 8 are inserted, FIG. 17 is an enlarged view of a portion A in FIG. 16, and FIG. 18 is a plan view thereof. As shown in FIGS. 16 to 18, the core is divided into four cells by the cross-shaped control rods 8 by dividing the cells partitioned by the upper grid 9 into grids, and the fuel storage space 10 is partitioned into grids. The fuel assemblies 4 are inserted into the storage spaces 10 by the fuel changer. The lower end portion of the fuel assembly 4 is supported by a seat (not shown). Here, the four fuel assemblies 4 surrounding each control rod 8 are taken in and out diagonally with respect to the control rod 8, and at that time, when the two fuel storage spaces 10 on the diagonal are empty, A double blade guide 11 for keeping the control rod 8 upright is inserted into the part. The double blade guide 11 is a simulated body simulating the shape of the two fuel assemblies 4 on a diagonal line, and serves as a dummy until the fuel assemblies 4 are inserted.
[0006]
[Problems to be solved by the invention]
In the operation of inserting the fuel assembly 4 by the fuel exchange device described above, conventionally, when the fuel assembly 4 is lowered at a designated position, the lower end portion of the fuel assembly 4 interferes with the adjacent fuel assembly 4. In some cases, the fuel storage space 10 may be caught in the middle (slack). In such a case, there is a problem that the fuel assembly 4 must be pulled up and the insertion operation must be performed again. Such a phenomenon is caused by the fact that the fuel assembly 4 generally has a length of 4 m or more and is also suspended by the long elevating mechanism 3. This is caused by the large shaking. Incidentally, the stop accuracy at the designated position of the fuel changer is about several millimeters, and the clearance margin of the fuel assembly 4 with respect to the fuel storage space 10 is about 10 mm, but the amplitude of the lower end due to the shaking of the fuel assembly 4 at the time of stoppage Easily exceed these dimensional levels.
[0007]
For this reason, conventionally, measures such as improving the rigidity of the entire fuel changer and suppressing the vibration of the elevating mechanism 4 by the damper have been taken, but satisfactory results have not been obtained. Currently, after stopping at the designated position, the fuel assembly The fuel assembly 4 is inserted after waiting as much as possible until the shaking of the body 4 is attenuated. However, this waiting time prolongs the refueling work, which in turn hinders the shortening of the periodic inspection period of the nuclear facility.
[0008]
On the other hand, the situation of the core in which the fuel assemblies 4 are taken in and out varies depending on the operation stage at each time, such as each fuel storage space 10 being empty, the double blade guide 11 being inserted, or the like. For this reason, each time the fuel assembly 4 is handled, the worker visually confirms the condition of the core. However, depending on the state of the water that fills the core (fluctuation, transparency, etc.), the situation cannot be fully understood. In such a case, there is no choice but to rely on the travel / transverse positioning accuracy of the fuel changer and the data of the position detector. was there.
[0009]
Therefore, first of all, the problem of the present invention is to suppress the shaking at the stop position of the fuel assembly supported suspended from the fuel changer, and improve the stop accuracy and expand the inlet space of the fuel insertion passage. The object is to prevent interference and slack with adjacent fuel when the fuel assembly is inserted, and to shorten the fuel exchange time.
[0010]
Another object of the present invention is to improve the reliability of the fuel replacement work by making it possible to grasp the condition of the core without visual observation.
[0011]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention suspends a fuel assembly having a suspension handle from a tip of an elevating mechanism and transfers it to a designated position, and the fuel assembly is placed in a fuel storage space partitioned by a grid. At the time of insertion, a sheath-like fuel insertion guide covering the fuel assembly is slidably attached to the tip of the elevating mechanism, and the fuel containing space is guided while the fuel assembly is guided by the fuel insertion guide. And a fuel exchange device for a nuclear facility configured to seat the tip of the fuel insertion guide on the upper surface of the adjacent fuel assembly before inserting the fuel assembly into the fuel accommodating space. In
The fuel insertion guide has a hollow rectangular tube shape whose inside dimension is approximately equal to the interval between the opposing side surfaces of adjacent fuel assemblies, and a plate-like guide on the four side surfaces of the tip portion. A pad is joined, and when the fuel insertion guide is seated on the adjacent fuel assembly, the guide pad is pressed against a suspension handle of the adjacent fuel assembly. The fuel assemblies that are adjacent to each other are pushed out to the outside (Claim 1). According to the first aspect, the fuel assembly suspended by the elevating mechanism hits the fuel insertion guide that covers the outer side of the fuel assembly when the fuel assembly swings.
[0012]
Further, by seating the tip of the fuel insertion guide on the upper surface of the adjacent fuel assembly, the tip of the fuel insertion guide is moored to the adjacent fuel assembly, and at the same time, the lifting mechanism is attached to the adjacent fuel assembly via the fuel insertion guide. Due to the restraint, the fuel assembly shakes further.
[0013]
Further, by pressing the guide pad provided on the tip side of the fuel insertion guide hanging handle adjacent fuel assemblies, fuel insertion guide is guided in the adjacent fuel assemblies around as a result, the center of the fuel accommodating space Aligned towards At this time, the inlet of the fuel insertion passage is widened by pushing the adjacent fuel assembly outward.
[0014]
Further, the present invention resides in that in Claim 1, the tip of the fuel insertion guide, it is assumed that a sensor to check the status of the peripheral insertion position of the fuel assembly (claim 2). By using the fuel insertion guide and providing a sensor for confirming the situation around the fuel assembly insertion position at the tip, the situation of the core can be accurately grasped in the operation room without relying on visual observation.
[0015]
The sensor confirms the presence or absence of the adjacent fuel assembly or double blade guide (Claim 3 ), confirms the presence or absence of the control rod or the vertical position thereof (Claim 4 ), and the position of the upper grid And it can comprise as what confirms direction (Claim 5 ).
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. First, FIG. 1 shows the raising / lowering mechanism 3 provided with the fuel insertion guide, FIG. 1 (A) is a longitudinal cross-sectional view, and FIG. 1 (B) is a bottom view. In FIG. 1, the elevating mechanism 3 has a telescopic structure as in the conventional example of FIG. 13 , and is composed of five tubes 3a made of stainless steel pipes having different diameters so as to be extendable and contractable. The outermost tube 3a is vertically supported by the traversing mechanism 2 (see FIG. 12) via the connecting portion 3b, and the four inner tubes 3a are sequentially drawn downward from the illustrated storage position. At the center of the elevating mechanism 3, the grip portion 5 is suspended by a wire rope 7 so as to be able to move up and down, and the wire rope 7 is wound around a drum 6 (see FIG. 13). The grip 5 has a hook 5a, and the fuel assembly 4 is suspended by a suspension handle 4a hung on the hook 5a.
[0017]
Here, a fuel insertion guide 12 that covers the fuel assembly 4 outside the suspended fuel assembly 4 is attached to the grip portion 5 . As shown in FIG. 1B, the fuel insertion guide 12 has a square tube shape with a square cross section, and its upper end is closed by an end plate 12a, and the fuel insertion guide 12 is hung on the upper surface of the grip portion 5 through the end plate 12a. It is supported so as to be slidable with respect to the grip portion 5. The wire rope 7 loosely penetrates the center hole of the end plate 12a. The fuel insertion guide 12 is formed from a stainless steel tube into, for example, a hollow rectangular tube having a thickness of about 6 mm, and guide pads 12b having a thickness of about 15 mm cut out from the stainless steel plate are joined to the four side surfaces of the tip by welding. . An inclined surface 12c is formed by chamfering at the tip corner of the guide pad 12b.
[0018]
For example, if the outer shape of the fuel assembly 4 is a square shape with a side of about 150 mm, the inner dimension of the fuel insertion guide 12 is determined to be about 200 mm per side, which is inserted into the fuel assembly 4 as will be described later. The distance D (FIG. 4) between the opposing side surfaces of the fuel assemblies 4 adjacent to each other in the front, rear, left and right of the fuel storage space 10 to be obtained is substantially equal. The length of the fuel insertion guide 12 is determined such that the lower end portion protrudes below the lower end portion of the fuel assembly 4 suspended from the grip portion 5.
[0019]
On the other hand, in FIG. 1, slide pieces 3 c are attached to the outer peripheral surfaces of the upper ends of the four tubes 3 a except for the fuel insertion guide 12 and the outermost part at equal pitches. The slide piece 3c has a role of a spacing piece for maintaining a spacing between the tubes 3a and between the innermost tube 3a and the fuel insertion guide 12, and an engagement piece for coordinating expansion and contraction operations described later. It also serves as a role. Moreover, the same slide piece 3d is attached to the inner peripheral surface of the lower end part of the five tubes 3a. The slide pieces 3c and 3d have rollers in a block-shaped body, and the rollers rotate in contact with the adjacent surfaces of the adjacent tube 3a and the fuel insertion guide 12. Furthermore, the engagement piece 3e which becomes the other party of the slide piece 3a as an engagement piece is attached to the inner peripheral surface of the upper end part of the five tubes 3a so that it may overlap with the upper surface of each slide piece 3c.
[0020]
In such an elevating mechanism 3, when the wire rope 7 is rewound and the grip portion 5 supporting the fuel assembly 4 is lowered, the fuel insertion guide 12 hung on the grip portion 5 is also lowered. Eventually, when the slide piece 3c attached to the outer peripheral surface of the upper end portion of the fuel insertion guide 12 reaches the slide piece 3d attached to the inner peripheral surface of the lower end portion of the innermost tube 3a, the engagement between the slide pieces 3c and 3d is performed. As a result, the innermost tube 3a is also lowered. Thereafter, similarly, the second to fourth tubes 3a from the inner side are also lowered, and the extension of the elevating mechanism 3 is finished when the fourth tube from the inner side (second from the outer side) has been lowered. FIG. 2 is a side view showing the lifting mechanism 3 that has finished extending in this manner, and the total length of the lifting mechanism 3 in the illustrated extended state is, for example, about 18 m.
[0021]
In the extended lifting mechanism 3, the fuel insertion guide 12 is pulled up by pulling up the grip 5, and then the slide piece 3c attached to the outer peripheral surface of the upper end is attached to the inner peripheral surface of the upper end of the innermost tube 3a. When the engagement piece 3e is engaged, the innermost tube 3a is pulled up. Thereafter, similarly, the outer tube 3a is sequentially pulled up and contracted as shown in FIG. In this contracted state, since the fuel insertion guide 12 is housed in the tube 3a, the total length of the elevating mechanism 3 is almost the same as the conventional one.
[0022]
The operation of the fuel changer having such a lifting mechanism 3 will now be described with reference to the process diagram of FIG. (1) to (9) in FIG. 3 represent the order of steps. Now, in FIG. 3, (1) is in a standby state, and the empty gripping part 5 is in the upper limit position. When the work is started, the lifting mechanism 5 is moved to a specified position on the fuel storage rack, for example, in (2) , and the fuel insertion guide 12 is lowered until it is seated on the upper surface of the fuel assembly 4. At this stage, the empty gripper 5 is at the upper limit in the fuel insertion guide 12. Next, in (3) , the grip 5 is lowered and the fuel assembly 4 is gripped. When the fuel assembly 4 is gripped, the grip portion 5 is raised in (4) , the fuel assembly 4 is accommodated in the fuel insertion guide 12, and the fuel insertion guide 12 is detached from the fuel storage rack.
[0023]
Next, in (5) , the elevating mechanism 3 is moved, and the fuel assembly 4 is transferred to a designated position in the core and stopped. When stopped, the grip 5 is lowered in (6) , and the fuel insertion guide 12 is seated on the upper surface of the adjacent fuel assembly 4. Next, in (7) , the grip portion 5 is lowered and the fuel assembly 4 is inserted into the designated fuel storage space 10. When the insertion is completed, the fuel assembly 4 is released in (8) , the empty gripping portion 5 is raised to the upper limit, the lifting mechanism 3 is moved, and the process waits in (9) . In the above description has described the case of inserting the fuel assemblies 4 in fuel storage racks in the core, the core and base lotus withdrawal and insertion operation of the fuel assembly 4 between fuel storage racks and fuel transportation cask mutually same This is done in the same way.
[0024]
FIG. 4 is an enlarged view of a main part in a state in which the fuel insertion guide 12 is seated on the upper surface of the adjacent fuel assembly 4 (specifically, the upper end surface of the channel box 4c ) in (2) or (6) of FIG. 5 is a cross-sectional view taken along line VV in FIG. 4 and 5, when the fuel insertion guide 12 descends toward the fuel storage space 10, it interrupts between the suspension handles 4a of the adjacent fuel assemblies 4 via the inclined surface 12c of the guide pad 12b. The adjacent fuel assembly 4 is pushed outward by the side surface of the guide pad 12b via the suspension handle 4a. Then, the end face of the fuel insertion guide 12 is seated on the end faces of the channel box 4c of the fuel assembly 4 adjacent. Thereafter, the gripper 5 is lowered, and the fuel assembly 4 accommodated in the fuel accommodating space 10 is inserted into the fuel accommodating space 10 while being guided by the fuel insertion guide 12, or the fuel already accommodated in the fuel accommodating space. The assembly 4 is pulled out while being gripped by the grip portion 5 and guided by the fuel insertion guide 12.
[0025]
In such a fuel exchange operation, the fuel assembly 4 suspended from the grip portion 5 is guided by the fuel insertion guide 12 and inserted into the fuel storage space 10, so that the fuel assembly 4 swings relative to the grip portion 5. Is suppressed by the fuel assembly 4 hitting the inner wall surface of the fuel insertion guide 12. Further, since the fuel insertion guide 12 is seated on the upper surface of the adjacent fuel assembly 4, the tip of the fuel insertion guide 12 is moored to the adjacent fuel assembly 4 to suppress the shaking, and at the same time, the elevating mechanism 3 is also connected to the fuel insertion guide 4. Since the vibration is suppressed by being constrained by the adjacent fuel assembly 4 via 12, the vibration of the fuel assembly 4 is further reduced.
[0026]
Furthermore, since the fuel insertion guide 12 seated on the adjacent fuel assembly 4 pushes the adjacent fuel assembly 4 outward through the suspension handle 4a, the restraint of the fuel insertion guide 12 by the adjacent fuel assembly 4 is strong. On the other hand, the inlet of the fuel insertion passage is expanded to facilitate the insertion of the fuel assembly 4, and the fuel insertion guide 12 is accurately positioned with respect to the fuel accommodating space 10, as shown in FIG. That is, the outline shown by the chain line in FIG. 4 represents the fuel insertion guide 12 that has been lowered and decentered by the dimension e with respect to the center P of the fuel storage space 10. In this case, the fuel insertion guide 12 is in the process until seating. The fuel is pushed back to the adjacent fuel assembly 4 and aligned to the normal position indicated by the solid line.
[0027]
As described above, according to the illustrated fuel changer, when the fuel assembly 4 is transferred to the designated position, the fuel assembly 4 can be shifted to the insertion operation without waiting for a long time until the shaking is attenuated. Is inserted smoothly and at high speed while being guided by the fuel insertion guide 12 without getting on the adjacent fuel assembly 4 or being caught on the inner wall of the fuel accommodating space 10. Also, when the fuel assembly 4 is pulled out, the lifting mechanism 3 is positioned accurately. In the illustrated embodiment, an example of a telescopic structure is shown as an elevating mechanism. However, the present invention is applicable to a general fuel changer that suspends and transfers a fuel assembly to an elevating mechanism regardless of the structure of the elevating mechanism. is there.
[0028]
6 to 11 show an embodiment in which a sensor is provided at the tip of the fuel insertion guide 12 described above. First, FIG. 6 shows an embodiment using a contact type sensor. In FIG. 6, first to fourth sensors 13 to 16 are provided at the tip of the fuel insertion guide 12. The 1st-3rd sensors 13-15 confirm the presence or absence of an adjacent fuel assembly, and the 4th sensor 16 confirms the presence or absence of a double blade guide. Each of the sensors 13 to 16 has a shape difference, but each has a contact 17 that strikes the object to be confirmed, a rod 18 that is coupled to the contact 17, and a sensor element 19 that faces the end surface of the rod 18 with a gap therebetween. is doing. The rectangular contact 17 of the sensors 13 and 14 is guided in a guide pad 12b on two adjacent side surfaces of the fuel insertion guide 12 so as to be slidable up and down.
[0029]
In FIG. 6, the corner portion between the sensors 13 and 14 of the fuel insertion guide 12 is cut out, and an arcuate auxiliary member 20 is joined to the auxiliary member 20 by welding as shown in the figure. An arc-shaped contact 17 is guided through a rod 18 so as to be slidable up and down. Further, a rectangular auxiliary member 21 is joined to the side surface of the fuel insertion guide 12 so as to be positioned between the sensor 13 and the sensor 15, and the rectangular contact 17 of the sensor 16 is connected to the auxiliary member 21 with a rod. 18 is slidably guided up and down via 18. The contacts 17 are all biased downward by a back spring (not shown), and the contacts 17 of the sensors 13 to 15 are stopped in the same plane at the lower limit position slightly protruding from the lower end surface of the fuel insertion guide 12. The sixteen contacts 17 are stopped at a lower illustrated lower limit position. The contact 17, the rod 18, and the auxiliary members 20 and 21 are all made of stainless steel.
[0030]
FIG. 7 is a plan view schematically showing the positional relationship of the sensors 13 to 15 with respect to the adjacent fuel assembly 4 when the fuel insertion guide 12 of FIG. 6 is seated at the specified position of the core. As shown in FIG. 6, the contacts 17 of the sensors 13 and 14 hit the upper surface of the channel box 4c of the fuel assembly 4 adjacent to the side surface of the insertion designated position 22 in the core, and the contacts 17 of the sensor 15 are inserted. It hits the upper surface of the corner of the channel box 4c of the fuel assembly 4 adjacent on the diagonal line of the designated position 22.
[0031]
Therefore, when the fuel insertion guide 12 is seated, each of the sensors 13 to 15 rises against the back spring when the corresponding adjacent fuel assembly 4 is inserted, and the rod 18 moves to the sensor element. Approach 19 As a result, the sensor element 19 generates a signal indicating that there is a fuel assembly. Further, if there is no corresponding fuel assembly 4 and the fuel storage space 10 in that portion is empty, no signal is generated. Similarly, FIG. 8 shows the positional relationship of the sensor 16 with respect to the double blade guide 11. When the double blade guide 11 is inserted, the contact 17 abuts against the hanger 11 a of the double blade guide 11. As a result, a signal indicating that there is a double blade guide is generated in the sensor element 19, and no signal is generated unless the double blade guide 11 is inserted. A known magnetic or ultrasonic proximity switch, photoelectric switch, limit switch, or the like is used as the sensor element 19 that generates a signal by raising the contact 17.
[0032]
Next, FIG. 9 shows an embodiment using a non-contact type sensor. In FIG. 9, a known hatching portion using ultrasonic waves, microwaves, infrared rays, or the like is used for the hatched portions of the auxiliary members 23 joined along the guide pads 12b on the two side surfaces of the fuel insertion guide 12 and the corners therebetween. The non-contact sensors 13 to 16 are embedded. FIG. 10 is a plan view schematically showing the positional relationship of the sensors 13 to 16 with respect to the adjacent fuel assembly 4 when an ultrasonic sensor is used. In FIG. 10, the first and second sensors 13 and 14 confirm the presence or absence of the fuel assembly 4 adjacent to the side surface of the insertion designation position 22. The third sensor 15 includes three sensors 15a to 15c, and the center sensor 15b confirms the presence / absence of the adjacent fuel assembly 4 on the diagonal line of the insertion designation position 22, and the sensors 15a and 15c on both sides thereof are controlled. Check the presence / absence and vertical position of the bar 8. Incidentally, when the fuel assembly 4 is inserted, the control rod 8 needs to be pulled up to a predetermined height. As shown in FIG. 11, the fourth sensor 16 confirms the presence or absence of the double blade guide 11. In FIG. 10, if a fifth ultrasonic sensor 24 is provided separately, the insertion failure of the adjacent fuel assembly 4 can be found by confirming the relative height position of the adjacent fuel assembly 4 with respect to the upper grid 9. Can do.
[0033]
In the illustrated embodiment, the confirmation of the existence of the adjacent fuel assembly 4 and the double blade guide 11 is mainly shown, but in particular, if the distance measurement function and the shape determination function of the non-contact type sensor are used more widely, Various monitoring and inspections are performed, such as finding a mistake in the stop position of the fuel assembly 4 by confirming the relative position based on the position and orientation of the upper grid 9 and calibrating the lift stroke of the lift mechanism 3 with respect to the core. It becomes possible.
[0034]
【The invention's effect】
As described above, according to the present invention, the sheath-like fuel insertion guide covering the fuel assembly is attached to the tip of the lifting mechanism so as to be slidable in the axial direction, and the fuel is accommodated while the fuel assembly is guided by the fuel insertion guide. By inserting into the space, the fuel assembly can be prevented from shaking and the time required for fuel replacement by waiting for the vibration to decay can be eliminated, and as a result, the inspection period of the nuclear facility can be greatly shortened. Can do.
[0035]
Further, in that case, the fuel insertion guide can be further restrained by allowing the tip of the fuel insertion guide to be seated on the upper surface of the adjacent fuel assembly, and the guide pad provided at the tip of the fuel insertion guide. By pushing the adjacent fuel assembly outward, the positioning mechanism can be accurately positioned according to the adjacent fuel assembly, and the inlet of the fuel insertion passage is widened to make the fuel assembly smoother and faster. Can be inserted.
[0036]
On the other hand, by using a fuel insertion guide to provide a sensor at the tip of the fuel assembly to confirm the situation around the insertion position of the fuel assembly, the situation of the core can always be grasped on the side of the operation room. This makes it possible to improve the reliability and safety of the fuel replacement work, and eliminate the need for visual confirmation of the core, thereby improving the efficiency of the fuel replacement work.
[Brief description of the drawings]
1A and 1B show an embodiment of the present invention, in which FIG. 1A is a longitudinal sectional view of an elevating mechanism of a fuel changer, and FIG. 1B is a bottom view thereof.
FIG. 2 is a side view of the lift mechanism shown in FIG. 1 in an extended state.
FIG. 3 is a process diagram for explaining the operation of the fuel changer in FIG. 1;
4 is an enlarged view of a main part of FIG. 3;
5 is a cross-sectional view taken along line VV in FIG.
FIG. 6 is a perspective view showing a tip portion of a fuel insertion guide provided with a contact type sensor.
7 is a plan view schematically showing the positional relationship of the sensor in FIG. 6 with respect to an adjacent fuel assembly.
8 is a plan view schematically showing the positional relationship of the sensor in FIG. 7 with respect to the double blade guide.
FIG. 9 is a perspective view showing a tip portion of a fuel insertion guide provided with a non-contact type sensor.
10 is a plan view schematically showing the positional relationship of the sensor in FIG. 9 with respect to an adjacent fuel assembly.
11 is a plan view schematically showing the positional relationship of the sensor in FIG. 9 with respect to the double blade guide.
FIG. 12 is a perspective view showing a general appearance of a fuel exchange device.
FIG. 13 is a longitudinal sectional view showing in principle a lifting mechanism of a conventional fuel changer.
FIG. 14 is a longitudinal sectional view showing a general fuel assembly.
FIG. 15 is a perspective view showing a general control rod.
16 is a longitudinal sectional view showing a part of the core into which the fuel assembly of FIG. 14 is inserted.
FIG. 17 is an enlarged view of a part A in FIG.
FIG. 18 is a plan view of FIG. 17;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Traveling trolley 2 Traversing trolley 3 Lifting mechanism 4 Fuel assembly 4a Suspension handle 5 Grip part 5a Hook 8 Control rod 9 Upper grid 10 Fuel storage space 11 Double blade guide 12 Fuel insertion guides 13-16, 24 Sensor 22 Fuel insertion specification position

Claims (5)

The fuel assembly having a hanging handle, when transferred to a specified position hung on the tip of the lifting mechanism, inserting the fuel assemblies in the fuel accommodating space partitioned into meshes, the tip of the lifting mechanism, the A sheath-like fuel insertion guide covering the fuel assembly is slidably mounted in the axial direction, and the fuel assembly is inserted into the fuel storage space while being guided by the fuel insertion guide, and the fuel storage space is inserted into the fuel storage space. Before inserting the fuel assembly, a fuel exchange device for a nuclear facility configured to seat the tip of the fuel insertion guide on the upper surface of the adjacent fuel assembly,
The fuel insertion guide has a hollow rectangular tube shape whose inside dimension is approximately equal to the interval between the opposing side surfaces of adjacent fuel assemblies, and a plate-like guide on the four side surfaces of the tip portion. A pad is joined, and when the fuel insertion guide is seated on the adjacent fuel assembly, the guide pad is pressed against a suspension handle of the adjacent fuel assembly. A fuel exchange apparatus for a nuclear facility, wherein the adjacent fuel assemblies are pushed outward . 2. A fuel exchange apparatus for a nuclear facility according to claim 1, wherein a sensor for confirming a situation around an insertion position of the fuel assembly is provided at a tip of the fuel insertion guide. The nuclear fuel facility refueling apparatus according to claim 2 , wherein the sensor is configured to confirm presence or absence of the adjacent fuel assembly or double blade guide. 3. The fuel exchange apparatus for a nuclear facility according to claim 2 , wherein the sensor confirms the presence or absence of a control rod or the vertical position thereof. The nuclear fuel facility refueling apparatus according to claim 2, wherein the sensor is for confirming a position and an orientation of the upper grid.

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