JP4762215B2 - Spacer wire removal device from spent nuclear fuel element and nuclear fuel element used in the device - Google Patents

Description

  The present invention relates to a spacer wire removing device from a spent nuclear fuel element, and more particularly to a spacer wire removing device from a spent nuclear fuel element that enables stable separation of a fuel pin and a wire.

  A fast breeder reactor (hereinafter referred to as “FBR”) fuel element (hereinafter also referred to as “fuel pin”) has a spiral spacer wire (hereinafter simply referred to as “wire”) to secure a coolant passage between the fuel pins. It is wound around.

  FIG. 13 is a diagram showing a general configuration of a fuel pin used in a wire spacer type core fuel assembly. As shown in the figure, the fuel pin 1000 has an upper end plug portion 1000a, a lower end plug portion 1000b, and a cladding tube portion 1000c, and a cladding tube portion between the upper end plug portion 1000a and the lower end plug portion 1000b. In 1000c, a wire 1000d serving as a spacer having a diameter of about 1 mm is spirally wound several times at a predetermined pitch (about 200 mm). Both ends of the wire 1000d are welded to the upper end plug portion 1000a and the lower end plug portion 1000b, respectively. The fuel pin 1000 has an outer dimension of approximately a diameter of about 10 mm and a length of about 3 m.

  In the domestic reprocessing of FBR spent fuel, it is assumed that a large number of fuel pins are sheared together. Until now, the fuel pins are sheared with the wire wound and sent to the melting process. Technological development is underway on the premise. However, in a post-irradiation test facility intended to process a limited number of fuel pins, the operator uses a manipulator to remove the wires. Moreover, in the fuel stabilization processing facility (hereinafter referred to as FCF) of the fast experimental reactor EBR-II in the United States, the wire is removed remotely and automatically.

  When the fuel pin is sheared with the wire wound, the wire cut at one end with the shear may be released and sent to the melting process without being sufficiently sheared. It is worried that it will become a cause of blockage. If it is assumed that more than 1000 fuel pins will be processed every day, as in a future practical reprocessing facility, wire removal by the operator is not practical as in post-irradiation tests, and remote automation is required. It becomes. Details of the wire removal device in FCF are not disclosed, but it seems to be insufficient in terms of processing speed and reliability to be adopted in a practical reprocessing facility. For this reason, it is necessary to develop a wire removal device using a completely different method.

  A known technique for removing the spacer wire from the fuel rod is to contact the spacer wire in a control device that controls the cutting of the fuel rod spacer wire that occurs when cutting to a cutting potential different from the reference portion potential. And a device for measuring the difference between the potential of the contact portion and the potential of the reference portion, the contact portion being placed around the rod and downstream of the cutting device There is a control device that is a conical hollow conical portion that moves along a displacement axis and rubs its outer surface with a spacer wire (see, for example, Patent Document 1).

According to Patent Document 1, the contact portion 10 has a hollow conical shape because its first action is to separate the spacer wire 1 from the rod 20. The contact portion 10 is also known as a contact cone and is installed concentrically on the main axis 4 and the fuel rod 20.
Japanese Patent Laid-Open No. 5-113492

  However, it is known that the outer diameter of the fuel pin increases by up to 5% by irradiation in the furnace. In addition, the fuel pin is helically deformed by the tension of the spacer wire, and a maximum bending of about 5 cm is also generated by the thermal stress caused by irradiation in the furnace. Thus, the spent nuclear fuel pin is deformed in various ways.

  According to the control device of Patent Document 1, in order to separate the spacer wire 1 from the rod 20, a contact portion having a hollow conical shape is used, but when the contact portion having a hollow conical shape is used, the outer diameter Since a work with a high degree of difficulty is required to insert the fuel pin that has changed due to the deformation into the hollow portion of the contact portion, a complicated insertion mechanism is required. Further, a mechanism for causing the hollow conical contact portion to follow the fuel pin that has been deformed or bent is further required.

  Moreover, since the separated spacer wire is long, the volume becomes large at the time of collection. For this reason, in the control apparatus of patent document 1, the spacer wire is cut | disconnected each time by predetermined length. However, an increase in the number of cutting operations is disadvantageous in terms of processing time, and there is a problem that the cutting mechanism becomes complicated.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide an apparatus capable of stably removing a spacer wire from a spent nuclear fuel element.

The apparatus for removing a spacer wire from a spent nuclear fuel element according to the present invention has a first end plug portion and a second end plug portion at both ends of the main body, and the spacer wire is spirally wound. Both ends are joined to the first end plug portion and the second end plug portion, respectively, and the spacer wire from the nuclear fuel element having a recess at a position where the spacer wire winds at the boundary between the first end plug portion and the main body. A first end plug gripping mechanism for gripping the first end plug of the nuclear fuel element, and a second end plug gripping mechanism for gripping the second end plug of the nuclear fuel element , A shear blade that cuts only the first end plug portion of the nuclear fuel element without cutting the spacer wire at the boundary between the first end plug portion and the nuclear fuel element body, the first end plug portion, and the nuclear fuel Spacer at the boundary with the element body A nuclear fuel element that rotates a first end plug cutting mechanism section and a second end plug gripping mechanism section in a direction to unwind the spacer wire. A fuel pin rotation mechanism, the nuclear fuel element rotation mechanism rotates the nuclear fuel element gripped by the second end plug gripping mechanism, and when the detection unit detects the spacer wire, the nuclear fuel element rotation mechanism Stops the rotation of the nuclear fuel element, and the first end plug cutting mechanism section moves the shear blade in the shear direction to cut the first end plug section.

  According to the spacer wire removing device from the spent nuclear fuel element of the present invention, it is possible to stably remove the spacer wire from the spent nuclear fuel element.

  Below, the spacer wire removal apparatus from the spent nuclear fuel element which is embodiment of this invention is demonstrated with reference to figures.

(1) Overall Configuration FIG. 1 is a diagram showing the overall configuration of the spacer wire removing device from the spent nuclear fuel element of the present embodiment. The spacer wire removing device 100 from the spent nuclear fuel element according to the present embodiment includes a fuel pin supply mechanism unit 10, a lower end plug gripping mechanism unit 20, a fuel pin rotation mechanism unit 30, and an upper end plug gripping mechanism unit 40. The upper end plug cutting mechanism unit 50, the wire pulling mechanism unit 60, the scrape mechanism unit 70, the lower end plug cutting mechanism unit 80, and the sorting mechanism unit 90 are provided.

(2) Fuel Pin FIG. 2 is a diagram showing a configuration of a fuel pin that is a target of wire removal by the spacer wire removing device from the spent nuclear fuel element of the present embodiment. As shown in the figure, the fuel pin 1 of the present embodiment has an upper end plug portion 1a, a lower end plug portion 1b, and a fuel pin main body portion 1c, and includes an upper end plug portion 1a and a lower end plug portion 1b. A wire 1d serving as a spacer having a diameter of about 1 mm is spirally wound several times at a predetermined pitch (about 200 mm) around the fuel pin main body 1c. Both ends of the wire 1d are welded to the upper end plug portion 1a and the lower end plug portion 1b, respectively.

  Unlike the conventional fuel pin, the fuel pin 1 of the present embodiment has a constricted portion 1e between the upper end plug portion 1a and the fuel pin main body portion 1c, and the lower end plug portion 1b and the fuel pin main body portion. It has a constricted portion 1f between 1c.

  End plugs to be described later are recessed portions 1e and 1f for both the upper and lower end plugs. This is because the shear area is narrow, the necessary shear force can be reduced, and the shear position can be easily detected.

  Moreover, since a predetermined gap is formed between the wire 1d and the fuel pin 1 by using the constricted portion 1e as a cutting portion, only the upper end plug portion 1a can be cut without cutting the wire 1d. It becomes easy.

  In addition, although the constriction part was formed in the fuel pin 1 of this embodiment, it is not restricted to this, What is necessary is just a shape which can make a predetermined clearance gap between the wire 1d and the fuel pin 1 main body. For example, the fuel pin 1 main body may be provided with a notch or the like.

(3) Fuel Pin Supply Mechanism FIG. 3 is a diagram showing the configuration of the fuel pin supply mechanism unit of the present embodiment. The fuel pin supply mechanism 10 of the present embodiment includes a fuel pin supply drive motor 11, a fuel pin feed link mechanism 12, a pair of fuel pin feed guides 13, a pair of fuel pin pedestals 14, and the like.

  The fuel pin feed guide 13 includes V-shaped grooves 13a to 13e that can accommodate the fuel pins 1 at a predetermined pitch in the upper part. The fuel pin cradle 14 includes U-shaped grooves 14 a to 14 e that can accommodate the fuel pins 1 at the same pitch as the V-shaped grooves 13 a to 13 e of the fuel pin feed guide 13.

  By driving the fuel pin supply drive motor 11, the fuel pin feed guide 13 performs a steady circle operation (feed operation) via the fuel pin feed link mechanism 12.

  The fuel pins 1 waiting to be supplied are respectively arranged in the U-shaped grooves 14a to 14e of the fuel pin pedestal 14 and adjacent to each other by one pitch by the steady circular motion of the V-shaped grooves 13a to 13e of the fuel pin feed guide 13. While being conveyed to the grooves 14a to 14e, it is finally supplied to the gripping positions of the upper end plug gripping mechanism portion 40 and the lower end plug gripping mechanism portion 20 described later.

(4) Lower end plug gripping mechanism section FIG. 4 is a diagram showing the configuration of the lower end plug gripping mechanism section and the fuel pin rotation mechanism section of the present embodiment.

  The lower end plug gripping mechanism 20 of the present embodiment includes a clamp cylinder 21, a clamp arm 22, and a clamp base 23. The lower end plug gripping mechanism portion 20 is a mechanism for gripping the fuel pin 1 set on the clamp base 23 with the clamp arm 22 to grip the lower end plug portion 1 b of the fuel pin 1 by driving the clamp cylinder 21.

  The clamp arm 22 includes a non-rotating plunger 24, and is provided in the lower end plug portion 1b of the fuel pin 1 in the event that a slip in the rotation direction occurs when the fuel pin 1 rotates after the lower end plug portion 1b is gripped. By inserting the distal end portion of the non-rotating plunger 24 into the hole, slipping can be prevented and the gripping can be surely performed.

(5) Fuel Pin Rotating Mechanism Unit The fuel pin rotating mechanism unit 30 of the present embodiment includes a fuel pin rotating motor 31, a rotation driving unit 32, and the like. The fuel pin rotation motor 31 supplies a rotational force to the rotation drive unit 32. The rotation drive unit 32 is composed of a plurality of gears and flanges.

  The lower end plug gripping mechanism 20 is attached to the flange so that the rotation axis of the flange and the central axis of the fuel pin 1 gripped by the lower end plug gripping mechanism 20 are coaxial. Then, the lower end plug gripping mechanism unit 20 is rotated by the rotation of the fuel pin rotation mechanism unit 30, and the fuel pin 1 gripped and fixed to the lower end plug gripping mechanism unit 20 is rotated.

(6) Upper end plug gripping mechanism section FIG. 5 is a diagram showing the configuration of the upper end plug gripping mechanism section of this embodiment. The upper end plug gripping mechanism 40 of the present embodiment includes a clamping cylinder 41, clamp arms 42a to 42c, a rotating drum mechanism 43, a thrust direction positioning switch 44, and the like.

  The upper end plug gripping mechanism portion 40 moves to the gripping position in the thrust direction (axial direction) of the fuel pin 1 with respect to the set fuel pin 1 by an XY table of the wire pulling mechanism portion 60 described later.

  The positioning of the upper end plug gripping mechanism 40 in the thrust direction (axial direction) at this time is executed by detecting the position of the end face of the fuel pin 1 by the thrust direction positioning switch 44 and stopping at the gripping position.

  If the thrust direction positioning switch 44 malfunctions, the positioning cannot be performed at a predetermined position. If the upper end plug gripping mechanism 40 moves further in the thrust direction (axial direction), the fuel pin 1 is out of the predetermined position. Since there is a risk of being cut at a position (for example, a pellet portion), a thrust direction mechanical stopper 45 is provided.

  After the upper end plug gripping mechanism 40 is positioned by the thrust direction positioning switch 44, the upper end plug portion 1a of the fuel pin 1 is gripped by the three clamp arms 42a to 42c by driving the clamp cylinder 41.

(7) Upper End Plug Cutting Mechanism Unit FIG. 6 is a diagram showing the configuration of the upper end plug cutting mechanism unit of this embodiment. The upper end plug cutting mechanism 50 of the present embodiment includes a cutting mechanism upper / lower cylinder 51, a shearing cylinder 54, a shearing blade 52, a cradle 53, a wire detection microswitch 55, a wire detection plate 56, and the like. The

  As shown in FIGS. 6A to 6C, the upper end plug cutting mechanism 50 of the present embodiment holds the upper end plug 1a after gripping the upper end plug 1a (FIG. 6C). It descends to the cutting position (FIG. 6 (b)). Thereafter, the shearing cylinder 54 is driven, and the fuel pin 1 is cut by the shearing blade 52 (FIG. 6A).

  FIG. 7 is a diagram showing the configuration of the wire detection microswitch and the wire detection plate by the upper end plug cutting mechanism of the present embodiment. As shown in the figure, the position where the fuel pin 1 is rotated by the fuel pin rotating mechanism 30 so that the wire 1d contacts the wire detection plate 56 and the wire detection microswitch 55 is turned ON is the position of the wire 1d of the fuel pin 1. And In addition, the method of wire detection is not restricted to this, It can also comprise using a well-known contact-type or non-contact-type sensor.

  FIG. 8 is a diagram showing a procedure for cutting the upper end plug portion by the upper end plug cutting mechanism portion of the present embodiment. After descending to the cutting position, the fuel pin 1 is rotated by the fuel pin rotation mechanism 30, and the rotation of the fuel pin is stopped at the position where the wire 1d contacts the wire detection plate 56 and the wire detection microswitch 55 is turned on. That is, it stops at the cutting position (FIG. 8A).

  By driving the shearing cylinder 54, the cradle 53 is applied to the fuel pin (FIG. 8B), and then the constricted portion 1 e of the fuel pin 1 is cut by the shearing blade 52. At this time, only the upper end plug portion 1a is cut leaving the wire 1d (FIG. 8C).

  In order to prevent the wire 1d from being cut, the portion of the shearing blade 52 (A portion in the figure) adjacent to the wire 1d at the time of cutting is inclined downward, and the surface cannot be cut without providing the shearing blade. Is good.

(8) Wire Pulling Mechanism Unit and Scraping Mechanism Unit FIG. 9 is a diagram showing the configuration of the wire pulling mechanism unit and the scrape mechanism unit of this embodiment.

  In the spacer wire removing apparatus 100 from the spent nuclear fuel element of this embodiment, it is possible to execute a method of loosening the wire 1d and removing it from the fuel pin 1 and a method of scraping the wire 1d and removing it from the fuel pin 1. It is.

  When removing the wire by loosening, only the operation of the wire pulling mechanism unit 60 is performed. However, when removing by scraping, the operation of the scraping mechanism unit 70 is performed together with the operation of the wire pulling mechanism unit 60.

  In this description, the case where the wire pulling operation and the scraping operation are performed simultaneously will be described, but it is of course possible to perform them individually.

  The wire pulling mechanism 60 of the present embodiment includes an X-axis slide mechanism 61 composed of a linear guide and a ball screw, a Y-axis slide mechanism 62 composed of a linear guide and a ball screw, a wire pull X-axis motor 63, and a wire pull A Y-axis motor 64 is used.

  Further, the scrape mechanism portion 70 of the present embodiment is provided substantially in parallel with the X-axis motor 71 for sliding, the cylinder 72 for raising and lowering the scraping round bar, the rounding rod 73 for scraping, and the gripped fuel pin 1. It is comprised by the X-axis slide mechanism 74 which consists of a linear guide and a ball screw.

  10 and 11 are views showing the operation of the wire pulling mechanism unit and the scraping mechanism unit of the present embodiment.

  After cutting the upper end plug portion 1a, while rotating the fuel pin 1 in the direction in which the wire 1d can be unwound, the wire pulling mechanism 60 moves the upper end plug portion 1a toward the near side by the Y-axis operation so that the fuel pin 1 and the wire A predetermined gap is formed between 1d. The scrape round bar 73 of the scrape mechanism part 70 is lowered, and the scrape round bar 73 is inserted into the gap between the fuel pin body 1c and the wire 1d connected to the moved upper end plug part 1a (FIG. 11B). )).

  The round rod 73 for scraping has a function of guiding and suppressing the scraping function of the wire 1d, deformation and deflection of the fuel pin 1, bending of the fuel pin 1 in the wire pulling direction that occurs during scraping, and the like.

  While rotating the fuel pin 1 in the direction opposite to the winding direction of the wire 1d, the upper end plug portion 1a is moved forward by the Y-axis operation of the wire pulling mechanism 60 (FIG. 10B).

  While rotating the fuel pin 1 in the direction in which the wire 1d can be unwound, the wire pulling mechanism 60 moves the upper end plug portion 1a portion toward the right front side of the device to remove the wire 1d (FIG. 10 (c), FIG. 11 (c)).

  At the end of wire removal, the scraped round bar 73 has a mechanism in which the removed wire 1d enters the rod-shaped bending protrusion 73a installed on the wire side (front side) opposite to the fuel pin 1 of the scrape round bar 73. This is to prevent the wire 1d from falling to the pin collection side when the pin is dropped when the lower end plug portion 1b is cut.

(9) Lower end plug cutting mechanism section The configuration of the lower end plug cutting mechanism section 80 of the present embodiment is substantially the same as that of the upper end plug cutting mechanism section 50, and thus the description thereof is omitted. However, unlike the upper end plug cutting mechanism unit 50, the wire 1d is also cut at the same time when the lower end plug unit 1b is cut. Therefore, the wire detection microswitch and the wire detection plate are not installed.

(10) Sorting Mechanism Unit FIG. 12 is a diagram showing a configuration of the sorting mechanism unit of the present embodiment. The separation mechanism unit 90 of this embodiment includes a separation switching cylinder 91, a movable shooter 92, a wire collection box 93, a pin collection box, and the like.

  By driving the separation switching cylinder 91, the movable shooter 92 is moved back and forth within a certain range of angles to perform pin recovery and wire recovery.

  In the initial position, the movable shooter 92 is located in the direction of pin recovery. After cutting the lower end plug portion 1 b, the fuel pin 1 falls, is separated by the movable shooter 92, and is collected in the pin collection box 93.

  After the pins are collected, the movable shooter 92 is moved in the direction of collecting the wire 1d, the upper end plug grasping mechanism 40 and the lower end plug grasping mechanism 20 are released, and the wire 1d is dropped into the wire collection box 93 and collected. .

  Next, the actual operation of the spacer wire removing device from the spent nuclear fuel element of this embodiment will be described in order.

(1) Preparation for operation In preparation for operation, the fuel pin supply mechanism 10 of the spacer wire removing device 100 from the spent nuclear fuel element according to the present embodiment moves to a position for receiving the fuel pin, and the lower end plug gripping mechanism 20 grips. The mechanism is released, the fuel pin rotating mechanism 30 is stopped, the upper end plug cutting mechanism 50 and the lower end plug cutting mechanism 80 are retracted, and the wire pulling mechanism 60 opens the upper end plug grasping mechanism 40. Then move to the retreat position and prepare for operation.

(2) Fuel Pin Supply The fuel pin 1 is supplied to the lower end plug gripping mechanism 20 and the upper end plug gripping mechanism 40 one by one by the fuel pin supply mechanism 10.

(3) Fuel pin lower end plug gripping The lower end plug gripping mechanism portion 20 grips the lower end plug portion 1b of the fuel pin 1.

(4) Upper end plug cutting position detection Lower end plug grasping mechanism 20 is rotated by fuel pin rotating mechanism 30. The position of the wire 1d is detected by the wire detection microswitch 55 arranged in the upper end plug cutting mechanism 50, and when the wire 1d comes to the cutting position, the rotation of the fuel pin 1 is stopped.

  The wire pulling mechanism portion 60 is operated to position the upper end plug gripping mechanism portion 40 at the position of the upper end plug portion 1 a of the fuel pin 1. At this time, the thrust direction positioning switch 44 detects the position of the upper end plug portion 1a and stops the movement of the wire pulling mechanism portion 60.

(5) Upper end plug gripping The upper end plug gripping mechanism 40 grips the upper end plug portion 1 a of the fuel pin 1.

(6) Upper end plug cutting The upper end plug cutting mechanism 50 cuts the upper end plug 1a. At this time, the wire 1d is not cut and remains connected to the upper end plug portion 1a. As described above, the upper end plug cutting mechanism unit 50 is movable together with the wire pulling mechanism unit 60. If the position of the upper end plug unit 1a can be detected, the upper end plug cutting mechanism unit 50 is set to a predetermined position. The upper end plug portion 1a can be cut at the cutting position.

(7) Wire removal (no wire pull)
In the method of loosening and separating the wire 1d and collecting the wire 1d together with the upper end plug portion 1a, the lower end plug gripping mechanism portion 20 is rotated in the direction of unwinding the wire 1d by the fuel pin rotating mechanism portion 30, and the wire 1d is removed from the fuel pin. Unscrew from 1 and perform wire removal.

(8) Wire removal (with wire pull)
In the system in which the wire 1d is loosened and separated, and the wire 1d is recovered together with the upper end plug portion 1a, the lower end plug gripping mechanism portion 20 is further rotated in the direction of unwinding the wire 1d by the fuel pin rotating mechanism portion 30, and the wire 1d is removed. While being unwound from the fuel pin 1, the wire pulling mechanism portion 60 pulls the upper end plug gripping mechanism portion 40 in the axial direction of the fuel pin 1 to remove the wire 1d.

(9) Wire removal (with scraping operation)
In the method of separating the wire 1d by the scrape round bar 73 and collecting it together with the upper end plug portion 1a, the lower end plug gripping mechanism portion 20 is rotated in the direction of unwinding the wire 1d by the fuel pin rotating mechanism portion 30, and the wire 1d The upper end plug gripping mechanism 40 is pulled obliquely from the fuel pin 1 by the wire pulling mechanism 60 while the fuel pin 1 is being unwound, thereby creating a gap between the fuel pin 1 and the wire 1d.

  A scrape round bar 73 is inserted into the gap, and the fuel pin 1 is rotated in the direction of unwinding the wire 1d in accordance with the winding pitch of the wire 1d around the fuel pin 1 (adopting the design value at the time of fuel production). The scrape rod 73 is moved in the axial direction along the fuel pin 1 from the upper end plug portion 1a side to the lower end plug portion 1b side. At this time, the insertion position of the scrape round bar 73 is preferably a position separated by 5 cm or more in consideration of deformation of the fuel pin 1.

  The fuel pin 1 and the wire 1d may be fixed by the coolant during the FBR operation, and the fuel pin 1 and the wire 1d are separated only by rotating the fuel pin 1 in the direction of unwinding the wire 1d. It is also assumed that this is difficult. In this embodiment, the fuel pin 1 and the wire 1d can be stably separated by adding the operation of pulling the wire and adding the scraping operation.

(10) Lower end plug cutting The lower end plug cutting mechanism 80 cuts both the lower end plug 1b and the wire 1d.

(11) Fuel Pin Recovery The movable shooter 92 is positioned in the pin recovery direction, and the fuel pin 1 from which the upper and lower end plug portions 1a and the wires 1d have been removed is recovered.

(12) Upper end plug and wire recovery The movable shooter 92 is moved in the direction of recovery of the wire 1d, the upper end plug gripping mechanism 40 is opened, and the upper end plug portion 1a and the wire 1d are recovered.

(13) Lower end plug recovery The lower end plug gripping mechanism is opened and the lower end plug portion 1b is recovered.

  Return to the beginning and continue the series of operations.

  As described above, in the spacer wire removal device from the spent nuclear fuel element of the present embodiment, first, the upper end plug is grasped and only the upper end plug is cut without cutting the wire. There is no need to handle the wire, making it possible to reduce the difficulty of handling the wire.

  In addition, the spacer wire can be easily detached from the fuel pin by gripping the lower end plug and rotating the fuel pin in the direction of loosening the wire.

  In addition, since the wire is pulled while rotating the fuel pin in the direction of loosening the wire by grasping the lower end plug, the spacer wire can be easily detached from the fuel pin and the wire can be prevented from being tangled with the fuel pin. .

  Furthermore, in the spacer wire removal apparatus of this embodiment, the fuel pin and the wire can be stably separated by adding a scraping operation.

It is a figure which shows the whole structure of the spacer wire removal apparatus from the used nuclear fuel element of this embodiment. It is a figure which shows the structure of the fuel pin used for the spacer wire removal apparatus from the used nuclear fuel element of this embodiment. It is a figure which shows the structure of the fuel pin supply mechanism part of this embodiment. It is a figure which shows the structure of the lower end stopper gripping mechanism part and fuel pin rotation mechanism part of this embodiment. It is a figure which shows the structure of the upper end stopper gripping mechanism part of this embodiment. It is a figure which shows the structure of the upper end plug cutting | disconnection mechanism part of this embodiment. It is a figure which shows the structure of the microswitch for wire detection by the upper end plug cutting | disconnection mechanism part of this embodiment, and the plate for wire detection. It is a figure which shows the procedure of the cutting | disconnection of the upper end plug part by the upper end plug cutting mechanism part of this embodiment. It is a figure which shows the structure of the wire tension | pulling mechanism part and scrape mechanism part of this embodiment. It is a figure which shows operation | movement of the wire tension | pulling mechanism part and scrape mechanism part of this embodiment. It is a figure which shows operation | movement of the wire tension | pulling mechanism part and scrape mechanism part of this embodiment. It is a figure which shows the structure of the classification mechanism part of this embodiment. It is a figure which shows the general structure of the fuel pin used for a wire spacer type | mold core fuel assembly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100: Spacer wire removal apparatus from spent nuclear fuel element 10: Fuel pin supply mechanism part 20: Lower end plug gripping mechanism part 30: Fuel pin rotation mechanism part 40: Upper end plug gripping mechanism part 50: Upper end plug cutting mechanism part 60: Wire pulling mechanism part 70: Scraping mechanism part 80: Lower end plug cutting mechanism part 90: Sorting mechanism part

Claims (5)

A first end plug portion and a second end plug portion are provided at both ends of the main body, the spacer wire is spirally wound, and both ends of the spacer wire are respectively connected to the first end plug portion and the second end plug portion. A removal device for removing the spacer wire from a nuclear fuel element having a recess at a position where at least the spacer wire is wound around the boundary between the first end plug portion and the main body.
A first end plug gripping mechanism for gripping the first end plug of the nuclear fuel element;
A second end plug gripping mechanism for gripping the second end plug of the nuclear fuel element;
A shear blade for cutting only the first end plug at the boundary between the first end plug and the nuclear fuel element body; and the spacer wire at the boundary between the first end plug and the nuclear fuel element body A first end plug cutting mechanism having a detection unit that detects the position at which the shearing blade does not interfere with the shearing direction,
A nuclear fuel element rotating mechanism for rotating the second end plug gripping mechanism in the direction of unwinding the spacer wire;
With
The nuclear fuel element rotating mechanism rotates the nuclear fuel element gripped by the second end plug gripping mechanism, and when the detecting unit detects the spacer wire, the nuclear fuel element rotating mechanism is Spacer wire removal from the spent nuclear fuel element, wherein the rotation of the element is stopped, and the first end plug cutting mechanism moves the shear blade in the shear direction to cut the first end plug apparatus.   The wire pulling mechanism part which moves the said 1st end plug gripping mechanism part in the direction which pulls the said spacer wire joined to the said 1st end plug part from the said nuclear fuel element is further provided. A spacer wire removal device from the spent nuclear fuel element as described.   A scrape round bar inserted in a gap between the nuclear fuel element and the spacer wire, and the inserted scrape round bar from the first end plug side of the nuclear fuel element to the second end; The apparatus for removing a spacer wire from a spent nuclear fuel element according to claim 1 or 2, further comprising a scraping mechanism section that operates along the nuclear fuel element on the plug side.   4. The nuclear fuel element supply mechanism section for supplying the nuclear fuel elements one by one to the first end plug gripping mechanism section and the second end plug gripping mechanism section. The spacer wire removal apparatus from the spent nuclear fuel element in any one. It is used for the spacer wire removal apparatus from the spent nuclear fuel element in any one of Claim 1 to 4, It has a 1st end plug part and a 2nd end plug part at both ends, and a spacer wire is helical. And each end of the spacer wire is a nuclear fuel element joined to the first end plug portion and the second end plug portion,
Nuclear fuel element according to claim and the first end plug portion or the second end plug portion at a boundary between the nuclear fuel element body, be provided with a concave portion.

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