Apparatus for installing and removing fixing device for handling spent nuclear fuel assembly

Abstract

An apparatus for installing and removing a fixing device for handling a spent nuclear fuel assembly is disclosed. The apparatus for installing and removing a fixing device for handling a spent nuclear fuel assembly is an apparatus for installing or removing the fixing device, provided between an upper fixture and a guide pipe constituting a nuclear fuel assembly, to or from the spent nuclear fuel assembly, and comprises: a rod part including a rotating rod with one end detachably connected to the fixing device, and at least one cover rod in which the rotating rod is positioned; and an operation part connected to the rod part so as to vertically move or rotatably operate the rotating rod and the cover rod.

Description

Installation and dismantling device for fixed devices for handling spent nuclear fuel assemblies

[0001] The present invention relates to a device for installing and dismantling a fixed device for handling a spent nuclear fuel assembly, which strengthens the bonding force between an upper fixed body and a guide tube forming a nuclear fuel assembly prior to handling the spent nuclear fuel assembly.

[0002] Typically, a nuclear fuel assembly has a number of fuel rods positioned between an upper and lower fixture, and the fuel rods are supported by a skeleton composed of a support grid, guide tubes, and instrumentation tubes.

[0003] The support grids are arranged in groups of 10 to 13, one above the other, and welded to a 4-meter-long guide tube. Fuel assembly is completed by loading the fuel rods into the skeleton and then attaching and securing the upper and lower support members. These fuel assemblies are installed so that the fuel rods maintain a constant spacing between the upper and lower support members by the support grids and guide tubes.

[0004] Meanwhile, the installation and dismantling of the above-mentioned fixing device is usually carried out in a tank where spent nuclear fuel is stored wet, and since close work is difficult, separate dedicated equipment is required for the installation and dismantling of the fixing device.

[0005] One embodiment of the present invention provides a device for installing and dismantling a fixed device for handling a spent nuclear fuel assembly, which strengthens the bonding force between an upper fixed body and a guide tube forming a nuclear fuel assembly before handling the spent nuclear fuel assembly.

[0006] One embodiment of the present invention is a device for installing or removing a fixing device installed between an upper fixing body and a guide tube forming a nuclear fuel assembly, the device including a rotating rod that is detachably connected to the fixing device, a load portion that has the rotating rod positioned inside and includes at least one cover rod, and an operating portion that is connected to the load portion and moves the rotating rod and the cover rod up and down or rotates them.

[0007] The cover rod may include a first cover rod having a plurality of ball inserts formed at equal intervals along an outer surface thereof, each ball inserting portion that surrounds a rotating rod and accommodates a bearing ball and provides a passage for the bearing ball to move, and a second cover rod that surrounds the first cover rod and moves up and down according to the operation of the operating portion to advance the bearing ball toward the center through the ball inserts, and the bearing ball presses a groove formed at the top of the fixing device to clamp the fixing device.

[0008] The fixing device may include a housing having a plurality of free ends formed to be divided by slots formed longitudinally cut from a lower end in a hollow cylindrical shape and a fixing projection formed protruding at the end of the free end, a rod formed to extend from an upper portion of the housing and having threads formed therein and having a fixing nut formed therein at an upper end, a locking nut movably coupled along the threads of the rod, and an extension rod including a coupling head having a portion inserted into the interior of the housing, an upper end protruding above the locking nut, and an outer surface having a groove formed therein into which a bearing ball is inserted.

[0009] A fixing wrench portion may be formed at the bottom of the first cover rod to accommodate and restrain a fixing nut formed at the top of the housing of the fixing device.

[0010] An inclined surface is formed on the inner surface of the second cover rod along which the bearing balls move, so that the bearing balls can move forward or backward along the ball insertion portion.

[0011] A wrench groove may be formed on the upper surface of the extension rod.

[0012] A wrench that is inserted into a wrench groove can be formed at the bottom of the rotating rod.

[0013] The cover rod may further include a third cover rod that surrounds the second cover rod and has a socket-shaped rotating wrench portion formed on the lower inner surface for rotating the locking nut of the fixing device.

[0014] The load section may include first to fourth loads connected to each other by coupling couplers.

[0015] The load section may include a first pipe coupled to the rotating load by a first coupler, a second pipe with the first pipe positioned inside and coupled to the first cover load by a second coupler, a third pipe with the second pipe positioned inside and coupled to the second cover load by a third coupler, and a fourth pipe with the third pipe positioned inside and coupled to the third cover load by a fourth coupler.

[0016] The operating unit may include a first operating unit connected to a first pipe and having a protruding ring for controlling the up-and-down operation of the rotary rod, a second operating unit installed at a lower portion of the first operating unit and connected to a second pipe to transmit rotary force to the second pipe, a third operating unit installed at a lower portion of the second operating unit and connected to a third pipe to be raised and lowered by air pressure and transmit a lifting driving force to the second cover rod, and a fourth operating unit installed at a lower portion of the third operating unit and connected to a fourth pipe to transmit a lifting driving force to the third cover rod.

[0017] A torque wrench insertion portion into which a torque wrench for transmitting rotational force is inserted can be formed on the side of the fourth operating unit.

[0018] According to one embodiment of the present invention, the installation and removal work of a fixing device for handling spent nuclear fuel assemblies is very convenient and easy, and in particular, it is possible to stably lift the nuclear fuel assemblies.

[0019] FIG. 1 is a perspective view schematically illustrating a device for installing and dismantling a fixed device for a spent nuclear fuel assembly according to one embodiment of the present invention.

[0020] Figure 2 is a side view of the installation and disassembly device for the fixed device for the spent nuclear fuel assembly of Figure 1.

[0021] Figure 3 is a cross-sectional view of part A of the installation and disassembly device for the fixed device for the spent nuclear fuel assembly of Figure 1.

[0022] Figure 4 is a cross-sectional view of part B of the installation and disassembly device for the fixed device for the spent nuclear fuel assembly of Figure 2.

[0023] Figure 5 is a cross-sectional view of part C of the installation and disassembly device for the fixed device for the spent nuclear fuel assembly of Figure 2.

[0024] Figure 6 is an enlarged view of part F of Figure 5.

[0025] FIG. 7 is a drawing showing a fixing device for handling a spent nuclear fuel assembly according to an embodiment of the present invention.

[0026] Figure 8 is an exploded perspective view schematically illustrating the fixing device for handling the spent nuclear fuel assembly of Figure 7.

[0027] Figures 9 to 13 are diagrams showing the process of removing a fixing device using a fixing device installation / disassembly tool for handling a spent nuclear fuel assembly and then fixing it to a spent nuclear fuel assembly.

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description have been omitted to clearly explain the present invention, and the same reference numerals have been used throughout the specification to refer to identical or similar components.

[0029] The installation and disassembly device (100) for a spent nuclear fuel assembly described below refers to a device for installing or disassembling a fixing device (200) installed between an upper fixing member (400) and a guide tube (401) forming a nuclear fuel assembly to or from a nuclear fuel assembly. This will be described in detail below with reference to the drawings.

[0030] FIG. 1 is a perspective view schematically illustrating a device for installing and dismantling a fixed device for a spent nuclear fuel assembly according to one embodiment of the present invention, FIG. 2 is a side view of the device for installing and dismantling a fixed device for a spent nuclear fuel assembly of FIG. 1, FIG. 3 is a cross-sectional view of part A of the device for installing and dismantling a fixed device for a spent nuclear fuel assembly of FIG. 1, and FIG. 4 is a cross-sectional view of part B of the device for installing and dismantling a fixed device for a spent nuclear fuel assembly of FIG. 2.

[0031] FIGS. 1 to 4 illustrate a device (100) for installing and dismantling a fixed device for a spent nuclear fuel assembly according to one embodiment of the present invention, including a rotating rod (135) that is detachably connected to a fixed device (200), a load section (130) in which the rotating rod (135) is positioned inside and at least one cover rod (161, 162, 163) is included, and an operating section (110) connected to the load section (130) to move the rotating rod (135) and the cover rod (161, 162, 163) up and down or rotate them.

[0032] A fixing device (200) for a spent nuclear fuel assembly may include an operating unit (110) located at the top and a loading unit (130) located at the bottom.

[0033] The load section (130) can be manufactured to a length of several meters depending on the work environment, and can be manufactured to have a structure that can be separated into multiple pieces considering the transportation and storage conditions accordingly.

[0034] That is, in the present embodiment, the load section (130) can be separated into four split loads, namely, a first load (B), a second load (C), a third load (D), and a fourth load (E), and each split load can be coupled through a plurality of coupling couplers (137) at the interconnection portion. The load section (130) is exemplarily described as being connected to four split loads below, but is not necessarily limited thereto, and can also be installed so as to be able to be separated and coupled in an appropriate number and length depending on changes in the work environment.

[0035] This load section (130), as shown in the drawing, is connected to the operating section (110) by being installed as a quadruple pipe, and may include a first pipe (131), a second pipe (132), a third pipe (133), and a fourth pipe (134) sequentially from the innermost side.

[0036] That is, the diameter of the load section (130) increases from the innermost first pipe (131) to the outermost fourth pipe (134), and a predetermined space for connecting the split rods, which will be described later, can be formed between adjacent pipes.

[0037] Fig. 5 is a cross-sectional view of part C of the installation and disassembly device for the fixed device for the spent nuclear fuel assembly of Fig. 2, and Fig. 6 is an enlarged view of part F of Fig. 5.

[0038] Referring to FIGS. 5 and 6, the first pipe (131) in the fourth rod (E) constituting the rod section (130) can be coupled to the rotary rod (135) via the first coupler (151).

[0039] This load section (130) may include a first pipe (131) coupled to a rotating rod (135) by a first coupler (151), a second pipe (132) in which the first pipe (131) is positioned inside and coupled to a first cover rod (161) by a second coupler (152), a third pipe (133) in which the second pipe (132) is positioned inside and coupled to a second cover rod (162) by a third coupler (153), and a fourth pipe (134) in which the third pipe (133) is positioned inside and coupled to a third cover rod (163) by a fourth coupler (154).

[0040] The rotary rod (135) is formed with a diameter smaller than the inner diameter of the first pipe (131), extends along the central axis of the rod portion (130), and can protrude outside the second pipe (132) to the fourth pipe (134).

[0041] The first pipe (131) is installed with a rotary rod (135) inserted therein as described above, and can be coupled to the rotary rod (135) by the first coupler (151).

[0042] The second pipe (132) can be coupled to the first cover rod (161) by the second coupler (152) provided at the bottom of the first coupler (151).

[0043] The first cover rod (161) may be installed to surround the rotary rod (135) in the form of a hollow tube. A fixing wrench portion (1611) may be formed on the lower inner surface of the first cover rod (161) to accommodate and restrain the outer side of the fixing nut (217) of the fixing device (200) and thereby suppress the rotation of the fixing device (200).

[0044] Additionally, a ball insertion part (1612) into which a bearing ball (140) that moves forward and backward in the direction of the central axis is inserted may be provided above the fixed wrench part (1611).

[0045] These bearing balls (141) are arranged in multiple equal intervals in the ball insertion portion (1612), and can be inserted into the ball insertion portion (1612) so as not to be detached from the ball insertion portion (1612).

[0046] Meanwhile, the third pipe (133) can be coupled to the second cover rod (162) by the third coupler (153) installed below the second coupler (152).

[0047] The second cover rod (162) can be installed to surround the first cover rod (161) in the form of a hollow tube. An inclined surface (1621) is formed at the lower end of the second cover rod (162), so that when the second cover rod (162) moves up and down, the bearing ball (140) can move forward and backward along the inclined surface (1621) through the ball insertion portion (1612).

[0048] The fourth pipe (134) can be coupled to the third cover rod (163) by the fourth coupler (154) installed below the third coupler (153).

[0049] The third cover rod (163) can be installed to surround the second cover rod (162) in the form of a hollow tube.

[0050] A rotating wrench portion (1631) in the shape of a socket wrench can be formed on the lower inner surface of the third cover load (163).

[0051] The rotating wrench part (1631) is installed on the lower inner surface of the third cover rod (163) and can be formed in a socket wrench shape to rotate the locking nut (220) described later.

[0052] Meanwhile, referring to FIGS. 1 to 6, the operating unit (110) is connected to the upper portion of the load unit (130) and can be installed so that the load unit (130) can be individually manipulated through a separate manipulator.

[0053] To be more specific, the operating unit (110) may include a first operating unit (111) that is connected to a first pipe (131) and has a protruding ring that controls the up-and-down operation of the rotary rod, a second operating unit (112) that is installed at the lower portion of the first operating unit (111) and is connected to a second pipe (132) and transmits a rotary force to the second pipe (132), a third operating unit (113) that is installed at the lower portion of the second operating unit (112) and is connected to the third pipe and is raised and lowered by air pressure to transmit a lifting driving force to the second cover rod (162), and a fourth operating unit (114) that is installed at the lower portion of the third operating unit (113) and is connected to a fourth pipe (134) and transmits a lifting driving force to the third cover rod (163).

[0054] A ring (1111) for operating the rotary rod (130) up and down to fasten the wrench (135) and the wrench home (223) can be combined at the top of the first operating section (111).

[0055] The ring (1111) is detachably protruded from the top of the first operating part (111) to minimize interference or prevent interference from occurring when rotating using a torque wrench or the like.

[0056] The second operating part (112) may be provided on one side of the lower portion of the first operating part (111) and may be connected to the second pipe (132). This second operating part (112) may enable the fixed wrench part (1611) formed at the end of the first cover rod (161) to receive the outer side of the fixed nut (217) through the rotation of the second pipe (132).

[0057] According to the operation of this second operating part (112), the fixing nut (217) is restrained by the first cover rod (161), and the fixing device (200) can be maintained in a certain direction within the guide tube (401), while at the same time preventing the fixing projection (213) of the fixing device (200) from being separated from the bulge (402).

[0058] The third operating part (113) may be provided below the second operating part (112) and connected to the third pipe (133). This third operating part (113) may be installed to move the second cover rod (162) up and down by air pressure while moving the bearing ball (140) forward or backward toward the central axis through the ball insertion part (1612).

[0059] When the second cover load (162) is moved downward, the bearing ball (140) can advance toward the central axis along the inclined surface (1621). Accordingly, the bearing ball (140) is pushed into the groove (222) located opposite the ball insertion portion (1612) and pressure is applied, thereby clamping the fixing device (200).

[0060] The fourth operating part (114) is provided below the third operating part (113) and can be connected to the fourth pipe (134). The fourth operating part (114) can be fastened to the locking nut (220) provided at the middle of the fixing device (200) by moving the third cover rod (163) up and down.

[0061] Accordingly, the fourth operating unit (114) can rotate the locking nut (220) to secure the fixing device (200) onto the upper fixing body (400) of the spent nuclear fuel assembly (300).

[0062] A torque wrench insertion portion (1141) into which a torque wrench can be inserted to rotate the locking nut (220) with a constant torque may be formed on the outer surface of the fourth operating portion (114).

[0063] FIG. 7 is a drawing showing a fixing device for handling a spent nuclear fuel assembly according to an embodiment of the present invention, and FIG. 8 is an exploded perspective view schematically showing the fixing device for handling a spent nuclear fuel assembly of FIG. 7.

[0064] Meanwhile, referring to FIGS. 7 and 8, the fixing device (200) may be formed in a hollow cylindrical shape, with a plurality of free ends (212) divided by slots (211) cut in the longitudinal direction at the lower portion.

[0065] At the end of the free end (212), a housing (210) may be provided with a fixing projection (213) formed to protrude outward.

[0066] A rod (214) having a screw thread (215) formed thereon may be formed integrally extended at the upper portion of the housing (210). This housing (210) may be configured on the opposite side of the free end (212).

[0067] A locking nut (216) is coupled to the screw thread (215) to move up and down on the screw thread (215). A square-shaped fixing nut (217) may be formed on the top of the housing (210).

[0068] Additionally, an extension rod (220) having a screw thread of a certain length formed at the bottom can be inserted into the inside of the housing (210).

[0069] A joining head (221) is provided at the top of the extension rod (220), and a groove (222) is formed along the outer surface of the joining head (221), and the bearing ball (140) described above can be clamped into the concavely formed groove (222).

[0070] Additionally, a wrench groove (223) corresponding to the shape of the wrench (136) of the above-described rotary rod (135) may be formed on the upper part of the coupling head (221).

[0071] Meanwhile, the fixed projection (213) is inserted into the bulge (402) and may not be formed over the entire section of the housing (210), but may be formed only at the lower end of the divided free end (212).

[0072] Meanwhile, an inlet socket (230) may be provided in which a leg (231) is formed in a shape that is inserted into the slot (211).

[0073] The inlet socket (230) is formed in a cylindrical shape, and has an insertion hole formed in the center thereof, and has a female thread formed therein so that the aforementioned expansion rod (220) can be screw-connected, so that the inlet socket and the expansion rod (230) can be screw-connected to each other.

[0074] Additionally, a pressure portion (232) with an inclined surface whose outer diameter gradually increases from the top to the bottom can be formed at the end of the leg (231).

[0075] Accordingly, when the extension rod (220) rotates in place without vertical movement, the lead-in socket (230) can be elastically deformed by pressing the free end (212) in a radial (outer side of the housing) direction while moving vertically along the male screw thread (224) of the extension rod (220). Accordingly, the fixing device (200) can be fixed to the guide tube (401) while the fixing projection (213) is maintained in a state of being pressed and closely contacted with the bulge portion (402).

[0076] In addition, a spring (240) may be interposed between the housing (210) and the inlet socket (230). That is, the spring (240) is interposed between a step (not shown, near the bottom of the screw thread (215)) formed inside the housing (210) and the inlet socket (230) and is compressed, and the play between the inlet socket (230) and the housing (210) is eliminated by the restoring force of the spring (240).

[0077] Meanwhile, a stopper (250) inserted and fastened at the lower end of the extension rod (220) may be installed to prevent the inlet socket (230) from being separated from the extension rod (220) when moving vertically downward.

[0078] As described above, the present embodiment makes it very convenient and easy to install and remove the fixing device for handling spent nuclear fuel assemblies, and in particular, it is possible to stably lift the nuclear fuel assemblies.

[0079] Hereinafter, the usage status of the installation and dismantling tool for the fixed device for handling spent nuclear fuel assemblies of the present invention configured as described above will be described in more detail.

[0080] Figures 9 to 13 are diagrams showing the process of removing a fixing device using a fixing device installation / disassembly tool for handling a spent nuclear fuel assembly and then fixing it to a spent nuclear fuel assembly.

[0081] First, referring to FIG. 9, the worker uses a fixing device installation / disassembly tool (100) to remove a fixing device (200) from a work plate (700) (partially shown) on which various configurations necessary for lifting a nuclear fuel assembly are prepared and installed.

[0082] Specifically, the entire fixture installation / disassembly tool (100) can be inserted toward the guide hole (701) formed in the work plate (700).

[0083] Accordingly, the fixing device (200) is accommodated inside the first cover rod (161) of the fixing device installation / disassembly tool (100) including the joining head (221) and the fixing nut (217), and at this time, the first cover rod (161) can be rotated through the second operating unit (112) so that the fixing nut (217) can be accommodated accurately in the correct direction in the fixing wrench unit (1611).

[0084] Referring to Fig. 10, the fixing nut (217) is received and restrained in the fixing wrench part (1611), and the work is completed by fixing the fixing device (200) on the upper fixing body (400) of the nuclear fuel assembly (300) by the locking nut (220).

[0085] Meanwhile, if the work is performed in the reverse order of the above-mentioned order using the fixing device installation / disassembly tool (100), it is possible to dismantle the fixing device (200) from the nuclear fuel assembly (300).

[0086] Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the attached drawings, and it is obvious that this also falls within the scope of the present invention.

Claims

1. A device for installing or dismantling a fixing device installed between the upper fixing body and the guide tube forming the nuclear fuel assembly to the nuclear fuel assembly. It includes a rotating rod that is detachably connected to the above-mentioned fixing device, a load portion that has the rotating rod positioned inside and includes at least one cover rod, and an operating portion that is connected to the load portion and moves the rotating rod and the cover rod up and down or rotates them. The above cover load is, A first cover rod having a plurality of ball inserts formed at equal intervals along the outer surface thereof, each ball insert being configured to surround the rotating rod, accommodate bearing balls, and provide a passage for the bearing balls to move; and A second cover rod that surrounds the first cover rod and moves up and down according to the operation of the operating unit to advance the bearing ball toward the center through the ball insertion portion, and the bearing ball presses a groove formed at the top of the fixing device to clamp the fixing device; A device for installing and dismantling a fixed device for handling spent nuclear fuel assemblies, including:

2. In paragraph 1, The above fixing device is, A housing having a hollow cylindrical shape, a plurality of free ends formed to be divided by slots cut longitudinally at the lower end, and a fixing projection formed protruding at the ends of the free ends; A rod formed on the upper part of the housing, having a thread formed therein and a fixing nut formed on the upper part; A locking nut movably coupled along the screw thread of the above load; and An extension rod including a coupling head having a portion inserted into the interior of the housing, an upper portion protruding above the locking nut, and an outer surface having a groove formed therein into which the bearing ball is inserted; A device for installing and dismantling a fixed device for handling spent nuclear fuel assemblies, including:

3. In paragraph 2, A device for installing and dismantling a fixed device for handling spent nuclear fuel assemblies, wherein a fixed wrench portion is formed at the lower end of the first cover rod to receive and restrain the fixed nut formed at the upper end of the housing of the fixed device.

4. In paragraph 3, A device for installing and dismantling a fixed device for handling spent nuclear fuel assemblies, wherein an inclined surface is formed on the inner surface of the second cover rod on which the bearing ball moves, so that the bearing ball moves forward or backward along the ball insertion portion.

5. In paragraph 4, A wrench groove is formed on the upper surface of the above extension rod, A device for installing and disassembling a fixed device for handling spent nuclear fuel assemblies, in which a wrench is formed at the bottom of the above-mentioned rotary rod to be inserted into the above-mentioned wrench groove.

6. In paragraph 5, The above cover load is, A device for installing and dismantling a fixed device for handling spent nuclear fuel assemblies, further comprising a third cover rod that surrounds the second cover rod and has a socket-shaped rotating wrench formed on the lower inner surface for rotating the locking nut of the fixed device.

7. In paragraph 6, The above load section is a fixed device installation and disassembly device for handling spent nuclear fuel assemblies, including first to fourth loads connected to each other by a coupling coupler.

8. In paragraph 7, The above load section, A first pipe coupled to the above rotating rod by a first coupler; A second pipe positioned inside the first pipe and coupled to the first cover rod by a second coupler; A third pipe positioned inside the second pipe and coupled to the second cover rod by a third coupler; and A fourth pipe, wherein the third pipe is positioned inside and is coupled to the third cover rod by a fourth coupler; A device for installing and dismantling a fixed device for handling spent nuclear fuel assemblies, including:

9. In paragraph 8, The above operating part, A first operating unit connected to the first pipe and having a protruding ring for controlling the up and down movement of the rotating rod; A second operating unit installed at the lower portion of the first operating unit and connected to the second pipe, and transmitting rotational force to the second pipe; A third operating unit installed at the lower portion of the second operating unit and connected to the third pipe, which is raised and lowered by pneumatic pressure to transmit the lifting driving force to the second cover rod; and A fourth operating unit installed at the lower portion of the third operating unit and connected to the fourth pipe, and transmitting the lifting driving force to the third cover load; A device for installing and dismantling a fixed device for handling spent nuclear fuel assemblies, including:

10. In paragraph 9, A device for installing and dismantling a fixed device for handling spent nuclear fuel assemblies, in which a torque wrench insertion portion for transmitting rotational force is formed on the side of the fourth operating unit.

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