Automatic changing device, automatic changing system, and wheels of automatic changing device

Abstract

To provide an automatic changing device which prevents floating or lateral slippage due to an earthquake and does not fall off from rails.SOLUTION: In order to achieve the above objective, an automatic changing device of the present embodiment, which is installed on annular rails protruding radially inward from the inside surface of a pedestal that supports a nuclear reactor pressure vessel in order to change a control rod drive mechanism disposed in the nuclear reactor pressure vessel, is characterized by being provided with: a wheel for traveling on the top surface of the rail and supporting a load in the vertically downward direction; a side skip prevention wheel for traveling on the inside surface of the rail and supporting a load in the horizontal direction; and a floating prevention wheel for traveling on the underside of the rail and supporting a load in the vertically upward direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to an autochanger, an autochanger system, and an autochanger wheel for use in a nuclear reactor pressure vessel lower section. [Background technology]

[0002] The reactor pressure vessel is provided with freely retractable control rods for controlling reactions within the reactor. The pedestal supporting the reactor pressure vessel is provided with control rod drive mechanisms for driving these control rods. These control rod drive mechanisms are replaced by an automatic replacement device provided on the pedestal during periodic plant inspections. This automatic replacement device is structured to be able to rotate on an annular rail provided on the inner wall of the pedestal so that it can be connected to all of the control rod drive mechanisms provided on the pedestal.

[0003] In the seismic design of nuclear power plants, buildings, structures, equipment piping systems, etc. are classified into seismic classes. Specifically, equipment with the function of preventing the release of radioactive materials, equipment for safely shutting down the reactor, and equipment for maintaining a cooling state are classified into seismic classes S, B, and C according to their importance. Each class is required to ensure appropriate seismic resistance. For example, seismic class S requires that safety functions be maintained against the design basis earthquake motion and that seismic resistance be maintained against an earthquake force 3.6 times the seismic force specified in the Building Standards Act.

[0004] Currently, in order to restart nuclear power plants, it is essential to comply with the new regulatory standards that were established after the Fukushima Daiichi Nuclear Power Plant accident. As part of this compliance, water level gauges, which are seismic class S equipment, will be installed on the pedestal, and it has become necessary to ensure that equipment installed near the water level gauges does not have a ripple effect on the water level gauges. As a result, earthquake resistance is also required for automatic switching equipment, which is seismic class C equipment. Conventional automatic switching equipment has a platform that rests on rails via wheels, and this structure is prone to lifting and sliding, so earthquake reinforcement work was necessary. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 54-98494 [Patent Document 2] Japanese Patent Publication No. 145495 / 1983 Summary of the Invention [Problem to be solved by the invention]

[0006] Conventional automatic exchange devices have a structure that can cause them to lift up or slide sideways during an earthquake, which poses the risk of the wheels coming off the rails and the automatic exchange device falling off the rails.

[0007] The present invention addresses these circumstances, and the problem that the present invention aims to solve is to provide an automatic exchange device, an automatic exchange system, and wheels for the automatic exchange device that are prevented from lifting up or sliding sideways due to an earthquake and do not fall off the rails. [Means for solving the problem]

[0008] In order to achieve the above object, the automatic exchange device of this embodiment is installed on an annular rail that protrudes radially inward from the inner surface of a pedestal that supports a reactor pressure vessel in order to exchange a control rod drive mechanism provided in the reactor pressure vessel, and is characterized by comprising: wheels that run on the upper surface of the rail and support a load in a vertically downward direction; anti-skid wheels that run on the inner surface of the rail and support a load in a horizontal direction; and anti-lift wheels that run on the lower surface of the rail and support a load in a vertically upward direction.

[0009] In order to achieve the above object, the automatic exchange system of this embodiment is characterized by including the above-mentioned automatic exchange device.

[0010] Furthermore, in order to achieve the above object, the wheels of the automatic exchange device of this embodiment are wheels of an automatic exchange device that are installed on annular rails that protrude radially inward from the inner surface of a pedestal that supports a reactor pressure vessel in order to exchange a control rod drive mechanism provided in the reactor pressure vessel, and are characterized by comprising wheels that are capable of running on the upper surface of the rails and capable of supporting a vertically downward load on the automatic exchange device, anti-skid wheels that are capable of running on the inner surface of the rails and capable of supporting a horizontal load on the automatic exchange device, and anti-lift wheels that are capable of running on the underside of the rails and capable of supporting a vertically upward load on the automatic exchange device. [Effects of the Invention]

[0011] The embodiments of the present invention have been made to solve the above-mentioned problems, and thereby make it possible to prevent the automatic exchange device from floating up or sliding sideways due to an earthquake, and to prevent the automatic exchange device from falling off the rail. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing the overall configuration of an automatic exchange system according to a first embodiment. [Figure 2] P-P arrow view in Figure 1. [Figure 3] FIG. 2 is an enlarged cross-sectional view including a wheel of the automatic exchanger according to the first embodiment. [Figure 4] FIG. 10 is an enlarged cross-sectional view including a wheel of an automatic changer according to a second embodiment. [Figure 5] FIG. 11 is an enlarged cross-sectional view including a wheel of an automatic changer according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] An automatic exchange device, an automatic exchange system, and wheels of an automatic exchange device according to embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below are merely examples of embodiments of the present invention and are not intended to limit the scope of the invention. Furthermore, in the drawings referred to in the embodiments, identical parts or parts having similar functions are denoted by the same or similar reference numerals, and their description may be omitted. Furthermore, the dimensional ratios in the drawings may differ from the actual ratios, and some components may be omitted from the drawings.

[0014] (First embodiment) An automatic exchange system 100 according to a first embodiment will be described with reference to Figures 1 and 2. Figure 1 is a cross-sectional view showing the overall configuration of the automatic exchange system 100 according to the first embodiment. Figure 2 is a view taken along the line P-P in Figure 1. The automatic exchange system 100 in Figure 1 includes a reactor pressure vessel 1, a pedestal 2, a control rod drive mechanism guide tube 3, a control rod drive mechanism 4, rails 5, an automatic exchange device 10, a loading / unloading rail 20, a transport cart 21, and a control rod drive mechanism repair device 25.

[0015] The reactor pressure vessel 1 is a steel vessel that contains the reactor core, which is made of fuel. The reactor pressure vessel 1 is designed to boil water using the heat generated by the nuclear fission of the uranium fuel, generating steam that powers the turbines.

[0016] The pedestal 2 is provided on the lower side (hereinafter simply referred to as the lower side) of the reactor pressure vessel 1 in the direction of gravity. The pedestal 2 is the base of the reactor pressure vessel 1 and is provided to support the reactor pressure vessel 1. The pedestal 2 is formed in a cylindrical shape, and an internal space 2a is formed inside the cylinder. The pedestal 2 also has a loading / unloading port 2b that connects the internal space 2a with the outside.

[0017] A plurality of control rod drive mechanism guide tubes 3 are installed vertically at the bottom of the reactor pressure vessel 1 so as to communicate with the internal space 2a of the pedestal 2. The control rod drive mechanism guide tubes 3 are provided to enable the control rod drive mechanisms 4 to be smoothly moved in and out. Note that the bottom of the reactor pressure vessel 1 may be configured so that, in addition to the control rod drive mechanism guide tubes 3, a neutron measurement guide tube for measuring neutrons inside the reactor pressure vessel 1 is further provided.

[0018] The control rod drive mechanism 4 is provided so as to be attachable to the control rod drive mechanism guide tube 3. The control rod drive mechanism 4 is fixed to the control rod drive mechanism guide tube 3 with attachment members such as bolts. The control rod drive mechanism 4 is provided to move control rods (not shown) into and out of the core inside the reactor pressure vessel 1 via the control rod drive mechanism guide tube 3. At the start of a periodic inspection of the reactor pressure vessel 1, the control rod drive mechanism 4 is removed by an automatic exchange device 10, disassembled, inspected, cleaned, and repaired, and at the end of the periodic inspection of the reactor pressure vessel 1, the control rod drive mechanism 4 is attached by the automatic exchange device 10. Note that the control rod drive mechanism 4 referred to here may be an improved control rod drive mechanism that is driven electrically or hydraulically. In this case, the control rod drive mechanism 4 may be configured by combining a motor unit, a motor bracket, and other devices for driving the control rod drive mechanism 4.

[0019] The rail 5 is provided on the side surface 2c of the internal space 2a of the pedestal 2, protruding radially inward (hereinafter simply referred to as the radially inward) about the direction of gravity. The rail 5 is provided in a ring-shaped form on the side surface 2c of the internal space 2a of the pedestal 2. The rail 5 is provided as a foothold for the automatic exchange device 10 to support the automatic exchange device 10. The rail 5 may be provided with a ring-shaped groove, protrusion, or the like that can serve as a foothold for the automatic exchange device 10.

[0020] The automatic exchange device 10 is installed above the rails 5 in the internal space 2a of the pedestal 2. Specifically, the automatic exchange device 10 is installed by placing wheels 12 of the automatic exchange device 10 on the rails 5. The automatic exchange device 10 is installed to replace the control rod drive mechanism 4 during periodic inspection of the plant. The automatic exchange device 10 includes a platform 11, wheels 12, a traveling carriage 13, a rotating frame 14, a lifting carriage 15, a gripping arm 16, a bolter carriage 17, and a bolter 18. The automatic exchange device 10 is controlled by a control device (not shown). The automatic exchange device 10 is also provided with a position detection sensor (not shown), and the automatic exchange device 10 is controlled so as to be able to select a position to which it moves in accordance with the position detection sensor.

[0021] The platform 11 is provided above the rails 5. As shown in FIG. 2, the platform 11 has a disk shape and is the base of the automatic exchange device 10.

[0022] The wheels 12 are provided on the platform 11. Specifically, as shown in FIG. 2, a plurality of wheels 12 are provided on the radially outer portion of the platform 11, and are arranged to run along the rails 5. When the wheels 12 run along the rails 5, the platform 11 rotates in the circumferential direction within the horizontal plane of the internal space 2a of the pedestal 2. The detailed structure of the wheels 12 will be described later. Note that, although FIG. 2 illustrates a case where three wheels 12 are provided, the present invention is not intended to be limited to this case.

[0023] The traveling carriage 13 is provided on the platform 11. Specifically, the traveling carriage 13 is provided on the center line of the platform 11, as shown in Fig. 2. The traveling carriage 13 moves on the platform 11 in the radial direction of the platform 11.

[0024] The rotating frame 14 is mounted on the traveling carriage 13. When the control rod drive mechanism 4 is attached to or detached from the control rod drive mechanism guide tube 3, the rotating frame 14 is mounted on the traveling carriage 13 with the direction of gravity as its longitudinal direction (in a vertical position). On the other hand, when the control rod drive mechanism 4 is transported between the pedestal 2 and the outside, the rotating frame 14 is mounted on the traveling carriage 13 with the direction perpendicular to the direction of gravity as its longitudinal direction (in a horizontal position). In other words, the rotating frame 14 is mounted so as to rotate from a vertical position to a horizontal position or from a horizontal position to a vertical position.

[0025] The lifting cart 15 is provided on the rotating frame 14. The lifting cart 15 is provided so as to slide along the longitudinal direction of the rotating frame 14. Specifically, the lifting cart 15 slides upward when removing the control rod drive mechanism 4 from the control rod drive mechanism guide tube 3 or when installing the control rod drive mechanism 4 in the control rod drive mechanism guide tube 3. On the other hand, the lifting cart 15 slides downward when withdrawing the control rod drive mechanism 4 from the control rod drive mechanism guide tube 3 or after completing installation of the control rod drive mechanism 4 in the control rod drive mechanism guide tube 3.

[0026] The gripping arm 16 is provided on the rotating frame 14. The gripping arm 16 is provided to protrude in a direction perpendicular to the longitudinal direction of the rotating frame 14. The gripping arm 16 is provided to hold the control rod drive mechanism 4.

[0027] The bolt attaching / detaching machine cart 17 is provided below the platform 11. Specifically, the bolt attaching / detaching machine cart 17 is installed on rails (not shown) provided on the underside of the platform 11 so as to be movable together with the traveling cart 13. The bolt attaching / detaching machine cart 17 is fixed to the traveling cart 13 below the platform 11 and the traveling cart 13 and outside the lifting range of the lifting cart 15. The bolt attaching / detaching machine cart 17 is provided to hold the bolt attaching / detaching machine 18.

[0028] The bolt remover 18 is provided so as to be attachable to and detachable from the lifting cart 15, and also so as to be attachable to and detachable from the remover cart 17. Specifically, when the bolt remover 18 is to remove the control rod drive mechanism 4 from the control rod drive mechanism guide tube 3, or when the bolt remover 18 is to attach the control rod drive mechanism 4 to the control rod drive mechanism guide tube 3, the bolt remover 18 moves from the remover cart 17 to the lifting cart 15 and rises together with the lifting cart 15.

[0029] On the other hand, when the control rod drive mechanism 4 has been completely extracted from the control rod drive mechanism guide tube 3 or when the control rod drive mechanism 4 has been completely attached to the control rod drive mechanism guide tube 3, the bolter / removal machine 18 descends together with the lifting cart 15 and returns to the bolter / removal machine cart 17. The bolter / removal machine 18 is provided so that it can attach and detach mounting members such as bolts for fixing the control rod drive mechanism 4 to the control rod drive mechanism guide tube 3, and is provided so that it can hold the control rod drive mechanism 4.

[0030] The loading / unloading rails 20 are provided to connect the automatic exchange device 10 and the control rod drive mechanism repair device 25. Specifically, the loading / unloading rails 20 pass through the loading / unloading entrance 2b of the pedestal 2 and the loading / unloading entrance 25a of the control rod drive mechanism repair device 25, connecting the platform 11 and the control rod drive mechanism repair device 25.

[0031] The transport cart 21 is provided above the carry-in / out rails 20. The transport cart 21 is provided for carrying in and out the control rod drive mechanism 4. Specifically, the transport cart 21 retrieves the control rod drive mechanism 4 that has been removed from the control rod drive mechanism guide tube 3, and transports it from the internal space 2a of the pedestal 2 to the control rod drive mechanism repair device 25 via the carry-in / out rails 20. The transport cart 21 also transports the control rod drive mechanism 4 to be attached to the control rod drive mechanism guide tube 3 from the control rod drive mechanism repair device 25 to the internal space 2a of the pedestal 2 via the carry-in / out rails 20.

[0032] The control rod drive mechanism repair device 25 is provided outside the pedestal 2 and is configured to be able to disassemble, inspect, clean, and repair the transported control rod drive mechanism 4. The control rod drive mechanism repair device 25 is connected to the automatic exchange device 10 via its loading / unloading entrance 25a.

[0033] According to the above-described automatic exchange system 100, when the control rod drive mechanism 4 is to be removed from the control rod drive mechanism guide tube 3 provided in the lower part of the reactor pressure vessel 1, the automatic exchange device 10 provided in the internal space 2a of the pedestal 2 operates to remove the control rod drive mechanism 4. Specifically, the platform 11, wheels 12, and traveling carriage 13 move according to instructions from a control device (not shown).

[0034] Then, the lifting cart 15 rises along the rotating frame 14, which is in a vertical position. At this time, the bolter / removal machine 18 moves from the remover / removal machine cart 17 to the lifting cart 15 and rises together with the lifting cart 15. Then, the bolter / removal machine 18 loosens mounting members such as bolts that secure the control rod drive mechanism 4 to the control rod drive mechanism guide tube 3, and holds the control rod drive mechanism 4 in place.

[0035] Next, the lifting cart 15 descends along the rotating frame 14, which is in a vertical position, while supporting the control rod drive mechanism 4. At this time, the bolter / removal machine 18 moves from the lifting cart 15 to the bolter / removal machine cart 17 after the gripping arm 16 has held the control rod drive mechanism 4. When the control rod drive mechanism 4 is completely withdrawn from the control rod drive mechanism guide tube 3, the rotating frame 14 rotates from the vertical position to the horizontal position.

[0036] Thereafter, platform 11, wheels 12, and traveling carriage 13 move in accordance with instructions from a control device (not shown), and rotating frame 14 hands over control rod drive mechanism 4 to transport carriage 21. Transport carriage 21 transports control rod drive mechanism 4 to control rod drive mechanism repair device 25 via loading / unloading rails 20. When attaching control rod drive mechanism 4 to control rod drive mechanism guide tube 3 provided at the bottom of reactor pressure vessel 1, the procedure described above is reversed.

[0037] Next, a detailed structure of the wheel 12 of the automatic exchanger 10 according to the first embodiment will be described with reference to Fig. 3. Fig. 3 is an enlarged cross-sectional view including the wheel 12 of the automatic exchanger 10 according to the first embodiment.

[0038] The wheels 12 include a drive wheel 12a, a skid prevention wheel 12b, and a lift prevention wheel 12c. The drive wheel 12a, the skid prevention wheel 12b, and the lift prevention wheel 12c are connected by a connecting member 12d.

[0039] A plurality of drive wheels 12a are provided on the radially outer portion of the platform 11, and are arranged to run on the upper surface of the rails 5 along the rails 5. The drive wheels 12a are connected to the drive units 12e and rotate by the driving force of the drive units 12e. When the drive wheels 12a rotate by the driving force of the drive units 12e and run along the rails 5, the platform 11 rotates in the circumferential direction within the horizontal plane of the internal space 2a of the pedestal 2. The drive wheels 12a support the vertically downward load on the automatic exchange device 10. Note that one drive wheel 12a may be connected to one drive unit 12e, or multiple drive wheels 12a may be connected to one drive unit 12e.

[0040] A plurality of anti-skid wheels 12b are provided on the radially outer portion of the platform 11, and are arranged to run along the rail 5 on the radially inner surface of the rail 5 (hereinafter simply referred to as the inner surface). When the drive wheel 12a runs due to the driving force of the drive unit 12e, the anti-skid wheels 12b run together with the drive wheel 12a. The anti-skid wheels 12b are arranged to support the horizontal load on the automatic exchange device 10. In other words, the anti-skid wheels 12b are arranged to prevent the wheels 12 from skidding in the horizontal direction.

[0041] A plurality of anti-lift wheels 12c are provided on the radially outer portion of the platform 11, and are arranged to run along the underside of the rail 5. When the drive wheels 12a run due to the driving force of the drive unit 12e, the anti-lift wheels 12c run together with the drive wheels 12a. The anti-lift wheels 12c are provided to support a load in the vertically upward direction on the automatic exchange device 10. In other words, the anti-lift wheels 12c are provided to prevent the wheels 12 from rising up in the vertically upward direction.

[0042] As described above, according to the automatic exchanger 10 of the first embodiment, the wheels 12, each equipped with the drive wheel 12a that supports a vertically downward load on the automatic exchanger 10, the anti-skid wheel 12b that supports a horizontal load on the automatic exchanger 10, and the anti-lift wheel 12c that supports a vertically upward load on the automatic exchanger 10, are configured to sandwich the rail 5. This prevents the automatic exchanger 10 from lifting up or skidding due to the effects of seismic motion. This prevents the automatic exchanger 10 from falling off the rail 5.

[0043] In the first embodiment, the drive wheels 12a, skid prevention wheels 12b, and lift-up prevention wheels 12c are connected by the connecting member 12d, but this is not limited to this. For example, only the skid prevention wheels 12b and the lift-up prevention wheels 12c may be connected by the connecting member 12d and mounted on the platform 11. In this case, the same functions and effects as those described above are also achieved.

[0044] Furthermore, for example, the drive wheels 12a, the anti-skid wheels 12b, and the anti-lifting wheels 12c may be independently provided on the platform 11. In this case as well, the same functions and effects as those described above can be achieved.

[0045] Furthermore, in the first embodiment, the case where the drive unit 12e is connected to the drive wheel 12a is illustrated, but this is not limited to this. For example, the drive unit 12e may be connected to the skid prevention wheel 12b or the lift-up prevention wheel 12c, so that the skid prevention wheel 12b or the lift-up prevention wheel 12c plays a role equivalent to that of the drive wheel 12a. In this case, too, the same functions and effects as those described above can be achieved.

[0046] Furthermore, in the first embodiment, the automatic exchange device 10 has been described as a device for exchanging the control rod drive mechanism 4, but this is not limiting. For example, the automatic exchange device 10 may be configured to enable replacement of a motor provided in an in-reactor coolant recirculation pump (not shown) in addition to replacement of the control rod drive mechanism 4. That is, the wheel 12 according to the first embodiment is not limited to being applied to an automatic exchange device 10 that only replaces the control rod drive mechanism 4, but may also be applied to an automatic exchange device 10 that replaces the motors provided in the control rod drive mechanism 4 and the reactor coolant recirculation pump (not shown). In this case, the same actions and effects as those described above can be achieved. This also applies to the following embodiments.

[0047] (Second embodiment) The detailed structure of the wheel 32 of the automatic exchanger 10 according to the second embodiment will be described using Figure 4. Figure 4 is an enlarged cross-sectional view including the wheel 32 of the automatic exchanger 10 according to the second embodiment. Hereinafter, only the parts that differ from the first embodiment will be described, and the other parts will be assigned the same drawing numbers as those in the first embodiment and descriptions of their configurations will be omitted.

[0048] The wheels 32 include a drive wheel 12a and a lift-prevention wheel 12c. The drive wheel 12a and the lift-prevention wheel 12c are connected by a connecting member 32d. That is, the wheels 32 of the second embodiment differ from the wheels 12 of the first embodiment in that they do not include wheels corresponding to the skid prevention wheels 12b.

[0049] In addition to the rail 5 described above, the rail 50 has an annular support portion 50a that protrudes radially inward from the pedestal 2 above the rail 5 and has an inner diameter larger than that of the rail 5. The support portion 50a is provided to support horizontal loads on the automatic exchanger 10. In other words, the support portion 50a is provided to prevent the wheels 32, particularly the wheel 12a, from skidding horizontally. The drive wheel 12a runs on the upper surface of the rail 5 along the support portion 50a.

[0050] Additionally, the rail 50 has an annular support portion 50b below the rail 5 that protrudes radially inward from the pedestal 2 and has an inner diameter larger than that of the rail 5. The support portion 50b is provided to support the horizontal load on the automatic exchanger 10. That is, the support portion 50b is provided to prevent the wheels 32, particularly the wheel 12c, from skidding in the horizontal direction. The anti-lift wheel 12c runs on the underside of the rail 5 along the support portion 50b.

[0051] As described above, according to the automatic exchanger 10 of the second embodiment, the wheels 32, each equipped with the drive wheels 12a that support vertically downward loads on the automatic exchanger 10 and the lift-up prevention wheels 12c that support vertically upward loads on the automatic exchanger 10, are configured to sandwich the rails 50 that support horizontal loads on the automatic exchanger 10. This prevents the automatic exchanger 10 from lifting up or skidding due to the effects of seismic motion. This prevents the automatic exchanger 10 from falling off the rails 50.

[0052] In the second embodiment, the rail 50 is illustrated as having support portions 50a and 50b on the upper and lower sides thereof for supporting a horizontal load, but the present invention is not limited to this. For example, the rail 50 may have grooves on the upper and lower surfaces thereof that are deep enough to support a horizontal load on the automatic exchanger 10. The drive wheels 12a and anti-lifting wheels 12c may run in the respective grooves. In this case, the same functions and effects as those described above can be achieved.

[0053] In the second embodiment, the drive wheels 12a and the lift-prevention wheels 12c are connected by the connecting member 32d, but this is not limited to this. For example, the drive wheels 12a and the lift-prevention wheels 12c may be provided independently on the platform 11. In this case, the same functions and effects as those described above can be achieved.

[0054] (Third embodiment) The detailed structure of the wheel 42 of the automatic exchanger 10 according to the third embodiment will be described using Figure 5. Figure 5 is an enlarged cross-sectional view including the wheel 42 of the automatic exchanger 10 according to the third embodiment. Hereinafter, only the parts that differ from the first and second embodiments will be described, and the other parts will be assigned the same drawing numbers as those in the first and second embodiments and description of their configurations will be omitted.

[0055] The wheels 42 include a drive wheel 12a and an anti-skid wheel 42b. The drive wheel 12a and the anti-skid wheel 42b are connected by a connecting member 42d. That is, the wheels 42 of the third embodiment differ from the wheels 12 of the first embodiment and the wheels 32 of the second embodiment in that they do not include wheels corresponding to the anti-skid wheel 12b and the anti-lifting wheel 12c, but include the anti-skid wheel 42b.

[0056] In addition to the rail 5 described above, the rail 55 includes an annular support portion 55a that protrudes vertically upward from a radially inner portion of the upper surface of the rail 5. Grooves 55b are formed on the inner and outer surfaces of the support portion 55a. The grooves 55b are provided to accommodate anti-skid wheels 42b. Specifically, the grooves 55b are deep enough to support vertically upward and vertically downward loads on the automatic exchanger 10. That is, the support portion 55a is provided to prevent the wheels 42, particularly the anti-skid wheels 42b, from lifting up vertically upward. Note that the third embodiment illustrates an example in which the support portion 55 protrudes vertically upward from a radially inner portion of the upper surface of the rail 5, but this is not limiting. For example, the support portion 55 may protrude vertically downward from a radially inner portion of the lower surface of the rail 5. Although the third embodiment illustrates the case where the grooves 55b are provided on the inner and outer surfaces of the support portion 55a, the present invention is not limited to this. For example, the grooves 55b may be provided on either the inner or outer surface of the support portion 55a.

[0057] A plurality of anti-slip wheels 42b are provided on the radially outer portion of the platform 11, and are arranged to run along the side of the rail 55. Specifically, the anti-slip wheels 42b are arranged to run in grooves 55b formed in support portions 55a of the rail 55. When the drive wheels 12a run due to the driving force of the drive units 12e, the anti-slip wheels 42b run along the grooves 55b together with the drive wheels 12a. The anti-slip wheels 42b are arranged to support a horizontal load on the automatic exchange device 10. In other words, the anti-slip wheels 42b are arranged to prevent the wheels 42 from skidding in the horizontal direction.

[0058] As described above, according to the automatic exchanger 10 of the third embodiment, the wheels 42, each equipped with the drive wheels 12a that support vertically downward loads on the automatic exchanger 10 and the anti-skid wheels 42b that support horizontal loads on the automatic exchanger 10, are configured to sandwich the rails 55 that support vertically upward loads and vertically downward loads on the automatic exchanger 10. This prevents the automatic exchanger 10 from lifting up or skidding due to the effects of seismic motion. This also prevents the automatic exchanger 10 from falling off the rails 55.

[0059] In the third embodiment, the drive wheels 12a and the skid prevention wheels 42b are connected by the connecting member 42d, but this is not the only possible configuration. For example, the drive wheels 12a and the skid prevention wheels 42b may be provided independently on the platform 11. In this case, the same functions and effects as those described above are also achieved.

[0060] Furthermore, in the third embodiment, the case where the drive unit 12e is connected to the drive wheel 12a is illustrated, but this is not limited to this. For example, the drive unit 12e may be connected to the skid prevention wheel 42b, so that the skid prevention wheel 42b plays a role equivalent to that of the drive wheel 12a. In this case, the same functions and effects as those described above are also achieved.

[0061] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0062] 1...reactor pressure vessel, 2...pedestal, 3...control rod drive mechanism guide tube, 4...control rod drive mechanism, 5...rail, 10...automatic exchange device, 11...platform, 12...wheel, 12a...drive wheel, 12b...anti-skid wheel, 12c...anti-lift wheel, 12d...connecting member, 12e...drive device, 13...traveling cart, 14...rotating frame, 15...lifting cart, 16...grabbing arm, 17...removal machine cart, 18...bolt removal machine, 20...loading / unloading rail, 21...transport cart, 25...control rod drive mechanism repair device, 32...wheel, 32d...connecting member, 42...wheel, 42b...anti-skid wheel, 42d...connecting member, 50...rail, 50a...support portion, 50b...support portion, 55...rail, 55a...support portion, 55b...groove, 100...automatic exchange system.

Claims

1. 1. An automatic control rod drive mechanism exchange device installed on an annular rail protruding radially inward from an inner surface of a pedestal supporting a reactor pressure vessel, for exchanging a control rod drive mechanism provided in the reactor pressure vessel, comprising: a wheel that travels on an upper surface of the rail and supports a vertically downward load on the automatic exchange device; anti-skid wheels that run on the inner surface of the rail and support a horizontal load on the automatic exchange device; anti-lift wheels that run on the underside of the rail and support a vertically upward load on the automatic exchange device; An automatic exchange device comprising:

2. 1. An automatic control rod drive mechanism exchange device installed on an annular rail protruding radially inward from an inner surface of a pedestal supporting a reactor pressure vessel, for exchanging a control rod drive mechanism provided in the reactor pressure vessel, comprising: a wheel that travels on an upper surface of the rail along a support portion provided on the upper surface of the rail to support a horizontal load on the automatic exchanger, and supports a vertically downward load on the automatic exchanger; anti-lift wheels that run on the underside of the rail along support portions provided on the underside of the rail to support a horizontal load on the automatic exchange device and support a vertically upward load on the automatic exchange device; An automatic exchange device comprising:

3. 1. An automatic control rod drive mechanism exchange device installed on an annular rail protruding radially inward from an inner surface of a pedestal supporting a reactor pressure vessel, for exchanging a control rod drive mechanism provided in the reactor pressure vessel, comprising: a wheel that travels on an upper surface of an annular support portion that protrudes vertically upward from the rail and supports a vertically downward load on the automatic exchange device; anti-skid wheels that run in grooves provided on the side surfaces of the support portions to support loads on the automatic exchange device in vertically upward and vertically downward directions, and that support loads on the automatic exchange device in horizontal directions; An automatic exchange device comprising:

4. An automatic switching system comprising the automatic switching device according to any one of claims 1 to 3.

5. A wheel of an automatic control rod drive mechanism exchange device is installed on an annular rail protruding radially inward from an inner surface of a pedestal supporting a reactor pressure vessel, in order to exchange a control rod drive mechanism provided in the reactor pressure vessel, a wheel capable of running on an upper surface of the rail and supporting a load in a vertical downward direction on the automatic exchange device; anti-skid wheels that can run on the inner surface of the rail and can support a horizontal load on the automatic exchange device; anti-lift wheels that can run on the underside of the rail and can support a vertically upward load on the automatic exchange device; A wheel changer for an automatic wheel changer, comprising:

6. A wheel of an automatic control rod drive mechanism exchange device is installed on an annular rail protruding radially inward from an inner surface of a pedestal supporting a reactor pressure vessel, in order to exchange a control rod drive mechanism provided in the reactor pressure vessel, a wheel capable of running on an upper surface of the rail along a support portion provided on the upper surface of the rail to support a horizontal load on the automatic exchanger, and capable of supporting a vertically downward load on the automatic exchanger; anti-lift wheels that can run on the underside of the rail along support portions provided on the underside of the rail to support a horizontal load on the automatic exchange device, and that can support a vertically upward load on the automatic exchange device; A wheel changer for an automatic wheel changer, comprising:

7. A wheel of an automatic control rod drive mechanism exchange device is installed on an annular rail protruding radially inward from an inner surface of a pedestal supporting a reactor pressure vessel, in order to exchange a control rod drive mechanism provided in the reactor pressure vessel, a wheel capable of running on an upper surface of an annular support portion protruding vertically upward from the rail and capable of supporting a vertically downward load on the automatic exchange device; anti-skid wheels that can run in grooves provided on the side surfaces of the support portions to support loads on the automatic exchange device in vertically upward and vertically downward directions, and that can support loads on the automatic exchange device in a horizontal direction; A wheel changer for an automatic wheel changer, comprising:

Images