JP5028023B2 - Preventive maintenance method and preventive maintenance device for reactor annulus - Google Patents

Description

  The present invention relates to a method for preventing and maintaining a reactor pressure vessel and its internal structure during the operation period of a nuclear power plant, and a device applied thereto, and particularly, a state in which the reactor pressure vessel is filled with cooling water. The present invention relates to a preventive maintenance method and apparatus suitable for performing preventive maintenance work of each welded part by accessing an annular annulus portion surrounded by a reactor pressure vessel, a shroud support cylinder and a shroud support baffle plate.

Conventionally, as a preventive maintenance method for a reactor pressure vessel and its internal structure performed during the operation period of a nuclear power plant, a method of improving residual stress in a welded part by injecting cavitation bubbles into the required welded part Is known (for example, see Patent Document 1). As a method for allowing the repair device to access the narrow gap between the shroud support cylinder in the annulus and the jet pump diffuser or the gap between the reactor pressure vessel and the jet pump diffuser, A self-propelled repair device that runs with the cooling water removed (for example, see Patent Documents 2 and 3) and a self-propelled repair device that fills the reactor pressure vessel with cooling water. What is made to run (for example, refer to patent documents 4 and 5) is known.
JP 2003-337192 A JP 2004-37087 A JP 2002-168992 A JP-A-11-174192 Japanese Patent Laid-Open No. 11-109082

  However, the technique disclosed in Patent Document 1 includes a fixing mechanism part in which the inspection / prevention / maintenance device holds and fixes itself to the structure inside the pressure vessel or the guide pipe, and a plurality of movably attached to the fixing mechanism part. In order to carry out inspection / prevention / maintenance of the annulus, the structure in the pressure vessel or the guide pipe is completed every time the operation within the range in which the main body can be moved is completed. Unfixing, moving, and re-fixing of the fixing mechanism with respect to the above must be sequentially repeated, and it cannot be said that the work efficiency is necessarily high. Moreover, since the technology disclosed in Patent Documents 2 and 3 causes the self-propelled repair device to run with the cooling water in the reactor pressure vessel removed, a high degree of airtight processing is required and the equipment is large. There is a problem of becoming. Furthermore, since the technologies disclosed in Patent Documents 4 and 5 run the self-propelled repair device in a state where the reactor pressure vessel is filled with cooling water, the self-propelled repair device is stabilized in the target direction. There is a problem that it is difficult to run.

  The present invention has been made to solve such deficiencies in the prior art, and its purpose is to enable the preventive maintenance mechanism to move stably in water and to provide welding in a wide range in the annulus of the reactor. It is an object of the present invention to provide a method and an apparatus for easily and efficiently preventing and maintaining a part.

In order to solve the above problems, the present invention relates to a preventive maintenance device for an annulus portion in a reactor. First, a reactor pressure vessel and a core shroud that are carried into an annulus portion of a reactor pressure vessel and constitute the annulus portion. , A preventive maintenance device for a nuclear pressure vessel that performs preventive maintenance on each welded portion of a shroud support cylinder, a shroud support ring and a shroud support baffle plate, the rail feed mechanism installed on the shroud support baffle plate, and the rail A rail laid in a gap between the reactor pressure vessel and a jet pump diffuser attached to the shroud support baffle plate or a gap between the shroud support cylinder and the jet pump diffuser using a feed mechanism; At the end of A cable / hose feed mechanism to be attached, and a feed from the cable / hose feed mechanism by rotating a cable / hose feed roller supplied from the upper part of the reactor pressure vessel and provided in the cable / hose feed mechanism And a cable / hose that is pulled into the cable / hose feed mechanism, and is connected to the tip of the cable / hose, and is guided by the rail by rotating the cable / hose feed roller. A preventive maintenance mechanism transported in a direction along a gap between a pressure vessel and a jet pump diffuser attached to the shroud support baffle plate or a gap between the shroud support cylinder and the jet pump diffuser, and the rail feed The mechanism features a rail feed pin A rail feed clamp mechanism, a travel rail that guides the rail feed clamp mechanism, and a drive source that drives the rail feed clamp mechanism along the travel rail, and the rail feed pin is attached to the rail. After inserting into the established rail feed pin hole and connecting the rail feed clamp mechanism and the rail, the drive source is driven to feed the rail along the running rail, and the end of the rail is The operation of moving to the connecting position with the other rail and then returning the rail feeding clamp mechanism to the original position is repeated as many times as necessary, and the two rails connected to each other are connected to the connecting position. The positioning pin provided at one end of the one rail is fitted into the positioning pin hole formed at the one end of the other rail. And is assembled integrally by screwing a bolt into a screw hole provided in one end of the other rail through a bolt through hole provided in one end of the one rail. And
When this preventive maintenance apparatus is used, the preventive maintenance mechanism can be guided along the rail, so that the preventive maintenance mechanism can be transported more safely and efficiently in a narrow annulus portion.

Secondly, the present invention relates to a preventive maintenance device for an in-reactor annulus section. The reactor pressure vessel, core shroud, shroud support cylinder, and shroud support ring that are carried into the annulus section of the reactor pressure vessel and constitute the annulus section. And a nuclear pressure vessel preventive maintenance device for performing preventive maintenance on each welded portion of the shroud support baffle plate, a rail feed mechanism installed on the shroud support baffle plate, and the nuclear reactor using the rail feed mechanism A gap between a pressure vessel and a jet pump diffuser attached to the shroud support baffle plate or a rail laid in a gap between the shroud support cylinder and the jet pump diffuser; and on the reactor pressure vessel or the core shroud of A cable / hose feed mechanism installed at a critical position and a cable / hose feed roller supplied from the upper part of the reactor pressure vessel and rotated by a cable / hose feed roller provided in the cable / hose feed mechanism. A cable hose to be fed out from the mechanism and pulled into the cable / hose feed mechanism, connected to the tip of the cable / hose and attached to one end of the rail, and the cable / hose feed roller By driving the rail feed mechanism while rotating, the gap between the reactor pressure vessel and the jet pump diffuser attached to the shroud support baffle plate or the gap between the shroud support cylinder and the jet pump diffuser Preventive maintenance transported along The rail feed mechanism includes a rail feed clamp mechanism provided with a rail feed pin, a travel rail for guiding the rail feed clamp mechanism, and the rail feed clamp mechanism along the travel rail. A drive source for driving, the rail feed pin is inserted into a rail feed pin hole formed in the rail, the clamp mechanism for rail feed and the rail are connected, and then the drive source is driven. A rail that requires the operation of feeding the rail along the traveling rail, moving the end of the rail to a connection position with the other rail, and then returning the rail feeding clamp mechanism to the original position. The two rails that are connected to each other by repeating a number of the positioning pins provided at one end of one of the rails at the connecting position, It was positioned by fitting into a positioning pin hole formed at one end of the rail, and was established at one end of the other rail through a bolt through hole provided at one end of the one rail. It is characterized by being assembled integrally by screwing a bolt into the screw hole .
By using this preventive maintenance device, the preventive maintenance mechanism can be transferred along the required gap with the rail mounted, so that the preventive maintenance mechanism can be transferred more safely and efficiently in a narrow annulus. .

  The present invention relates to a preventive maintenance device for an annulus portion in a reactor. Fourthly, in the preventive maintenance devices for the first to third reactor annulus portions, the preventive maintenance mechanism is injected to each welded portion. A cavitation generator that generates cavitation bubbles is provided. When this preventive maintenance apparatus is used, cavitation can be injected to the welded portion in the annulus portion, so that the cavitation collapse pressure can be applied to the welded portion, and the residual stress of the welded portion can be improved.

  Fifthly, the present invention relates to a preventive maintenance apparatus for an annulus section in a reactor, and in the preventive maintenance apparatus for an annulus section in a fourth reactor, cavitation bubbles are injected into a cavitation generator toward a required weld. A nozzle is provided. When this preventive maintenance device is used, the cavitation bubbles generated by the cavitation generator can be strongly injected from the nozzle toward the welded portion, so that the residual stress in the welded portion can be improved more efficiently.

  The present invention relates to a preventive maintenance device for an annulus portion in a reactor, sixthly, in the preventive maintenance devices for the first to third annulus portions in the reactor, the cable / hose feed mechanism includes the nuclear pressure vessel. A clamp mechanism is provided for installing the cable / hose feed mechanism at a predetermined position in the annulus portion by remote control from above. By using this preventive maintenance device, the cable / hose feed mechanism can be fixed at a desired position in the annulus using a clamp mechanism, so that the preventive maintenance mechanism can be transported stably and preventive maintenance work in the annulus can be performed. Highly efficient.

  Seventhly, the present invention relates to a preventive maintenance apparatus for an annulus section in a reactor, and in the preventive maintenance apparatus for an annulus section in a second or third reactor, the rail feed mechanism is provided above the nuclear pressure vessel. A clamp mechanism for installing the rail feed mechanism at a predetermined position in the annulus portion by remote control is provided. With this preventive maintenance device, the rail feed mechanism can be fixed at a desired position in the annulus using a clamp mechanism, so that the preventive maintenance mechanism can be transported stably and preventive maintenance work in the annulus can be performed efficiently. Can be done.

On the other hand, the present invention relates to a preventive maintenance method for a reactor pressure vessel. First, a required preventive maintenance device is carried into the annulus portion of the reactor pressure vessel, and the reactor pressure vessel and core constituting the annulus portion are provided. A preventive maintenance method for a nuclear pressure vessel that performs preventive maintenance on welds of a shroud, a shroud support cylinder, a shroud support ring, and a shroud support baffle plate, wherein the nuclear power vessel has cooling water in the reactor pressure vessel. A step of installing a rail feed mechanism on the shroud support baffle plate by remote control from above the pressure vessel, and the rail suspended from the top of the nuclear pressure vessel using the rail feed mechanism is moved to the reactor pressure. Jet pump attached to container and said shroud support baffle plate A step of laying in the gap between the diffuser or the gap between the shroud support cylinder and the jet pump diffuser, and a cable / hose feed mechanism suspended from above the nuclear pressure vessel at the end of the rail. The step of attaching together with the cable / hose feeding mechanism and the preventive maintenance mechanism connected to the tip of the cable / hose feeding mechanism, and rotating the cable / hose feeding roller provided in the cable / hose feeding mechanism. Accordingly, the driving force causes the preventive maintenance mechanism to move along the rail between the reactor pressure vessel and the jet pump diffuser attached to the shroud support baffle plate, or the shroud support cylinder and the jet pump diffuser. Gap The preventive maintenance mechanism is appropriately driven by remote control from above the nuclear pressure vessel, the welded portion of the reactor pressure vessel and the shroud support baffle plate, the shroud support baffle plate and the And a step of preventively maintaining the welded portion of the shroud support cylinder, the welded portion of the core shroud and the shroud support ring, and the welded portion of the shroud support cylinder and the shroud support ring, and the rail feed mechanism includes a rail feed pin. A rail feed clamp mechanism, a travel rail for guiding the rail feed clamp mechanism, and a drive source for driving the rail feed clamp mechanism along the travel rail, and the rail on the shroud support baffle plate In the process of installing the feed mechanism The rail feed pin is inserted into a rail feed pin hole provided in the rail to connect the rail feed clamp mechanism and the rail, and then the drive source is driven to make the rail into the running rail. The operation of moving the end of the rail to the connecting position with the other rail and then returning the rail feeding clamp mechanism to the original position is repeated as many times as necessary to connect the rails to each other. The two rails are positioned by fitting a positioning pin provided at one end of one rail into a positioning pin hole formed at one end of the other rail at the connection position, And through a bolt through hole opened at one end of one of the rails, a bolt is screwed into a screw hole opened at one end of the other rail. Ri According to this preventive maintenance method characterized by assembling together, it is possible to guide the preventive maintenance mechanism along the rail, it can be transported preventive maintenance mechanism safer and more high efficiency in a narrow annulus. Further, since the preventive maintenance mechanism can be stably moved in water, it is not necessary to discharge the cooling water from the reactor pressure vessel, and the time required for maintenance work of the reactor annulus portion can be shortened.

Secondly, the present invention relates to a preventive maintenance method for a reactor pressure vessel. Secondly, a required preventive maintenance device is carried into the annulus portion of the reactor pressure vessel, and the reactor pressure vessel, core shroud, and shroud support that constitute the annulus portion. A preventive maintenance method for a nuclear pressure vessel for performing preventive maintenance on each welded portion of a cylinder, a shroud support ring, and a shroud support baffle plate, wherein the reactor pressure vessel has cooling water in the state above the nuclear pressure vessel. A step of installing a rail feed mechanism on the shroud support baffle plate by remote control from the reactor, and a rail suspended from above the nuclear pressure vessel by using the rail feed mechanism, the reactor pressure vessel and the shroud Jet pump diffuser attached to support baffle plate Or a step of laying in a gap between the shroud support cylinder and the jet pump diffuser, and a required position on the reactor pressure vessel or the core shroud by remote operation from above the nuclear pressure vessel. Installing the cable / hose feed mechanism together with the cable / hose attached to the cable / hose feed mechanism and the preventive maintenance mechanism connected to the tip of the cable / hose feed mechanism; And the rail feed mechanism is driven while rotating the cable / hose feed roller provided in the cable / hose feed mechanism, and the preventive maintenance mechanism is driven by the driving force of the rail feed mechanism. The furnace pressure vessel and the shroud support baffle plate Transporting in a direction along the gap between the vacuum pump diffuser or the gap between the shroud support cylinder and the jet pump diffuser, and appropriately driving the preventive maintenance mechanism by remote control from above the nuclear pressure vessel, Welded part of reactor pressure vessel and shroud support baffle plate, welded part of shroud support baffle plate and shroud support cylinder, welded part of core shroud and shroud support ring, and welded part of shroud support cylinder and shroud support ring The rail feed mechanism includes a rail feed clamp mechanism provided with a rail feed pin, a travel rail for guiding the rail feed clamp mechanism, and the rail feed clamp mechanism running through the rail feed clamp mechanism. Leh The rail feed pin is inserted into a rail feed pin hole formed in the rail in the step of installing a rail feed mechanism on the shroud support baffle plate. after feeding clamping mechanism that connects the said rails, fed along the rails in the running rail by driving the driving source to move the end of the rail to the connection position between the other first rail, Next, the operation of returning the rail feeding clamp mechanism to the original position is repeated as many times as necessary, and the two rails connected to each other are provided at one end of one of the rails at the connection position. The positioning pin is positioned by fitting into a positioning pin hole formed at one end of the other rail, and the one rail Through bolt through holes which are opened at one end, characterized in that assembled together by screwing the bolt into a screw hole which is opened at one end of the other of said rails.
According to this preventive maintenance method, the preventive maintenance mechanism can be transferred along a required gap while being attached to the rail. Therefore, the preventive maintenance mechanism can be transferred more safely and efficiently in a narrow annulus. Further, since the preventive maintenance mechanism can be stably moved in water, it is not necessary to discharge the cooling water from the reactor pressure vessel, and the time required for maintenance work of the reactor annulus portion can be shortened.

According to the present invention, since the preventive maintenance mechanism is transferred using the driving force of the cable / hose feed mechanism and the rail feed mechanism installed in the annulus, the gap between the narrow shroud support cylinder and the jet pump diffuser The preventive maintenance mechanism can be stably transferred in the space between the reactor or the reactor pressure vessel and the jet pump diffuser, and a wide range of preventive maintenance work in the reactor annulus can be performed easily and efficiently. Therefore, it is possible to maintain the soundness of the plant and contribute to the safety and operation stability of the nuclear power plant.

  Prior to the description of the present invention, a reactor pressure vessel and a reactor internal structure to which the present invention is applied will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a cross-sectional view showing a reactor pressure vessel 1 and a reactor internal structure of a boiling water light water reactor. Reference numeral 1 denotes a reactor pressure vessel, and reference numeral 19 denotes a reactor well. In the nuclear pressure vessel 1, a dryer 2, a separator 3, a shroud support cylinder 4, a core shroud 5, a shroud support baffle plate 6, a jet pump 7, a fuel 12, a flange 14, and a guide rod 18 are installed. A hemispherical head 11 is detachably attached to the upper portion of the pressure vessel 1. The nuclear pressure vessel 1 is provided with a core spray pipe 9 and a water supply sparger 10. As shown in FIG. 2, the core shroud 5 is supported by the shroud support cylinder 4 via a shroud support ring 55, and the jet pump 7 is attached to the shroud support baffle plate 6.

  In the present invention, a space surrounded by the nuclear pressure vessel 1, the shroud support cylinder 4, the core shroud 5, the shroud support baffle plate 6, and the shroud support ring 55 is referred to as a reactor internal annulus portion 8.

  In the present invention, the welded portion 36 of the nuclear pressure vessel 1 and the shroud support baffle plate 6, the welded portion 37 of the shroud support baffle plate 6 and the shroud support cylinder 4, the shroud support cylinder 4 and the shroud support ring. The preventive maintenance method and the preventive maintenance device for the welded portion 56 of the core 55, the welded portion 38 of the core shroud 5 and the shroud support ring 55 are provided.

  Next, the access space of the preventive maintenance apparatus according to the present invention to the annulus portion 8 in the reactor will be described with reference to FIG.

  As shown in FIG. 3, jet pumps 7 are installed at equal intervals on the shroud support baffle plate 6 between the nuclear pressure vessel 1 and the core shroud 5 in addition to the reactor orientations of 0 ° and 180 °. Further, a core spray pipe 9 and a water supply sparger 10 are arranged above each jet pump 7. Therefore, as the access space of the preventive maintenance mechanism 26 to the annulus portion 8 in the reactor, only the narrow space shown by the shaded portion in FIG. 3 can actually be used.

  Hereinafter, a first embodiment of a preventive maintenance apparatus according to the present invention will be described with reference to FIGS. The preventive maintenance method of this example is characterized in that the preventive maintenance mechanism 26 is transferred within the rail 17.

  As shown in these drawings, the preventive maintenance device 13 of this example includes a preventive maintenance mechanism 26, a rail 17 for moving and running the preventive maintenance mechanism, a rail feeding mechanism 15 for sending out the rail 17, a cable 24, The cable / hose feed mechanism 16 is used to feed the hose 25.

  The rail 17 has a planar shape formed in an arc shape, and is configured so that a plurality of rails 17 can be sequentially connected. As shown in FIGS. 4 and 7, the rail 17 of this example has a U-shaped cross-sectional shape, and the lower end portion of the vertical side is configured to hold the preventive maintenance mechanism 26 so that it can run. A holding projection 17a is formed inward. As shown in FIG. 7, at the end of each rail 17, two positioning pins 39 protrude upward, and a first end portion in which a screw hole 53 is opened between each positioning pin 39; Two positioning pin holes 40 for fitting the two positioning pins 39 are formed, and a second end portion in which a bolt through hole 53a is opened is formed between the positioning pin holes 40. After the positioning pin 39 provided on one rail 17 is fitted into the positioning pin hole 40 provided on the other rail 17, the tip of the bolt 33 inserted into the bolt through hole 53 a is screwed into the screw hole 53. By combining, they are assembled together. The positioning pin hole 40 is formed wide so that it can follow the manufacturing tolerance of the nuclear pressure vessel 1 and the shroud support cylinder 4. Further, the rail 17 of the present example is provided with a roller 29 for enabling smooth movement on the shroud support baffle plate 6. Furthermore, the rail 17 of this example is provided with a rail fixing cylinder 30. The rail 17 can be fixed by protruding a movable portion of the cylinder 30 and clamping the jet pump 7, for example.

  The rail feed mechanism 15 is used for assembling the rail 17 and transporting the preventive maintenance mechanism 26, and is a rail feed mechanism fixing cylinder 31 and a suction pad 32, which are clamp mechanisms for fixing the rail feed mechanism 15 itself. And a rail feeding clamp mechanism 35, a traveling rail 51 for guiding the clamp mechanism 35, and a drive source (not shown) for driving the clamp mechanism 35. As a drive source for rail feeding, for example, a motor, a cylinder, or the like can be used.

  The preventive maintenance mechanism 26 is provided with a cavitation generator (not shown) for generating cavitation bubbles to be injected into the welded portion in the annulus portion 8. The cavitation generator directs the cavitation bubbles toward the welded portion. A nozzle 28 for spraying is provided. The preventive maintenance mechanism 26 is formed in such a size that it can move in the internal space of the rail 17 whose cross-sectional shape is formed in a downward U-shape.

  The cable 24 supplies power, a control signal, and the like to the rail feed mechanism 15 and the preventive maintenance mechanism 26, and the hose 25 supplies air to each clamp mechanism 30, 31, 32, 35 as a driving source thereof and the preventive maintenance mechanism. 26 for sending high-pressure water to 26.

  As shown in FIG. 4, the cable / hose feed mechanism 16 includes two sets of rollers 34 arranged to face each other with an interval at which the cable 24 and the hose 25 can be clamped.

  Hereinafter, welding of the reactor pressure vessel 1 and the shroud support baffle plate 6, and the shroud support baffle plate 6 and the shroud support cylinder 4 are welded using the preventive maintenance apparatus according to the first embodiment configured as described above. A method for preventing and maintaining the portion 37, the welded portion 38 of the core shroud 5 and the shroud support ring 55 and the welded portion 56 of the shroud support cylinder 4 and the shroud support ring 55 will be described. The preventive maintenance work is normally performed by visual inspection in the state in which the reactor well 19 is filled with water after removing in-reactor equipment such as the nuclear pressure vessel head 11, the dryer 2, and the separator 3 by a method that is usually performed by periodic inspection. This is performed when the inside of the unit 8 is inspected and no defect is found.

  First, as shown in FIG. 8A, the rail feed mechanism 15 is set at a position where the reactor orientation on the shroud support baffle plate 6 is 0 ° or 180 ° (STEP 1). As shown in FIGS. 9 and 10, the rail feed mechanism 15 is loaded onto the shroud support baffle plate 6 with the dryer 2, the separator 3, the head 11, and the fuel 12 removed from the reactor pressure vessel 1. This is performed by using an overhead crane 22 installed in the reactor building, a heavy machine installed in the fuel change carriage 20 or the work carriage 21, for example, a chain block 23. The same method is used for carrying in the rail 17 and carrying in the preventive maintenance device 13 into the annulus portion performed after the rail feeding mechanism 15 is carried in. The rail feed mechanism 15 is fixed to the shroud support baffle plate 6 by driving the rail feed mechanism fixing cylinder 31 and the suction pad 32 with air or high-pressure water supplied by the hose 25. The suction pad 32 is sucked by making the inside of the suction pad 32 a negative pressure with a suction machine or the like. The suction machine is installed on the operating floor, which is the work area. The air that serves as the drive source for the clamp is supplied from the air connection port of the reactor building facility or from the compressor. Thereby, as shown in FIG. 11, the rail feed mechanism 15 is set on the shroud support baffle plate 6.

  Next, the first rail 17 from the work area on the reactor is suspended from the work area on the reactor using a chain block 23 and the like to a portion where the rail feed mechanism 15 of the reactor annulus portion 8 is installed, and FIG. As shown, the first rail 17 is attached to the rail feed clamp mechanism 35 (STEP 2). As shown in FIG. 12, the rail feed pin provided in the rail feed clamp mechanism 35 is installed in the rail feed pin hole 44 formed in the rail 17, as shown in FIG. This is done by inserting 43.

  Next, as shown in FIG. 8C, the rail feeding clamp mechanism 35 is moved to the other end side, and the rail 17 is fed into the gap between the shroud support cylinder 4 and the jet pump diffuser 7 (STEP 3).

  Next, the second rail 17 from the work area on the reactor is suspended from the work area on the reactor using a chain block 23 or the like to the site where the rail feed mechanism 15 of the reactor annulus 8 is installed, and FIG. As shown, the end of the first rail 17 and the end of the second rail 17 are connected to each other (STEP 4). As shown in FIG. 7, the rail 17 is connected by fitting a positioning pin 39 provided in one rail 17 into a positioning pin hole 40 provided in the other rail 17 and then in a bolt through hole 53 a. This is done by inserting a bolt 33 and operating the bolt 33 from a work area on the reactor using a bolt 52 for tightening bolts. Next, the rail feeding clamp mechanism 35 is returned to the original position, the second rail 17 is clamped, and the second rail 17 is fed along the gap between the shroud support cylinder 4 and the jet pump diffuser 7. .

  Similarly, as shown in FIG. 8E, the required number of rails 17 are sequentially connected (STEP 5). The number of rails 17 connected can be adjusted as appropriate according to the length of each rail 17, but preventive maintenance of the gap between the shroud support cylinder 4 and the jet pump diffuser 7 over 180 ° in one operation. In order to be able to do so, it is desirable to make it at least 1/4 of the total length of the gap. As a result, the number of times of setting the rail feed mechanism 15 and the number of times of laying the rail 17 can be set to two times, the work at the position of the reactor azimuth 0 ° and the work at the position of the reactor azimuth 180 °. In addition, the required gap can be prevented and maintained all around.

  Next, the cable / hose feed mechanism 16 from the work area on the reactor using the chain block 23 and the like, the cable 24 and the hose 25 having one end held by the cable / hose feed mechanism 16, and the cable / hose 24 , 25 and the preventive maintenance mechanism 26 connected to the tip of the last rail 17 is hung down to the part where the last rail 17 is installed, and a cable hose is attached to the end of the last rail 17 as shown in FIG. The feed mechanism 16 is connected (STEP 6).

  Thereafter, a drive signal and a driving force are supplied to the preventive maintenance mechanism 26 through the cable 24 and the hose 25, and the cable 28 and the hose feed roller 34 are rotated to move the preventive maintenance mechanism 26 along the rail 17. The cavitation bubbles are jetted from and preventive maintenance of the required welds. Thereby, the gap between the shroud support cylinder 4 and the jet pump diffuser 7 can be prevented and maintained over the laying length of the rail 17. If the rail 17 and the cable / hose feed mechanism 16 are transferred to the opposite side of the rail feed mechanism 15 from the state shown in FIG. 8 (f), preventive maintenance on the opposite side is performed by repeating the same operation as described above. Can do. Further, by providing the rail feed mechanism 15, the cable / hose feed mechanism 16 and the rail 17 in the gap between the reactor pressure vessel 1 and the jet pump diffuser 7, preventive maintenance can be performed on the gap. In addition, the rail feed mechanism 15, the cable / hose feed mechanism 16 and the rail 17 are moved from the position of the reactor orientation 0 ° to the position of the reactor orientation 180 °, or from the position of the reactor orientation 180 ° to the reactor orientation 0 °. By re-setting the position, preventive maintenance can be performed on the remaining portion.

  After the preventive maintenance work is completed, the inside of the annulus portion 8 is inspected by visual inspection, and the cable / hose feed mechanism 16, the rail 17, and the rail feed mechanism 15 are sequentially removed to restore the nuclear reactor.

  In the preventive maintenance method of this example, the rail 17 is used to guide the preventive maintenance mechanism 26. Therefore, the preventive maintenance mechanism 26 can be stably transferred within a desired gap, and a predetermined preventive maintenance work can be performed with high efficiency. be able to.

  In carrying out the preventive maintenance method of this example, in order to further stabilize the transfer of the rail 17, a rail feed mechanism 15 provided with a rail positioning guide can be used as shown in FIG.

  Hereinafter, a second embodiment of the preventive maintenance method according to the present invention will be described with reference to FIGS. The preventive maintenance method of this example is characterized in that the preventive maintenance mechanism 26 is not transferred within the rail 17, but the preventive maintenance mechanism 26 attached to the tip of the rail 17 is transferred by driving the rail 17.

  In the preventive maintenance method of this example, as shown in FIG. 14, as the rail 17, the connection pin 41 protrudes upward at one end, and the connection hole 42 into which the connection pin 41 can be inserted is opened at the other end. Things are used. The rail 17 is not provided with the rail fixing cylinder 30 provided in the rail 17 of the first embodiment. As shown in FIGS. 15 to 17, the preventive maintenance mechanism 26 includes a cavitation generator 46, a nozzle 28 for injecting cavitation bubbles, a traverse rail 47 for traversing the cavitation generator 46, A mechanism including a lifting mechanism 48 of the cavitation generator 46 and a clamp arm 49 for fixing itself is used. The cavitation generator 46 traverses on the traverse rail 47 by driving a traverse drive motor. The elevating mechanism 48 is driven up and down by the elevating drive motor so that the elevating mechanism 48 is vertically expanded and the cavitation generator 46 is moved up and down. The fixing clamp mechanism projects the clamp arm 49 to clamp the jet pump 7 and fixes itself. Further, a traveling roller 50 may be provided to smoothly travel the annulus portion 8. Furthermore, in the preventive maintenance method of this example, the cable / hose feed mechanism 16 is attached to the reactor pressure vessel 1 or the core shroud 5 instead of the rail 17. In FIGS. 13 to 17, which are explanatory diagrams of the second embodiment, the cable / hose feed mechanism 16 is omitted.

  Also in this example, the setting of the rail feed mechanism 15 on the shroud support baffle plate 6 is performed in the same procedure as the preventive maintenance method according to the first embodiment except that the bolt 33 is not fastened. After the rail feed mechanism 15 is set on the shroud support baffle plate 6, one end is connected to the cable / hose feed mechanism 16 (not shown) and the cable / hose feed mechanism 16 from the work area on the reactor using the chain block 23 or the like. The held cable 24 and hose 25 and the preventive maintenance mechanism 26 connected to the tip of the cables and hoses 24 and 25 are suspended, and the reactor pressure vessel 1 or the core above the setting portion of the rail feed mechanism 15 is suspended. Attach to shroud 5. Thereafter, as shown in FIG. 13A, the preventive maintenance mechanism 26 is attached to the end of the last rail 17 by remote control from the work area (STEP 7).

  Next, as shown in FIG. 13B, the rail 17 that has been laid by driving the rail feed mechanism 15 is fed in the reverse direction, and the preventive maintenance mechanism 26 is transferred to a desired work position, and as shown in FIG. Then, the clamp arm 49 of the fixing clamp mechanism is protruded to clamp the preventive maintenance mechanism 26 to the jet pump diffuser 7 (STEP 8), and preventive maintenance work for the peripheral portion is performed. Each time the preventive maintenance work for the peripheral portion is completed, the transfer of the preventive maintenance mechanism 26 and the preventive maintenance work at that position are sequentially repeated. As shown in FIG. 13 (c), when the preventive maintenance mechanism 26 reaches the end of the transferable range, the other prepared preventive maintenance mechanism 26 is remotely operated from the reactor to the rail of the annulus portion 8. It is hung down to the site where the feed mechanism 15 is installed and connected to the other end of the rail 17 (STEP 9). Next, as shown in FIG. 13 (d), the rail 17 is transferred in the reverse direction, and preventive maintenance work is performed in the same manner as in STEP 8 (STEP 10). About others, since it is the same as the preventive maintenance method which concerns on 1st Embodiment, description is abbreviate | omitted.

  The preventive maintenance method of this example also has the same effect as the preventive maintenance method according to the first embodiment.

  Hereinafter, a third embodiment of the preventive maintenance method according to the present invention will be described with reference to FIGS. 19 and 20. The preventive maintenance method of this example is characterized in that the preventive maintenance mechanism 26 is transferred by the driving force of the cable / hose feed mechanism 16 without using the rail 17.

In the preventive maintenance method of this example, as shown in FIGS. 19 and 20, a cable / hose feed mechanism 16 is installed on the shroud support baffle plate 6. The cable / hose feed mechanism 16 is installed by hanging the cable / hose feed mechanism 16 in the annulus portion 8 by remote work from the reactor, and then protruding the cable / hose feed mechanism fixing cylinder 57 and the suction pad 32. This is done by adsorption. The structure of the cable / hose feed mechanism 16 is as described with reference to FIG.

  Next, the preventive maintenance mechanism 26 is hung down and installed at the place where the cable / hose feeding mechanism 16 is installed by remote work from the reactor. The preventive maintenance mechanism 26 is as described with reference to FIGS. 16 and 17. The roller drive motor of the cable / hose feed mechanism 16 is driven to rotate the cable / hose feed roller 34, the cable 24 and the hose 25 are fed, and the preventive maintenance mechanism 26 is operated between the shroud support cylinder and the jet pump diffuser or the reactor pressure. Deliver between container and jet pump diffuser. The cable 24 and the hose 25 are covered with a high friction material and can be easily fed by the cable / hose feed roller 34. Further, since the hose 25 is hard, the preventive maintenance mechanism 26 can be sent out without disturbing the travelability and directionality of the preventive maintenance mechanism 26 by sending the hose 25. After sending the preventive maintenance mechanism 26 to the narrow part, the welded part 36 of the reactor pressure vessel and the shroud support baffle plate, the welded part 37 of the shroud support baffle plate and the shroud support cylinder, and the welded part 56 of the shroud support cylinder and the shroud support ring. And preventive maintenance work of the welded portion 38 of the shroud and the shroud support ring.

  The preventive maintenance method of the present example has the same effects as the preventive maintenance method according to the first embodiment, and does not use the rail 17, so that the desired preventive maintenance work can be performed at a low cost and in a short time.

It is a figure which shows the nuclear reactor pressure vessel of a boiling water light water reactor, and its internal structure. It is the A section expanded sectional view of FIG. It is a figure which shows the access space of a nuclear reactor annulus part. It is a figure which shows the structure of the preventive maintenance apparatus which concerns on 1st Embodiment. It is a principal part top view which shows the attachment state to the reactor annulus part of the preventive maintenance apparatus which concerns on 1st Embodiment. It is a principal part side view which shows the attachment state to the reactor annulus part of the preventive maintenance apparatus which concerns on 1st Embodiment. It is a figure which shows the structure and connection method of the rail which concern on 1st Embodiment. It is a figure which shows the procedure of the preventive maintenance method which concerns on 1st Embodiment. It is a figure which shows the carrying-in method of the member to the annulus part in a reactor. It is a figure which shows the rail feeding apparatus in an annulus part, and the installation state of a rail. It is a figure which shows the installation state of the rail feeder in an annulus part. It is a figure which shows the engagement state of a rail feed mechanism and a rail. It is a figure which shows the procedure of the preventive maintenance method which concerns on 2nd Embodiment. It is a figure which shows the structure and connection method of the rail which concern on 2nd Embodiment. It is a principal part top view which shows the attachment state to the reactor annulus part of the preventive maintenance apparatus which concerns on 2nd Embodiment. It is a figure which shows the structure of the preventive maintenance mechanism which concerns on 2nd Embodiment. It is a figure which shows operation | movement of the preventive maintenance mechanism which concerns on 2nd Embodiment. It is a figure which shows the modification of the preventive maintenance mechanism which concerns on 2nd Embodiment. It is a principal part top view which shows the attachment state to the reactor annulus part of the preventive maintenance apparatus which concerns on 3rd Embodiment. It is a principal part side view which shows the attachment state to the reactor annulus part of the preventive maintenance apparatus which concerns on 3rd Embodiment.

Explanation of symbols

1: Reactor pressure vessel 2: Dryer 3: Separator 4: Shroud support cylinder 5: Core shroud 6: Shroud support baffle plate 7: Jet pump 8: Annulus section 9: Core spray piping 10: Feed water sparger 11: Nuclear pressure vessel head 12: Fuel 13: Preventive maintenance device 14: Nuclear pressure vessel flange 15: Rail feed mechanism 16: Cable / hose feed mechanism 17: Rail 18: Guide rod 19: Reactor well 20: Refueling carriage 21: Working carriage 22: Ceiling Crane 23: Chain block 24: Cable 25: Hose 26: Preventive maintenance mechanism 27: Jet pump diffuser 28: Nozzle 29: Roller 30: Rail fixing cylinder 31: Rail feed mechanism fixing cylinder 32: Suction pad 33: Rail fixing Bo 34: Cable / hose feed roller 35: Rail feed clamp mechanism 36: Reactor pressure vessel / shroud support baffle plate welded portion 37: Shroud support baffle plate / shroud support cylinder welded portion 38: Core shroud / shroud support ring welded portion 39: Positioning pin 40: Positioning pin hole 41: Connection pin 42: Connection hole 43: Rail feed pin 44: Rail feed pin hole 45: Rail positioning guide 46: Cavitation generator 47: Traverse rail 48: Lifting mechanism 49: Clamp Arm 50: Traveling roller 51: Traveling rail 52: Bolt tightening pole 53: Fixing bolt hole 54: Notch 55: Shroud support ring 56: Shroud support cylinder / shroud support ring weld 57: Buru Horse feed mechanism for fixing cylinder

Claims (8)

A nuclear pressure vessel that is carried into the annulus part of the reactor pressure vessel and performs preventive maintenance on the welds of the reactor pressure vessel, core shroud, shroud support cylinder, shroud support ring, and shroud support baffle plate that constitute the annulus part. A preventive maintenance device,
A rail feed mechanism installed on the shroud support baffle plate;
A rail laid in a gap between the reactor pressure vessel and the jet pump diffuser attached to the shroud support baffle plate or a gap between the shroud support cylinder and the jet pump diffuser using the rail feed mechanism;
A cable / hose feed mechanism attached to the end of the rail;
Feeding from the cable / hose feed mechanism by rotating a cable / hose feed roller supplied from the upper part of the reactor pressure vessel and provided in the cable / hose feed mechanism; A cable hose to be pulled in;
The gap between the reactor pressure vessel and the jet pump diffuser attached to the shroud support baffle plate is connected to the tip of the cable / hose and guided by the rail by rotating the cable / hose feed roller. Or a preventive maintenance mechanism transferred in a direction along a gap between the shroud support cylinder and the jet pump diffuser,
The rail feed mechanism includes a rail feed clamp mechanism including a rail feed pin, a travel rail that guides the rail feed clamp mechanism, and a drive source that drives the rail feed clamp mechanism along the travel rail; The rail feed pin is inserted into a rail feed pin hole formed in the rail to connect the rail feed clamp mechanism and the rail, and then the drive source is driven to run the rail. Feed along the rail, move the end of the rail to the connection position with the other one rail , then repeat the operation of returning the rail feeding clamp mechanism to the original position as many times as necessary,
The two rails to be connected to each other can be obtained by fitting a positioning pin provided at one end of one rail into a positioning pin hole formed at one end of the other rail at the connecting position. It is positioned and assembled integrally by screwing a bolt into a screw hole opened at one end of the other rail through a bolt through hole opened at one end of the one rail. Preventive maintenance equipment for reactor annulus. A nuclear pressure vessel that is carried into the annulus part of the reactor pressure vessel and performs preventive maintenance on the welds of the reactor pressure vessel, core shroud, shroud support cylinder, shroud support ring, and shroud support baffle plate that constitute the annulus part. A preventive maintenance device,
A rail feed mechanism installed on the shroud support baffle plate;
A rail laid in a gap between the reactor pressure vessel and the jet pump diffuser attached to the shroud support baffle plate or a gap between the shroud support cylinder and the jet pump diffuser using the rail feed mechanism;
A cable / hose feed mechanism installed at a required position on the reactor pressure vessel or the core shroud;
Feeding from the cable / hose feed mechanism by rotating a cable / hose feed roller supplied from the upper part of the reactor pressure vessel and provided in the cable / hose feed mechanism; A cable hose to be pulled in;
The reactor pressure vessel and the shroud support baffle are connected to the tip of the cable / hose and attached to one end of the rail, and the rail / feed mechanism is driven while rotating the cable / hose feed roller. A preventive maintenance mechanism transported in a direction along a gap between the jet pump diffuser attached to the plate or a gap between the shroud support cylinder and the jet pump diffuser,
The rail feed mechanism includes a rail feed clamp mechanism including a rail feed pin, a travel rail that guides the rail feed clamp mechanism, and a drive source that drives the rail feed clamp mechanism along the travel rail; The rail feed pin is inserted into a rail feed pin hole formed in the rail to connect the rail feed clamp mechanism and the rail, and then the drive source is driven to run the rail. Feed along the rail, move the end of the rail to the connection position with the other one rail , then repeat the operation of returning the rail feeding clamp mechanism to the original position as many times as necessary,
The two rails to be connected to each other can be obtained by fitting a positioning pin provided at one end of one rail into a positioning pin hole formed at one end of the other rail at the connecting position. It is positioned and assembled integrally by screwing a bolt into a screw hole opened at one end of the other rail through a bolt through hole opened at one end of the one rail. Preventive maintenance equipment for reactor annulus.   The in-reactor annulus part according to any one of claims 1 and 2, wherein the preventive maintenance mechanism includes a cavitation generator that generates cavitation bubbles to be injected into each welded part. Preventive maintenance equipment.   The preventive maintenance apparatus for an annulus portion in a nuclear reactor according to claim 3, wherein the cavitation generator includes a nozzle that injects cavitation bubbles toward a required weld.   The cable / hose feed mechanism is provided with a clamp mechanism for installing the cable / hose feed mechanism at a predetermined position in the annulus by remote control from above the nuclear pressure vessel. The preventive maintenance apparatus for an annulus portion in a nuclear reactor according to any one of claims 1 and 2.   2. The rail feed mechanism is provided with a clamp mechanism for installing the rail feed mechanism at a predetermined position in the annulus portion by a remote operation from above the nuclear pressure vessel. And the preventive maintenance apparatus of the annulus part in a reactor of any one of Claim 2 and Claim 2. Carry the required preventive maintenance equipment into the annulus part of the reactor pressure vessel, and preventive maintenance for each welded part of the reactor pressure vessel, core shroud, shroud support cylinder, shroud support ring and shroud support baffle plate that make up the annulus part A preventive maintenance method for a nuclear pressure vessel,
A step of installing a rail feed mechanism on the shroud support baffle plate by remote control from above the nuclear pressure vessel in a state where there is cooling water in the reactor pressure vessel;
A rail suspended from above the nuclear pressure vessel using this rail feed mechanism is used to cause a gap between the reactor pressure vessel and a jet pump diffuser attached to the shroud support baffle plate, or the shroud support cylinder and the jet. Laying in the gap with the pump diffuser;
The cable / hose feed mechanism suspended from above the nuclear pressure vessel at the end of the rail is connected to the cable / hose attached to the cable / hose feed mechanism and the tip of the cable / hose. Attaching with the maintenance mechanism;
By rotating the cable / hose feed roller provided in the cable / hose feed mechanism, the preventive maintenance mechanism is attached to the reactor pressure vessel and the shroud support baffle plate along the rail by the driving force thereof. Transferred in a direction along the gap between the jet pump diffuser or the gap between the shroud support cylinder and the jet pump diffuser, and appropriately driving the preventive maintenance mechanism by remote operation from above the nuclear pressure vessel, Welds between the reactor pressure vessel and the shroud support baffle plate, welds between the shroud support baffle plate and the shroud support cylinder, welds between the core shroud and the shroud support ring, and shroud support cylinders and shrouds And a step of preventive maintenance welds port ring,
The rail feed mechanism includes a rail feed clamp mechanism including a rail feed pin, a travel rail that guides the rail feed clamp mechanism, and a drive source that drives the rail feed clamp mechanism along the travel rail; In the step of installing a rail feed mechanism on the shroud support baffle plate, the rail feed pin is inserted into a rail feed pin hole provided in the rail, and the rail feed clamp mechanism and the rail are inserted. After the connection, the drive source is driven to feed the rail along the traveling rail, the end of the rail is moved to a connection position with the other rail, and then the rail feeding clamp mechanism is Repeat the operation of returning to the original position for the required number of rails,
The two rails to be connected to each other can be obtained by fitting a positioning pin provided at one end of one rail into a positioning pin hole formed at one end of the other rail at the connecting position. Atom is characterized by positioning and assembling together by screwing a bolt into a screw hole provided at one end of the other rail through a bolt through hole provided at one end of the one rail. Preventive maintenance method for furnace annulus. Carry the required preventive maintenance equipment into the annulus part of the reactor pressure vessel, and preventive maintenance for each welded part of the reactor pressure vessel, core shroud, shroud support cylinder, shroud support ring and shroud support baffle plate that make up the annulus part A preventive maintenance method for a nuclear pressure vessel,
A step of installing a rail feed mechanism on the shroud support baffle plate by remote control from above the nuclear pressure vessel in a state where there is cooling water in the reactor pressure vessel;
A rail suspended from above the nuclear pressure vessel using this rail feed mechanism is used to cause a gap between the reactor pressure vessel and a jet pump diffuser attached to the shroud support baffle plate, or the shroud support cylinder and the jet. Laying in the gap with the pump diffuser;
A cable / hose feed mechanism is attached to a required position on the reactor pressure vessel or the core shroud by remote control from above the nuclear pressure vessel, the cable / hose attached to the cable / hose feed mechanism, and the cable / Installing with a preventive maintenance mechanism connected to the tip of the hose;
Attaching the preventive maintenance mechanism to one end of the rail;
By driving the rail feed mechanism while rotating the cable / hose feed roller provided in the cable / hose feed mechanism, the preventive maintenance mechanism is driven by the driving force of the rail feed mechanism, the reactor pressure vessel and the reactor Transfer to the gap between the jet pump diffuser attached to the shroud support baffle plate or the gap between the shroud support cylinder and the jet pump diffuser, and preventive maintenance by remote control from above the nuclear pressure vessel By appropriately driving a mechanism, a welded portion of the reactor pressure vessel and the shroud support baffle plate, a welded portion of the shroud support baffle plate and the shroud support cylinder, a welded portion of the core shroud and the shroud support ring, and a shroud support And a step of preventive maintenance of weld Toshirinda and shroud support rings,
The rail feed mechanism includes a rail feed clamp mechanism including a rail feed pin, a travel rail that guides the rail feed clamp mechanism, and a drive source that drives the rail feed clamp mechanism along the travel rail; In the step of installing a rail feed mechanism on the shroud support baffle plate, the rail feed pin is inserted into a rail feed pin hole provided in the rail, and the rail feed clamp mechanism and the rail are inserted. After the connection, the drive source is driven to feed the rail along the traveling rail, the end of the rail is moved to a connection position with the other rail, and then the rail feeding clamp mechanism is Repeat the operation of returning to the original position for the required number of rails,
The two rails to be connected to each other can be obtained by fitting a positioning pin provided at one end of one rail into a positioning pin hole formed at one end of the other rail at the connecting position. Atom is characterized by positioning and assembling together by screwing a bolt into a screw hole provided at one end of the other rail through a bolt through hole provided at one end of the one rail. Preventive maintenance method for furnace annulus.

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