JPH0569198B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a guide for an internal pump handling tool that guides a handling tool for handling an internal pump of an internal pump boiling water reactor (hereinafter referred to as A-BWR). Regarding equipment. [Technical Background of the Invention] A conventional example will be described below with reference to FIGS. 4 and 5. FIG. 4 is a vertical cross-sectional view showing the schematic structure of the A-BWR, and reference numeral 1 in the figure is a reactor pressure vessel. A coolant 2 and a reactor core 3 are housed within the reactor pressure vessel 1 . The reactor core 3 is composed of a plurality of fuel assemblies and control rods 4 (not shown), and includes a shroud 5, a core support plate 6, and an upper grid plate 7 installed in the reactor pressure vessel 1.
It is accommodated and supported by. The control rod 4 is driven by a control rod drive mechanism 8. A steam separator 9 is installed above the core 3, and
Furthermore, a steam dryer 10 is installed above it. A water supply pipe 11 is connected to the reactor pressure vessel 1 located below the steam separator 9, and this water supply pipe 11 is connected to a water supply spargeer 12 disposed within the reactor pressure vessel 1. . Further, a plurality of internal pumps 14 are installed at equal intervals in the circumferential direction at the lower part of the downcomer section 13 between the shroud 5 and the reactor pressure vessel 1. Further, a main steam pipe 15 is connected to the upper part of the reactor pressure vessel 1. Next, the structure of the internal pump 14 will be explained with reference to FIG. The internal pump 14 includes a pump section 21 and a motor section 22. The pump section 21 is an impeller 2
3, a differential user 24, a differential user ring 25, etc., and the impeller 23
is connected to the motor section 22 via a pump shaft 26. A nozzle 1A is provided inwardly protruding from the lower mirror portion of the reactor pressure vessel 1. The diff user 24 is fixed to the upper part of the nozzle 1A by a stretch tube 27. Further, the stretch tube 27 is fixed by a stretch tube nut 28. Reference numeral 29 in the figure is a secondary seal installed below the stretch tube nut 28. The motor section 22 is composed of a rotor 30, a stator 31, etc., and these motor section components are housed in a pump casing 32. The motor casing 32 has its tip inserted into the nozzle 1A and is welded to the upper end of the nozzle 1A. Cooling water is circulated inside the cladding tube 33 to prevent the motor section 22 from burning out. According to the above configuration, the coolant 2 supplied through the water supply pipe 11 is injected from above the downcomer portion 13 via the water supply spargeer 12. Then, it is transferred to the lower part of the reactor core 3 by the internal pump 14. The transferred coolant 2 flows upward through the reactor core 3, and its temperature increases due to the heat of nuclear reaction in the reactor core 3. The heated coolant 2 becomes a two-phase flow state of water and steam, and is introduced into the steam/water separator 9 to be separated into steam and water. The separated internal steam is introduced into the steam dryer 10 and becomes dry steam. The dry steam is transferred to a turbine system (not shown) via the main steam pipe 15 and used for power generation. The steam that has done work in this turbine system is introduced into a condenser (not shown), where it is condensed and liquefied to become low-temperature condensate. The condensate is supplied into the reactor pressure vessel 1 via the water supply pipe 11. The same cycle is repeated thereafter. The A-BWR with this configuration does not require an external recirculation system compared to a normal boiling water reactor (BWR), so there is no need for space for recirculation system piping, and the reactor pressure is reduced. Space around the container 1 can be secured easily. Furthermore, since the motor section 22 is housed in a motor casing 32 with excellent watertightness, a sliding shaft sealing device is not required.
Reliability can be improved by reliably preventing reactor water leaks. Furthermore, in the case of the A-BWR having the above configuration, maintenance and inspection of the internal pump 14 must be performed periodically. This periodic inspection is performed by removing the internal pump 14 from inside the reactor pressure vessel 1. To briefly explain the process of removing the internal pump 14, first, the impeller 13 and the pump shaft 26 are pulled out from above the reactor pressure vessel 1. Next, the motor section 22 is removed from below the pump casing 33. Then, from above the reactor pressure vessel 1, the differential user 24 and the differential user ring 25 are
and remove the stretch tube 27. [Problems with Background Art] The above configuration has the following problems. The removal and installation work of the internal pump 14 will be carried out in an extremely narrow space.
And it is done by remote control. As a result, they are forced to perform difficult tasks. Especially reactor pressure vessel 1
When loading equipment from above, it is necessary to detour the equipment to avoid interference with the water supply spargeer 12 installed on the inner wall of the reactor pressure vessel 1, piping, etc. . In this situation, the internal pump 14
Maintenance and inspection work takes a long time, which is not desirable in terms of reducing radiation exposure for workers, and is also an obstacle to improving plant operation rates. [Object of the Invention] The present invention has been made based on the above points, and its purpose is to guide the internal pump handling tool when removing and installing the internal pump remotely, and to avoid obstacles. To provide a guide device for an internal pump handling tool, which can bypass the internal pump by remote control and perform removal and installation work of the internal pump with simple operation and in a short time. There is a particular thing. [Summary of the Invention] That is, the guide device for an internal pump handling tool according to the present invention includes a shroud that is inserted between a reactor pressure vessel and a shroud, is attached to the main body of a handling tool for handling an internal pump, and serves as a guide on the shroud side. a side guide mechanism, a reactor pressure vessel side guide mechanism that is attached to the handling tool body and serves as a guide for the reactor pressure vessel side, and a reactor pressure vessel side guide mechanism that guides the reactor pressure vessel side to a guide position and equipment in the reactor pressure vessel. The reactor pressure vessel side guide mechanism driving means is selectively located at one of the standby positions to avoid interference with the nuclear reactor pressure vessel side and can be remotely operated. In other words, when inserting the internal pump handling tool between the reactor pressure vessel and the shroud, it is first guided by the shroud-side guide mechanism and the reactor pressure vessel-side guide mechanism, and at the same time is placed inside the reactor pressure vessel. In order to avoid interference with equipment, the reactor pressure vessel side guide mechanism is appropriately positioned at a standby position by the reactor pressure vessel side guide mechanism driving means. [Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. For the configurations of the A-BWR and internal pump, the symbols shown in FIGS. 4 and 5 are used as they are. FIG. 1 is a sectional view showing a state in which a handling tool equipped with a guide device according to the present invention is installed in a downcomer part 13,
Reference numeral 101 in the figure indicates an internal pump handling tool main body (hereinafter referred to as the handling tool main body). This handling tool main body 101 is suspended from above the reactor pressure vessel 1 into the downcomer section 13 by a wire rope using an operation pole (not shown) as a guide. A guide device 102 is attached to the handling tool 101. The configuration of this guide device 102 will be explained below. This guide device 102 includes a shroud side guide mechanism 105 that serves as a guide on the shroud 5 side,
It is composed of a reactor pressure vessel side guide mechanism 106 that serves as a guide on the reactor pressure vessel 1 side, and a reactor pressure vessel side guide mechanism driving means 107 that drives this reactor pressure vessel side guide mechanism 106.
The shroud side guide mechanism 105 will be explained below. Reference numeral 111 in the figure represents an arm, and this arm 1
11 is the shroud 5 from the upper part of the handling tool 102.
It is installed protruding in the direction. A guide roller 113 is rotatably attached to the tip of the arm portion 111. On the other hand, a guide rail 115 is installed at a predetermined position on the side of the shroud 5, and when the handling tool main body 101 gradually descends from above, the guide roller 114 moves onto the guide rail 115.
begins to roll. As a result, the handling tool main body 101
Its position is restricted in the horizontal direction. Next, the reactor pressure vessel side guide mechanism 106 will be explained. Reference numeral 112 in the figure is an arm;
A guide roller 114 is rotatably installed at the tip of this arm portion 112. The arm portion 112 rotates as shown by the arrow in FIG. 1, thereby moving the driving means to the guide position (the state shown by the solid line in FIG. 1) and the standby position (the state shown by the two-dot chain line in the figure). 107 as appropriate. Next, the structure of the driving means 107 will be explained with reference to FIGS. 2 and 3. An air cylinder 121 is installed on the upper part of the handling tool main body 101, and this air cylinder 121 is operated by air pressure supplied through an air supply port 122. Note that two air cylinders 121 are installed as shown in FIG. 3. Further, the air cylinder 121 is controlled by a control circuit (not shown). The piston rod 123 of the air cylinder 121 is connected to the arm portion 112 via a pin 124. In addition, the reference numeral 125 in the figure is the driving means 1.
This is a frame body that accommodates 07. In the normal case, the piston 123 is in a retracted state, and the pin 124 is at the position indicated by A in the figure. At this time, when the arm 111 is in the guide position, the roller 113 is brought into sliding contact with the inner surface of the reactor pressure vessel 1. On the other hand, in order to avoid interference between the arm 112 and an obstacle such as a water supply spargeer, the air cylinder 121 is operated to cause the piston 123 to protrude. The position of the pin 124 at that time is indicated by reference numeral B in the figure. Piston 1 like this
23 protrudes, the arm 112 rotates around the fulcrum 111A as shown by the two-dot chain line in the figure, and the frame 12
5 and comes to the standby position. This is intended to prevent interference between the arm 112 and the water supply spargeer 12. In FIG. 3, the guide roller 114 is shown in the guide position on the right side, and the guide roller 114 in the standby position is shown on the left side. Further, a spring (not shown) is incorporated inside the arm portion 112, and the structure is such that the unevenness of the inner wall surface of the reactor pressure vessel 1 can be absorbed by the spring. The operation will be explained based on the above configuration. For example, when suspending the pump shaft 26, the procedure is as follows. First, the handling tool main body 101 is suspended into the downcomer section 13 using a wire rope (not shown). As a result, the pair of guide rollers 114 and 113 roll along the inner peripheral surface of the reactor pressure vessel 1 and the outer peripheral surface of the shroud 5. Then, as it gradually descends, it reaches near the water supply spargeer 12. Therefore, in order to avoid interference with the water supply spargeer 12, the air cylinder 121 is driven to rotate the arm portion 112, housed in the frame 125, and positioned at the standby position. As a result, the arm portion 112
Interference between the water supply spargeer 12 and the water supply spargeer 12 is prevented. When the handling tool main body 101 is further lowered, the rollers 113 roll along the guide rails 115, and the horizontal position is regulated. In this state, the impeller shaft 26 is inserted from above and placed in a predetermined position by the handling tool main body 101. According to this embodiment, the following effects can be achieved. That is, the arm portion 112 for carrying the handling tool main body 101 can be rotated as appropriate by the operation of the air cylinder 121 and moved from the guide position to the standby position.
Interference with the second class can be prevented. At this time, the handling tool main body 101 is installed at a predetermined position without any need to move, and the impeller shaft etc. can be installed thereafter. This makes it easier to handle the internal pump, reduces the time required for the work, and improves the operating rate of the plant. Furthermore , it goes without saying that the guide device 102 can be operated remotely. [Effects of the Invention] As detailed above, according to the guide device for an internal pump handling tool according to the present invention, the handling tool main body can be easily and quickly placed in a predetermined location while avoiding interference with equipment in the reactor pressure vessel. As a result, it is possible to improve the work efficiency of internal pump handling work, shorten the work time, and thereby reduce the radiation exposure of workers and improve the operation rate of Plato. The effect is great.

[Brief explanation of the drawing]

1 to 3 are diagrams showing one embodiment of the present invention, and FIG. 1 is a front view showing a state in which the guide device is attached to the handling tool main body and inserted into the reactor pressure vessel;
Fig. 2 is a diagram showing the configuration of the arm and air cylinder, Fig. 3 is a view taken in the direction of - arrow in Fig. 2, Fig. 4 is a vertical sectional view showing the schematic configuration of an internal pump type boiling water reactor, FIG. 5 is a longitudinal sectional view showing the structure of the internal pump. 1... Reactor pressure vessel, 5... Shroud, 1
01... Handling tool body, 102 ... Guide device, 1
05... Shroud side guide mechanism, 106... Reactor pressure vessel side guide mechanism, 107... Reactor pressure vessel side guide mechanism driving means.

Claims (1)

[Claims] 1. A shroud-side guide mechanism that is inserted between the reactor pressure vessel and the shroud and is attached to the handling tool body that handles the internal pump and serves as a guide on the shroud side, and a shroud-side guide mechanism that is installed on the handling tool body and is attached to the reactor pressure vessel side. A reactor pressure vessel side guide mechanism that serves as a guide for the reactor pressure vessel, and a reactor pressure vessel side guide mechanism that is selectively positioned at either a guide position or a standby position to avoid interference with equipment within the reactor pressure vessel. What is claimed is: 1. A guide device for an internal pump handling tool, comprising a remotely controllable reactor pressure vessel side guide mechanism drive means.