JPH0223296A - Upper blank cap for internal pump handling device - Google Patents

Abstract

PURPOSE:To enable whether or not a handling device is properly operatively inserted to be confirmed by providing a lower plug engaged with the lower end of a stretch tube and having a seal, an upper plug, a TV camera on one of two window glasses in a bottom plate and an underwater illumination lamp on the other. CONSTITUTION:The upper end of a handling device ascending to approach the lower end of a stretch tube in a motor casing can be observed by a supercompact type TV camera 36 taking pictures under the illumination of an underwater illumination lamp 38 provided in a lower plug 31. Then, the small diameter portion of the upper end of a handling device can be easily properly inserted into the lower end of the stretch tube. The operation of the handling device after the insertion can be performed while monitoring with the TV camera 36, so that the handling device can be properly operated. Then whether or not the insertion is properly carried out or the operation is properly performed can be necessarily easily confirmed.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is a boiling water nuclear reactor equipped with an internal pump, in which a stretch tube nut of the internal pump is moved by a stretch tube nut handling device. This relates to an upper blind cover for an internal pump handling device that is used to prevent reactor water from flowing into the motor casing when it is attached or detached.

(Conventional technology d) FIG. 3 is a vertical sectional view showing a schematic configuration of a conventional internal pump. In this figure, a shroud 2 (not shown) surrounding the reactor core is provided inside the reactor pressure vessel 1.
An internal pump 3 is provided at the bottom of the pressure vessel 1. The internal pump 3 is connected to the pressure vessel 1
It has a pump section 4 located inside the pressure vessel 1 and a drive section 5 located outside the pressure vessel 1.

The pump section 4 includes an impeller 7 driven by a shaft 6a detachably connected to the output shaft of a motor 6 of the drive section 5, and a differential user 8 surrounding the impeller 7. Further, the impeller 7 is attached to the tip of a pump mounting nozzle 10 protruding from the bottom of the pressure vessel 1 by tightening a stretch tube nut 91) screwed onto the lower end of a stretch tube 9a that concentrically surrounds the shaft 6a. Fixed.

Further, the motor casing 11 of the drive unit 5 provided outside the pressure vessel 1 has a distal end portion 11a that tightly surrounds most of the lower part of the stretch tube 9a, and the motor casing 11 has the distal end portion 11a that is connected to the pump. Mounting nozzle 1
0 to extend and engage.

It is fixed to the bottom of the pressure vessel 1 by welding.

Furthermore, a removable motor cover 6b is provided on the bottom surface of the motor casing 11.

The motor 6 provided in the motor casing 11 is of a water immersion type, and is operated despite the presence of reactor water that has entered from the pump attachment nozzle 10.

Incidentally, reference numerals 12 and 13 in the figure indicate studs and nuts for detachably attaching the motor cover 6b to the motor casing 11.

The internal pump described above is periodically disassembled and removed, and each removed component is taken outside the reactor containment vessel for inspection and repair. To disassemble and remove this internal pump 3, first release the connection between the output shaft of the motor 6 and the shaft 6a, and then tighten the nut 13.
This is done by removing the motor 6 and pulling the motor 6 downward from the motor casing 11, then pulling the impeller 7 and shaft 6a upward, and then removing the stretch tube nut 9b and removing the diffuser 8 upward.

By the way, when removing the differential user 8 from the pump attachment nozzle 10, conventionally, an upper blind plug 20 as shown in FIG. 4 is used. The upper blind plug 20 has a main portion 21 that is hollow and cylindrical and has an outer diameter approximately equal to the inner diameter of the diffuser 8. At the lower end of the main part 21 of the knee, a solid lower guide 21a is provided which engages the upper end of the stretch tube 9a at its maximum diameter and has a truncated cone shape whose diameter decreases downward. Further, the upper end of the main portion 21 is reduced in diameter upwardly to form an upper guide 21b. Further, a seal 22 is provided on an annular flat portion around the maximum diameter portion of the lower guide 21a.

Further, a central opening 2 provided at the center of the main portion 21 in the axial direction
3a, a partition wall 23 having notches 23b provided equidistantly in the circumferential direction is provided on the periphery.

Furthermore, a hollow cylindrical stud guide 25 having a guide hole 25a for the stud 24 at the bottom and at the center of the top plate is concentrically attached to the upper surface of the partition wall 23. The upper end of the stud 24 is a spherical end 24a, and the lower end is a tapered end 24b that engages with a tapered seat 26a provided in an opening in the flat surface of the lower guide of a through hole 26 passing through the solid lower guide 21a.

The upper blind plug 20 having the above configuration is used as follows.

That is, the stud 24 is grasped by an upper handling tool (not shown) in the pressure vessel 1, the upper blind plug 20 is engaged in the differential user 8 as shown in FIG.
The seal 22 is brought into pressure contact with the upper end of the stretch tube 9a by its own weight of 0 and the water pressure of the reactor water in the pressure vessel 1, thereby sealing the upper end opening of the stretch tube 9a. With reactor water being prevented from leaking into the motor casing 11 in this way, the motor cover 6b is removed and the reactor water in the motor casing 11 is discharged.

Next, the motor 6 is pulled out from the motor casing 11 by a lifting device (not shown), and a polyurethane tube nut handling device (hereinafter simply referred to as the handling device) 27 is inserted into the motor casing 11 using the lifting device (not shown). , install. In this case, the handling device 27
The small diameter portion 27a provided at the upper end is the stretch tube 9a.
must be inserted correctly within the bottom edge of the

(Problem to be Solved by the Invention) However, since the difference between the inner diameter of the stretch tube 9a and the outer diameter of the small diameter portion 27a is very small, not only is it extremely difficult to insert the tube correctly, but also the insertion is difficult. Since the insertion position is deep in the upper part of the motor casing 11, it is impossible for the operator to check whether the insertion has been done correctly. Furthermore, even if the insertion and installation have been performed correctly and the handling device 27 is being operated, it is not possible to confirm whether or not the handling device is operating normally.

The present invention has been made based on the above circumstances.

Upper blind lid for internal pump handling device that allows the operator to easily check whether the handling device is correctly inserted into the lower end of the stretch tube and whether the inserted handling device is operating correctly. is intended to provide.

[Structure of the Invention] (Means for Solving the Problem!) The upper blind lid for an internal pump handling device of the present invention has a diameter reduced downward, engages the lower end of the stretch tube, and has a flange at the maximum diameter part. A hollow truncated conical lower plug having a seal on the lower surface of the flange, and a solid rod guide fixed to the flange of the lower plug and having a rod passed through the center thereof and a rod guide at the center of the upper surface for guiding the rod. an upper plug, two glass windows provided in the bottom plate of the lower plug, a TV camera installed in the lower plug and facing one of the windows, and a TV camera also installed in the lower plug, and the like. and an underwater lighting lamp opposed to the other side of the window.

(Function) In the upper blind lid for an internal pump handling device of the present invention having the above configuration, the motor casing is lifted up and stretched by an ultra-compact TV camera that takes an image under the illumination of the underwater lighting lamp provided in the lower plug. Since the upper end of the handling device that is close to the lower end of the tube can be detected, the small diameter portion at the upper end of the handling device can be easily and correctly inserted into the lower end of the C-edge tube. Furthermore, since the handling device can be operated after insertion while being monitored by the TV camera, the handling device can be operated correctly. Furthermore, it is naturally possible to easily check whether or not it has been inserted correctly and whether it is operating correctly.

(Embodiment) FIG. 1 is a longitudinal sectional view of an embodiment of the present invention. In this figure, the upper blind lid 30 for an internal pump handling device of the present invention has a hollow truncated conical shape whose maximum diameter is approximately equal to the inner diameter of the stretch tube 9a and whose diameter decreases downward, and whose maximum diameter is larger than the inner diameter of the stretch tube 9a. a lower plug 31 with a flange of diameter;
It has a solid upper plug 32 having a right cylindrical portion having the same diameter as the flange and a truncated conical portion that is connected to the right cylindrical portion and whose diameter decreases upward. The upper end of the rod 33 passing through the center opening of the upper plug 32 is a spherical end 33a, and the lower end is a tapered end 33b corresponding to the tapered seat 34a provided in the opening on the inner surface of the bottom plate of the through hole 34 in the center of the bottom plate of the lower plug 31.
It is said that Further, a collar 33c serving as a stopper is provided at a portion of the rod 33 located inside the lower plug 31.

Furthermore, two glass windows 35a and 35b are provided on the bottom plate of the lower plug 31 on the same diameter and sandwiching the center of the bottom plate. A waterproof cover 37 containing a camera 36 is attached in a watertight manner.

Above the other glass window 35b is an underwater lighting lamp 38.
A protective tube 39 surrounding the lower plug 31 is suspended and supported by a support fitting 40 provided on the inner surface of the lower plug 31. In addition, 4 in the figure
1 is a TV camera cable pulled out from the top plate of the upper plug, 42 is a cable for an underwater lighting lamp pulled out in the same way, 43 is a rod guide provided on the upper surface of the upper plug 32, and 44 is a seal provided on the lower surface of the flange of the lower plug. are shown respectively.

The manner of use of the upper blind lid for an internal pump handling device of the present invention having the above structure is completely the same as that of the conventional one explained with reference to FIG. Ultra-compact T that captures images under illumination
As shown in FIG. 2, the V-camera allows observation of the upper end of the handling device 27 that is elevated inside the motor casing 11 and is close to the lower end of the stretch tube 9a. It can be easily and correctly inserted into the lower end of the stretch tube 9a. Furthermore, the operation of the handling device after insertion is also controlled by the TV camera 3.
6, the handling device 27 can be operated correctly. Also, whether or not it was inserted correctly.

Of course, it is also easy to check whether or not it is operating correctly.

[Effects of the Invention] As is clear from the above, according to the upper blind cover for an internal pump handling device of the present invention, it is possible to accurately insert and install the stretch tube nut handling device into the lower end of the stretch tube, which has been considered difficult in the past.

Accurate operation of the handling device and confirmation thereof can be easily made, which not only improves workability and reliability when handling stretch tubes, but also saves labor and shortens working time. .

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 2 is a schematic diagram showing the state in use, Fig. 3 is a longitudinal sectional view showing an outline of the internal pump, and Fig. 4 is a conventional internal pump. FIG. 5 is a longitudinal cross-sectional view of the upper blind lid for an internal pump handling device, and is a schematic diagram showing the state of use of the conventional upper blind lid for an internal pump handling device.

Claims (1)

[Claims] A lower plug in the shape of a hollow truncated cone whose diameter decreases downward and engages with the lower end of the stretch tube and has a flange at its maximum diameter and a seal on the lower surface of the flange, and a rod fixed to the lower plug at the flange and at the center thereof. a solid upper plug having a rod guide passing through the rod and guiding the rod at the center of the upper surface; two glass windows provided in the bottom plate of the lower plug; and two glass windows installed in the lower plug. An upper blind lid for an internal pump handling device, characterized in that it has a TV camera facing one of the windows, and an underwater illumination lamp also provided in the lower plug and facing the other of the windows.