JPH0792291A - Device and method for detecting leak of internal pump - Google Patents

Abstract

PURPOSE:To detect a leak in an internal pump by a method wherein a television camera is installed inside a casing and a reactor-water leak can be detected by a remote control operation. CONSTITUTION:The leak detector 18 for an internal pump is composed of a large flange 19 whose mounting size to a casing 3 is the same as a motor flange which blocks up the lower-end part of the casing 3, of a rotation and movement means which is composed of an operating motor 24, a gear 22 and the like which are installed on the large flange 19, of a television camera 26 and an illumination means 27 which are installed on the gear 22 and whose field-of-view direction is variable, of a control device which controls the field-of-view direction of the television camera 26 and the illumination means 27 as well as the rotation and movement means and of a monitor which displays an image photographed by the television camera 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the assembly of an internal pump for recirculating reactor water in a boiling water reactor, and more particularly to an internal pump leak confirmation device for observing leaks in a shaft water seal and its confirmation method.

[0002]

2. Description of the Related Art In a boiling water reactor, an internal pump that penetrates through a reactor pressure vessel and circulates reactor water directly is used as shown in the longitudinal sectional view of FIG. The casing 1 of the internal pump 2 is fixed by penetrating through the through hole of the vessel 1, and the casing 3
Insert the shaft 4 in the center of the.

An impeller 7 is fixed at the upper end of the shaft 4 inside a diffuser 6 attached to a shroud 5 in a reactor pressure vessel vessel 1, and at the lower part of the shaft 4 a reactor is provided. Inside the casing 3 outside the pressure vessel vessel 1, the shaft 4
A water immersion motor 8 including a rotor 8a fitted to the above and keyed together and a stator 8b fixed to the casing 3 is built in, and a lower end of the casing 3 is watertightly closed by a motor flange 9.

The portion of the casing 3 that penetrates the reactor pressure vessel vessel 1 has a small diameter and the outside has a large diameter. A stretch tube 10 is fitted between the casing 3 and the shaft 4 at the penetrating portion, and the lower portion thereof is fastened to the casing 3 by a fastening nut 11. Further, the lock sleeve 12 is fixed to the casing 3 to prevent the tightening nut 11 from rotating.

Further, the shaft 4 is provided in front of the tightening nut 11.
A pressure seal 13, which is a shaft watertight portion, is provided so as to be bent around the circumference of, and its inner side faces the shaft 4 with a small gap, and its outer side is in close contact with the casing 3. This pressure seal 13
The water pressure from the pressure water pipe 14 that penetrates through the casing 3 is directly applied to the inner elastic body at the lower part of the water pressure, and when the internal pump 2 is stopped, the water pressure from the pressure water pipe 14 is stopped. To closely seal the shaft 4 with water.

Further, the water pressure applied from the leak pipe 15 overflows the inside and outside of the stretch tube 10 and becomes overflow water into the reactor pressure vessel Vessel 1, and the reactor water is supplied to the internal pump 2 during operation. Prevent infiltration. In addition, cooling water is introduced into the water immersion motor 8 portion in the casing 3 from a cooling water inlet 16 at a lower portion of the casing 3,
Although the inside is cooled and sent out from the cooling water outlet 17, this cooling water is cooled in a cooler (not shown) and circulates.

When disassembling and repairing the internal pump 2, first, the impeller 7 and the shaft 4 are removed from inside the reactor.
After extracting the diffuser 6 and the stretch tube 10, a water sealing plug (not shown) is attached to the tip of the casing 3 to prevent the reactor water from flowing into the casing 3. Next, after draining the cooling water in the casing 3,
The motor flange 9 is removed, the water immersion motor 8 and the pressure seal 13 inside are disassembled and taken out, and the impeller 7 and the stretch tube 10 are inspected and repaired.

When the inspection and repair are completed and the internal pump 2 is to be assembled, the above-mentioned parts, which have been disassembled and inspected in advance, are assembled in the following order. First, the motor flange 9 is attached to the casing 3 to fill the inside with fresh water. Next, remove the water seal plug that was previously installed from inside the reactor.

After attaching the diffuser 6 and the stretch tube 10 and fitting the water seal plug inside the diffuser boss, the fresh water is drained and the motor flange 9 is removed from the casing 3 again. Next, insert a dedicated device into the casing 3, attach the lock sleeve 12 to the casing 3,
Tighten the stretch tube 10 with the tightening nut 11.

Further, after the pressure seal 13 is attached, the motor flange 9 is attached again, and the casing 3 is filled with fresh water, and the water seal plug is pulled out.
And insert the shaft 4. Here, while applying water pressure from the pressure water pipe 14 to the pressure seal 13, clear water is drained from the casing 3 to open the motor flange 9 of the casing 3,
The rotor 8a is fixed to the shaft 4 and the stator 8b is fixed to the casing 3 to assemble the water immersion motor 8.

After the above steps are completed, the casing 3 is sealed with the motor flange 9, the casing 3 is filled with fresh water, and the assembly of the internal pump 2 is completed. The supply of water pressure from the pressure water pipe 14 is stopped, the pressurization of the pressure seal 13 is released, and normal operation is always made after the test operation.

[0012]

[Problems to be Solved by the Invention] Internal Pump 2
In the assembling process, the assembling work of the water immersion motor 8 is performed with the motor flange 9 at the lower end of the casing 3 opened, so that if the pressure seal 13 is assembled, the reactor water leak from the reactor. In this case, the leaked reactor water drips above the worker's head, and the working environment is bad and the worker is contaminated, resulting in an increase in radiation dose.

Therefore, in order to improve the working environment of the worker and reduce the radiation dose, it is necessary to prevent the reactor water leak from the pressure seal 13 which is the shaft water sealing portion in the state where the pressure seal 13 is installed. It is necessary to start the assembling work of the water immersion motor 8 after confirming that there is no such thing, and there has been a demand for development of a confirmation measure for this reactor water leak.

An object of the present invention is to provide a leak checking device for an internal pump and a checking method therefor, in which a television camera is mounted in a casing and a reactor water leak can be checked by remote control during assembly work of the internal pump. To provide.

[0015]

In order to achieve the above object, a leak confirmation device for an internal pump according to a first aspect of the present invention has a large size in which the motor flange for closing the lower end portion of the casing of the internal pump and the mounting dimensions for the casing are the same. A flange, a rotating means provided on the large flange and including an operation motor, a gear, and the like, a television camera and an illumination means which are installed on the rotating means and have a variable view direction, and a view direction of the television camera and the illumination means. And a control device for controlling the illuminance and the rotating means, and a monitor for displaying an image picked up by a television camera.

According to a second aspect of the present invention, there is provided a leak checking device for an internal pump in a casing after the shaft is inserted into a shaft water sealing portion assembled in the casing when the internal pump is assembled. After mounting, the rotation of the rotating means and the view direction of the television camera are controlled by a control device from outside the casing to control the water seal between the pressure seal and the shaft, and the water seal between the pressure seal and the casing. Is observed on a monitor.

[0017]

In the leak confirming device for the internal pump according to the first aspect of the present invention, the large flange that is the base can be replaced with the motor flange that closes the casing of the internal pump, so that it can be easily attached to the casing. To be The illumination means illuminates the shaft water seal part, the television camera photographs the shaft water seal part, and the image is displayed on the monitor. Also,
When the rotation device is rotated by the control device, the entire circumference of the axial water seal portion is photographed. Further, the control device records the captured image.

According to a second aspect of the present invention, the shaft water seal portion is assembled in the casing of the internal pump, the shaft is inserted, the water in the casing is removed, and then the motor flange is removed to remove the internal pump. Install the leak confirmation device. By operating the control device to activate the lighting means and the TV camera, the state of the shaft water seal part can be observed on the monitor. Furthermore, if the rotating device is rotated by operating the control device, the entire circumference of the shaft water seal part can be observed. About leak water can be confirmed. Also, this image is stored in the image recording device in the control device to be used as a reference material for later examination.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. It should be noted that the same components as those of the above-described conventional technique are designated by the same reference numerals, and detailed description thereof will be omitted. The vertical sectional view of FIG. 1 shows a state in which the leak confirmation device 18 of the internal pump is attached to the internal pump 2.

Internal pump leak confirmation device 18
Is a casing 3 fixed to the reactor pressure vessel vessel 1.
At the lower end of the, the mounting dimensions are the same as the motor flange 9,
A large flange 19 that can be replaced with the motor flange 9 and attached to the casing 3 is provided as a base. The bolts and the like used for the casing 3 are the same as those used for the motor flange 9.

At the center of the large flange 19, a gear shaft 21 directly connected to a small flange 20 which is a rotating means is rotatably geared.
22 is incorporated, and the operation motor 24 is fixed to the frame 23 provided on the large flange 19 at the outer periphery of the gear 22. A pinion that meshes with the gear 22 is provided on the rotary shaft of the operation motor 24.
25 is attached. Further, a plurality of studs 19a are provided on the lower surface of the large flange 19 to facilitate the temporary placement of the leak confirmation device 18 of the internal pump on the floor or the like, and the inspection of each component.

Further, the gear 22 is provided with a TV camera 26 and an illumination means 27, which can change the visual field and the illumination direction by changing the direction of a built-in prism, for example, by a control motor (not shown) at the tip, and a turnbuckle 28 in the middle. The rod 29 provided is set up so that the turnbuckle 28 can adjust the visual field direction and the axial length of the television camera 26 and the illumination means 27 at the tip.

The cable 30 connected to the television camera 26 and the illumination means 27 is an optical cable and an electric cable, which are rotated around the gear shaft 21 in the frame 23,
The cable 30 is not entangled with the rotation of the TV camera 26, and the rotation of the TV camera 26 is prevented from being disturbed, and the cable 30 is pulled out to the outside via the seal plug 31.

FIG. 2 is a schematic view of a television camera or the like, in which the television camera 26 and the illumination means 27 are connected by a cable 30, and the operation motor 24 is connected by a cable 32 to a control device 33 outside the casing 3 and this control device is connected. The monitor 33 is connected to a monitor 34 for displaying the image of the television camera 26, an operation board 35, and a power source. The control device 33 controls the visual field direction of the television camera 26 and the illumination means 27 and the operation motor 24, adjusts the sharpness of the image, adjusts the illuminance of the illumination means, and has a built-in video recording device as necessary. The image on the monitor 34 can be recorded.

Next, the operation of the above configuration will be described. When disassembly of the internal pump 2 and inspection of each part are completed and assembly is started, the lock sleeve 12 is attached to the casing 3 by a dedicated device, the stretch tube 10 is tightened with the tightening nut 11, and the pressure seal 13 is attached. After mounting, the casing 3 is sealed and filled with fresh water, a water seal plug (not shown) is removed, and the shaft 4 with the impeller 7 is inserted.

After that, the water seal plug is fitted again, and the pressure seal 13 is pressed by the water pressure from the pressure water pipe 14 so that the pressure seal 13 is brought into close contact with the shaft 4 to prevent the leakage of the reactor water, and then the fresh water in the casing 3 is prevented. After removing, the motor flange 9 is removed from the casing 3, and instead, a leak confirmation device 18 of the internal pump is inserted from the lower part of the casing 3 and attached by the large flange 19.

At this time, the positions of the television camera 26 and the illuminating means 27 with respect to the pressure seal 13, which is the axial water seal portion, are set in advance by the rod.
The turnbuckle 28 provided in 29 adjusts the position to an optimum position, and then the control unit 33 activates the illumination means 27 and the television camera 26. Then, the state around the pressure seal 13 located inside and inside the narrow casing 3 is controlled. Is clearly displayed on the monitor 34.

In order to confirm the leak state of the pressure seal 13, the operator operates the operation board 35 of the control unit 33 to first attach the television camera 26 and the illumination means 27 to the shaft 4 side of the pressure seal 13. And further operate the operation motor 24. As a result, the gear 22 rotates and the TV camera 26 and the illumination means 27
Continuously displays images of the entire circumference of the pressure seal 13 on the shaft 4 side on the monitor 34, so that the operator can observe the state of the pressure seal 13 and the shaft 4 in detail. It is possible to easily check how much leak water is generated.

Next, the operator operates the operation board 35 to operate the television camera 26 and the illumination means 27 by a control motor (not shown).
Of the pressure seal 13 toward the casing 3 side,
The state of the pressure seal 13 and the casing 3 is observed. Also in this case, the operating motor 24 is operated in the same manner as the shaft 4 side of the pressure seal 13 to operate the casing 3 of the pressure seal 13.
Observe the entire circumference of the side.

As a result, the sealing effect of the pressure seal 13 of the shaft water seal can be confirmed in detail, so that if the leak water is not observed, the pressure seal 13 is installed properly, and even if there is a leak, If there is water, record the extent and position of it in the control device 32, re-disassemble the casing 3 and perform repair and then re-assembly, and then attach the leak check device 18 of the internal pump again and repair. Check the results.

If no reactor water leak phenomenon is found, the pressure seal 13 is installed well, so the large flange 19
Is removed from the lower end of the casing 3, and the leak confirmation device 18 of the internal pump is taken out.

Next, an operator mounts the rotor 8a on the shaft 4 in the casing 3 and the stator 8b on the casing 3, and it has been confirmed that there is no leak water as described above. As a result, there is no problem that the worker is contaminated by dripping leaked water, and safe work can be performed. When the assembling of the water immersion motor 8 is completed, the casing 3 is sealed with the motor flange 9, the casing 3 is filled with fresh water, and the assembly of the internal pump 2 is completed.

Internal Pump Leak Confirmation Device 18
Since the internal pump 2 can be attached to the casing 3 with a large flange 19 having the same size as the motor flange 9, the internal pump 2 can be easily handled. Further, since the operation can be performed while being monitored by the monitor 34 from a remote place, the operation is easy and the operator is not exposed to the radiation.

If the leak confirmation device 18 of the internal pump has an appropriate water resistant structure, cleaning can be easily performed when the leaked reactor water is dropped. If a night-vision camera is adopted as the TV camera 26, the illumination means 27
It is possible to fully observe with the natural light of the surroundings.

[0035]

As described above, according to the present invention, it is possible to preliminarily confirm that there is no reactor water leak from the nuclear reactor in the casing for the work in the casing such as installation of the water immersion motor in the inspection and repair of the internal pump. Because you can check
This has the effect of reducing worker radiation exposure and improving work safety and efficiency.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a leak confirmation device for an internal pump according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a television camera or the like according to an embodiment of the present invention.

FIG. 3 is a vertical sectional view of an internal pump.

[Explanation of symbols]

1 ... Reactor pressure vessel vessel, 2 ... Internal pump, 3 ... Casing, 4 ... Shaft, 5 ... Shroud,
6 ... Diffuser, 7 ... Impeller, 8 ... Water immersion motor, 8
a ... rotor, 8b ... stator, 9 ... motor flange, 10
… Stretch tube, 11… Tightening nut, 12… Lock sleeve, 13… Pressure seal, 14… Pressure water pipe, 15… Leak water pipe, 16… Cooling water pipe inlet, 17… Cooling water pipe outlet, 18… Internal pump leak Confirmation device, 19 ... Large flange, 19a
… Studs, 20… small flanges, 21… gear shafts, 22… gears,
23 ... Frame, 24 ... Operation motor, 25 ... Pinion, 26 ... TV camera, 27 ... Lighting means, 28 ... Turnbuckle, 29 ...
Rod, 30, 32 ... Cable, 31 ... Seal stopper, 33 ... Control device, 34 ... Monitor, 35 ... Operation board.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Watanabe 4-7-7 Shiba, Minato-ku, Tokyo Aitel Technical Service Co., Ltd.

Claims (2)

[Claims] 1. A motor flange for closing a lower end portion of a casing of an internal pump, a large flange having the same mounting dimensions with respect to the casing, a rotating means formed on the large flange and comprising an operating motor and a gear, and the like. It comprises a television camera and lighting means installed on the moving means, the viewing direction being variable, a control device for controlling the viewing direction and illuminance of the television camera and lighting means, and the rotating means, and a monitor for displaying a video image taken by the television camera. A leak confirmation device for an internal pump, which is characterized in that 2. When assembling the internal pump, after inserting the shaft into the shaft water seal part assembled in the casing, a leak confirmation device for the internal pump is mounted in the casing, and the device is rotated by a control device from outside the casing. By controlling the rotation of the moving means and the viewing direction of the television camera, the water seal between the pressure seal and the shaft, which is the shaft water seal, and the water seal between the pressure seal and the casing are observed on a monitor. How to check the leak of the null pump.