JPS62229096A - Diffuser wear ring treater for internal pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to the installation of a diffuser wear ring of an internal pump in a new type of boiling water nuclear reactor (hereinafter referred to as A-BWR). This invention relates to a diffuser wear ring handling device for an internal pump.

(Conventional technique) In general, in a boiling water reactor (已～'R), cold material (e.g. water, hereinafter referred to as cooling water) in the reactor pressure vessel is forcibly sent into the reactor core. A coolant recirculation system is provided to Figure 3 is a diagram showing the configuration of a conventional BWR. Figure 3 shows the configuration of a conventional BWR, and the number 1 in the figure is a pressure vessel for a secondary reactor. A reactor core 2 is housed in a shroud 3.A reactor core 2 is formed by being housed in a shroud 3. Above the reactor core 2, there is provided a water supply system 5 connected to a water supply pipe 4, and roughly above the reactor core 2, a steam separator 6 and A steam dryer 7 is provided.

On the other hand, a plurality of jet pumps 8 are installed within a downcomer portion formed by the shroud 3 and the inner wall of the reactor pressure vessel 1. These jet pumps 8 jet the cooling water supplied from the recirculation pump 10 via the coolant recirculation system piping 9 to the lower part of the reactor core 2 as a jet stream. In addition, the reference numeral 11 in the figure is the main steam piping for extracting the steam generated within the reactor pressure vessel 1, and the reference numeral @12 is the I
ll and insert the p rod 13 into the reactor core 2 to increase the reactor output to 1
This is a special offer for the purpose of making the capital the capital.

In the BWR having such a configuration, the cooling water supplied from the water supply pipe 4 into the reactor pressure vessel 1 is passed through the water supply sparger 5.
It flows out from the downcomer section and flows into the recirculation pump 10.
is sucked into the jet pump 8 via the recirculation system piping 9.
is supplied to The jet pump 8 roughly jets the liquid below the core 2 and forcibly feeds it into the core 2. When the cooling water forcibly fed into the reactor core 2 rises through the reactor core 2, its temperature rises due to the heat response of the core skin, resulting in a two-phase flow state of water and steam. The cooling water in a two-phase flow state is introduced into the steam-water separator 6 and separated into steam and water.

The separated steam is introduced into the steam dryer B7 and dried to become dry steam. This dry steam is transferred to a turbine (not shown) via a main steam pipe 11 connected to the reactor pressure vessel 1, where it is used for power generation. The steam that has done work in the turbine is introduced into a condenser (not shown), becomes condensate, and is supplied as low-temperature cooling water into the reactor pressure vessel 1 via the water supply pipe 4. The water separated in the steam/moisture 1 m vessel 6 flows down through the downcomer part together with the water supplied from the water supply sparger 5, and is sucked by the recirculation pump 1o. The same cycle is repeated thereafter.

By the way, in such conventional B to VR, the recirculation pump 10 for supplying cooling water as a driving stream to the jet pump 8 is installed outside the reactor pressure vessel 1, which may cause some kind of accident. If the recirculation system piping 9 is ruptured due to such reasons, the cooling water will flow out of the reactor pressure vessel 1. Such outflow of cooling water may cause the cooling water to drop down to a diameter of 8 mm, and may also damage the fuel rods constituting the fuel assembly. Therefore, in conventional BWR,
There is a separate emergency core cooling system for emergency cooling of core 2!
2 It is hazy. However, when such an emergency core cooling system is installed, there are problems in that the amount of equipment, piping, etc. increases, the configuration becomes complicated, and the plant becomes larger.

Therefore, the above-mentioned A-BWR is the last thing to consider.

This A-B~■R is the so-called internal pump type B
~■R, and has a configuration in which an internal pump is installed inside the reactor pressure vessel 1.

The AB to VRtTl side gourd will be explained below with reference to FIGS. 4 and 5. Figure 4 shows A-B W R
FIG. 5 is a sectional view showing the structure of the internal pump. Note that the same parts as in FIG. 3 are indicated by the same reference numerals, and the explanation thereof will be omitted. The reference numeral 20 in the figure is an internal pump. This internal pump 20 is placed at equal intervals in the circumferential direction at the lower part between the reactor pressure volume S1 and the shroud 3. ! Two units are installed. As shown in FIG. 5, this internal pump 20 is composed of a pump section 21 and a motor section 22. The pump section 21 includes an impeller 23, a diffuser 24 . and a diffuser wear ring 25. The impeller 23 is connected to the motor section 22 via a drive shaft 26. The diuser 24 is fixed by a trench tube 27 to the upper part of the nozzle 1a which is protruded from the bottom of the reactor pressure vessel 1. This stretch tube 27 is fixed by a stretch tube 7 socket 28. A secondary seal 29 is installed at the bottom of the stretch tube nut 28.

The motor section 22 is composed of a rotor 30, a stator 31, etc., and these components of the motor section 22 are the nozzle 1.
The pump casing 32 is housed in a pump casing 32 which is welded to the reactor pressure vessel 1 by inserting its tip into the reactor pressure vessel 1 and into the reactor pressure vessel 1 by welding. This pump casing 3
Cooling water is circulated inside 2 via circulation piping 33,
This is to prevent the motor section 22 from burning out.

A-BWR with such an internal pump 2o
is outside the reactor pressure vessel 1 like the BWR mentioned above.
Since the structure does not include a ring pump, a structure corresponding to conventional recirculation system piping is not required. Therefore, the installation space within the reactor containment vessel, which is the secondary containment vessel, can be significantly reduced, and the assumed fracture cross-sectional area in the liquid phase portion can be significantly reduced. Furthermore, as for the internal pump 20, the motor section 22 is housed in the pump casing 32 with excellent watertightness, and there is no need for a shaft-type shaft sealing device, so the configuration is simple and there is a possibility that reactor water may leak. It also has low reliability and is excellent in maintainability.

However, even in the case of such an internal pump 20, it is necessary to perform regular inspections. The inspection work for this internal pump will be explained below. The internal pump 20 is removed from above and below the reactor pressure vessel 1. In this case, the impeller 23 is first attached to the drive shaft 2 from above the reactor pressure vessel 1.
6 and closes the opening of the diffuser 24 to prevent the inflow of reactor water. Next, after draining the reactor water in the pump casing 32, the motor section 22 is removed from below the reactor pressure vessel 1, and the secondary seal 29 and stretch tube nut 28 are removed from below the reactor pressure vessel 1. Next, the lower surface of the pump casing 32 is sealed to prevent reactor water from flowing out, and then the diffuser 24, diffuser wear ring 25, and stretch tube 27 are removed from above the reactor pressure vessel 1.

However, such work for removing or installing the internal pump needs to be carried out in a narrow space and remotely, and is expected to be difficult to perform in one operation. In particular, the diffuser wear ring 25 incorporated in the upper part of the diffuser 24 is a wear member and is a small part compared to other parts, so it is difficult to wear it, and as a result, the work time required for maintenance and inspection work becomes longer. This is not only a concern for workers' exposure to radiation, but is also not desirable in terms of improving the r&Itl ratio of the plant.

(Problems to be Solved by the Invention) As described above, it is difficult to attach and detach the internal pump, especially the attachment and detachment of the diffuser wear ring, which prolongs the work and reduces the exposure of workers and the damage to the plant. There is a concern that the illumination rate will decrease, and the present invention was made based on this point, and its purpose is to make it possible to easily attach and detach the diffuser wear ring, thereby simplifying the work and An object of the present invention is to provide a diffuser wear ring handling device for an internal pump that can reduce working time.

[Structure of the Invention] (Means for Solving the Problems) That is, the internal pump diffuser wear ring handling device according to the present invention has the following features: The main body, the diffuser wear ring which is attached to the main body of this handling device and which grips the diffuser wear ring of the internal pump, and the above grip which is attached to the main body of the above handling device and which dents the diffuser wear ring. The present invention is characterized in that it is equipped with a diffuser wear ring pulling mechanism that pulls up the diffuser wear ring in the open state.

(Function) In other words, when removing the diffuser wear ring of the internal pump, it is necessary to use the diffuser air ring quickening mechanism and diffuser wear ring lifting mechanism.
The main body of the reactor is suspended from above and installed in a predetermined position within the reactor pressure vessel. Next, the diffuser wear ring is grabbed by the diffuser wear ring 3 lifting mechanism, and in this state is pulled up by the diffuser wear ring pull-up am.

After that, the body of the tax collector will be removed.

(Fuura Example) An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The configuration of the A-BWR and ink-null pump is shown in Figures 4 and 5 used to explain the conventional example.
Explain using diagrams.

FIG. 1 is a partially cutaway front view showing the configuration of a diffuser wear ring handling device for an internal pump according to the present embodiment, and FIG. 2 is a plan view.

Reference numeral 101 in the figure is a handling device main body, and a stud 101a is fixed to the upper part of the handling device main body 101. When the handling device main body 101 is carried into the reactor pressure vessel 1, the stud 101a By connecting an operating ball and a wire lobe (not shown), it is carried in by hanging down from above.

Diffuser wear ring grips fill, 3jll are attached to the lower part of the handling device main body 101, and the diffuser wear ring 25 is gripped by the diffuser wear ring grips i*m+,-. Further, a positioning guide 103 is installed near the diffuser wear ring gripper mFA 2, extending over a position 4B, as shown in FIG.

The above diffuser wear ring gripping mechanism m is the above a″!
An air cylinder 104 installed in a main body 101, a piston rod 105 movably installed in the air cylinder 104, and two arms 105 and 105 connected to the piston rod 104. It is configured. Claw members 106 are fixed to the tips of these arms 105. This claw member 106 forms a groove 25a (fifth
(as shown).

The positioning guide 103 has four locking pins 25b implanted on the upper surface of the diffuser wear ring 25.
(shown in Figure 5) penetrates from below. This allows the handling device main body 101 to be accurately positioned. A lever 107 is attached to the upper part of the positioning guide 103, and the lever 107 is pushed up by the locking pin 25b passing through the positioning guide 103, thereby activating the limit switch 108. The operation of the limit switch 108 turns on the lamp 110 via the battery 109. As a result, the handling device main body 10
1 is installed at a predetermined position. Further, reference numeral 111 in the figure is an air supply port, and this air supply port 111
Operating air is supplied to the air cylinder 104 through the air cylinder 104.

Then, when the air cylinder 104 is actuated by supplying air to cause the pawl member 106 to perform a barring operation (closing operation, shown in the center of FIG. 1), the block 112 moves in the direction shown by the arrow in FIG. Activate switch 113.

Due to the operation of this limit switch 113, the lamp 114
lights up. This allows the diffuser wear ring 2
Check that 5 is held by the diffuser wear ring grip a groove mc.

Reference numeral 115 in the figure is a diffuser wear ring lifting mechanism. With this pull-up mechanism 222, the diffuser wear ring 25 is grabbed by the above-mentioned aim and then pulled up and removed. As shown in FIG. 2, this lifting mechanism 115 is connected to an air cylinder 116a installed at four locations on the outer periphery of the handling device main body 101, and Ga! 171 screw I-”i rod 1
16b, a connecting rod 117 connected to the piston rod 116bIP, and a base 118.

When operating air is supplied to the air cylinder 116a from the air supply port 111, the connecting rod 117 protrudes downward via the piston rod 116b. As a result, the diffuser wear ring 25 is pulled up through the stand 118, thereby pulling the diffuser wear ring 25 upward. Note that the lower part of the main body 101 is covered with a cover 119. This is to protect small parts, piping, cables, etc. installed at the bottom of the handling device main body 101. The reference numeral 121 in the figure is a guide roller, which is connected to the handling device main body 10.
1 into the reactor pressure vessel 1, the guide roller 121 is made to run along a rail laid within the reactor pressure vessel 1.

The action will be explained based on the above constituent components. First, the handling device main body 101 is suspended from above the reactor pressure vessel 1 using an operating pole and a wire lobe. Then, the guide roller 121 attached to the handling device body 101 is caused to run along a rail (not shown) provided in the reactor pressure vessel 1, and positioned directly above the internal pump 2o. Then, when the handling device 101 is further lowered, the O-loading bin 25b penetrates the positioning guide 103 from below,
The position of the handling device main body 101 is thereby determined.

At that time, the lever 107 is
is energized and the limit switch 108 is activated. This turns on the lamp 110. By lighting the lamp 110, it can be confirmed that the handling device main body 101 has been positioned at a predetermined position. At this time, the claw member 106 with gripping compensation <m is in an open state (the state shown in FIG. 1).
It is located on the upper side of the diffuser wear ring 25. Next, air is supplied to the air cylinder 104 of the grip 811i25 to move the piston rod 105 upward in the figure. Due to this sliding movement of the piston rod 105, the two arms 105 are pulled upward as shown by the chain heald in FIG.

At that time, the block 112 moves and the limit switch 11
3, and as a result, the lamp 114 lights up at 16°, which causes the claw member 1061. : Confirm that you have grabbed Yoritif User Wear Ring 25.

Next, start pulling it up and removing it. That is, by supplying air to the air cylinder 116a, the piston rod 11
6b to push down the connecting rod 117. As a result, the diuser wear ring 25 is held in tension via the stand 118, and as a result, the diuser wear ring 25 is gripped by the claw member 106.
is raised.

If the handling device main body 101 is taken out of the reactor pressure vessel 1 in this state, the work of removing the diffuser wear ring 25 is completed.

According to this embodiment, the following effects can be achieved.

(1) First, by using the handling device according to this embodiment, it is possible to easily and quickly get out of the diffuser wear ring 25 even if the problem is narrow. Therefore, the work becomes easier and the working time is shortened, so the worker's work time is reduced. ! It is possible to reduce exposure and improve plant operation.

(2) Also, the positioning of the handling Vi mushroom basic body 01 is also in second place! This can be done reliably by fitting the locking pin 25b into the determining guide, and this can be confirmed by lighting the lamp 110, so remote work can be done reliably.

(3) This also applies when the diffuser wear ring 25 is grabbed by the claw member 106, and the lamp 114
This can be confirmed by the lighting.

[Effects of the Invention] As detailed above, according to the internal pump diffuser wear ring handling system according to the present invention, the internal pump diffuser wear ring can be easily removed even in an extremely narrow space. , thereby making maintenance and inspection work easier. : The long time required can be significantly shortened. Therefore, it is possible to reduce the 1i exposure of workers and improve the inspection work of the plant.

[Brief explanation of drawings]

Figure 1 F3. ．． f, and Fig. 2 are views showing an embodiment of the present invention, Fig. 1 is a sectional view of the diffuser wear ring handling device, Fig. 2 is a plan view of the diffuser wear ring handling device, and Fig. 3 is a boiling water ring handling device. FIG. 4 is a cross-sectional view showing the schematic structure of a new type boiling water reactor, and FIG. 5 is a cross-sectional view showing the structure of an internal pump. 22... Internal pump, 25... Diffuser wear ring, 101... Handling device main body, 102...
... Diffuser wear ring grip structure, 115...
Diffuser wear ring raised 1 bridge. Applicant's agent Patent attorney Takehiko Suzue 2nd v? J Figure 3) Prisoner I4

Claims (2)

[Claims] (1) A handling device body that is suspended from above into the reactor pressure vessel and can be taken in and out, a diffuser wear ring gripping mechanism that is attached to the handling device body and grips the diffuser wear ring of the internal pump, and the above-mentioned handling device body A diffuser wear ring handling device for an internal pump, comprising: a diffuser wear ring pulling mechanism attached to the above-mentioned gripping mechanism for pulling up the diffuser wear ring while gripping the diffuser wear ring. (2) A positioning guide is attached to the handling device body, and the position of the handling device body is determined by fitting the locking pin protruding from the upper end of the diffuser wear ring into this positioning guide. An internal pump diffuser wear ring handling device according to claim 1.