JP2859462B2 - Reactor internal pump connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

 [Object of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal pump of a nuclear reactor for circulating a cooling fluid in a nuclear reactor pressure vessel, and more particularly to a connection portion of a cable thereof.

[0002]

2. Description of the Related Art FIG. 3 is a partially cutaway perspective view of a nuclear reactor in which a plurality of internal pumps are provided at the bottom of a reactor pressure vessel, and FIG. Is vertically and airtightly penetrated around the bottom outer wall of the reactor pressure vessel 1 with its upper end protruding inside the reactor pressure vessel 1 as described in detail later, as shown by an arrow 43 in FIG. Reactor water inside the reactor pressure vessel 1 is sucked in from above and discharged downward as indicated by an arrow 44, so that the reactor core housed in the center of the reactor pressure vessel 1 is drawn.
Cool 45 to a predetermined temperature. This internal pump 2
Usually, eight or ten are arranged at equal intervals on the outer wall of the reactor pressure vessel 1.

Next, FIG. 5 is an enlarged longitudinal sectional detail view of the internal pump 2 shown in FIGS. In the figure, a vertically long internal pump 2 is a reactor pressure vessel 1.
Main impeller 6, which will be described later, protrudes into the bottom side
And projecting downward from the bottom side surface of the reactor pressure vessel 1 in a cylindrical shape and inserted from below into a motor housing cylinder 36 integrally formed with the reactor pressure vessel 1, and the main impeller section 6 described above. And a reverse rotation preventing device 21 inserted inside the lower end of the motor housing cylinder 36.

The main impeller 6 includes a main impeller 10 having a lower half fitted and fixed to an upper end of a pump shaft 9 fitted into the inside of a submersible motor 7, and an outer periphery of the main impeller 10. It is provided coaxially with the main impeller 10, and has guide vanes 11 whose outer periphery and lower end are fixed to the reactor pressure vessel 1.

On the other hand, the underwater motor unit 7 has a tubular motor shaft 13 inserted through a key (not shown) in the lower half of the pump shaft 9 penetrating the shaft, and an outer periphery of the motor shaft 13. A rotor 14 fitted into the motor casing 15, a motor casing 15 fitted into the inner periphery of the motor housing cylinder 36, and a motor casing 15
And a stator 16 fitted around the inner periphery of the motor.

The outer periphery of the upper end of the motor shaft 13 is an upper radial bearing 18 fitted and fixed to the inner periphery of the upper end of the motor casing 15. Similarly, the outer periphery of the lower end of the motor shaft 13 is fitted to the inner periphery of the lower end of the motor casing 15. Each of the inserted lower radial bearings 19 is supported in the radial direction.

On the other hand, the lower end of the motor shaft 13 has an impeller 17
An upper thrust bearing 20 is provided on the lower surface of the motor casing 15 facing the upper surface of the impeller 17. A lower thrust bearing 21 is provided between the upper surface of the cylindrical cover 36a fitted and fixed to the lower end of the motor housing cylindrical portion 36 via a seal (not shown) and the lower surface of the impeller 17,
The pressure caused by the discharge of the reactor water in the direction of arrow 44 in FIG. 4 by the main impeller 10 is due to the upper thrust bearing 20, and the load of the pump shaft 9, the rotor 14, the main impeller 10, the impeller 17 and the like at rest is Each is supported by a lower thrust bearing 21.
Further, the lower cover 23 is inserted and fixed to the center of the cylindrical lid 36a from below through a seal (not shown).
a, an impeller inlet 31 is formed at the center between the lower cover 23 and the impeller 17.

On the other hand, a motor upper chamber 27 is formed above the upper end of the motor casing 15, and a through hole communicating with the motor upper chamber 27 is provided at the upper end of the motor housing cylinder 36.
A small-diameter joint (not shown) is screwed into the female screw outside the through hole, and a pipe 12 for injecting high-pressure purge water into the joint is connected to the joint.

A slightly large-diameter joint 28a is screwed below the small-diameter joint. One end of a pipe 28 is connected to the joint 28a, and the other side of the pipe 28 is connected to one side of a heat exchanger 29. One side of a pipe 30 is connected to the other side of the heat exchanger 29, and the other side of the pipe 30 is screwed into a motor housing cylinder portion 36 on the side surface of the impeller suction port 31 to have a slightly larger diameter. It is connected to the joint 30a.

In the internal pump 2 configured as described above, the interior of the underwater motor 7 is completely shut off from the interior of the reactor pressure vessel 1 by the purge water injected into the interior from the pipe 12 at high pressure. Then, it is cooled to about 40 ° C. or less by cooling water refluxed from the heat exchanger 29.

On the other hand, a terminal box 33 is fixed to the side surface of the lower end of the motor housing cylinder portion 36 with bolts, and an epoxy resin insulator 33a is provided on the upper wall inside the terminal box 33 at right angles to the plane of FIG. Three inverted L-shaped conductors 34 are fixed to the lower ends of these insulators 33a, respectively. The right end of the cable 32A is connected to the lower side surface of the conductor 34, and the left end of the cable 32A is connected to the terminal of the underwater motor unit 7 provided on the cylindrical cover 36a.

A cable 32B is connected to the other side of the conductor 34, and a glass tape is wrapped around the connection between the cable 32A and the conductor 24, and an epoxy resin 35 is applied and cured. The other side (not shown) of the connection cable 32B is a three-core cable having a coating outer diameter of 125 mm and is fixed by a fixing part (not shown).

Incidentally, the reactor pressure vessel 1 is thermally expanded during operation of the reactor and increases in radius by about 20 to 30 mm as shown by an arrow 40 in FIG. On the other hand, when the motor shaft 13 is pulled out during the periodic inspection of the
To remove 36a, the epoxy resin 35 covering the connection between the cable 32A and the conductor 34 is removed, and after assembling, the glass tape is wound again and the epoxy resin 35 is applied as described above.

[0014]

However, at the connection portion of the internal pump of the reactor constructed as described above, the position of the submersible motor unit 7 due to the thermal expansion of the reactor pressure vessel 1 described above is changed. 32B is pulled and receives a compressive force when the reactor is stopped. Then, the reaction force is applied to the insulator 33a as a moment, and acts on the joint between the motor housing cylinder portion 36 and the reactor pressure vessel 1 similarly.
The insulator 33a may be broken.

On the other hand, the work of connecting the cable 32A to the conductor 24 takes a long time in taping a glass tape or applying and hardening an epoxy resin, and the work time in the radiation control area becomes longer. Therefore, an object of the present invention is to provide a connection part of an internal pump of a nuclear reactor, in which maintenance of the internal pump is easy and stress of each part due to thermal expansion and contraction of the nuclear reactor pressure vessel can be reduced. [Configuration of the Invention]

[0016]

SUMMARY OF THE INVENTION The present invention relates to a connection part of an internal pump of a nuclear reactor in which a cable is connected to a drive motor of the internal pump of the nuclear reactor.
By providing a terminal box on the side wall of the storage cylinder of the drive motor and providing an L-shaped connecting tool whose contact part comes into contact with and separates from the terminal box by inserting and removing it vertically, maintenance of the internal pump is easy,
This is the connection part of the internal pump of the reactor pressure vessel, which reduces the stress of each part due to the thermal expansion and contraction of the reactor pressure vessel.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a connection portion of an internal pump of a nuclear reactor according to an embodiment of the present invention. FIG.
2 is a side view showing a connection part of an internal pump of the nuclear reactor of the present invention, and FIG. 2 is a plan view of FIG.

In FIG. 1 and FIG.
A substantially trapezoidal box-shaped mounting base 3a in FIG. 2 is fixed to the side surface of the cylindrical lid 36a with bolts.
A rectangular and box-shaped terminal box 3 is fixed. A female side 4 of a substantially L-shaped plug-in terminal 4 is provided at an upper end of the terminal box 3.
b is attached, and the lower end (not shown) of the female side 4b is connected to the upper end of a cable 3a.
The core wire at the lower end is crimped to a female crimping portion (not shown) projecting into a terminal hole (not shown) provided on the side surface of the cylindrical lid 36a.

On the other hand, a multi-contact (not shown) is inserted into the female side 4b, and a round bar-shaped contact portion (not shown) below the male side 4a of the plug-in terminal 4 is inserted into the multi-contact from above. The upper part of the male side 4a is oblique in the plan view of FIG. Further, the cable 5 connected to the male side 4a is also bent rightward (in the direction of the reactor pressure vessel 1) as shown by an arrow R in FIG. It is fixed at the support.

At the connection part of the internal pump of the reactor constructed as described above, when the cylinder cover 36a is removed for the periodic inspection of the submersible motor part 7, the plug-in terminal 4
By pulling out the male side 4a upward, the cylindrical lid 36a can be removed together with the terminal box 3 downward. In addition, since the contact portion is fitted and separated from the plug-in terminal 4 when the plug-in terminal 4 is inserted and removed in the vertical direction, the thickness T of the terminal box 3 can be reduced. Interference can be reduced.

On the other hand, at the time of assembly, the female side 4a of the male side 4a
Since the cable 5 can be connected by inserting the cable 5 in the up and down direction, the recovery time can be shortened and the working time in the radiation control area can be reduced. Also, the reaction force of the cable 5 and the like due to the movement of the position of the underwater motor unit 7 due to the thermal expansion and contraction of the reactor pressure vessel 1 is caused by the rotational direction of the contact part between the contact part on the male side 4a and the multi-contact on the female side 4b. Since the sliding operation and the slight bending of the cable 5 are alleviated, it is possible to prevent the reaction force generating portion such as the support portion of the three-core cable from being damaged.

[0022]

As described above, according to the present invention, the terminal box is provided on the side wall of the storage cylinder of the drive motor at the connection part of the internal pump of the nuclear reactor where the cable is connected to the drive part of the internal pump of the nuclear reactor. By installing an L-shaped connector in this terminal box, the contact part of which comes into and away from the terminal box when it is inserted and removed in the vertical direction, the removal and installation of cables during maintenance and inspection of the internal pump is facilitated, and the reactor pressure is reduced. Reduced reaction force of the support part generated by the movement of the position of the underwater motor part due to thermal expansion and contraction of the vessel, so that the connection part of the internal pump of the reactor that is easy to maintain and can prevent damage to the cable support part etc. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a side view showing one embodiment of a connection portion of an internal pump of a nuclear reactor of the present invention.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a perspective view of a reactor pressure vessel and an internal pump to which a connection part of a conventional reactor internal pump is applied.

FIG. 4 is an explanatory view showing the operation of a conventional internal pump.

FIG. 5 is a longitudinal sectional view showing a connection part of an internal pump of a conventional nuclear reactor.

FIG. 6 is a side view showing the operation of a conventional internal pump of a nuclear reactor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Internal pump, 3 ... Terminal box, 4 ... Plug-in terminal, 5 ... Cable, 6 ... Main impeller part, 7 ... Underwater motor part, 36 ... Motor storage cylinder part.

Claims (1)

(57) [Claims] 1. A terminal box is provided on a side wall of a storage cylinder of a drive motor at a connection portion of a reactor internal pump in which a cable is connected to a drive motor of the internal pump of the reactor. A connection part for an internal pump of a nuclear reactor, wherein an L-shaped connection tool is provided in which a contact part comes into contact with and separates from the insertion part in a direction.