JPH05333185A - Internal pump and its handling device - Google Patents

Abstract

PURPOSE:To prevent the danger to lose parts in a reactor during the operation of the reactor and reduce the exposure dose on a worker when an internal pump is disassembled and inspected during a periodic inspection. CONSTITUTION:A small protruded pin 4 protruded on a diffuser 2 is coupled with a wear ring hole bored on a wear ring 3 to mount the wear ring 3 on the diffuser 2, and the small protruded pin 4 is limited in size not to be protruded from the upper face of the wear ring 3. The notch section of an internal pump 1 constituted of a diffuser notch 6 and a wear ring notch 14 is coupled with a positioning guide 9 protruded on an internal pump handling device 7 to position the internal pump handling device 7 mounted on the internal pump 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal pump installed in a reactor pressure vessel of a boiling water reactor and its handling device.

[0002]

2. Description of the Related Art An example of prior art relating to an internal pump and its handling device will be described with reference to FIGS.

FIG. 6 is an explanatory view of an internal pump installed type nuclear reactor, FIG. 7 is an explanatory view of a conventional internal pump,
FIG. 8 is a cross-sectional view of an internal pump installed type reactor, FIG. 9 is an explanatory view of an internal pump handling procedure, FIG. 10 is an explanatory view of a main part of an internal pump of a conventional example, 1 is an internal pump, 2 is a diffuser, 3 is a wear ring, 5 is a C ring, 7 is an internal pump handling device,
15 is a wear hole, 17 is a reactor pressure vessel, 18 is a nozzle part, 19 is a shroud, 20 is a pump deck part,
21 is a fuel assembly, 22 is an upper lattice plate, 23 is a core support plate, 24 is a steam separator, 25 is a shroud head, 26
Is an upper shroud, 27 is a shroud head bolt, 2
8 is a steam dryer, 29 is a reactor pressure vessel upper mirror, 30 is a rail, 31 is a pump part, 32 is a motor part, 33 is an impeller, 34 is a guide pin, 35 is a stretch tube, 3
6 is a shaft, 37 is a rotor, 38 is a stator, 39 is a pump casing, 40 is a shroud head bolt fastening flange portion, 41 is a notch portion, 42 is a fuel changer, 43
Is a hanger, and 44 is a reactor well.

In FIG. 6, an internal pump 1 is built in a lower portion of the reactor pressure vessel 17. The internal pump 1 is located inside the reactor pressure vessel 17 and is a pump deck portion 2 of an outer annular portion of the shroud 19.
It is installed at 0.

An upper lattice plate 22 and a core support plate 23 for directly supporting the fuel assembly 21 are set in the shroud 19, and a shroud head 25 having a steam separator 24 fixed to the upper part of the shroud 19. Is set.

The shroud head 25 is flanged to the upper shroud 26 via a shroud head bolt 27. A steam dryer 28 is installed above the steam separator 24.

In the above structure, the reactor pressure vessel upper mirror 2 is used at the time of periodic inspection of the internal pump installed reactor.
After removing 9, the steam dryer 28 is removed, and further the shroud head 25 to which the steam separator 24 is fixed is removed. Then, the fuel assembly 21 is replaced and the internal pump 1 is inspected. Has been done.

Further, the removal of the shroud head 25 is
By rotating the shroud head bolt 27 and releasing the flange fastening with the upper shroud 26,
The shroud head bolt 27 is attached to the shroud head 25.
Together with this, it is temporarily placed outside the reactor.

FIG. 7 shows the configuration of the internal pump 1. The internal pump 1 is composed of a pump unit 31 and a motor unit 32.

The pump portion 31 is composed of an impeller 33, a diffuser 2, a stretch tube 35, a wear ring 3, a shaft 36, etc., and the impeller 33 is connected to a motor portion 32 via a shaft 36.

The wear ring 3 is mounted on the diffuser 2, and the diffuser 2 is supported by a pump deck portion 20 and a nozzle portion 18 provided at a lower portion of the reactor pressure vessel 17, and fixed by a stretch tube 35. There is.

The stretch tube 35 is installed in the upper nozzle portion 18 in the pump casing 39, and is fixed by a stretch tube nut (not shown in the drawing). A secondary seal (not shown in the figure) is provided below the stretch tube nut.

On the other hand, the motor section 32 is composed of a rotor 37, a stator 38, etc., and is housed in a pump casing 39.

An internal-pump-installed reactor equipped with the internal pump 1 as described above does not have an external recirculation system as found in a conventional reactor, so that the piping space inside the reactor containment vessel is reduced. Can be significantly reduced.

Further, the motor unit 3 of the internal pump 1
No. 2 is housed in a watertight pump casing 39, it does not require a sliding type shaft sealing device, has a simple structure and is less likely to leak reactor water, and therefore has safety and reliability. Is excellent in

However, in the case of adopting the internal pump installed type reactor, it is necessary to regularly perform maintenance and inspection work of the internal pump 1.

FIG. 8 is a view of the inside of the reactor pressure vessel 17 after removing the reactor pressure vessel upper mirror 29, the steam dryer 28 and the shroud head 25 from above, and shows a shroud head bolt fastening flange portion 40. The notch portion 41 provided at is a portion through which the internal pump handling device 7 passes, as described later.

FIG. 9 is an explanatory view of the work of mounting and removing the internal pump 1 in the reactor pressure vessel, which is performed at the time of maintenance and inspection of the internal pump 1.

When inspecting the internal pump 1,
First, the operation of the reactor is stopped, the reactor pressure vessel 17 is filled with water to shield the radiation, and then the reactor pressure vessel upper mirror 29 shown in FIG. 6 is removed, and the reactor well 44 is also filled with water. And the steam dryer 28, steam separator 24 and shroud head 25 are removed, and then the internal pump 1
Is being removed from or attached to the reactor pressure vessel 17.

The removal work of the internal pump 1 is performed from above the reactor pressure vessel 17, and the installation work is performed in the reverse procedure of the removal work.

In the removal work, first, the water in the pump casing 39 is drained, and then the motor section 32 is removed from below the reactor pressure vessel 17.

Next, the flange of the pump casing 39 is closed to prevent outflow of reactor water, and then the reactor pressure vessel 1
7 from above, the impeller 33 shown in FIG.
It is removed together with. After that, the opening of the diffuser 2 is closed to drain the reactor water in the pump casing 39, and the secondary seal (not shown in the drawing) and the stretch tube nut (not shown in the drawing) are attached to the reactor pressure vessel 17. Removed from below.

Next, the flange portion of the pump casing 39 is closed to prevent outflow of reactor water, and then the reactor pressure vessel 1
Diffuser 2 and stretch tube 35 from above 7.
The procedure is to remove and.

The work for removing or installing the internal pump 1 as described above is performed remotely in a narrow space. That is, the internal pump handling device 7 is suspended from above the reactor pressure vessel 17 by a suspending tool 43 such as a wire rope and passed through the cutout portion 41 of the shroud head bolt fastening flange portion 40. The internal pump handling device 7 is moved horizontally in a narrow annular portion between the inner wall of the container 17 and the outer wall of the shroud 19 to a mounting position immediately above the predetermined internal pump 1.

The internal pump handling device 7 that has been moved to a position just above the predetermined mounting position is then replaced by a guide roller (not shown in the drawing) of the internal pump handling device 7.
The rail 30 laid on the shroud 19 rolls down, is placed on the internal pump 1, grips the pump parts of the internal pump 1, and is pulled up above the reactor pressure vessel 1 in the reverse order of the above. ..

That is, as described above, in the internal pump 1, the impeller 33 and the shaft 36 and the diffuser 2 and the stretch tube 35 are pulled up integrally, while the wear ring 3 is pulled up independently. However, all are carried out by a dedicated handling device.

The procedure for mounting the internal pump is the reverse of the above-described removal procedure.

FIG. 10 shows a main part of a conventional internal pump. FIG. 10 (a) is a view of the diffuser part viewed from above, and FIG. 10 (b) is a guide. It is explanatory drawing of a pin part.

A through hole provided in the wear ring 3 is passed through a guide pin 34 provided so as to largely protrude from the diffuser 2, the C ring 5 is expanded from the inside of the guide pin 34, and the guide pin 34 is engaged with the guide pin 34. The wear ring 2 is fixed to the diffuser 3.

Japanese Patent Laid-Open No. 62-229096 discloses a related art.

[0031]

However, there are the following problems in the internal pump and its handling device in the conventional internal pump setting type reactor.

In the inspection of the internal pump during the periodic inspection of the nuclear reactor, the internal pump installed in the reactor pressure vessel several tens of meters below the water surface is removed / installed. Accurate positioning work of the internal pump handling device has been extremely difficult, and guide rails and guide pins have been used for this positioning.

That is, if the above-described positioning is not performed, it takes a lot of time to remove / install the internal pump, and the exposure dose to the operator increases.
Therefore, the guide rail and the guide pin cannot be deleted.

However, since the guide pin is provided on the diffuser of the internal pump so as not to break, the guide pin does not always break. If the guide pin breaks, it will become a loss component in the reactor, causing a serious accident. Could cause.

Further, at the time of the periodic inspection, when the internal pump is taken out of the reactor pressure vessel by using the handling device of the internal pump for overhaul and inspection, and the internal pump has a recessed portion, the recessed portion There is a possibility that the amount of radiation received by workers will increase because the clad will accumulate in the area.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an internal pump and a handling device therefor, in which the workability of the internal pump is drastically improved.

[0037]

The above object can be achieved as follows.

(1) When inspecting an internal pump equipped with a diffuser and a wear ring, and an internal pump installed in a boiling water reactor pressure vessel,
An internal pump comprising an internal pump handling device for handling an internal pump mounted on an internal pump and the handling device thereof, wherein a diffuser has several small protruding pins projecting upward, The ring has a plurality of holes extending vertically, and the small protruding pin does not protrude from the upper surface of the wear ring.

(2) When inspecting an internal pump equipped with a diffuser and a wear ring, and an internal pump installed in a boiling water reactor pressure vessel,
An internal pump handling device for handling an internal pump, which is placed on an internal pump, and an internal pump handling device, comprising: an internal pump handling device for an outer peripheral portion of a wear ring; and an outer peripheral upper portion of a diffuser. A plurality of positioning notches are installed, and a plurality of pins that fit into the positioning notches are provided on the internal pump handling device in a protruding manner.

(3) Have the matters described in (1) and (2) together.

In (4) and (2), the diameter of the outer peripheral portion of the diffuser is made smaller in the lower portion than in the upper portion of the diffuser, and a plurality of notches installed in the upper outer peripheral portion of the diffuser are vertically arranged. Must have a shape that penetrates in the direction.

(5) When inspecting an internal pump equipped with a diffuser and a wear ring, and an internal pump installed in a boiling water reactor pressure vessel,
For positioning an internal pump handling device in the vicinity of each outer circumference of the diffuser and the wear ring in the internal pump and its handling device, which is mounted on the internal pump and handles the internal pump. Plural holes are installed, and plural pins that fit into the positioning holes are projected on the internal pump handling device.

(6) In (5), the diameter of the outer peripheral portion of the diffuser is made smaller at the lower portion than the upper portion of the diffuser, and a plurality of holes installed near the outer periphery of the diffuser are arranged in the vertical direction. Must have a shape that is penetrated through.

[0044]

According to the present invention, a plurality of small protruding pins are provided on the outer peripheral portion of the upper surface of the diffuser, and a plurality of holes are formed through the outer peripheral portion of the wear ring. Wearing is installed on the diffuser. Further, in this case, the small protruding pin is prevented from protruding from the upper surface of the wear ring, and the protruding portion from the upper surface of the wear ring is eliminated.

Therefore, the generation of lossy parts is prevented during the operation of the reactor, and the reliability during the operation of the reactor is improved.

Further, the notches of the internal pumps provided in the peripheral portion of the upper surface of the diffuser and the peripheral portion of the wear ring, and the positioning protrudingly provided on the lower surface portion of the internal pump handling device that is suspended from above the reactor pressure vessel The internal pump handling device mounted on the internal pump is positioned by fitting with the guide.

Therefore, at the time of periodic inspection, accurate positioning work can be performed in a short time at the time of removal / installation work of the internal pump installed several tens of meters below the water surface in the reactor pressure vessel. The exposure dose received is reduced.

Further, the above notch is replaced with a hole. In this case, the positioning work effect can be obtained as in the case of the above-mentioned cutout, so that the exposure dose to the worker can be similarly reduced.

Further, in the above-mentioned notch or hole, the peripheral part of the diffuser has a vertically passing shape with no recess, so that the risk of clad deposition in the recess during operation of the reactor is eliminated. The exposure dose to workers during overhaul and inspection is reduced.

[0050]

Embodiments of the present invention will be described with reference to FIGS.

FIG. 1 is a front view and a side view of a first embodiment of the present invention, FIG. 2 is a view taken along the line A--A of FIG. 1 (a), FIG. 3 is an explanatory view of the second embodiment, and FIG. Is an explanatory view of the third embodiment, and FIG.
It is explanatory drawing of an Example, 4 is a small protrusion pin, 6 is a notch of a diffuser, 8 is an insertion guide, 9 is a positioning guide, 1
Reference numeral 0 is a grip hook, 11 is a drive air cylinder, 12 is a grip detector, 13 is a seating detector, 14 is a wear ring notch, 16 is a through hole, and others are the same as the above-mentioned symbols.

FIG. 1 and FIG. 2 show one component of the internal pump 1 such as a diffuser 2 and a wear ring 3, which is installed in the reactor pressure vessel 17 several tens of meters below the water surface, and its handling device. 1A is a front view, FIG. 1B is a side view, and FIG. 2 is A in FIG.
FIG.

Incidentally, in the cross section on the left side of the internal pump 1 of FIG. 1 (a), when the internal pump 1 of FIG. 1 (a) is rotated by 90 ° about its axis, The portion of the diffuser notch 6 and the wear ring notch 14 is shown.

The diffuser 2 has a small protruding pin 4 and a diffuser notch 6, and the wear ring 3 has a wear ring notch 14, a wear ring hole 15 and a C ring 5, respectively. 6 and the wear ring notch 14 have the same notch shape.

The internal pump handling device 7 has an insertion guide 8 at the bottom and a grip hook 1 at the top.
0, a driving air cylinder 11 and a grip hook 1 beside it
Grasping detector 12 at 0 end, and seating detector 1 at other places
3 and the positioning guide 9 are arranged respectively.

Next, each operation of the internal pump 1 and the internal pump handling device 7 will be described.

As shown in FIG. 1, the wear ring 3 is mounted on the diffuser 2 by fitting the small projecting pin 4 projecting on the diffuser 2 and the wear ring hole 15 penetrating the wear ring 3. , C ring 5 is expanded from the inside.

In this case, the small projecting pin 4 projecting from the diffuser 2 is limited to a size that does not project from the upper surface of the wear ring 3, whereby the small projecting pin 4 is broken and becomes a loss component during operation of the reactor. It reduces the possibility that it will occur and improves the reliability during reactor operation.

Further, the notch portion of the internal pump 1 including the diffuser notch 6 provided in the diffuser 2 and the wear ring notch 14 provided in the wear ring 3 and the positioning guide provided in the internal pump handling device 7. 9 is fitted to accurately position the internal pump handling device 7 mounted on the internal pump 1 installed several tens of meters below the surface of the water to facilitate the work by the internal pump handling device 7. ing.

FIG. 3 shows the case of the second embodiment of the present invention.
FIG. 3A is a view of the wear ring 3 viewed from above,
FIG. 3B is an explanatory diagram of a fitting portion between the positioning guide 9 and the notch.

When arranging the cutouts between the diffuser 2 and the wear ring 3 in the internal pump 1, due to the structural limitation of the internal pump 1, there is a small space in the vicinity of the C ring 5, so that there is little space in the wear ring 3. It is difficult to increase the size of the wear ring notch 14.

In this embodiment, the wear ring notch 14 of the wear ring 3 is installed at the position opposite to the C ring 5, and therefore the diffuser notch 6 of the diffuser 2 and the internal pump handling are provided on the same side. The positioning guide 9 of the device 7 is installed.

As a result, the wear ring notch 14
And the diffuser notch 6 are made larger to improve the fitting property of the positioning guide 9 and the notch, thereby improving workability.

Further, the notch of the internal pump 1, which is composed of the diffuser notch 6 and the wear ring notch 14, has a shape which vertically penetrates. As a result, the accumulation of the clad at the fitting portion of the positioning guide 9 and the notch including the wear ring notch 14 and the diffuser notch 6 during the operation of the reactor is suppressed, and the disassembling inspection at the time of the periodic inspection is performed. It is possible to reduce the exposure dose to workers.

FIG. 4 shows the case of the third embodiment of the present invention.
FIG. 4A is a view of the wear ring 3 viewed from above,
FIG. 4B is an explanatory diagram of a fitting portion between the positioning guide 9 and the notch.

Both the diffuser notch 6 and the wear ring notch 14 are semicircular. That is, the notch shape in each of the first and second embodiments described above is rectangular, but even if the notch shape is semicircular,
Good fitability with the positioning guide 9 is obtained.

FIG. 5 shows the case of the fourth embodiment of the present invention.
FIG. 5A is a view of the wear ring 3 seen from above,
FIG. 5B is an explanatory diagram of a fitting portion between the positioning guide 9 and the notch.

In this case, instead of the diffuser notch 6 and the wear ring notch 14, a plurality of through holes 16 are provided in the diffuser 2 and the wear ring 3, and the through hole 16 is provided in the internal pump handling device 7. A plurality of positioning guides 9 to be fitted are installed respectively.
Also in this case, as in the case of having the above-mentioned notch, it has a good fitting property with the positioning guide 9.

Further, because of the through holes 16, it is possible to reduce the deposition of the clad at the fitting portion, which occurs during the operation of the nuclear reactor.

[0070]

According to the present invention, it is possible to eliminate the risk of loss of components in the reactor during the operation of the reactor and reduce the possibility of causing a serious accident.

Further, during the removal / installation work of the internal pump, the accurate positioning work of the internal pump handling device mounted on the internal pump can be performed in a short time, and the radiation dose received by the worker is reduced. To be done.

Further, since the clad is less likely to be accumulated in the internal pump, it is possible to reduce the exposure dose received by the operator during the overhaul of the internal pump during the periodic inspection.

[Brief description of drawings]

FIG. 1 is a front view and a side view of a first embodiment of the present invention.

FIG. 2 is a view taken along the line AA of FIG.

FIG. 3 is an explanatory diagram of a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of a fourth embodiment of the present invention.

FIG. 6 is an explanatory diagram of an internal pump installed reactor.

FIG. 7 is an explanatory diagram of a conventional internal pump.

FIG. 8 is a cross-sectional view of an internal pump installed reactor.

FIG. 9 is an explanatory diagram of a handling procedure of the internal pump.

FIG. 10 is an explanatory diagram of a main part of an internal pump of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal pump, 2 ... Diffuser, 3 ... Wear ring, 4 ... Small protruding pin, 6 ... Diffuser cutout, 7 ... Internal pump handling device, 9 ... Positioning guide, 14 ... Wearing cutout, 16 ... Penetration Hole, 1
7 ... Reactor pressure vessel.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichi Matsumura 3-1-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Shiro Nakahira 603 Kandachimachi, Tsuchiura City, Ibaraki Prefecture Nitate Manufacturing Co., Ltd. Tsuchiura factory

Claims (6)

[Claims] 1. When inspecting an internal pump provided with a diffuser and a wear ring, and the internal pump installed in a boiling water reactor pressure vessel,
An internal pump comprising an internal pump handling device that is mounted on the internal pump and handles the internal pump, and the handling device thereof, wherein the diffuser has a plurality of small protruding pins protruding upward. The internal pump and its handling device, wherein the wear ring has a plurality of holes penetrating in the vertical direction, and the small protruding pin does not protrude from the upper surface of the wear ring. 2. An internal pump provided with a diffuser and a wear ring, and an inspection of the internal pump installed in a boiling water reactor pressure vessel,
An internal pump and an apparatus for handling the internal pump, which are mounted on the internal pump and handle the internal pump, wherein an outer peripheral portion of the wear ring and an upper outer peripheral portion of the diffuser respectively include A plurality of positioning notches for the internal pump handling device are provided, and a plurality of pins that fit into the positioning notches are provided so as to project from the internal pump handling device. Null pump and its handling equipment. 3. An internal pump having the features described in claim 1 and claim 2 and a handling device therefor. 4. The diameter of the outer peripheral portion of the diffuser is smaller in the lower portion than in the upper portion of the diffuser, and a plurality of notches installed in the upper outer peripheral portion of the diffuser penetrate vertically. The internal pump and the handling device thereof according to claim 2, which have a shaped shape. 5. An internal pump having a diffuser and a wear ring, and the internal pump installed in a boiling water reactor pressure vessel are inspected.
An internal pump and an apparatus for handling the internal pump, which is placed on the internal pump and handles the internal pump, in the vicinity of each outer periphery of the diffuser and the wear ring,
A plurality of positioning holes for the internal pump handling device are provided, and a plurality of pins that fit into the positioning holes are projectingly provided on the internal pump handling device. Pumps and their handling equipment. 6. The diameter of the outer peripheral portion of the diffuser is made smaller in the lower portion than in the upper portion of the diffuser, and a plurality of holes provided near the outer periphery of the diffuser are vertically penetrated. 6. It has a curved shape.
The described internal pump and its handling device.