JP3124827B2 - Internal pump and its handling device - Google Patents

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 an apparatus for handling the internal pump.

[0002]

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

FIG. 6 is an explanatory view of a reactor equipped with an internal pump, FIG. 7 is an explanatory view of a conventional internal pump,
FIG. 8 is a cross-sectional view of a reactor equipped with an internal pump, FIG. 9 is an explanatory view of an internal pump handling procedure, FIG. 10 is an explanatory view of a main part of a conventional internal pump, 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 grid plate, 23 is a core support plate, 24 is a steam separator, 25 is a shroud head, 26
Is the upper shroud, 27 is the 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 section, 32 is a motor section, 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 cutout portion, 42 is a fuel changer, 43
Denotes a hanging tool, and 44 denotes a reactor well.

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

The shroud 19 is provided with an upper lattice plate 22 for directly supporting the fuel assembly 21 and a core support plate 23. Above the shroud 19, a shroud head 25 for fixing a steam separator 24 is provided. Is set.

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

[0007] In the above configuration, during the periodic inspection of the internal pump-installed reactor, the reactor pressure vessel upper mirror 2
After removing the steam dryer 9, the steam dryer 28 is removed, and the shroud head 25 to which the steam separator 24 is fixed is further removed. Thereafter, the replacement of the fuel assembly 21 and the inspection of the internal pump 1 are performed. Is being done.

The removal of the shroud head 25 is as follows.
It is performed by rotating the shroud head bolt 27 and releasing the flange fastening with the upper shroud 26,
The shroud head bolt 27 is
At the same time, it is temporarily placed outside the reactor.

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

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

The wear ring 3 is mounted on the diffuser 2, and the diffuser 2 is supported by a pump deck 20 and a nozzle 18 provided below the reactor pressure vessel 17, and is fixed by a stretch tube 35. I have.

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

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

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

The motor unit 3 of the internal pump 1
2 is housed in a pump casing 39 having excellent water tightness, so that a sliding type shaft sealing device is not required, the structure is simple and the possibility of reactor water leakage is small, so that safety and reliability are improved. Is excellent.

However, when employing an internal pump-installed nuclear reactor, it is necessary to periodically perform maintenance work on the internal pump 1.

FIG. 8 is a top view of the reactor pressure vessel 17 after removing the reactor pressure vessel upper mirror 29, the steam dryer 28 and the shroud head 25, and shows a shroud head bolt fastening flange 40. The notch portion 41 provided at the position 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 during maintenance and inspection of the internal pump 1.

When inspecting the internal pump 1,
First, the operation of the reactor was stopped, the reactor pressure vessel 17 was filled with water to shield radiation, the reactor pressure vessel upper mirror 29 shown in FIG. , And after removing the steam dryer 28, the steam separator 24 and the shroud head 25, the internal pump 1
Of the reactor pressure vessel 17 or mounting work.

The operation of removing the internal pump 1 is performed from above the reactor pressure vessel 17, and the operation of mounting the internal pump 1 is performed in the reverse order of the operation of removing the internal pump 1.

In the removing operation, 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 portion of the pump casing 39 is closed to prevent outflow of reactor water, and then the reactor pressure vessel 1 is closed.
7, the impeller 33 shown in FIG.
And removed together. Thereafter, the opening of the diffuser 2 is closed, the reactor water in the pump casing 39 is drained, and the secondary seal (not shown in the drawing) and the stretch tube nut (not shown in the drawing) are connected to the reactor pressure vessel 17. Removed from below.

Next, the flange portion of the pump casing 39 is closed to prevent reactor water from flowing out.
7 and the diffuser 2 and the stretch tube 35 from above.
And the procedure to remove them together.

The work of removing or attaching the internal pump 1 as described above is performed in a narrow space and remotely. 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 is passed through the notch 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 a predetermined internal pump 1.

After the internal pump handling device 7 is moved to a position immediately above the predetermined mounting position, the guide roller (not shown in the drawing) of the internal pump handling device 7
The rail 30 laid on the shroud 19 descends while rolling, is mounted on the internal pump 1, grasps the pump parts of the internal pump 1, and lifts the reactor 30 above the reactor pressure vessel 1 in the reverse order. .

That is, as described above, the impeller 33 and the shaft 36 and the diffuser 2 and the stretch tube 35 of the internal pump 1 are integrally lifted, while the wear ring 3 is independently lifted. However, they are all performed by dedicated handling equipment.

The procedure for mounting the internal pump is the reverse of the procedure for removing the internal pump.

FIGS. 10A and 10B show a main part of a conventional internal pump. FIG. 10A is a view of the diffuser viewed from above, and FIG. 10B is a guide. It is explanatory drawing of a pin part.

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

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

[0031]

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

In the inspection of the internal pump at the time of periodic inspection of the reactor, the internal pump installed / removed several tens meters below the water surface in the reactor pressure vessel is removed / attached. It is very difficult to accurately position an internal pump handling device, and a guide rail and a guide pin are used for this positioning.

That is, when the above positioning is not performed, a large amount of time is required for removing / attaching the internal pump, and the exposure dose to the worker increases.
Therefore, the above-mentioned guide rail and guide pin could not be deleted.

However, since the guide pins protrude from the diffuser of the internal pump, they are not necessarily broken. If the guide pins are broken, they become lost parts in the nuclear reactor. 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 internal pump handling device and the disassembly and inspection is performed, if the internal pump has a concave portion, the concave portion is provided. Since the cladding accumulates, there is a possibility that the radiation dose received by the worker may increase.

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 device for handling the internal pump in which the handling efficiency of the internal pump is drastically improved.

[0037]

The above object can be achieved as follows.

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

(2) When checking the internal pump provided with the diffuser and the wear ring and the internal pump installed in the boiling water reactor pressure vessel,
In an internal pump and an internal pump handling device mounted on the internal pump and configured to handle the internal pump, the internal pump handling device is provided on an outer peripheral portion of the wear ring and an upper peripheral portion of the diffuser, respectively. A plurality of positioning notches are provided, and a plurality of pins that fit into the positioning notches are protrudingly provided on the internal pump handling device.

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

(4) In (2), the diameter of the outer peripheral portion of the diffuser is smaller at the lower portion than at the upper portion of the diffuser. To have a shape penetrated in the direction.

(5) When checking the internal pump equipped with the diffuser and the wear ring and the internal pump installed in the boiling water reactor pressure vessel,
An internal pump and an internal pump handling device mounted on the internal pump and configured to handle the internal pump, and for positioning the internal pump handling device near each outer periphery of the diffuser and the wear ring. A plurality of holes are provided, and a plurality of pins that fit into the positioning holes are protruded from the internal pump handling device.

(6) In (5), the diameter of the outer peripheral portion of the diffuser is smaller at the lower portion than at the upper portion of the diffuser, and a plurality of holes installed near the outer periphery of the diffuser are vertically aligned. To have a shape penetrated through.

[0044]

According to the present invention, a plurality of small projecting pins project from the outer peripheral portion of the upper surface of the diffuser, and a plurality of holes extend through the outer peripheral portion of the wear ring. Wearing is mounted on the diffuser. Further, in this case, the small projecting pin is prevented from projecting from the upper surface of the wear ring, and the projecting portion from the upper surface of the wear ring is eliminated.

Therefore, occurrence of lost parts during operation of the reactor is prevented, and reliability during operation of the reactor is improved.

Further, notches of an internal pump provided on a peripheral portion of an upper surface of the diffuser and a peripheral portion of a wear ring, and positioning provided on a lower portion of an internal pump handling device suspended from above the reactor pressure vessel. The guide is fitted to the internal pump to position the internal pump handling device mounted on the internal pump.

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

The above-mentioned notch is replaced by a hole. In this case, as in the case of the above-described notch, the positioning operation effect can be obtained, so that the exposure dose received by the worker can be similarly reduced.

Further, in the above-mentioned notch or hole, the peripheral portion of the diffuser has a vertical shape without a concave portion, so that the danger of clad deposition in the concave portion during operation of the reactor is eliminated. In addition, the radiation dose received by workers during overhaul is reduced.

[0050]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment 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 on line AA of FIG. 1A, FIG. 3 is an explanatory view of the second embodiment, FIG. Is an explanatory view of the third embodiment, and FIG.
FIG. 4 is an explanatory view of the embodiment, wherein 4 is a small protruding pin, 6 is a diffuser notch, 8 is an insertion guide, 9 is a positioning guide, 1
Reference numeral 0 denotes a grip hook, 11 denotes a driving air cylinder, 12 denotes a grip detector, 13 denotes a seating detector, 14 denotes a wear ring notch, 16 denotes a through hole, and others denote the above-mentioned symbols.

FIGS. 1 and 2 show one part of the internal pump 1 such as the diffuser 2 and the wear ring 3 installed several tens of meters below the water surface in the reactor pressure vessel 17 and a device for handling the same. 1 (a) is a front view, FIG. 1 (b) is a side view, and FIG. 2 is A in FIG. 1 (a).
FIG.

The left cross section of the internal pump 1 shown in FIG. 1A is formed by rotating the internal pump 1 shown in FIG. 1A around its axis by 90 °. The parts of the diffuser notch 6 and the wear ring notch 14 are shown.

The diffuser 2 has a small projecting 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 1 at the top.
0, drive air cylinder 11 next to it, grip hook 1
Grasping detector 12 at 0 end, other sitting detector 1 in place
3 and a positioning guide 9 are provided respectively.

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

As shown in FIG. 1, the mounting of the wear ring 3 on the diffuser 2 is performed by fitting a small protruding pin 4 protruding from the diffuser 2 and a wear ring hole 15 penetrating through the wear ring 3. , The C ring 5 is extended from the inside.

In this case, the small protruding pins 4 protruding from the diffuser 2 are limited to dimensions that do not protrude from the upper surface of the wear ring 3, whereby the small protruding pins 4 are broken and lost parts during reactor operation. To reduce the likelihood of the reactor becoming operational and improve its reliability during reactor operation.

Further, a notch portion of the internal pump 1 comprising a diffuser notch 6 provided in the diffuser 2 and a wear ring notch 14 provided in the wear ring 3, and a positioning guide provided in the internal pump handling device 7. 9 to accurately position the internal pump handling device 7 mounted on the internal pump 1 installed several tens of meters below the water surface, thereby facilitating the operation of the internal pump handling device 7. ing.

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

In arranging the notch between the diffuser 2 and the wear ring 3 in the internal pump 1, the space around the C-ring 5 is small due to structural restrictions of the internal pump 1, so that the wear ring 3 It is difficult to make the wear ring notch 14 large.

In this embodiment, the wear ring notch 14 of the wear ring 3 is provided at a position opposite to the C ring 5, and accordingly, the diffuser notch 6 of the diffuser 2 and the internal pump A positioning guide 9 of the device 7 is provided.

As a result, the wear ring notch 14
And the diffuser notch 6 are enlarged to improve the fit between the positioning guide 9 and the notch, thereby improving workability.

Further, a notch of the internal pump 1 including the diffuser notch 6 and the wear ring notch 14 is formed to penetrate vertically. This suppresses the deposition of the cladding in the fitting portion between the notch composed of the wear ring notch 14 and the diffuser notch 6 and the positioning guide 9 during the operation of the reactor, and reduces the risk of disassembly and inspection during the periodic inspection. Workers can be reduced in exposure dose.

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

The shapes of the diffuser notch 6 and the wear ring notch 14 are both semicircular. That is, although the notch shape in each of the first and second embodiments is a square shape, even if the notch shape is a semicircle shape,
Good fit 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 as viewed from above,
FIG. 5B is an explanatory view of a fitting portion between the positioning guide 9 and the notch.

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

Further, since the through holes 16 are formed, it is possible to reduce the deposition of cladding on the fitting portion during the operation of the reactor.

[0070]

According to the present invention, during the operation of the nuclear reactor, the danger of generating lost parts in the reactor can be eliminated, and the possibility of causing a serious accident can be reduced.

In addition, when removing / attaching the internal pump, accurate positioning 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 operator can be reduced. Is done.

Further, since it is difficult for the clad to accumulate in the internal pump, it is possible to reduce the radiation dose received by the operator during the overhaul of the internal pump during the periodic inspection.

[Brief description of the 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 nuclear reactor.

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

FIG. 8 is a cross-sectional view of the internal pump-installed nuclear 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 a conventional internal pump.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal pump, 2 ... Diffuser, 3 ... Wearing, 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.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Seiichi Matsumura 3-1-1, Sakaimachi, Hitachi-shi, Ibaraki Co., Ltd. Hitachi Plant, Ltd. Hitachi, Ltd. Tsuchiura Plant (58) Fields investigated (Int. Cl. ⁷ , DB name) G21C 15/243 G21C 19/02

Claims (6)

(57) [Claims] When checking an internal pump provided with a diffuser and a wear ring and the internal pump installed in a boiling water reactor pressure vessel, etc.
An internal pump and an internal pump, which are mounted on the internal pump and include an internal pump handling device for handling the internal pump, wherein the diffuser has a plurality of small projecting pins projecting upward. An internal pump and a device for handling the internal pump, wherein the wear ring has a plurality of holes penetrating vertically, and the small projecting pin does not project from the upper surface of the wear ring. 2. Inspection of an internal pump provided with a diffuser and a wear ring and the internal pump installed in a boiling water reactor pressure vessel, etc.
An internal pump and an internal pump that are mounted on the internal pump and include an internal pump handling device that handles the internal pump.In the outer peripheral portion of the wear ring and the outer peripheral upper portion of the diffuser, The internal pump handling device is provided with a plurality of positioning notches, and a plurality of pins that fit into the positioning notches are projected from the internal pump handling device. Null pump and its handling equipment. 3. An internal pump having the features described in claim 1 and 2 and a handling device thereof. 4. A diameter of an outer peripheral portion of the diffuser is smaller in a lower portion than an upper portion of the diffuser, and a plurality of notches provided in an upper peripheral portion of the diffuser penetrate vertically. 3. The internal pump according to claim 2, wherein the internal pump has a predetermined shape. 5. When checking an internal pump having a diffuser and a wear ring and the internal pump installed in a boiling water reactor pressure vessel, etc.
On the internal pump and the internal pump handling device that is mounted on the internal pump and comprises an internal pump handling device that handles the internal pump, in the vicinity of each outer periphery of the diffuser and the wear ring,
A plurality of positioning holes of the internal pump handling device are provided, and a plurality of pins that fit into the positioning holes are projected from the internal pump handling device. Pumps and their handling equipment. 6. A diameter of an outer peripheral portion of the diffuser is smaller at a lower portion than an upper portion of the diffuser, and a plurality of holes provided near an outer periphery of the diffuser are vertically penetrated. 6. A curved shape.
The internal pump and the handling device described in the above.