JP2892166B2 - Reactor refueling machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a boiling water reactor provided with an internal pump, which is used for replacing fuel in the reactor and replacing the internal pump. Replacement machine.

[0002]

2. Description of the Related Art In a conventional general boiling water reactor, a jet pump is housed in a reactor pressure vessel, and a part of reactor water is taken out of the reactor pressure vessel.
A method has been adopted in which the taken out reactor water is pressurized by a recirculation pump, sent to the jet pump as drive water, and the jet pump circulates the reactor water in the core.

[0003] However, this method not only has a problem that the structure is considerably complicated, but also is not preferable because a pipe connecting the jet pump and the recirculation pump is disposed outside the reactor.

[0004] In recent years, a boiling water reactor equipped with an internal pump has been developed as shown in FIG. 6 in which a recirculation pump is formed in a nuclear reactor to eliminate piping.

In this type of boiling water reactor, a shroud 2 is provided in a reactor pressure vessel 1 as shown in FIG.
The reactor core 3 is accommodated in the shroud 2, and a plurality of, for example, about ten internal pumps 4 (see FIG. 5) are arranged at the bottom of the reactor pressure vessel 1. The reactor water in the reactor pressure vessel 1 is
It descends in the downcomer 5 formed between the outer peripheral surface of the shroud 2 and the inner peripheral surface of the reactor pressure vessel 1, is sent below the core 3 by the internal pump 4, and further flows into the core 3. It has become.

The reactor water that has flowed into the reactor core 3 boils due to heat generated by the nuclear reaction, flows upward as a two-phase flow of water and steam, and flows into the steam-water separator 6 disposed above the reactor core 3. Is separated into water and steam. Then, the separated steam is sent to a turbine (not shown) or the like after the moisture is removed by the steam dryer 7, while the separated water is supplied together with the water supplied from the water supply sparger 8. , And is sent again into the core 3 by the internal pump 4.

The reactor core 3 of the reactor pressure vessel 1 has, for example, about 200 control rods (not shown) and about 8 control rods.
About 00 fuel rods (not shown) are provided.
These fuel rod, control rod and control rod drive (not shown)
Thus, the control rod is inserted or withdrawn into the core 3 to control the half concentration or the like of the core 3.

As shown in FIG. 8, each of the internal pumps 4 is provided with a pump section 11 having a diffuser 9 and an impeller 10.
Is connected to a motor casing 15 which is pressed against a pump nozzle 14 of the reactor pressure vessel 1 by a stretch tube 12 and a stretch tube nut 13 and is inserted into the pump nozzle 14 from below.

A water immersion type motor 16 is housed in the motor casing 15.
A motor cover 17 is attached to the lower end of the motor. The motor cover 17 is disposed in close contact with the lower surface of the motor casing 15 and is fastened and fixed to the motor casing 15 by a nut 19 screwed to a stud bolt 18, thereby maintaining fluid tightness and fixing the motor 16. It is configured to be fixed inside the motor casing 15. The motor 16 and the impeller 10 are connected to a shaft 20.
And drives the impeller 10 via the shaft 20.

The internal pump 4 having the above configuration
Must be disassembled and removed periodically, and the removed parts must be inspected and repaired elsewhere outside the containment vessel.

In order to disassemble and remove the internal pump 4, first, the connection between the motor 16 and the shaft 20 is released, and the nut 1 is removed.
9 is removed, and the motor 16 is pulled downward from the motor casing 15. In this state, after pulling out the impeller 10 and the shaft 20 upward to remove the two 10, 20 integrally,
This is performed by removing the stretch tube nut 13 and pulling the diffuser 9 upward together with the stretch tube 12. The impeller 10 and the shaft 20, and the diffuser 9 and the stretch tube 12 of the removed pump unit 11 are located above the annular downcomer 5 formed by the inner peripheral surface of the reactor pressure vessel 1 and the outer peripheral surface of the shroud 2, respectively. It is carried out of the reactor pressure vessel 1 through the space by the carry-in / out port A or B formed in the top guide 25 shown in FIG.

The motor 16 removed from the internal pump 4 passes through a pedestal that supports the reactor pressure vessel 1 and is carried out of another equipment (not shown) from a device entrance formed in the pedestal.

The assembling and assembling of the internal pump 4 is performed in the reverse order.

On the inner peripheral wall surface of the reactor pressure vessel 1, a number of projections such as a water supply sparger 8, a low-pressure water injection sparger 22, and a core spray pipe 23 (see FIG. 2) are mounted. Further, a disk-shaped top guide 25 is housed around the upper lattice plate 24 of the cylindrical shroud 2 in close proximity to the inner peripheral wall of the reactor pressure vessel 1. Therefore, at present, the margin in the annular space formed by these components is considerably small.
The impeller 10 and shaft 20, and the diffuser 9 and stretch tube 12 are generally quite large and heavy.

Since the internal pump 4 is housed in the bottom of the reactor pressure vessel 1 and is always in the reactor water, the pump section 11 is removed from the pump nozzle 14 and the internal pressure of the reactor pressure vessel 1 is reduced. Work to be carried out, or the pump unit 11 to be carried into the reactor pressure vessel 1 and the pump nozzle 1
The replacement work to attach to 4 is extremely troublesome.

Therefore, conventionally, the work of replacing the pump section 11 of the internal pump 4 has been generally performed using a fuel changing machine as shown in FIGS. 9 and 10.

That is, the conventional general refueling machine is:
As shown in FIG.
A traveling vehicle 26 provided so as to be able to travel across the vehicle, and a traveling vehicle 27 provided so as to be able to traverse the traveling vehicle 26;
A hoist 28 provided on the traversing carriage 27, a wire rope 30 suspended from the hoist 28 via a pulley 29 into the reactor pressure vessel 1, and a gripper 45 supported at a lower end of the wire rope 30 And this grabber 4
An air hose 32 for driving the air hose 5, a hose reel (hose winding device) 33 for winding and rewinding the air hose 32 in conjunction with the lifting and lowering operation of the gripper 45, and the gripper 45.
Operation monitoring signal transmission cable 34 and this cable 34
And a cable reel (cable winding device) 35 for winding and rewinding in conjunction with the raising and lowering operation of the gripper 45, and is operated by an operation panel 36 provided on the traversing carriage 27. I have. In the drawing, reference numeral 37 denotes a refueling floor, and reference numeral 65 denotes a traveling rail for traveling the traveling vehicle 26.

[0018]

The replacement of the pump section 11 of the internal pump 4 by the refueling machine is performed while the reactor pressure vessel 1 is filled with water. It is necessary to perform this replacement work while monitoring the operation status of the replacement machine. However, the internal pump 4 is connected to the inner peripheral wall of the reactor pressure vessel 1 and the shroud 2.
Is accommodated in the pump nozzle 14 disposed at the bottom of the downcomer 5 formed in an annular shape with the outer peripheral wall of the refueling machine.
Orbital operation must be performed with the traversing operation, so that the operation of the refueling machine requires advanced driving techniques and complicated circular orbital interlocks to prevent the deviation of the driving route. It was necessary at present.

The pump section 1 of the internal pump 4
Since 1 is housed in a narrow location in a deep part, many observers are arranged on the refueling machine and a plurality of underwater TV cameras 66 are hung down, as shown in FIG.
It is necessary to replace the pump unit 11 of the internal pump 4 while monitoring the position and operation status of the pump unit 5 and the unloading path of the pump unit 11 of the internal pump 4. There was also a problem that invited.

The present invention has been made in view of such a problem, and does not require a complicated interlock, and does not require a large number of observers on the refueling machine. It is an object of the present invention to provide a unit which can safely and reliably perform a unit replacement operation by remote control.

[0021]

In order to achieve the above object, a refueling machine according to the present invention includes a traveling bogie provided above a reactor pressure vessel so as to be able to travel across the vessel.
Replacement of the traversing trolley that can traverse on the traveling trolley and the pump part of the internal pump arranged at the bottom of the reactor pressure vessel by operating the gripper suspended from the traversing trolley into the reactor pressure vessel Of a nuclear reactor refueling machine equipped with an internal pump replacement device for performing the operation and remotely controlled by a command from a remote control room, with a pulley device provided at the tip that is rotatable around a vertical axis. Arm and
A gripper detachably supported at the tip of a wire rope suspended from the reactor pressure vessel via the pulley device according to a replacement, the wire rope, the gripper driving air hose, and an operation monitoring signal. An internal pump replacement device including a hoist, a hose winding device, and a cable winding device for respectively winding a transmission cable is mounted below the traversing carriage.

[0022]

According to the present invention constructed as described above, the swivel arm that swivels around the vertical axis of the internal pump replacement device provided below the traversing bogie allows the internal pump to be replaced in the replacement path of the pump section. The gripper for gripping the pump part of the internal pump can be moved along with a certain circular orbital operation, and this enables complex circular orbital control by driving the traveling vehicle and the traversing vehicle and an interlock for preventing orbital deviation. The pump section of the internal pump can be replaced reliably with relatively simple operation control without making it unnecessary.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an embodiment of a refueling machine according to the present invention.
, A traveling vehicle 26 provided so as to be able to travel across the vessel 1, a traveling vehicle 27 provided so as to be able to traverse on the traveling vehicle 26, and a traveling vehicle 26 An internal pump replacement device 21 having a hoist 28 and a TV camera device 40 for underwater monitoring are attached to the lower part of the traversing carriage 27 mainly with a fuel replacement mast 38 to be lowered.

The internal pump replacement device 21 comprises:
As shown in detail in FIG. 3, a swivel bearing 39 supported by the transverse carriage 27, a swivel arm 41 attached to the lower end of the swivel bearing 39, and a swivel arm 4
1, a pulley device 43 provided at the tip of the first arm 1, an arm extending / contracting mechanism 44 for extending / contracting the turning arm 41 in the horizontal direction, a turning drive mechanism 42 for also turning the turning arm 41 about a vertical axis, and a reactor pressure vessel 1. It is mainly composed of a wire rope 30 suspended inside and a hoist 28 for winding the wire rope 30. The pumping unit 11 of the internal pump 4 is replaced by a gripper 45 that is detachably supported at the tip of the wire rope 30 according to a replacement.

An air hose 32 for driving the gripper 45 and an operation monitoring signal transmission cable 34 are connected to the gripper 45, and the air hose 32 is wound and rewinded in conjunction with the raising / lowering operation of the gripper 45. (Hose take-up device) 33 and a cable reel (cable take-up device) 35 that takes up and rewinds the cable 34 in conjunction with the lifting / lowering operation of the gripper 45.

Here, the pulley device 43 includes a pulley 46,
Frame 47, pulley shaft 48, shaft 49 and load cell 50
It is mainly composed of The arm extension mechanism 4
Reference numeral 4 mainly includes a ball screw 51 and a drive motor 52, and the turning drive mechanism 42 mainly includes a spur gear 53 and a drive motor 54.

As described above, the underwater surveillance TV camera device 40 is attached to the traversing carriage 27. As shown in FIG. The TV camera 55 with the zoom lens and the lighting device 56 suspended from the pulley device 43 of the null pump replacement device 21, and the hoisting device 57 for raising and lowering the TV camera 55 with the zoom lens and the lighting device 56
And the TV camera 5 with a zoom lens.
5 is displayed on the monitor TV 62 installed in the remote control room 58.
Here, the hoisting device 57 mainly includes a hoisting drum 59 and a drive motor 60.

Further, on the refueling floor 37 on which the traveling vehicle 26 is installed, a plurality of TV cameras 61 for monitoring the operation status of the traveling vehicle 26 and the traversing vehicle 27 are installed. The images captured by these TV cameras 61 are displayed on a monitor television 62 installed in a remote control room 58, similarly to the underwater monitoring TV camera device 40. In the figure, reference numeral 63
Is an operation panel provided in the remote operation room 58.

In the above configuration, the replacement path of the pump unit 11 in the replacement work of the pump unit 11 of the internal pump 4 is defined by the inner peripheral surface of the reactor pressure vessel 1 and the outer peripheral surface of the shroud 2. Since the narrow annular space (circular track carrying-in / out route) of the formed downcomer 5 is formed, the trolley 27
This can be dealt with by the circular orbital operation by the turning operation of the turning arm 41 of the internal pump replacement device 21 attached to the lower part of the internal pump replacement device. The narrow annular space is used as a carry-in path for the pump section 11 of the internal pump 4 and the internal pump 4 housed at the bottom of the downcomer 5.
In order to perform the replacement work of the pump unit 11, the pulley device 43 attached to the traversing carriage 27 at the tip of the turning arm 41
, The TV camera with zoom 55 is suspended in the water,
An image captured by the TV camera with zoom 55 is displayed on a monitor television 62 installed in the remote control room 58.

As described above, the internal pump replacement device 21 and the underwater monitoring TV camera device 40
And an underwater monitoring TV in the remote control room 58.
A monitor television 62 for displaying an image captured by the camera device 40 is installed, and furthermore, the gripper 45 is turned through the turning arm 41 of the internal pump replacement device 21 to perform circular orbit operation. As a result, safe and reliable control can be performed without the need for complicated circular orbit control and the related interlock function.

On the other hand, the internal pump 4 can be replaced while the position and the operation state of the grip 45 are monitored by the monitor television 62 of the remote control room 58 by the underwater monitoring TV camera device 40. There is no need to arrange a monitor on the replacement machine, and the exposure of the monitor can be reduced.

In the present embodiment, the underwater monitoring TV camera device 40 can be hung on both sides of the gripping tool 45 hung from the internal pump replacement device 21, respectively. By doing so, it is possible to avoid interference with the furnace internals and to eliminate the blind spot of monitoring.

[0034]

Since the present invention has the above configuration,
A gripper that grips the internal pump along a circular orbital operation, which is the replacement path of the pump section of the internal pump, by a swivel arm that rotates around the vertical axis of the internal pump replacement device provided below the traversing carriage. This eliminates the need for complicated circular orbit control and interlocks for preventing orbital departure, and allows the pump section of the internal pump to be replaced reliably with relatively simple operation control. it can.

Further, the internal pump can be replaced while monitoring the position and the operating condition of the gripping device for the internal pump on the monitor television of the remote control room. The replacement work of the internal pump can be performed safely and reliably by remote control without arranging a supervisor on top.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing one embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view when an internal pump is replaced.

Fig. 3 Internal pump replacement device and TV for underwater monitoring
The principal part expanded sectional view which shows a device.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a plan view of FIG. 2;

FIG. 6 is a sectional view showing a reactor equipped with an internal pump.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

FIG. 8 is a longitudinal sectional view of the internal pump.

FIG. 9 is a schematic perspective view of a fuel changing machine provided with a conventional internal pump changing device.

FIG. 10 is a plan view of FIG. 9;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 reactor pressure vessel 3 reactor core 4 internal pump 11 pump section 21 internal pump replacement device 26 traveling trolley 27 traversing trolley 28 hoist 30 wire rope 32 air hose 33 hose reel (hose winding device) 34 cable 35 cable reel (cable) Take-up device) 38 Refueling mast 40 Underwater monitoring TV camera device 41 Swivel arm 42 Swivel drive mechanism 43 Pulley device 44 Arm expansion and contraction mechanism 45 Gripping tool 51 Ball screw 55 TV camera with zoom lens 57 Hoisting device 58 Remote operation Room 62 Monitor TV

Claims (1)

(57) [Claims] 1. A traveling vehicle provided above a reactor pressure vessel so as to be able to run over the vessel, a traversing vehicle traversable on the traveling vehicle, and a traveling vehicle suspended from the traversing vehicle into the reactor pressure vessel. An internal pump replacement device that operates the gripper to be lowered to replace the pump section of the internal pump disposed at the bottom of the reactor pressure vessel, so that it can be remotely operated by a command from the remote control room In the nuclear reactor refueling machine, a swivel arm which is rotatable around a vertical axis and is provided with a pulley device at the tip thereof, and a wire rope suspended from the reactor pressure vessel through the pulley device at the tip thereof. A gripper detachably supported in accordance with a replacement, a hoist for winding the wire rope, the air hose for driving the gripper, and an operation monitoring signal transmission cable, a hose winding device, and a cable, respectively. Refueling machine of the reactor, characterized in that the internal pump replacement device and a winding device is mounted below the transverse carriage.