JPS5931034B2 - Control rod drive mechanism exchange device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In order to carry out maintenance and inspection of the control rod drive mechanism in a nuclear power plant, the present invention is designed to remove the control rod drive mechanism from a nuclear reactor or remove the control rod drive mechanism from the reactor. Relating to a switching device.

Generally, in a boiling water nuclear reactor, a control rod drive mechanism for controlling the reaction of X is disposed at the bottom of the pressure vessel.

After a certain period of time, this control rod drive mechanism is removed from the reactor and inspected in a separate inspection room.

However, replacing the control rod drive mechanism requires a large number of workers, and there are also health and safety problems.

Therefore, a control rod drive mechanism replacement device has been proposed that does not require a large number of workers as described above and is intended for the safety of the workers.

That is, FIGS. 1 to 3 are schematic diagrams of the control rod drive mechanism replacement device, in which a cylindrical control rod drive mechanism replacement work chamber 1 is provided at the bottom of the reactor, and its surrounding wall 2 is provided with a supporting body 3 projecting into the cylindrical working chamber 1, and an annular rail 4 is mounted and fixed on this supporting body 3.

A platform 5 is placed on the annular rail 4,
Furthermore, a trolley 6 is placed on the platform 5 and can run along the platform 5.

An elevating frame 9 that can be moved up and down by a hydraulic cylinder 8 along a guide column 7 is attached to the cart 6, and the elevating frame 9 is pivoted between vertical and horizontal positions by a hydraulic cylinder or an electric motor. Possible beam 10
is pivoted.

Sprockets NL12 are attached to both ends of the beam 10 in the longitudinal direction, and both sprockets) 11, 1
A chain 13 is wound between the two, and a support stand 14 is attached to the chain 13 so that the support stand 14 can move along the beam 10.

The support stand 14 not only can directly support the control rod drive mechanism 15, but also has a mechanism for removing and tightening the bolts that attach the control rod drive mechanism 15 to the reactor pressure vessel, and a mechanism for tightening the control rod drive mechanism 15 to the reactor pressure vessel. The structure is such that it can be equipped with a drainage device 16 that has the function of absorbing reactor water released when reactor 15 is extracted from the pressure vessel.

On the other hand, gripping arms 17 are attached to appropriate positions on the beam 10.

This gripping arm 17 can be stored inside the beam 10 so as not to hinder the movement of the support base 14, and when necessary, the gripping arm 17 can be stored inside the beam 10.
It protrudes from inside and is configured to be able to support and grip the control rod drive mechanism so that it does not fall.

Therefore, when removing the control rod drive mechanism 15, the beam 10 is held vertically, the support stand 14 is placed at the lower limit position, and the drainage tool 16 is placed on the support stand 14.

Subsequently, the chain 13 is rotated to raise the support stand 14, and the drainage tool 16 is pressed into contact with the control rod drive mechanism 15 mounted on the pressure vessel, thereby supporting the control rod drive mechanism 15.

Then, the drain tool 16 is operated and the bolts fastening the control rod drive mechanism 15 to the pressure vessel are removed.

After removing the bolts in this way, when the support stand 14 is lowered, the control rod drive mechanism 15 is also lowered, but before the upper end of the control rod drive mechanism 15 is completely removed from the pressure vessel, When the platform 14 is below the position of the gripping arm 17, the gripping arm 17 is projected to loosely hold the control rod drive mechanism from both sides and guide it.

When the control rod drive mechanism 15 is pulled out by a predetermined amount, the support base 1
4 is temporarily stopped from descending, and the gripping arm 17 is placed in the gripping state (Fig. 1).

Subsequently, the support stand 14 is lowered to the lower limit position, the drainage tool 16 is removed from the support stand 14, and the support stand 14 is raised again to support the lower end of the control rod drive mechanism 15.

After that, the gripping arm 17 is returned to the guiding state, and the support base 14 is again
is lowered together with the control rod drive mechanism 15 to the lower limit position (Fig. 2).

Next, after fixing the control rod drive mechanism with the grip arm 17, the beam 10 is swung to a horizontal state using a hydraulic cylinder or the like, and the lift frame 9 is raised together with the beam holding the control rod drive mechanism using the hydraulic cylinder 8. Then, the carriage 18 is pulled under the control rod drive mechanism 15 from the entrance (FIG. 3).

Then, the hydraulic cylinder 8 is operated again to lower the control rod drive mechanism 15 onto the transport vehicle 18, the grip arm 17 is released, and the control rod drive mechanism 15 is completely placed on the transport vehicle 18.
Thereafter, the transport cart is carried out through the entrance 19 and transported to a separately provided inspection work room.

Furthermore, the work of installing the pressure vessel of the control rod drive mechanism is performed in the reverse order of the work described above.

However, even in this type of equipment, the drainage equipment must be attached to or removed from the support stand manually, which leaves work to be done in areas with high radioactive contamination, and it is difficult to maintain the health of workers. However, since the transport cart is carried into the bottom of the furnace, there are disadvantages such as the complexity of the exchange device mechanism.

In view of these points, it is an object of the present invention to provide a control rod drive mechanism replacement device that does not have the above-mentioned drawbacks.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 4 to 12.

In the figure, reference numeral 20 denotes a bogie running beam arranged approximately diametrically in the SS rod drive mechanism replacement work room 1, and the bogie running beam 20 is shaped like a ring through wheels 21 and 21 attached to both ends. It is supported on rails 4 of i and is capable of pivoting movement on said rails 4.

A movable carriage 21 is mounted on the carriage running beam 20 so as to be movable in its longitudinal direction.

That is, rails 22a and 22b extending in the longitudinal direction are attached to both the upper and lower surfaces of the bogie running beam 20, and the movable bogie 21 still has running wheels 23 rolling on the upper surface of the rail 22a and both rails 22a. .

Guide wheels 24, 24 are provided which engage with both sides of 22b, respectively.

If the traveling wheels 23 are driven by an appropriate drive mechanism (not shown), the movable cart 21 moves along the beam 20 while being guided by the guide wheels 24,24.

A beam 26 is pivotally attached to the moving truck 21 by a horizontal shaft 25, and the Ω beam 26 is moved between vertical and horizontal positions by a hydraulic cylinder device 27 disposed between the moving truck 21 and the moving truck 21. It is configured to obtain.

Sprockets) 28 and 29 are still attached to the upper and lower ends of the beam 26, respectively, and both sprockets) 2
A chain (not shown) driven by a drive mechanism 1 is appropriately wound between the 8 and 29.

On the other hand, on the front side of the beam 26 is a lifting cart 30 connected to the chain and capable of running along the front edge of the beam.
is installed.

As shown in FIG. 6, the lifting truck 30 includes a guide wheel 32 which clamps a flange 31 formed at the front edge of the beam 26 and guides the lifting truck along the beam.
32, and furthermore, a substantially L-shaped swinging member 33 is provided on the front of the lifting cart 30, and a vertical pin 34 is provided at the center of the swinging member 33.
It is pivoted by.

One side of the swinging member 33 is formed as a support base 35 that can directly support the control rod drive mechanism, and the other side has a mechanism for removing and tightening the bolts that attach the control rod drive mechanism to the pressure vessel. Furthermore, a drainage device 36 is fixedly installed to accommodate the reactor water discharged when the control rod drive mechanism is extracted.
By swinging the swinging member 33 by a hydraulic cylinder device 37 interposed between the swinging member 33 and the lifting cart 30, the support stand 35 or the drainage tool 36 can be selectively moved to the front surface of the beam 26. It's centrally located.

Furthermore, gripping arms 38 having claws that can be opened and closed with each other are attached to appropriate positions on the beam 26.

This gripping arm 38 can be stored in the beam 26 so as not to interfere with the running of the lifting truck 30, and when necessary, is projected to the front of the beam 26 by an appropriate mechanism (not shown) so that it does not fall down the control rod drive groove. It is constructed so that it can be supported or held in one place.

The reference numeral 39 in the figure is a control panel in which a control rod, a control for operating the drive mechanism exchange device, a discharge device, and a hydraulic device are incorporated.

Next, the operation of this device will be explained.

First, when removing the control rod drive mechanism 15, the beam 26 is positioned by appropriately rotating the bogie running beam 20 and moving the moving bogie 21 along the beam 20, and the draining tool 36 is placed in the center of the front surface of the beam 26. After that, the elevating cart 30 is raised and the lower end of the control rod drive mechanism 15 is supported by the drainage tool 36 (FIG. 7).

Next, by rotating the chains wound around the sprockets 28 and 29, the lifting cart 30 is lowered to an appropriate position.

During this lowering, before the upper end of the control frame drive mechanism 15 is completely pulled out from the pressure vessel, the drainage tool 36 is connected to the gripping arm 38.
When the control rod drive mechanism 15 is in a lower position than the lower position, the gripping arm 38 is projected and its claws are held to constitute a guide member, loosely holding the control rod drive mechanism 15 from both sides and guiding it.

In this way, when the control rod drive mechanism 15 is pulled out to a certain extent, the descent of the lifting carriage 30 is temporarily stopped, and the gripping arm 38
is in a gripping state (Fig. 8).

Subsequently, the lifting cart 30 is lowered to the lower limit position.

At this time, since the control rod drive mechanism 15 is clamped by the gripping arm 38, it is suspended in the air and does not move (FIG. 9).

Therefore, the hydraulic cylinder device 37 is operated and the swinging member 33
The support base 35 is moved to the front center of the beam 26 (
directly below the control rod drive mechanism held by the gripping arm 38), and raise the lifting cart 30 again.
The lower end of the control rod 1 drive mechanism 15 is directly supported by the support stand 35 .

After that, the gripping arm 38 is returned to the guiding state, and the lifting carriage 3 is again
0 is lowered together with the control rod drive mechanism 15 and returned to the lower limit position.

At this time, the control rod drive mechanism 15 is completely removed from the reactor vessel (FIG. 10).

When the control rod 5 drive mechanism 15 reaches the lower limit position in this manner, the control rod drive mechanism is gripped again by the gripping arm 38.

Therefore, the moving cart 21 is moved to approximately the center of the beam 20, and further rotated so that the direction of the beam 20 is perpendicular to the loading port 19, and then the beam 26 is brought into a horizontal state using the hydraulic cylinder device 27. (11th
figure).

Subsequently, after loosening the gripping arm 28 and setting it in the guiding state, the lifting cart 30 is moved along the beam 26, and the control rod 1 drive mechanism 15 is pushed out toward the loading port 19, and the transfer cart installed at the loading port 19 is moved. 40 (Fig. 12).

Next, after the gripping arm 38 is completely opened, the transfer carriage 40 carrying the control rod drive mechanism is carried out from the control rod 1 drive mechanism replacement work room 1 at the bottom of the reactor via the loading port 19.

In this case, the extruded control rod drive mechanism may not be directly placed on the transfer cart, but the extruded control rod drive mechanism may be lifted up and carried out using a mobile crane.

The work to install the control rod drive mechanism 15 to the pressure vessel is still underway.
This can be done by reversing the removal procedure described above.

As explained above, the present invention includes a beam that is swingably attached to a movable cart disposed below a pressure vessel, a gripping arm for guiding and gripping a control rod drive mechanism is provided on the beam, and The elevating cart that can run along the beam is equipped with a support stand and a draining device that can be selectively positioned in the center of the front of the beam, so when replacing the control rod drive mechanism, the draining device can be installed or removed manually. Most of the control rod drive mechanism replacement work can be done automatically or by remote control, without the need for additional equipment, and the work can be continued without the need for workers to enter the lower chamber of the reactor floor, where radioactivity is high, improving worker safety. It has effects such as being able to improve sexual performance.

[Brief explanation of the drawing]

1 to 3 are schematic illustrations of a conventional control rod drive mechanism exchange device, FIG. 4 is a perspective view of the control rod drive mechanism exchange device of the present invention, FIG. 5 is a side view of the same, and FIG. The plan view of the lifting cart and FIGS. 7 to 12 are explanatory diagrams of the operation of the device of the present invention, respectively. 15... Control rod drive mechanism, 20... Bogie running beam, 2
DESCRIPTION OF SYMBOLS 1... Moving trolley, 26... Beam, 30... Lifting trolley, 33... Swinging member, 35... Support stand, 36...
...Drainage equipment, 27.37...Hydraulic cylinder device, 38
...grabbing arm.

Claims (1)

[Claims] 1. A bogie running beam mounted on the bogie running beam rotatably mounted on an annular rail provided on the side wall of the control rod drive mechanism replacement work room located below the reactor pressure vessel, and a bogie running beam attached to the bogie running beam. a moving carriage capable of traveling along a traveling beam; a beam attached to the moving carriage so as to be able to swing between vertical and horizontal positions; and a beam attached to the beam capable of guiding and gripping a control rod drive mechanism. a gripping arm; a drainage device and a support mounted on the beam so as to be able to run along the front edge of the beam; and selectively positioned in the center of the front surface of the beam; A control rod drive mechanism exchange device comprising: