JP2656347B2 - Re-shield ring pump handling device in reactor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an apparatus for handling a recirculation pump in a reactor used when a recirculation pump in a reactor is installed.

(Prior Art) A boiling water reactor is provided with a recirculation pump inside a reactor for feeding cooling water to a reactor core at the bottom of a reactor pressure vessel.

When the recirculation pump in the reactor is mounted, as shown in FIG. 6, when the motor unit 2 of the recirculation pump 1 in the reactor is housed in the casing 4 provided at the lower part of the reactor pressure vessel 3, , Guide screw 6 of lifting device 5 and handling cart 7
At the same time, the lug 9 of the motor cover 8 at the lower end of the motor unit 2 and the lifting nut 10 of the guide screw 6 are connected.

Further, an overturn prevention mechanism 13 is provided on the upper part of the motor section 2 as shown in FIGS. The overturn prevention mechanism 13 is supported by a plurality of bolts 15 extending from the upper disk 14 and prevents the overturn of the motor section 2 by holding the upper portion of the motor section 2 and the guide screw 6 therebetween.

Thereafter, the motor unit 2 is raised by about 1.5 m by rotating the guide screw 6 with a drive motor (not shown) for driving the guide screw 6 attached to the handling cart 7 shown in FIG. At this point, the motor unit 2 is
A tension bar 18 of a tension mechanism 17 for preventing the pump shaft 16 from being pushed up when moving up the inside is attached.

As shown in FIG. 9, the tension bar 18 has an upper bar 18a connected to a coupling stud 19 attached to a lower end of the pump shaft 16 in the casing 4 via a turnbuckle 20, and the upper bar 18a It extends through the center of the motor unit 2 to below the motor cover 8. A lower bar 18b is connected to a lower end of the upper bar 18a via a turnbuckle 21 as shown in FIG. 10, and a lower end of the lower bar 18b is connected to a central portion of the handling cart 7 via a load cell 22. Connected. The turnbuckle 21 is provided with a handle 23. By rotating the handle 23, a downward pulling force is applied to the pump shaft 16.

After that, the motor unit 2 is moved up again by the elevating device 5 and housed in the casing 4.

(Problems to be Solved by the Invention) However, the fall prevention mechanism 13 has a total weight of about 100 kg, and one part exceeds about 30 kg even with the weight divided into three parts. In addition, the work is performed at a high place, and the work of attaching and detaching the fall prevention mechanism 13 involves a considerable risk.

Also, when the tension bar 18 is mounted, work is performed under the motor unit 2 with the motor unit 2 raised to some extent, and about 3000 kg in an unstable state.
It is not preferable from the viewpoint of safety that a worker enters the lower part of the motor unit 2.

Furthermore, since the upper end of the upper bar 18a of the tension bar 18 is connected to the coupling stud 19 via the turnbuckle 20, the turnbuckle 20 cannot penetrate the inside of the motor unit 2 and handling is inconvenient. .

The present invention has been made in view of the above circumstances, and the installation and removal of the overturn prevention mechanism is easy, and the work can be performed simultaneously with the installation and removal of the tension bar. An object of the present invention is to provide a recirculation pump handling device in a nuclear reactor capable of improving workability and safety.

[Configuration of the invention]

(Means for Solving the Problems) The present invention relates to an elevating device for elevating a motor unit to a casing when a recirculation pump in a reactor is mounted, and a tipping prevention mechanism for preventing the motor unit from tipping when the motor unit is raised. A tension mechanism for preventing the pump shaft from being pushed up when the motor unit is mounted in the casing, wherein the tension mechanism is connected to a lower end of the pump shaft. And a cylinder mechanism for applying a downward pulling force to the pump shaft via the tension bar. The tension bar is connected to a coupling stud at the lower end of the pump shaft via an internal screw. While being connected, the tension bar and the cylinder mechanism are connected by pin connection to prevent the tipping over. The mechanism holds the upper part of the motor unit and grips the tension bar via all bearings.

(Operation) Since the tension bar is connected via the internal screw, the tension bar can penetrate the motor unit during the elevating operation. Also,
Since the tension bar and the cylinder mechanism are connected by the pin connection, handling is easy, and mounting and dismounting can be performed simultaneously with mounting and dismounting of the overturn prevention mechanism. Further, since the overturn prevention mechanism grips the tension bar via the ball bearing, the overturn prevention mechanism can be reduced in weight and can be easily handled.

(Embodiment) An embodiment of a device for handling a recirculation pump in a nuclear reactor according to the present invention will be described with reference to the accompanying drawings.

In FIG. 1, the same parts as those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted.

The upper end of the tension bar 18A of the tension mechanism 17A
As shown in FIG. 2, the coupling stud 19A is screwed and connected to an internal screw 25 formed at the lower end of the coupling stud 19A so as to be able to penetrate the inside of the motor unit 2. The tension bar 18A extends downward through the center of the motor unit 2. As shown in FIGS. 3 and 4, the upper part of the motor unit 2 is held from both sides by a fall prevention mechanism 13A, and is tightened by bolts 26. A tension bar 18A penetrates the center of the overturn prevention mechanism 13A, and the overturn prevention mechanism 13A holds the tension bar 18A via a ball bearing 27, thereby preventing the motor unit 2 from overturning.

The lower end of the tension bar 18A is connected to the handling cart 7 via a hydraulic cylinder mechanism 28 as shown in FIG. The hydraulic cylinder mechanism 28 is fixed to the handling trolley 7 by bolts or the like, and a piston 30 is housed in the cylinder 29 so as to be able to reciprocate up and down. Hydraulic hoses 33 and By supplying or discharging pressure oil from 34, a downward pulling force is generated. A coupling portion 36 is formed at the upper end of a piston shaft 35 extending upward from the piston 30, and the coupling portion 36 and the lower end of the tension bar 18A are
Combined by eight. The tensile force generated by the hydraulic cylinder mechanism 28 is detected by a load cell 39 provided around the piston shaft 35 and displayed on a monitor 40.

 Next, the operation of the above embodiment will be described.

When housing the motor unit 2 in the casing 4, first, the upper screw portion of the tension bar 18A is connected to the inner screw 25 of the coupling stud 19A attached to the lower end of the pump shaft 16 in the casing 4, and A fall prevention mechanism 13A is installed at the upper end of the section. In this state, in a state where the motor unit 2 is seated on the handling trolley 7, the motor unit 2 is raised to a joint portion between the guide screw 6 and the handling trolley 7.

After that, the hydraulic cylinder mechanism 28 is connected to the lower part of the tension bar 18A by the pin 38 via the coupling plate 37. At this time, since the connection can be made by the pins 38, the operation can be performed extremely easily and quickly. After connecting the hydraulic cylinder mechanism 28, pressure oil is supplied into the cylinder 29, a downward pulling force is applied to the pump shaft 16 via the tension bar 18A, and the motor unit 2 is raised by the lifting device 5 in that state. Just before the motor unit 2 enters the casing 4, the overturn prevention mechanism 13A is removed, and then the motor unit 2 is housed in the casing 4 in the same manner as in the related art.

In this case, since the upper end of the tension bar 18A is connected to the coupling stud 19A via the internal screw 25, the coupling portion can pass through the inside of the motor unit 2. Further, since the overturn prevention mechanism 13A has a structure that prevents the motor portion 2 from overturning by gripping the tension bar 18A, the overturn prevention mechanism 13A may have a simple and lightweight structure, and is easy to handle. . In addition, ball bearings
27 can also serve as a vibration control mechanism during elevating.

As described above, according to the above-described embodiment, the weight of the overturn prevention mechanism 13A is reduced and the handling thereof is facilitated, thereby improving the workability of maintenance and inspection. Further, the ball bearing 27 has a vibration damping effect at the time of elevating.

Further, since the lower end of the tension bar 18A is connected to the hydraulic cylinder mechanism 28 by the pin 38, the connection can be made extremely quickly and easily, and the safety is significantly improved. In addition, since the upper part of the tension bar 18A is connected to the coupling stud 19A via the internal screw 25, the connection part can penetrate the inside of the motor part 2, and
It is not necessary to remove the upper part of the tension bar 18A in the unstable state, and safety can be improved.

〔The invention's effect〕

According to the present invention, the tension mechanism has a tension bar connected to the lower end of the pump shaft and vertically suspended, and a cylinder mechanism that applies a downward pulling force to the pump shaft via the tension bar. Connected to the coupling stud at the lower end of the pump shaft via an internal screw, the tension bar and the cylinder mechanism are connected by pin connection, and the overturn prevention mechanism holds the upper part of the motor unit and Since it is gripped via ball bearings, it is easy to attach and remove the overturn prevention mechanism, and at the same time as installing and removing the tension bar, the workability and safety during maintenance and inspection of the recirculation pump in the reactor are improved. Can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a device for handling a recirculation pump in a nuclear reactor according to the present invention, FIG. 2 is an enlarged view of II in FIG. 1, FIG. 3 is an enlarged view of III in FIG. Figure 4 is the third
FIG. 5 is a view taken along the line IV-IV in FIG.
FIG. 6 is an enlarged view, FIG. 6 is a configuration diagram showing a conventional apparatus for handling a recirculation pump in a nuclear reactor, FIG. 7 is an enlarged view of VII in FIG. 6, FIG. 8 is a view taken along line VIII-VIII in FIG. FIG. 9 is an enlarged view of IX in FIG. 6, and FIG. 10 is an enlarged view of X in FIG. 1 ... Recirculation pump in the reactor, 2 ... Motor part, 3 ...
Reactor pressure vessel, 4 ... Casing, 5 ... Lifting device,
6 ... Guide screw, 7 ... Handling trolley, 13A ... Overturn prevention mechanism, 16 ... Pump shaft, 17A ... Tension mechanism, 18A ... Tension bar, 19A ... Coupling stud, 25 ... Internal screw, 27… Ball bearing, 28… Hydraulic cylinder mechanism, 37… Coupling plate, 38… Pin.

Claims (1)

(57) [Claims] An elevating device for elevating a motor portion to a casing when a recirculation pump in a reactor is mounted; a tip-over prevention mechanism for preventing the motor portion from tipping over when the motor portion is raised; A tension mechanism for preventing the pump shaft from being pushed up when mounted, in the reactor recirculation pump handling device, wherein the tension mechanism is connected to the lower end of the pump shaft and is vertically suspended. A cylinder mechanism for applying a downward pulling force to the pump shaft via the tension bar, the tension bar being connected to a coupling stud at the lower end of the pump shaft via an internal screw, and The cylinder mechanism is connected by pin connection, and the overturn prevention mechanism holds the upper part of the motor section. Together, the reactor recirculation pump handling apparatus characterized by holding the tension bar via a ball bearing.