JPH0321514Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a nuclear reactor, and particularly to a device for handling control rod drive shafts and core structures inside the reactor pressure vessel.

[Prior art] During periodic inspections of nuclear power plants, the upper lid of the reactor pressure vessel is opened and the control rod drive shafts are pulled out from the upper core structure or inserted into the upper core structure. Conventionally, a special tool was used to do this one by one, which resulted in the problem that the removal and insertion operations took a long time. To solve this problem, a reactor control rod drive shaft loading/unloading device that handles the control rod drive shaft as an assembly has been proposed, but this loading/unloading device handles only the control rod drive shaft, so Separate handling equipment is required. Therefore, it is necessary to secure a place within the containment vessel to install and store the two devices, the core structure handling device and the control rod drive shaft loading/unloading device. This increases manufacturing costs. In addition, cranes are used to operate these devices, but when changing the operation target from core structure handling equipment to handling equipment, or vice versa, it is necessary to change the equipment using a crane each time.
Very poor operability.

[Problems to be solved by the invention] Therefore, the conventional technology requires a large installation and storage space,
There were problems such as high manufacturing costs and poor operability. The present invention aims to solve these problems.

[Means for solving the problem] For this purpose, the handling device of the present invention handles both the reactor core structure suspended and supported within the reactor pressure vessel and the control rod drive shaft inserted into the reactor core. The handling device has a frame body including a hollow vertical rod placed on the top surface of the core structure, a cylinder body that grips the control rod drive shaft, and the handling device A lifting platform is connected to a lifting device fixed to the body and is attached to the vertical rod so as to be movable up and down, and an operating rod is inserted through the hollow vertical rod and can freely engage with the core structure.

[Operation] This handling device is placed on the upper surface of the core structure exposed after removing the lid of the reactor pressure vessel. At that time, the operating rod inserted into the hollow vertical rod can be engaged with the core structure. On the other hand, this vertical rod is provided with a cylindrical body capable of gripping the control rod drive shaft and an elevating platform having an elevating device so as to be movable up and down. Therefore, the core structure can be handled by moving the handling device itself up and down, and the control rod drive shaft assembly can be handled by moving the lifting platform up and down. .

[Embodiments] Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the handling device of the present invention placed on the flange top surface 15b of the upper core structure 15 exposed by removing the lid (not shown) of the reactor pressure vessel 11. The handling device is
Multiple vertical rods 1 (two on the left and right are shown in the figure),
A frame is constituted by a lifting device mounting base 2 fixedly attached to an upper portion of the vertical rod 1 and a guide ring 3 disposed at a lower portion of the vertical rod 1.
A guide portion 13 having a through hole is provided at a proper position of the guide ring 3. The flange 11a of the reactor pressure vessel 11, which is exposed after removing the lid (not shown), has a bolt hole (not shown), and the guide stud 14 screwed into the bolt hole is inserted into the through hole of the guide part 13. ing.

The vertical rod 1 is provided with a vertically movable lifting platform 4 that holds a large number of control rod drive shaft protection cylinders 17 by means of upper and lower holding plates 4a and 4b. A control rod drive shaft gripping device 18 is provided, which may be of any suitable construction.

In order to drive this elevating table 4, an appropriate drive source 7 such as a motor is provided on the installation table 2 constituting the frame.
and a gear box 6 connected to a transmission shaft 5 driven by the drive source 7. Similarly, the vertical rod 1 constituting the frame is rotatably driven via the gear box 6. The lower end of the ball screw 8 is rotatably supported. A nut 9 screwed onto the ball screw 8 is fixed to the lifting platform 4. Therefore, by operating the drive source 7, the lifting platform 4 moves along with the vertical rod 1 along with the cylindrical body 17.
It is possible to move up and down along the These various parts 5~
9 constitutes an elevating device for the elevating table 4.

The vertical rod 1 is a hollow body, and an operating rod 10 extends in the axial direction inside the vertical rod 1. A handle 10c that can be operated from the deck 20 of the handling device is provided at the upper end of each operating rod 10. The structure of the lower end A portion of the vertical rod 1 and the operating rod 10 is as shown in FIG.

In FIG. 2, the lower end surface of the vertical rod 1 is placed on the flange upper surface 15b of the upper core structure 15. The lowermost end of the operating rod 10 is a threaded portion 10b, which can be screwed into a threaded hole 15a in the upper core structure flange by operating the handle 10c described above. Further, a protruding part 1a is formed inside the lower end of the vertical rod 1, and an enlarged diameter part 10a is formed above the threaded part 10b of the operating rod 10, and the protruding part 1a and the enlarged diameter part 10a cooperate with each other. It functions as a stopper for the operating rod 10.

Next, the operation of the handling device of the present invention having the above-described structure will be explained.

In Figures 1 and 2, reactor pressure vessel 1
After removing the lid body (not shown) of 1, the pressure vessel 1
The guide stud 14 is inserted into the bolt hole in the flange 11a of No. 1. After that, the lifting fitting 12 is lifted by a crane and the handling device is moved to the reactor pressure vessel 11.
carry it above and lower it. At this time, the guide stud 14 is inserted into the guide portion 13 of the guide ring 3,
While positioning the handling equipment, the lower end surface of the vertical rod 1 is aligned with the flange upper surface 15 of the upper core structure 15
Place it stably on b.

Next, turn the upper end handle 10c of the operating rod 10 to tighten the threaded portion 10b onto the flange of the upper core structure 15 until the bottom surface of the expanded diameter portion 10a of the operating rod 10 contacts the lower end protrusion 1a of the vertical rod 1. The handling device is screwed into the upper core structure 15 by inserting it into the provided screw hole 15a. Then, the elevating device is operated to lower the elevating table 4, and the control rod drive shaft 1 protruding from the upper surface of the upper core structure 15 is lowered.
6 is inserted into the cylindrical body 17 for protecting the control rod drive shaft, and when the tip reaches the gripping device 18, the lifting platform 4 is stopped. After that, after operating the gripping device 18 to grip the plurality of control rod drive shafts 16,
After raising the lifting platform 4 and storing the control rod drive shaft 16 in the handling device to the position shown in FIG.
If the hanging fitting 12 is lifted by a crane, the control rod drive shaft 16 and the upper core structure 15 can be moved to a predetermined position at the same time.

When inserting the control rod drive shaft 16 and the upper core structure 15 into the reactor pressure vessel 11, after positioning the handling device with the guide stud 14,
You can perform the operation in the reverse order of the above.

In addition, when handling the lower core structure 19, the handling procedure for the upper core structure 15 described above may be followed.

[Effects of the invention] As is clear from the above explanation, the handling device according to the present invention can handle a large number of control rod drive shafts and reactor core structures at the same time. Compared to technology, it requires less space for installation and storage, and the manufacturing cost is low.
It is also easy to operate. Furthermore, since the working time is shortened, the radiation exposure of workers is reduced, which is an extremely important effect.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view showing the handling device of the present invention placed on the upper surface of the flange of the upper core structure exposed by removing the cover of the reactor pressure vessel, and Fig. 2 is the same as Fig. 1. FIG. 2 is an enlarged sectional view of part A of FIG. 1... Vertical rod, 2... Lifting device installation stand, 3...
...Guide ring, 4... Lifting platform, 5... Transmission shaft, 6...
... Gearbox, 7 ... Drive source, 8 ... Ball screw, 9 ... Nut, 10 ... Operation rod, 11
...Reactor pressure vessel, 15...Upper core structure,
15a...Top surface, 16...Control rod drive shaft, 17...
... cylinder body, 18 ... gripping device, 19 ... lower core structure.

Claims (1)

[Scope of utility model registration request] A frame that handles a reactor core structure that is suspended and supported within a reactor pressure vessel and a control rod drive shaft that is inserted into the reactor core, and that includes a hollow vertical rod that is placed on the top surface of the reactor core structure. a lifting platform having a cylindrical body that grips the control rod drive shaft, connected to a lifting device fixed to the frame body, and attached to the vertical rod so as to be movable up and down; A handling device in a nuclear reactor, comprising an operating rod that is inserted through the control rod and can be freely engaged with the reactor core structure.