JPS62121396A - Hanging tool for structure in nuclear reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water-cooled nuclear reactor, and more particularly to a tool for lifting the internal structure of a nuclear reactor used when exchanging fuel.

[Prior Art] As is well known, in a typical water-cooled nuclear reactor such as a pressurized water reactor, a core tank is disposed hanging down within the reactor vessel, and the lower core of the core tank is A reactor core composed of a large number of fuel assemblies is disposed on a support plate. Further, a reactor internal structure having a guide tube for a control rod assembly is provided in the reactor core barrel just above the reactor core, and this reactor internal structure is also suspended and supported by the flange portion of the reactor vessel. As is well known, the control rod assembly is composed of various rods such as an output control control rod, a load following control rod, and a water removal rod.

Conventionally, as can be read from FIGS. 7 and 8, a control rod assembly 1 is composed of a plurality of rods 1a and a spider 4 that connects the tops of the rods to each other with screws, and usually, It is housed in a guide tube Za in the reactor internal structure 2. A drive shaft 3 is also connected to the spider 4, and the drive shaft 3 communicates with a control rod drive device (not shown) mounted on the upper lid of the reactor vessel (not shown).

During refueling of such a reactor, when the lid of the reactor vessel is removed, the control rod drive device is separated from the drive shaft 3, so the connection between the control rod assembly 1 and the drive shaft 3 is not restrained. The spider 4 of the control rod assembly 1 is placed on the bottom plate 5 of the guide tube 2a. Therefore, when the upper reactor inner structure 2 is lifted and moved during fuel exchange, a large number of control rods q7] hang below the upper core support plate 6 of the upper reactor internal structure 2 without any guide. It will be in a state where it is. Further, the control rod assembly 1, which is taken out from the nuclear reactor and hangs down in large numbers, must be inspected one by one.

``Problems to be Solved by the Invention'' Therefore, the conventional technology has problems such as difficulty in transporting the upper reactor internals and poor workability during inspection of control rod assemblies. The object of the invention is to provide a tool for lifting internal structures of a nuclear reactor, which can quickly solve these problems.

[Means for Solving the Problems] For the purpose of this, the present invention is a lifting tool for lifting a reactor internal ti structure having a guide tube for a control rod assembly together with the control rod assembly. an extending pedestal, a plurality of main columns depending from the pedestal and capable of being coupled to the 11th reactor internals;
a grip part that is supported so as to be movable up and down along the main column and that collectively grips a number of drive shafts connected to the control rod assembly; and a grip part that is provided in relation to the grip part and the main column. It is equipped with a lifting device that raises and lowers it.

[Operation] After removing the upper lid of the reactor vessel, the two hanging tools are carried onto the suspended reactor internals. Next, the main column is fixed to the reactor internals, and the drive shaft gripping section is operated to grip the two ends of the drive shaft. After that, if the lifting device is operated in a desired direction, the driving shaft gripping portion is associated with the lifting device, so that the driving shaft gripping portion moves upward along the main column as the lifting device is operated. do. Therefore, the control rod assembly related to the drive shaft gripped by the drive shaft gripping portion is also pulled upward and housed in the guide cylinder of the reactor internal structure.

[Embodiments] Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which the same reference numerals indicate the same or corresponding parts.

] U2I and FIG. 2 show a first embodiment of a lifting tool according to the present invention. The lifting tool has a horizontally extending workbench or pedestal 16, from which a plurality of main columns 11 (three in the embodiment) are suspended and supported.

Each main column 11 has an outer cylinder 11a and an inner shaft 1 lb.
The lower end of the shaft 11b can be attached to and detached from the flange portion of the upper reactor internal structure 2 by means such as screwing. This attachment/detachment operation and the operation of the drive shaft gripping portion and the gripping portion elevating device, which will be described later, can be performed from the pedestal 16 provided with such operation units (not shown).

A sliding block lie is fitted into these main columns 11 so as to be able to move up and down, and the sliding block lie is connected to the lifting section 15.
The sling block portion 14 having a horizontal shape is supported horizontally. A hanging fitting 18 is provided at the tip of the lifting part 15, and after the lifting tool of the present invention is installed in the furnace internal structure 2,
This hanging fitting 18 can be used to hang it using a crane (not shown). The sling block part 14 is provided with a drive shaft gripping part 13 below the sling block part 14, which grips a large number of drive shafts at once, as is well known. This drive shaft grip part 13
It is preferable to use a type that can latch and unlatch any drive shaft.

Further, a grip part lifting device 17 is associated with the sliding block part 14. In this embodiment, the lifting device 17 includes a hydraulic cylinder 17a fixed to the pedestal 16 (which may also be the main column 11), and a piston extending downward from the hydraulic cylinder 17a and fixed at its lower end to the sliding block llc. It is a hydraulic type consisting of a rod 17b.

The lifting tool of the present invention configured as described above operates as follows. In FIG. 1, after removing the upper lid of the reactor vessel (not shown), the hanging metal fitting 18 is removed using a crane or the like.
The lifting tool is suspended and transported onto the reactor internal structure 2. Next, from the pedestal 16, 1tlli111. Operate b! l
1lllllb to the flange part of the reactor internals 2, and operate the drive shaft grip part 13 to release the drive 1jll1.
3 (see Figure 7). After that, if a pressure fluid such as water is introduced into the hydraulic cylinder 1.7a as shown by arrow A by the same operation from the pedestal 16,
Screws 1 to 17b rise. A sliding bracket is fixed to the lower end of the screw rod 171), and a sling block portion 14 having a drive shaft gripping portion 13 is installed on the sliding block 11c, so that the piston rod 17b With the rise of the main column 11, the drive shaft gripping part 13, the lifting part 15, etc. move upward along the main column 11, as shown by chain lines in FIG. ＆e,
The control rod assembly 1 (see FIG. 7) associated with the drive shaft 3 gripped by the drive shaft grip part 13 is also pulled upward,
It is housed in the guide tube 2a (FIG. 7) of the reactor internals 2.

At this time, a part of the hanging part 15 and the hanging fittings 18 are connected to the frame 1.
6 and extends above the pedestal 16, so that a crane or the like can be hooked to the hanging fitting 18, and the upper reactor internal structure 2 can be secured by storing the control rod assembly 1 in the guide tube 2a.
It becomes possible to transport it together.

By reversing the above steps, you can move the control rod (J,
, 1 > rest 1 can be released.

In the first embodiment, the elevating device 17 was constructed from a hydraulic sill, etc., but various other elevating and lowering + A positions may be used. For example, as shown in FIGS. 3 and 4, a wire rope winding mechanism 17 consisting of a wire lobe 17d, a sheave 17e, an ISBS upper moving motor 17, etc. may be used, or as shown in FIGS. Alternatively, a chain hoisting mechanism using a 1.7g chain instead of the wire lobes may be used, which can operate substantially in the same manner as the lifting device 17 described in connection with FIGS. It has the following effects.

[Effects of the Invention] Since the lifting tool of the present invention has the above configuration and function, the control rod assembly can be stored in the guide tube when transporting the upper reactor internals during fuel exchange, etc. There will be no hindrance to the transportation of reactor internals.

This also extends to improving workability when inspecting control rod assemblies, and also allows control rods to be used as lifting tools! Since the assembly lifting device is built-in, there is no need to separately provide special lift crane equipment for lifting and lowering the control rod assembly.

[Brief explanation of drawings]

FIG. 1 is a side view showing the left half of the first embodiment of the lifting tool according to the present invention, FIG. 2 is a plan view of FIG. 1, and FIGS.
The figures correspond to FIGS. 1 and 2 of the second embodiment of the present invention, and FIGS. 5 and 6 correspond to FIGS. 1 and 2 of the third embodiment of the present invention. , No. 7 (2I is a cross-sectional view illustrating the transportation mode of conventional upper reactor internals, No. 80 is an enlarged cross-sectional view of the area ■ shown in an oval shape in FIG. 7. 1 Control rod assembly 2. ...Furnace internals 2a...Guide tube 3...Drive shaft 11-Main column 13
...Gripping part 16, pedestal 17, lifting device 2-Dou I

Claims (1)

[Claims] A lifting tool for lifting a nuclear reactor internal structure having a guide tube for a control rod assembly together with the control rod assembly, the lifting tool comprising a horizontally extending pedestal, and a plurality of units that hang down from the pedestal and can be coupled to the reactor internal structure. a main column, a grip part that is supported so as to be movable up and down along the main column and that collectively grips a large number of drive shafts connected to the control rod assembly, and a grip part that is provided in relation to the grip part and the main column. A lifting tool for a nuclear reactor internal structure, comprising a lifting device for raising and lowering a reactor.