JPH049272B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an in-reactor working device that performs operations such as visual inspection, fallen object recovery, and ultrasonic flaw detection inside a boiling water reactor during its service life. In particular, the present invention relates to an in-core working device suitable for performing work below the core support plate.

[Technical background of the invention and its problems]

Conventionally, when something is accidentally dropped into the reactor during the service life of a boiling water reactor, a simple handling tool is used to grasp and recover the fallen object from the operating floor.

However, with this method, it is relatively easy to work on fallen objects above the core support plate, but it is extremely difficult to recover objects below the core support plate, as the work is sometimes 25 meters below the water surface from the operation floor. .

Furthermore, although it is relatively easy to visually inspect the welded joint between the lower head plate of a nuclear reactor pressure vessel and the stud tube, ultrasonic flaw detection is difficult because it may damage the welded joint.

[Purpose of the invention]

The present invention was developed in view of the current situation, and it is extremely easy to perform operations above the core support plate, as well as operations below the core support plate, such as visual inspection, fallen object collection, and ultrasonic flaw detection, by remote control. The purpose of the present invention is to provide an in-furnace working device that can perform the following tasks.

[Summary of the invention]

As a means for achieving the above object, the present invention provides a belt that is stretched endlessly on both sides of a main body and is driven so as to protrude from the main body on both sides, a manipulator provided at the tip of the main body, and a belt provided at the tip of the manipulator. a mounted, swingable and rotatable remotely controlled optical head;
It is characterized in that it is equipped with an ITV camera and a driving device for each of the above-mentioned devices, and is capable of self-propelled movement by driving both of the above-mentioned belts in pressure contact with the in-furnace devices.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1, numeral 1 indicates the reactor pressure vessel, 1a
1 is a lower end plate of the pressure vessel, and a cylindrical shroud 2 is provided inside the reactor pressure vessel 1. A jet pump (not shown) is disposed in an annular portion formed by the reactor pressure vessel 1 and the shroud.

As shown in FIG. 1, a fuel assembly 6 whose upper and lower ends are supported by an upper grid plate 3 and fuel support fittings 5 attached to a core support plate 4 is stored in the shroud 2, and constitutes the reactor core. There is. Further, below the fuel support fitting 5, as shown in FIG. 1, a control rod guide tube 7 and a control rod drive mechanism housing (hereinafter
(referred to as CRD housing) 8 are sequentially provided,
As shown in FIG. 1, the CRD housing 8 is drawn out of the reactor pressure vessel 1 via a control rod drive mechanism stump tube (hereinafter simply referred to as a stump tube) 9 welded to the pressure vessel lower end plate 1a. And the in-furnace working device 20 according to this embodiment
As shown in FIG. 1, the device guide tube 21 includes the outermost fuel assembly 6, fuel support fittings 5, control rods (not shown), control rod guide tubes 7, and thermal tubes (not shown). The reactor pressure vessel 1 can be suspended inside the reactor pressure vessel 1 by using the space created by the removal. In addition, in Fig. 1, 10 is an in-core guide tube, and 11 is a differential pressure detection/
The boric acid water injection piping is shown.

The device guide tube 21 is equipped with a simple jig for lowering the in-furnace working device 20 onto the housing section of the in-furnace working device 20 and the pressure vessel lower end plate 1a, which will be described in detail later. As shown in FIG. 1, when it is suspended into the reactor pressure vessel 1, it passes through the upper grid plate 3, the core support plate 4, etc., and is fixed to the CRD housing 8.

On the other hand, the in-furnace working device 20 includes a rear main body 23 connected to the device guide tube 21 via a cable 22, and a front main body 24 connected to the front end thereof, as shown in FIG. The front main body 24 can be oscillated 25 by 90 degrees to both sides from a straight position relative to the rear main body 23. Both main bodies 2
As shown in FIG. 2, endless belts 27 are disposed on both side surfaces of the loops 3 and 24, and are stretched endlessly between the drive rollers 26 and 26 at both ends. , that is, main body 2
3, 24 from the inside side of the belt guide roller 28,
They are guided by 28 and rotated in a two-layered manner. When the in-furnace working device 20 is working, a link mechanism and a spring mechanism (none of which are shown), etc.
7 protrudes from both sides of the main bodies 23 and 24, and is pressed against the stud tube 9 so that it can run freely.

Inside the rear main body 23 there is an industrial
An ITV camera is built-in, and a driving device (not shown) for a manipulator 29 provided at the tip of the front body 23 is built-in. As shown in Figure 2, the manipulator 29 is a small one with a length of about 200 mm, and its handling wrist is flexible with two degrees of freedom to improve workability. There is. The manipulator 29 as a whole is rotatable and swingable. As shown in FIG. 2, a remote-controlled fiberscope 30 is provided at the handling wrist of the manipulator 29, and is designated by the reference numeral 31 in the figure. The field of view is now available.
The image obtained by this fiberscope 30 is sent to an industrial ITV camera built into the rear main body 23, where it is converted into an electrical signal.

Next, the operation of this embodiment will be explained.

When bringing the in-core working device 20 close to a work area below the core support plate 4, first the outermost fuel assembly 6, fuel support fitting 5,
Remove the control rod (not shown), control rod guide tube 7, and thermal tube (not shown). An operation floor (not shown) was installed above the reactor pressure vessel 1 using the removed space.
A device guide pipe 2 in which an in-furnace working device 20 is housed.
1, upper lattice plate 3 and core support plate 4
etc., and fix it to the CRD housing 8.

Next, the in-furnace working device 2 is inserted from inside the device guide pipe 21.
0 is taken out and suspended onto the pressure vessel lower end plate 1a. At this time, as shown in FIG.
is installed at the corner of the outermost CRD housing 8, so the in-furnace working device 20 can be suspended on the side where there is no adjacent CRD housing 8. Therefore, there is no possibility that the starting tool for hanging down will hit the adjacent CRD housing 8 or the stud tube 9. In addition, the hanging position is next to the outermost stump tube 9, and the inclination of the pressure vessel lower end plate 1a is about 45 degrees, so the in-furnace working device 20 can be easily lifted down without using complicated jigs. can.

Next, the belts 27 of both main bodies 23 and 24 of the suspended furnace working device 20 are made to protrude to both sides, and are brought into pressure contact with the stump tubes 9 on both sides as shown in FIG. In this state, the belt 27 is driven. Thereby, the work can be carried out by freely traveling between the stump tubes 9 where there is no in-core guide tube 10. A broken line 32 in FIG. 3 indicates an example of a travel route when working on 1/4 of the core (fallen object recovery work, ultrasonic flaw detection work, visual inspection work, etc.). In this case, the front body 24 is the rear body 23
Since it is designed to be oscillated by ±90 degrees 25 relative to the position, it is possible to travel around the stump tube 9, and even a small manipulator 29 can work over the entire area.

Since the in-core working device 20 is self-propelled, even work below the core support plate 4 can be performed sufficiently and quickly by remote control. Further, since the front body 24 of the in-furnace working device 20 can be oscillated 25 by ±90 degrees with respect to the rear body 23, the device 20 can be operated by making good use of the space between the stump tubes 9 where there is no in-core guide tube 10. It can be self-propelled. Therefore, the self-propelled range is widened, and a simple manipulator 29 is sufficient. Further, the belt 27 for self-propelling is moved from the inside of the main bodies 23 and 24 to a belt guide roller 28.
Since the inner space of the main bodies 23, 24 can be effectively utilized, the main bodies 23, 24 can be made smaller.

In the above-mentioned embodiment, a case has been described in which the in-furnace working device 20 is self-propelled using the stump tube 9, but it may be made to be self-propelled using other in-furnace equipment. Further, the manipulator 29 may be of an articulating type. Many other modifications and changes can be made without departing from the gist of the invention.

〔Effect of the invention〕

As explained above, the present invention enables self-propulsion by driving belts provided on both sides of the main body in pressure contact with furnace equipment, and allows the main body to travel within the furnace and perform work using the manipulator and optical head at the tip of the main body. As a result, operations such as visual inspection of the area below the core support plate, collection of fallen objects, and ultrasonic flaw detection can be performed extremely easily and satisfactorily by remote control. Therefore, the health of the nuclear reactor can be improved, and the amount of radiation exposure can be reduced.

[Brief explanation of drawings]

FIG. 1 is an overall view showing one embodiment of the present invention, and FIG.
The figure is a perspective view showing an example of an in-furnace working device, and FIG. 3 is an explanatory diagram showing an example of work using the in-furnace working device. 1...Reactor pressure vessel, 8...CRD housing,
9...Stup tube, 10...In-core guide tube,
20...Furnace working device, 21...Device guide tube, 23...
Rear body, 24... Front body, 27... Belt, 29
...Manipulator, 30...Fiberscope.

Claims (1)

[Scope of Claims] 1. In an in-reactor working device that performs operations such as visual inspection, fallen object recovery, and ultrasonic flaw detection inside the reactor of a boiling water reactor, an in-reactor working device that extends endlessly on both sides of the main body and extends from the main body A belt that protrudes from both sides and is driven, a manipulator provided at the tip of the main body, a remotely controlled optical head that is attached to the tip of the manipulator and can swing and rotate, and an industrial head disposed within the main body. An in-furnace working device comprising an ITV camera and a driving device for each of the devices, and is capable of self-propelled by driving both of the belts in pressure contact with the in-furnace devices. 2. The main body, a front body with a built-in drive device,
Consists of a rear body with a built-in ITV camera,
The in-furnace working device according to claim 1, wherein the front body and the rear body are connected so as to be bendable at right angles.