JPS584997B2 - Recovery device for used detectors in nuclear reactors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recovery device for used detectors (in-core type detectors) used in the cores of, for example, B, W, and R type nuclear reactors.

Conventionally, spent in-core detectors loaded in the core of this type of nuclear reactor are removed from the core during periodic inspections and stored by immersing them in a waste treatment pool.

That is, since the used detectors taken out from the core are loaded into a rope-shaped flexible tube and are highly radioactive, it is difficult to handle them as they are.

Conventionally, a lead cask placed on a trolley was transported directly below the reactor core, the lid of the cask was removed, and the spent detector was wound around the drum inside the cask from the bottom of the reactor core. After that, the lid is closed on the cask, and the cask is taken out together with the trolley, and the closed cask is immersed in water in a waste treatment pool for storage.

However, since the above-mentioned cask is a large lead container, immersing the entire cask in a waste treatment pool would not only take up a large amount of storage space and be uneconomical. Because it is a heavy item, it is not easy to handle.Moreover, when wrapping a highly radioactive used detector around the drum inside the cask, there is a risk that it will be unbalanced and wound around the drum, and the space inside the cask will be There are disadvantages such as being forced to design a thick cask (in fact, the entire cask must be made larger).

In order to eliminate the above-mentioned drawbacks, the present invention provides a rotating shaft that can be inserted into and removed from a bearing on a truck, and a cask body having a main lid and an auxiliary lid that passes through the rotating shaft and is mounted on the truck. A winding drum with a guide rope mounted inside a cartridge sunk inside the cask body is rotated together with the rotating shaft, so that the highly radioactive used detector can be safely recovered. The purpose of this project is to submit a recovery device for spent detectors in nuclear reactors.

Hereinafter, the present invention will be described with reference to an illustrated embodiment.

1 to 3, reference numeral 1 denotes a truck having a pair of front and rear wheels 2, 3, and a pair of handles 4, 5 are installed at both ends of the truck 10. A drive motor 6 is installed on the trolley 1 adjacent to the vehicle 5.

A coupling 7 is attached to the output shaft 6a of the drive motor 6, and a one-way clutch 8 is attached to the coupling 7.

Furthermore, the trolley 1 located close to this one-way clutch 8
A pair of bearings 910 are provided on the top, bearings 9 and 1.
A rotating shaft 12 having a bundle 11 is removably mounted on the shaft 0 .

Furthermore, a spline 13 is provided at the tip of the rotating shaft 12.
The spline 13 is fitted to the driven side of the one-way clutch 8 so as to be slidable in the axial direction, and rotates together with the one-way clutch 8.

On the other hand, a fitting part 12a having a square cross section is located in the middle of the rotating shaft 12, and is connected to a cartridge 2, which will be described later.
A cask body having a horseshoe-shaped cross section is disposed on the carriage 1 where the fitting portion 12a is located. 14
The cask body 14 is removably mounted by a pair of mounting bolts 15, and the cask body 14 is covered with a nighter 17 pasted on the outer periphery of a lead material 16 having a horseshoe-shaped cross section, as shown in FIG. This is what I did.

Furthermore, the upper opening 14a of the cask body 14 is removably closed with a main lid 18 and an auxiliary lid 19 that are integral with each other. Each removal member 20 planted on the surface,
21 so that it can be tightened and fixed.

On the other hand, on both inner surfaces of the cask body 140, as shown in FIG. A cartridge 23 having a shape is removably installed.

(See Figure 3). Further, each bearing portion 23a is formed at the inner end of both sides of this cartridge 230, and each bearing portion 23a is formed at the inner end of both sides of this cartridge 230.
A winding drum 24 having a spiral groove 24a is rotatably mounted on the outer periphery of the winding drum 3a.

Furthermore, the fitting portion 12a of the rotary shaft 12 is fitted into the winding drum 24 so as to slide in the axial direction and rotate together with the winding drum 24.

On the other hand, on a part of the outer peripheral surface of the winding drum 24.

As shown in FIGS. 2 and 3, a notch 25 is formed, and a base 26a of a guide rope 260 is fixed to this notch 25 with a mounting bolt 27.

Further, the outer end portion 26b of this guide rope 26 is exposed to the outside through a notch hole 28 provided in the top plate 23b of the cartridge 230 and a gap in the auxiliary lid 19 that has been removed in advance. outer end 26 of
b) Spent detector inside the core (in-core type detector) 29
is designed to be removably attached.

A hanging ring 30 is provided at the center of the top plate 23b of the cartridge 230, and a hanging rope 31 is attached to this hanging ring 30.

Further, as shown in FIG. 1, a pair of ears 32 are provided on both sides of the cask body 140, and each ear piece 32 is provided with a lifting rope 33.

Each of these lifting ropes 33 pulls out the rotating shaft 12,
Furthermore, when the mounting bolts 15 are removed, the cask body 14 is lifted up by a hoisting machine (not shown) and used when being transported to a waste treatment pool.

Therefore, when the spent detector 29 is taken out from the core and stored in the waste treatment pool during periodic inspection,
As shown in FIG. 1, the cask body 14 is placed on the trolley 1 in advance and fixed with the mounting member 15, and the rotating shaft 12 is fitted onto the winding drum 24 of the cartridge 23 inside the cask body 14. Further, it is mounted on the driven side of the one-way clutch 8.

The cart 1 is then transported to the bottom of the reactor, and the spent detector 29 is attached to the outer end 26b of the guide lobe 26.

Next, by driving the bundle 11 or the drive motor 6, the spiral groove 24a is formed on the outer peripheral surface of the winding drum 24.
The used detector 29 is wound up and stored in the cartridge 23 according to the following.

Then, the auxiliary lid 19 is closed to the main lid body 18 using each removal member 21.

In this way, the used detector 29 housed in the cartridge 23 is transported to the outside together with the cart 1.

Next, the rotating shaft 11 is pulled out in the direction indicated by the arrow in FIG. 1 and taken out.

Then, the mounting bolts 15 of the cask body 14 are removed, and the combined lifting rope 33 is connected to the hook of the hoisting machine. After being immersed in water in the waste treatment pool, the main lid 18 and the auxiliary lid 19 are opened from the cask body 14, and then the cartridge 23 is taken out with the hanging rope 31 and stored.

On the other hand, the cask body 14 can be taken out of the water, inserted with a new cartridge, and used again.

Note that when the rotating shaft 11 is pulled out, the cask body 1
Although large holes are formed on both sides of the hole 40, each blind plate 34 shown in FIG. 3 can be attached and sealed.

As described above, according to the present invention, the rotating shaft 12 is removably provided in each of the bearings 9 and 10 on the truck 1.
A cask body 14 is provided on the trolley 1 passing through the cask 2,
A pair of main lid body 18 and auxiliary lid 19 are closed at the upper opening of the cask body 14, a car ridge 23 is sunk into the cask body 14, and a guide lobe is mounted inside the cartridge 23. Since the winding drum 24 with 26 is configured to rotate together with the rotating shaft 12, the highly radioactive used detector 29 can be safely recovered (in addition, it can be configured to be small and occupy less space). It has excellent effects such as being smaller in size and being able to be stored economically.

[Brief explanation of the drawing]

Fig. 1 is a side view of a spent detector recovery device in a nuclear reactor according to the present invention, Fig. 2 is an enlarged vertical sectional view showing only the main parts of the invention, and Fig. 3 shows only the main parts of the invention. It is a side view, and is a diagram showing a half cross section. 1... Trolley, 9,10. ...Bearing, 12
...... Rotating axis, 14... Cask body,
18...Main lid body, 19...Auxiliary lid, 2
3-... Cartridge, 24...- Winding drum, 26-... Guide rope, 29...°
. Used detector.

Claims (1)

[Claims] 1. A rotating shaft that is removably installed in a bearing on a truck, a cask body that is installed on the truck that passes through this rotating shaft, and a pair of cask bodies that are closed in the upper opening of the cask body. A used nuclear reactor comprising a lid body and an auxiliary lid, a cartridge submerged in the cask body, and a winding drum with a guide rope mounted inside the cartridge ridge and rotated together with the rotating shaft. Detector recovery device.