JP3075640B2 - Cart drive mechanism and radioactive solid waste cutting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cart for holding radioactive solid waste, and more particularly to a cart driving mechanism for raising and lowering the cart and a radioactive solid waste cutting apparatus using the same.

[0002]

2. Description of the Related Art For example, in a conventional cart driving mechanism of a radioactive solid waste cutting apparatus, a driving mechanism using a ball screw has been used. Examples of this known technique include the following. 1. Highly radioactive solid waste cutting equipment (Japanese Patent Laid-Open No. 60-166)
899) 2. 2. Cutting control method for high radioactive solid waste volume reduction device (Japanese Patent Laid-Open No. 60-181699) Highly radioactive solid waste cutting equipment (Japanese Patent Laid-Open No. 61-165)
693) 4. Cutting device for highly radioactive solid waste (Japanese Patent Laid-Open No. 61-17 / 1986)
In each of these, a drive mechanism for vertically moving a cart holding radioactive solid waste is used to rotate a vertical shaft provided in a vertical direction and raise and lower the cart by a ball screw-nut mechanism. However, in the method using the ball screw, suspended solids in water are likely to adhere due to the structure, and since these adhered substances have a high radiation dose, it has been difficult to perform maintenance by pulling up from the water.

Therefore, a method has been devised in which a cart is suspended by a wire rope or a chain, and these carts are wound and fed by a drive mechanism on the ground to raise and lower the cart. The following are known art examples using a wire rope. 5. Method and apparatus for cutting highly radioactive solid waste (JP-A-63
This known technique will be described with reference to FIG. In the cart driving mechanism of FIG. 4, the wire drum 101 is rotated by the motor 126 fixed to the gantry 127 via the speed reducer 125, the joints 123 and 124, and the shaft 122.
The cart 105 attached to the wire rope and holding the radioactive solid waste is raised and lowered in the water by moving the wire rope 102 attached to the wire 01 up and down through the sheave 103.

A cart driving mechanism using a chain has already been put into practical use, and this will be described with reference to FIG.

The cart drive mechanism shown in FIG. 5 is used by Chugoku Electric Power Co., Inc. A sprocket 207 for driving a chain 208 includes a casing 201 and a top plate 202.
The cart rail 203
Attached to. The sprocket 207 is mounted on the motor 22 of the mount 227 fixed outside the casing 201.
6, the reduction gear 225, the joints 223, 224, and the shaft 2
10 and a chain 208 mounted on a sprocket 207 and a lower sprocket (not shown)
The cart (not shown) attached to the chain 208 and holding the radioactive solid waste is raised and lowered in the water.

[0006]

However, the above-mentioned known technique has the following problems.

The cart driving mechanism using a wire rope in the prior art 5 has a simple structure and is practical, but a wire rope 103 contaminated in water is wound by a wire drum 102 provided in the air above the apparatus. Therefore, there is a high possibility that the wire drum 102 is contaminated. Therefore, there is a possibility that the dose equivalent rate around the wire drum 102 increases and the worker is exposed.

The cart driving mechanism using the chain shown in FIG. 5 has a simple structure and high reliability.
Since the sprocket 207 for driving the 08 is installed in the air above the device, the chain 208 and the sprocket 207 contaminated by the ingress of suspended solids in the water come out into the air, increasing the dose equivalent rate in the surrounding area. Workers could be exposed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cart driving mechanism using a flexible member such as a wire rope or a chain, and to provide a structure capable of reducing the exposure of workers, and to use the cart driving mechanism. It is to provide a radioactive solid waste cutting device.

[0010]

In order to achieve the above object, the present invention provides a cart driving mechanism for raising and lowering a cart holding radioactive solid waste taken out of a nuclear reactor by means of a flexible member. A driving source connected to the cart, an underwater elevating means for elevating the cart while the whole is submerged in water, and a transmission means for transmitting the power of the driving source to the underwater elevating means.

[0011] Preferably, the flexible member is a wire rope or a chain.

Further, the present invention provides a cart holding radioactive solid waste taken out of a nuclear reactor, a cutting torch for cutting the radioactive solid waste, and a radioactive solid by moving the cart up and down by a flexible member. In a radioactive solid waste cutting device having a cart driving mechanism for vertically moving waste with respect to the cutting torch, the cart driving mechanism includes a driving source that outputs power, and a whole connected to the cart and submerged in water. Underwater elevating means for raising and lowering the cart while submerged, and transmission means for transmitting the power of the driving source to the underwater elevating means.

[0013]

In the cart driving mechanism of the present invention constructed as described above, the power of the drive source is transmitted to the underwater elevating means by the transmitting means, and the underwater elevating means raises and lowers the cart while immersed in the water. The contaminated part of the water elevating means to which the suspended matter from the radioactive solid waste held in the water is attached is always below the water surface and does not rise into the air.

Examples of the flexible member include a configuration using a wire rope and a configuration using a chain.

Further, in the radioactive solid waste cutting apparatus according to the present invention, the cart driving mechanism transmits the power of the driving source to the underwater elevating means by the transmitting means and raises and lowers the cart while immersed in the water to perform cutting. However, the contaminated portion of the underwater elevating means to which the suspended matter from the radioactive solid waste held by the cart adheres is always below the water surface and does not rise into the air.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, the cart driving mechanism of the present invention is applied to a radioactive solid waste cutting apparatus, and the entire structure is shown in FIG.

In FIG. 2, the radioactive solid waste cutting apparatus includes a cart rail 3, an upper sprocket 7 and a lower sprocket 54 attached to the cart rail 3, a chain 8 stretched between the upper sprocket 7 and the lower sprocket 54, The motor 26 and the motor 2 installed on the gantry 27
6 and a bevel gear 20, 19, 1 for transmitting an output from the speed reducer 25 to the upper sprocket 7.
Cart drive mechanism 100 having 2, 11 and chain 8
53 connected to the cart and moving up and down along the cart rail 3
Cutting torches 51 and 52 for cutting the radioactive solid waste 50 taken out of the reactor and held in the cart 53
And a casing 1 for preventing diffusion of suspended matter generated during cutting. The casing 1 has a door (not shown) for taking in and out the radioactive solid waste.

A side view of the cart 53 is shown in FIG. The cart 53 is inserted into the cart base 503, the upper guide 501 and the lower guide 502 that support the radioactive solid waste 50 from above and below, and the radioactive solid waste 50, as shown in the figure. Radioactive solid waste 5
It has an inner guide 504 for guiding 0. The cart base 503 is guided to the cart rail 3 by the guide roller 30, and the upper guide 501 is a holder 8 a of the chain 8.
Is fixed to the chain 8.

FIG. 1 shows the details of the cart driving mechanism 100. In FIG. 1, a cart driving mechanism 100 includes a motor 2
6, an output shaft 22 for outputting power from a speed reducer 25, an input shaft 10 of the upper sprocket 7, and an output shaft 2
Transmission shafts 17 and 1 for transmitting power from input device 2 to input shaft 10
And 3.

The output shaft 25a of the speed reducer 25 is connected to the output shaft 22 via joints 24 and 23. Output shaft 22
Has a bevel gear 20 at the tip and is supported by a bearing 21. The bearing 21 is fixed to the casing 1, and the output shaft 22 penetrates the casing 1. A top plate 2 is provided on the roof of the casing 1. The transmission shaft 17 is the bearing 1
8 has a bevel gear 19 at one end and meshes with a bevel gear 20 at one end, and has a joint 16 at the other end. Similarly, the transmission shaft 13 is vertically supported by a bearing 14, has a joint 15 connected to a joint 16 at one end, and has a bevel gear 12.
At the other end. The transmission shaft 17 exists in the air, but the transmission shaft 13 is in contact with the pool water surface 4 in the middle, and the joint 1
5 is in the air, and bevel gear 12 is in water. The upper sprocket 7 is attached to the cart rail 3 underwater via bearings 6 and 9, has one end supported by the bearing 5, and has a bevel gear 10 at the other end. The height of the upper end of the upper sprocket 7 is sufficiently lower than the pool water surface 4, and the chain 8 is configured so as not to appear in the air. In the above configuration, the power of the motor 26 is output through the speed reducer 25,
It is provided to the output shaft 22 via the joints 24 and 23. The output of the output shaft 22 is transmitted to the transmission shaft 17 via bevel gears 20 and 19, and further transmitted to the transmission shaft 13 via joints 16 and 15.
To rotate the input shaft 10 of the upper sprocket 7 via bevel gears 12 and 11. This raises and lowers the chain 8 between the underwater sprocket and the cart 5
3 moves up and down along the cart rail 3. At this time, the cutting torches 51 and 52 remain fixed to the casing 1, and the radioactive solid waste 50 held by the cart 53 moves up and down relative to the cutting torches 51 and 52.
Thereby, the radioactive solid waste 50 is cut vertically.

According to the present embodiment, the chain 8 and the sprocket 7, which are contaminated by suspended matter from the cut radioactive solid waste 50, always exist below the pool water surface 4 in the casing 1 and do not move into the air. Therefore, the diffusion of contamination onto water in the casing 1 is minimized. Therefore, since the diffusion of the contamination to the outside of the casing 1 is extremely low, the dose equivalent rate around the gantry 27 can be suppressed, and the exposure of the worker can be reduced. Further, even when the apparatus is not operating, there is no possibility that the dose equivalent rate around the gantry 27 will increase as in the related art.

In the above embodiment, the case where the cart driving mechanism of the present invention is applied to a radioactive solid waste cutting device has been described. However, other devices for handling radioactive solid waste, for example, channels of spent fuel assemblies The present invention may be applied to a channel box attaching / detaching machine for attaching / detaching a box, and in this case, the same effect is obtained. In the above embodiment, the chain 8 is used as a member for connecting the cart.
Although the example using is described, a configuration in which a wire rope is used in place of a chain, and the wire rope is wound and fed out by a drum to raise and lower the cart, and a configuration using other flexible members are also possible. In this case, a similar effect is obtained.

[0023]

According to the present invention, since the contaminated portion does not rise into the air, the dose equivalent rate around the apparatus mount is reduced. Therefore, exposure of the worker can be reduced. Further, even when the apparatus is not operating, there is no possibility that the dose equivalent rate around the apparatus mount will increase.

[Brief description of the drawings]

FIG. 1 is a detailed view of a cart driving mechanism according to an embodiment of the present invention.

FIG. 2 is an overall structural view of a radioactive solid waste cutting device.

FIG. 3 is a side view of the cart.

FIG. 4 is a structural view of a conventional cart driving mechanism.

FIG. 5 is a structural view of a conventional cart driving mechanism.

[Explanation of symbols]

 Reference Signs List 4 pool water surface 7 upper sprocket 8 chain 10 input shaft 11 bevel gear 12 bevel gear 13 transmission shaft 17 transmission shaft 19 bevel gear 20 bevel gear 22 output shaft 25 speed reducer 26 motor 50 radioactive solid waste 51,52 cutting torch 53 cart 54 Lower sprocket 100 Cart drive mechanism

Continuation of the front page (72) Inventor Tomiji Yoshida 3-1-1 Sachimachi, Hitachi-shi, Ibaraki Hitachi, Ltd. Hitachi Plant (56) References JP-A-58-62598 (JP, A) JP-A-62 -197799 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G21C 19/02 G21C 19/365 G21F 9/30 G21C 19/33

Claims (4)

(57) [Claims] 1. A cart driving mechanism for raising and lowering a cart holding radioactive solid waste taken out of a nuclear reactor by a flexible member, comprising: a driving source for outputting power; and a whole connected to the cart and submerged in water. A cart driving mechanism, comprising: an underwater elevating means for elevating and lowering the cart as it is; and a transmitting means for transmitting the power of the drive source to the underwater elevating means. 2. The cart driving mechanism according to claim 1, wherein said flexible member is a wire rope. 3. The cart driving mechanism according to claim 1, wherein said flexible member is a chain. 4. A cart for holding radioactive solid waste taken out of a nuclear reactor, a cutting torch for cutting said radioactive solid waste, and a cart for lifting and lowering said radioactive solid waste by said flexible member. In a radioactive solid waste cutting apparatus having a cart driving mechanism for moving the cutting torch in a vertical direction, the cart driving mechanism includes a driving source that outputs power, and a driving source that is connected to the cart and that is entirely submerged in water. A radioactive solid waste cutting apparatus, comprising: an underwater elevating means for elevating and lowering a cart; and a transmitting means for transmitting the power of the driving source to the underwater elevating means.