JPH06148392A - Cart driving mechanism and cutting device for radioactive solid waste - Google Patents

Abstract

PURPOSE:To furnish a construction enabling reduction of exposure of an operator in a cart driving mechanism using a flexible member such as a wire rope or a chain. CONSTITUTION:A power of a motor 26 is outputted through a reduction gear 25, given to an output shaft 17 through joints 23 and 24 and further transmitted to a transmission shaft 17 through bevel gear 20 and a bevel gear 19. This output is given to a transmission shaft 13 through joints 16 and 15 and makes an input shaft 10 of an upper sprocket rotate through bevel gears 12 and 11. Thereby a chain 8 is moved up and down between this sprocket and a lower sprocket in water and a cart goes up and down therewith. Since the chain 8 and the sprocket 7 which are contaminated are present in the water and are not shifted into the air, a dose equivalent rate at and around a frame 27 is suppressed and exposure of an operator is reduced.

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 drive mechanism for moving the cart up and down and a radioactive solid waste cutting device using the cart drive mechanism.

[0002]

2. Description of the Related Art For example, in a conventional cart drive mechanism for a radioactive solid waste cutting device, a drive mechanism using a ball screw has been conventionally used. The following are examples of this known technology. 1. Highly radioactive solid waste cutting device (JP-A-60-166)
899) 2. Cutting control method for high radioactive solid waste volume reduction device (Japanese Patent Laid-Open No. 60-181699) 3. Highly radioactive solid waste cutting device (JP-A-61-165)
693) 4. Highly radioactive solid waste cutting device (JP-A-61-17)
6894) In all of these, in the drive mechanism for vertically moving the cart holding the radioactive solid waste, the vertical shaft provided in the vertical direction is rotated to move the cart up and down by the ball screw-nut mechanism. However, in the method using this ball screw, suspended solids in water tend to adhere due to the structure, and since these adherents have a high radiation dose, it was difficult to perform maintenance by pulling them out of water.

Therefore, a method has been devised to elevate the cart by suspending the cart with a wire rope or a chain and winding and sending it out by a driving mechanism on the ground. The following are examples of known techniques using a wire rope. 5. Highly radioactive solid waste cutting method and device
-88550) This known technique will be described with reference to FIG. In the cart drive mechanism of FIG. 4, the wire drum 101 is rotated by the motor 126 fixed to the pedestal 127 via the speed reducer 125, the joints 123 and 124, and the shaft 122.
By moving up and down the wire rope 102 attached to 01 through the sheave 103, the cart 105 attached to the wire rope and holding the radioactive solid waste is moved up and down in water.

A cart drive 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 in China Electric Power Co., Ltd., and the sprocket 207 for driving the chain 208 has a casing 201 and a top plate 202.
The cart rails 203 are arranged separately in the interior of the
Is attached to. Further, the sprocket 207 is the motor 22 of the frame 227 fixed to the outside of the casing 201.
6 reducer 225, joints 223, 224, and shaft 2
A chain 208 that rotates through 10 and is attached to a sprocket 207 and a lower sprocket (not shown).
By moving up and down, a cart (not shown) attached to the chain 208 and holding radioactive solid waste is moved up and down in water.

[0006]

However, the above-mentioned known art examples have the following problems.

The cart drive mechanism using the wire rope in the known art 5 has a simple structure and is practical, but the wire rope 103 contaminated in water is wound up by the wire drum 102 provided in the air above the apparatus. Therefore, the wire drum 102 is likely to be contaminated. Therefore, there is a possibility that the dose equivalent rate around the wire drum 102 is increased and the worker is exposed to the radiation.

The cart drive mechanism using the chain shown in FIG. 5 has a simple structure and high reliability.
Since the 08 driving sprocket 207 is installed in the air above the device, the chain 208 and the sprocket 207 that are contaminated by the entrapment of suspended solids in the water come out in the air, and the dose equivalent rate in the vicinity increases. There was a possibility that the worker would be exposed to radiation.

An object of the present invention is to provide a structure for a cart drive mechanism using a flexible member such as a wire rope or a chain, which is capable of reducing the exposure of workers, and to use the cart drive mechanism. The object is to provide a radioactive solid waste cutting device.

[0010]

In order to achieve the above-mentioned object, the present invention outputs power in a cart drive mechanism that elevates and lowers a cart holding radioactive solid waste taken out from a nuclear reactor by a flexible member. And a submersible elevating means connected to the cart for elevating and lowering the cart while the whole is submerged in water, and a transmitting means for transmitting the power of the drive source to the submersible elevating means.

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

Further, according to the present invention, a cart for holding radioactive solid waste taken out from a nuclear reactor, a cutting torch for cutting the radioactive solid waste, and a cart for raising and lowering the cart by means of a flexible member are provided. In a radioactive solid waste cutting device having a cart drive mechanism for moving waste vertically with respect to the cutting torch, the cart drive mechanism is a drive source for outputting power, and the whole cart is connected to the cart to be submerged in water. It has an underwater lifting means for moving the cart up and down while it is submerged, and a transmission means for transmitting the power of the drive source to the underwater lifting means.

[0013]

In the cart drive mechanism of the present invention configured 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 underwater elevating means, to which the suspended solids from the radioactive solid waste retained in the above are attached, is always under the water surface and does not rise to the air.

Further, examples of the flexible member include a structure using a wire rope and a structure using a chain.

Further, in the radioactive solid waste cutting apparatus of the present invention, the cart driving mechanism transmits the power of the driving source to the underwater elevating means by the transmitting means to raise and lower the cart while submerged in water to perform cutting. , The contaminated part of the underwater elevating means, to which the underwater suspended matter from the radioactive solid waste held in the cart adheres, is always under the water surface and does not rise to the air.

[0016]

Embodiments of the present invention will be described below with reference to FIGS. The present embodiment is a case where the cart drive mechanism of the present invention is applied to a radioactive solid waste cutting device, and its entire structure is shown in FIG.

In FIG. 2, the radioactive solid waste cutting device comprises a cart rail 3, an upper sprocket 7 and a lower sprocket 54 attached to the cart rail 3, and a chain 8 stretched between the upper sprocket 7 and the lower sprocket 54. The motor 26 and the motor 2 installed on the frame 27
6 and a bevel gear 20, 19, 1 for transmitting the output from the speed reducer 25 to the upper sprocket 7
Cart drive mechanism 100 having 2, 11 and chain 8
A cart 53 that is connected to and moves up and down along the cart rail 3.
And 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 the diffusion of floating substances generated during cutting. Further, the casing 1 has a door (not shown) for taking in and out radioactive solid waste.

A side view of the cart 53 is shown in FIG. As shown in the figure, the cart 53 is inserted into the cart base 503 arranged at the bottom, 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. Radioactive solid waste 5
It has an inner guide 504 that guides 0. The cart base 503 is guided to the cart rail 3 by the guide rollers 30, and the upper guide 501 is the holder 8 a of the chain 8.
It is fixed to the chain 8 by.

The details of the cart drive mechanism 100 are shown in FIG. In FIG. 1, the cart drive mechanism 100 includes a motor 2
6, an output shaft 22 that outputs power from a speed reducer 25 connected to 6, an input shaft 10 of the upper sprocket 7, and an output shaft 2
Transmission shafts 17 and 1 for transmitting power from 2 to the input shaft 10.
3 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 its 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 portion of the casing 1. The transmission shaft 17 is the bearing 1
8 has a bevel gear 19 which is supported in the vertical direction and which meshes with a bevel gear 20 at one end and a joint 16 at the other end. Similarly, the transmission shaft 13 is vertically supported by a bearing 14 and has a joint 15 at one end which is connected to the joint 16 and has a bevel gear 12
At the other end. Although the transmission shaft 17 is present in the air, the transmission shaft 13 is in contact with the water surface 4 of the pool at the intermediate portion,
5 is in the air and bevel gear 12 is in the water. The upper sprocket 7 is attached to the cart rail 3 in water via bearings 6 and 9, and has one end supported by the bearing 5 and a bevel gear 10 at the other end. Further, 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 constructed 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 joints 24 and 23. The output of the output shaft 22 is transmitted to the transmission shaft 17 via the bevel gears 20 and 19, and further transmitted to the transmission shaft 13 via the joints 16 and 15.
Is transmitted to the input shaft 10 of the upper sprocket 7 via the bevel gears 12 and 11. This moves the chain 8 up and down between the lower 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 relatively to the cutting torches 51 and 52.
As a result, the radioactive solid waste 50 is vertically cut.

According to this embodiment, the chain 8 and the sprocket 7, which are contaminated by the suspended matter from the cut radioactive solid waste 50, are always below the pool water surface 4 in the casing 1 and do not move into the air. Therefore, the diffusion of contamination on the water in the casing 1 is minimized. Therefore, since the diffusion of contamination to the outside of the casing 1 is extremely low, it is possible to suppress the dose equivalent rate around the pedestal 27 and reduce the exposure of workers. Further, even when the apparatus is not in operation, there is no possibility that the dose equivalent rate around the pedestal 27 will increase unlike the conventional case.

In the above embodiment, the case where the cart drive mechanism of the present invention is applied to the radioactive solid waste cutting device has been described, but other devices for handling the radioactive solid waste, for example, the channels of the spent fuel assembly. 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 carts.
However, it is also possible to use a wire rope instead of a chain, wind this wire rope with a drum and feed it out to move the cart up and down, or with other flexible members. There is also a similar effect in this case.

[0023]

According to the present invention, since the contaminated part does not rise to the air, the dose equivalent rate around the equipment stand is reduced. Therefore, the exposure of the worker can be reduced. In addition, there is no fear that the dose equivalent rate around the equipment frame will increase even when the equipment is not operating.

[Brief description of drawings]

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

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

FIG. 3 is a side view of the cart.

FIG. 4 is a structural diagram of a conventional cart drive mechanism.

FIG. 5 is a structural diagram of a conventional cart drive mechanism.

[Explanation of symbols]

 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 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, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory

Claims (4)

[Claims] 1. A cart drive mechanism for elevating and lowering a cart holding radioactive solid waste taken out of a nuclear reactor by a flexible member, and a drive source for outputting power and the whole being submerged in water connected to the cart. A cart drive 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 drive mechanism according to claim 1, wherein the flexible member is a wire rope. 3. The cart drive mechanism according to claim 1, wherein the flexible member is a chain. 4. A cart that holds radioactive solid waste taken out from a nuclear reactor, a cutting torch that cuts the radioactive solid waste, and a flexible member that moves the cart up and down to move the radioactive solid waste. In a radioactive solid waste cutting device having a cart drive mechanism that moves in a vertical direction with respect to a cutting torch, the cart drive mechanism is a drive source that outputs power, and the cart drive mechanism is connected to the cart and the whole remains submerged in water. A radioactive solid waste cutting device comprising: an underwater elevating means for elevating and lowering a cart; and a transmitting means for transmitting the power of the drive source to the underwater elevating means.