JP3562879B2 - Radioactive drum carrier - Google Patents

Description

[0001]
[Industrial applications]
Low-level or medium-high level waste generated from facilities handling radioactive materials such as nuclear power plants, spent nuclear fuel reprocessing plants, and facilities handling radioactive isotopes are stored and stored in drums. The present invention relates to a vehicle for safely transporting such a drum.
[0002]
[Prior art]
Conventionally, low-level or medium-high level waste generated from facilities handling radioactive materials, such as nuclear power plants, spent nuclear fuel reprocessing plants, and facilities handling radioactive isotopes, is stored as is or with reduced volume. Some drums were stored without being transported outside of the facility. However, an increase in the number of drums to be stored has led to the depletion of storage locations or the need to transfer drums to another location due to a review of storage locations. Such a transfer operation has required manual operation for loading, unloading or transferring the drum to the transfer vehicle.
[0003]
[Problems to be solved by the invention]
Drum transport vehicles for transporting drums that store radioactive waste must be designed so that they do not expose the driver during operation and transport, and do not unnecessarily expose workers to the loading and unloading of the drums. It becomes. In addition, a high-level shield is required for vehicles with high-dose drums, and in order to shield the exposure dose below the legal limit, the required thickness of the shield increases and the drums are loaded. Since the weight of the container to be loaded becomes extremely large and the position of the center of gravity differs between when the door is closed and when the door is opened, a device that prevents an unexpected accident during the unloading operation is also required. The present invention is that the loading and unloading of the free and safe drum of leakage during transportation radiation of the drum to provide automatic operable drum transport vehicle.
[0004]
[Means for Solving the Problems]
The present invention is a transport vehicle in which a container is loaded and fixed on a vehicle body behind a driver's seat, a part or the whole of the container is covered with a radiation shield, and a door that can be opened and closed is provided on at least one surface of the container, contact portion between the door and the container at the time of closing of the door provided with a mechanism for covering the gap exits from a linear radiation from the inside, when opening the door, the center of gravity of the transport vehicle is Ri near within a predetermined range,
The present invention is a radioactive drum carrier having a door that opens and closes in a sliding manner, and is provided with legs that can move up and down at the lower edge of the door when the door is opened .
[0005]
Further, in these radioactive drum transport vehicles, the present invention also includes a radioactive drum transport vehicle in which a drum loading portion slides so as to be able to protrude outside the transport vehicle, and is provided with a jack. The present invention also includes a radioactive drum carrier, which includes a vehicle and is provided with a means for preventing a drum loaded on a pallet from tipping over.
[0006]
The container on which the radioactive drum is loaded must have a statutory radiation shielding level according to the radiation level of the radioactive drum on which it is loaded. That is, the thickness according to the material of the container may be ensured so that the dose on the surface of the transport vehicle, the dose at a place 1 m away from the surface of the transport vehicle, the dose on the driver's seat, and the like are lower than required levels.
[0007]
The door provided on the container can be provided at one or more locations on the side, top, or rear of the container. The method of opening and closing the door may be a sliding type (including a method of sliding with a single door and a method of dividing the door into two and sliding in opposite directions) or a double door, but in the case of the sliding type, it is up and down in the closed state. When the door fits in the groove, or when the ceiling, the floor or the door is deformed into an L-shape, radiation leakage from that part is blocked. Accordingly, in order to prevent leakage from the left and right edges, if the door has a size occupying the entire side surface of the container, leakage from the side surface can be prevented. A shielding plate that also serves to fix the door and blocks the door can be provided so as to protrude freely from the container side surface. Incidentally, one of the shield plates can be fixed to the door body or the container body. In the case of the double door system, it is necessary to provide a contact portion of the door with a mutually overlapping portion. The connecting portion between the door and the container body needs to cover the contact portion with the door with an L-shaped protrusion from the container.
[0008]
When transporting only low-level radioactive waste, the radiation exposure can be reduced to a predetermined amount or less by installing the radiation shield only on the portion of the container facing the driver's seat.
[0009]
When transporting drums for medium to high level radioactive waste, a high shielding capacity is required to reduce the transmitted radioactivity level on the drum surface to below the required level, and the thickness of the container wall increases. At the same time, the thickness of the door is increased, and the weight of the door is such that the balance of the vehicle body is impaired when the door is opened in a sliding manner. Therefore, one of the following measures is required.
[0010]
1. The center of gravity of the entire transport vehicle is designed not to move significantly when the door is opened and closed. That is, the movement of the center of gravity falls within a predetermined range, and the balance of the vehicle body can be maintained. For example, when the center of gravity moves from the center line of the axle in either the length direction or the width direction of the vehicle body when the door is closed and the door is opened, the length and width are reduced to 1/4 or less of the length and width. Preferably, it is designed to stop. Regardless of which of the following methods is applied, it is important in terms of safety to maintain the balance of the vehicle body.
[0011]
2. A liftable leg is provided at the lower edge of the door, and when the door is opened, the leg is lowered to support the door from the ground and maintain the weight balance of the entire transport vehicle.
[0012]
3. When the door is slid in the front-rear direction of the vehicle body, when the door is opened, a column that protrudes from both upper and lower ends of the door is provided, and the column holds the door weight between the container ceiling and the floor surface.
[0013]
4. In the same manner as in the above 3, it is possible to make the door more stable by sliding the door so as to protrude toward the driver's seat side.
[0014]
When the door is opened and closed in a sliding manner, bearings or wheels are attached to the upper and lower slide grooves to smoothly open and close the door.
[0015]
The loading / unloading of the drum is performed by loading the drum loaded on the pallet into or from the container by using a forklift having a shielding plate or an overhead crane. The drum is fixed in the container with a pallet securing device so that it does not move during transportation. A pallet pushing device is provided as an aid device for loading and unloading with a forklift as needed, and a device for pushing out of the container by sliding or lifting up and down is provided, so that the drum loading and unloading position by a forklift or overhead crane is very small Even if there is a large step, loading and unloading is possible without difficulty.
[0016]
In addition, the transporter is equipped with a jack so that the entire container loading section can be moved up and down by the jack to maintain the stability of the vehicle body.Also, by changing the position of the pallet loading part up and down, when loading and unloading with an automatic forklift Positioning and engagement are facilitated.
[0017]
【Example】
The present invention will be described in detail with reference to the drawings. A description will be given of a transport vehicle for loading radioactive waste into a ZI600 steel open drum (2001) and transporting four drums having a surface dose of 2.5 mSv / hr / body.
[0018]
One or four drums are stacked on a pallet. As the pallet, either a drum pallet (FIG. 1) or a box pallet (FIG. 2) can be used. As shown in FIG. 4 , the container is made of iron, is about 2.1 m in width, about 2.6 m in length, and about 1.9 m in height. The thickness of each side wall plate is determined by performing shielding design. . For example, as an example, the front side (driver's seat side) is 9 cm, the rear side is 4.5 cm, the door side is 5.5 cm, the ceiling is 4.5 cm, and the thickness of the transport vehicle is 5.5 cm below.
[0019]
As shown in FIG. 3, the low-level carrier has a total length of about 5.7 m, a total width of about 2 m, a total height of about 2.8 m, a vehicle body weight of about 3.0 tons, and a container weight of about 1.7 tons. Was. Also, as shown in FIG. 4, the middle and high level drum carrier has a rear wheel uniaxial tractor or dump truck with a total length of about 5.6 m, a total width of about 2.5 m, a total height of about 3.1 m, a vehicle body weight of about 6.5 tons, weight of the container was about 15 tons.
[0020]
The door was a sliding system on one side, and the top and bottom of the door were slide grooves as shown in FIG. 5, and 3 cm cars were attached to the upper and lower grooves every 8 cm. The outermost edge of the door on the advancing side has an L-shape protruding toward the container body, and is provided with a protruding leg operated by hydraulic pressure at a lower portion thereof. The other end protrudes from the container body side when closed [covered by a plate-like piece so as to prevent radiation leakage.
[0021]
With the four drums loaded on a medium-to-high-level carrier, the surface dose of the carrier was 2 mSv / hr or less, the dose at 1 m from the carrier surface was 0.1 mSv / hr or less, and the driver's seat dose was 0.02 mSv / hr or less. . A pallet extruder as shown in FIG. 6 was provided to facilitate loading and unloading of the drum.
[0022]
The pallet was provided with a pallet securing device as shown in FIGS. FIG. 9 is a conceptual diagram showing a method of providing a jig utilizing the outer wall of a container as a method of preventing overturning in the case of four drums by closing the door. FIG. 10 is a conceptual diagram in which the components are provided. FIG. 11 shows a method in which a guide for preventing the drum from tipping over is provided in the pallet pushing device. It is also possible to attach such a guide for preventing the drum from overturning to the pallet.
[0023]
As shown in FIG. 6, the pallet pushing device is provided with a photoelectric sensor, and when placing the drum on the pallet with a forklift, it is necessary to install a device for notifying a sound when the drum is pushed to a certain position. Preferred for safety.
[0024]
By jacking up the whole, the height of the pallet can be adjusted, the positioning with the automatic forklift can be facilitated, and the connection can be made. Pallet loading / unloading was performed according to the following procedure.
[0025]
Loading / unloading: Jack lowering → door opening → pallet securing release → pallet extrusion → loading / unloading of drum pallets.
[0026]
Loading: Drum loading pallet loading → pallet retraction → pallet securing → door closing → jack up.
[0027]
Such an operation can be automatically performed by a switch operation from the driver's seat, which can be performed by a conventional technique. A surveillance camera may be installed at one or several places as necessary to confirm operation and to confirm safety during operation. (For example, for monitoring the operation inside the bumper body, for checking the rear of the vehicle, etc.)
[0028]
【The invention's effect】
The present invention relates to a transport vehicle in which a container covered with a radiation shield is loaded and fixed on a vehicle body behind a driver's seat, wherein a door that can be opened and closed is provided on at least one surface of the container. A mechanism is provided to cover the gap where radiation comes in straight from the inside to the outside, and the center of gravity of the carrier stays within a predetermined position when the door is opened and the pallet is pushed out, so that the carrier moves. Work can be done safely during loading and unloading of medium and drums.
[Brief description of the drawings]
1 is a conceptual diagram of a container for a low-level radioactive drum carrier of the present invention.
FIG. 2 is a conceptual diagram of a container for a medium-high-level radioactive drum carrier of the present invention.
FIG. 3 is a conceptual diagram of the low-level radioactive drum carrier of the present invention.
FIG. 4 is a conceptual diagram of the medium-high-level radioactive drum carrier of the present invention.
FIG. 5 is a diagram illustrating an example of a container door.
FIG. 6 is a conceptual diagram of a pallet pushing device.
FIG. 7 is a conceptual diagram showing an example of a pallet securing device.
FIG. 8 is a conceptual diagram showing an example of a pallet securing device.
FIG. 9 is a conceptual diagram of a fall prevention method in the case of four drums.
FIG. 10 is a conceptual diagram of a method for preventing tipping over a single drum.
FIG. 11 is a conceptual diagram of a method in which a guide for preventing the drum from tipping over is provided on the pallet slide device.
[Explanation of symbols]
Reference Signs List 1 drum 2 pallet 3 securing device 4 slide door 5 container 6 jack 7 roller 8 pulley 9 cylinder 10 wire 11 guide rail 12 adjusting bolt 13 slide base 14 fixed roller 15 moving roller 16 rail 17 slide cylinder 18 guide 19 photoelectric switch 20 solid Binding cylinder 21 X-link 22 Drum fall prevention device 23 Drum fixing jig

Claims (5)

Behind the driver's seat, a transport vehicle in which a container is loaded and fixed on a vehicle body, a part or the whole of the container is covered with a radiation shield, and an openable / closable door is provided on at least one surface of the container, and when the door is closed, contact portion between the door and the container is provided with a mechanism for covering the gap exits from a linear radiation from the inside, when opening the door, Ri near the range centroid of the transport vehicle is in a predetermined,
A radioactive drum carrier, characterized in that the door is a door that can be opened and closed in a sliding manner, and a liftable leg is provided on a lower edge of the door when the door is opened . 2. The radioactive drum carrier according to claim 1 , wherein a drum loading portion is provided in the container, and the loading portion slides and can protrude out of the carrier. 3. The radioactive drum transporting vehicle according to claim 1, wherein the drum loading section moves up and down so as to be able to protrude above the transporting vehicle. The radioactive drum carrier according to any one of claims 1 to 3 , further comprising a jack. The radioactive drum carrier according to any one of claims 1 to 4, further comprising means for preventing a drum loaded on a pallet from overturning.

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