JP2001264494A - Transporting device for radioactive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To house a high dose radioactive material without being exposed in a sate that a transporting cask is placed on the ground. SOLUTION: The high dose radioactive material 1 is housed in a container 2 having a mesh 9, and the container 2 is hung with a hanging rope 3, and covered with a shielding cap 4 being hung with a crane 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radioactive article moving apparatus for moving a radioactive article having a high radiation level while shielding it.

[0002]

2. Description of the Related Art Conventionally, when a high-dose radioactive article such as irradiated fuel is moved, the article is stored in a container (cask) having an appropriate shielding ability. Further, when the article is in radioactively contaminated water, or when the article is heavy, the operation is performed by remote operation using a crane or the like.

[0003]

When the article is stored in a conventional cask, the worker is unavoidably exposed to radiation during the storing operation, so that a tongue for keeping the distance from the article is used. However, when the article is heavy, there is a problem that the article cannot be used.

[0004] In addition, by remote operation of a crane or the like, the article can be moved without being shielded.
Work is easy. However, the influence of radiation on the surrounding environment is unavoidable, and it is necessary to restrict access by workers and the like, and the measured values of an area monitor or a process monitor that constantly measures the radiation dose fluctuate. Therefore,
There is a problem that the radiation exposure of workers and the influence of radiation on the surrounding environment cannot be avoided.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a radioactive article moving apparatus that reduces radiation exposure of an operator and reduces the influence of radiation on the surrounding environment.

[0006]

According to the first aspect of the present invention, there is provided a container for accommodating a high-dose radioactive article, a suspending rope for suspending the container, an opening for the suspending rope through which the suspending rope is inserted, and It is characterized by comprising a shielding cap for covering the container from above and a hanging rope for suspending the shielding cap.

According to the present invention, during the movement of the high-dose radioactive article, since the parts other than the lower part are shielded by the shielding cap, the radiation exposure of the worker can be reduced and the influence of the radiation on the surrounding environment can be reduced. be able to.

The invention according to claim 2 is characterized in that the opening for the hanging rope is formed in a meandering shape. According to the present invention, radiation is linearly emitted in a beam form from the suspension rope opening on the upper surface of the shielding cap by forming the suspension rope opening in a meandering shape such as a spiral and forming a shape other than a straight line. Can be prevented.

[0009] The invention of claim 3 is characterized in that a water outflow member for discharging the water inside is provided on the bottom or side surface of the container. According to the present invention, when the container immersed in water is lifted in the air, the water that has entered the container flows out, so that it can be moved without dripping radiation-contaminated water or the like. Also, when stored in the transport container, unnecessary liquid does not need to be filled.

The invention according to a fourth aspect is characterized in that a cask for accommodating the shielding cap or a cask fitted to a lower end portion of the shielding cap is provided. According to the present invention, the high-dose radioactive article does not come into an unshielded exposed state, and the parts can be stored in the transport cask, so that the radiation exposure of the worker can be reduced and the surrounding environment can be reduced. The effect of radiation can be reduced.
In addition, since the lower surface of the shielding cap and the upper surface of the shielding cask are fitted to each other, the stacking of the shielding cap and the shielding cap is stabilized, and furthermore, when the hanging rope is loosened and the container is hung in the transport cask, the shielding is required. Radiation can be prevented from being emitted in a beam form from the joint surface between the cap and the shielding cask.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a radioactive article moving apparatus according to the present invention will be described with reference to FIGS. In FIG. 1, a high-dose radioactive article 1 is stored in a container 2 having a liquid outflow member a, for example, in a mesh shape on the bottom surface, and the container 2 is suspended by a suspension rope 3. The rope 3 is led out through a hanging rope opening 6 provided in the upper end plate of the shielding cap 4. Shielding cap 4
Is a suspension ring 7 for hooking the wire 8 on the crane hook 5
have.

FIG. 2 shows a state in which a high-dose radioactive article 1 stored in pool water 10 is stored in a container 2 and the container 2 is held by a hanging rope 3. FIG. 3 shows a state in which the shielding cap hung on the crane hook 5 and suspended by the crane has been moved directly above the container 2.

In the present embodiment, as shown in FIG. 1, the hanging rope 3 is pulled from the state shown in FIG. 3, and the high-dose radioactive article 1 is excessively raised while the container 2 is housed in the shielding cap 4. Instead, when moving at an appropriate height from the floor, the area other than the lower part of the high-dose radioactive article 1 is shielded, so that the radiation exposure of the worker can be reduced and the influence of the radiation on the surrounding environment can be reduced. be able to.

Further, by providing a water outflow member 9 for discharging the liquid inside the container 2 such as a mesh structure on the lower surface or the side surface of the container 2, when the container 2 is lifted from the pool water 10 into the air, Since the pool water flows out through the water outflow member 9, radioactive contaminated water or the like can be moved without dripping, and when stored in the shielding cask, unnecessary liquid does not need to be put into the shielding cask.

In this embodiment, when the high-dose radioactive article 1 is moved in the state shown in FIG. 1, if the hanging rope 3 is loosened, the container 2 will be located below the shielding cap 4. This causes a problem that the article 1 is exposed without shielding.

In order to prevent such a problem, a drop prevention stopper using a ratchet or the like is installed on the suspension rope 3. As a result, the container 2 accommodated in the shielding cap 4 does not come out of the shielding cap 4 unless the fall prevention stopper is opened, so that the article 1 can be prevented from being exposed without shielding.

Further, in the present embodiment, the article 1 is moved in the state of FIG. 1 through FIGS. 2 and 3 and when the suspension rope 3 is pulled to the state of FIG. It is necessary to confirm that it is securely housed in 4.

However, when the transparency of the underwater pool water 10 on which the article 1 is placed is poor, it cannot be easily visually monitored. Therefore, in the present embodiment, the hanging rope 3 is marked to clearly indicate a predetermined hanging position.
Thereby, when the hanging rope 3 is pulled until it matches the marking, the container 2 is securely stored in the shielding cap 4, and it is easy to confirm that the container 2 is stored in the shielding cap 4. be able to.

Next, a second embodiment of the radioactive article moving device according to the present invention will be described with reference to FIG. FIG. 4 is a longitudinal sectional view showing only the upper part of the shielding cap 4. This embodiment is different from the first embodiment in that an opening for a linear hanging rope provided at the center of the upper surface of the shielding cap 4 in FIG. Part 6
Instead of forming a spiral, a spiral opening 11 is provided.

According to the present embodiment, by forming the hanging rope opening in a meandering shape other than a straight line, radiation is emitted in a beam form from the rope opening 6 on the upper surface of the shielding cap 4. Can be prevented.

Next, a third embodiment of the radioactive article moving device according to the present invention will be described with reference to FIG. In this embodiment, as shown in FIG. 5, a container 2 containing the article 1 and a shielding cap 4 covering the container 2 are stored in a large transport cask 12 and transported to the upper end opening of the large transport cask 12. That is, the cask lid 13 is provided. At the upper ends of the lid 13 and the large-sized transport cask 12, a fitting portion 14 is formed.

A large transport cask in which the article 1 moved by the moving method described in the first embodiment is prepared in advance.
Store in 12. Thereafter, the suspension rope 3 is cut, and the suspension of the shielding cap 4 is removed from the crane hook 5. Finally, the transport cask lid 13 is attached.

According to the present embodiment, the article 1 does not come to an unshielded exposed state, and the article 1 can be stored in the large-sized transport cask 12, so that radiation exposure of the worker is reduced. And the effect of radiation on the surrounding environment can be reduced.

Next, a fourth embodiment of the radioactive article moving device according to the present invention will be described with reference to FIG. FIG. 6 shows a state in which the container 2 in which the article 1 is stored is surrounded by the shielding cap 4, and the shielding cap 4 is placed and stacked on a small transport cask 15 having the same diameter. This embodiment is shown in FIG.
As shown in (1), only the container 2 containing the article 1 is stored in the small transport cask 15 and is composed of the container 2, the shielding cap 4 and the small transport cask 15.

The container 2 containing the article 1 moved by the method described in the first embodiment is covered with the shielding cap 4, and the shielding cap 4 is stacked on the small transport cask 15 prepared in advance. At this time, the lower end surface of the shielding cap 4 is formed with a fitting portion 14 with a small transport cask 15 to form a fitting structure.

The container 2 is stored in the small transport cask 15 by loosening the hanging rope 3, and then the hanging rope 3 is cut on the shielding cap 4. Next, the shielding cap 4 is moved by a crane or the like, and the transport cask lid is attached to the small transport cask 15.

According to the present embodiment, since the lower end of the shielding cap 4 and the upper surface of the small transport cask 15 are the fitting portions 14, the stacking of the shielding cap 4 and the small transport cask 15 is stabilized, and the hanging rope When the container 2 is suspended in the small transport cask 15 by loosening the container 3, radiation can be prevented from being emitted in a beam form from the joint surface between the shielding cap 4 and the small transport cask 15.

[0028]

According to the present invention, the radiation exposure of the worker can be reduced, and the influence of the radiation on the surrounding environment can be reduced. Further, by providing the water outflow member in the container for storing the high-dose radioactive article, the water in the container flows out when the container is lifted from the water, so that the water can be moved without dripping radioactive contaminated water or the like. In addition, it is possible to prevent unnecessary liquid from flowing into the transport cask. Further, by forming the shielding cap and the transport cask into a fitting structure, the high-dose radioactive article is stored and used as a transport container (cask) without exposing the high-dose radioactive article while the transport cask is placed on the ground. Can be.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a radioactive article moving device according to the present invention.

FIG. 2 is a longitudinal sectional view showing a state in which the container is suspended in water in FIG.

FIG. 3 is a longitudinal sectional view showing a state where a shielding cap is suspended from the state of FIG. 2;

FIG. 4 is a longitudinal sectional view showing a main part of a second embodiment of the radioactive article moving device according to the present invention.

FIG. 5 is a longitudinal sectional view showing a third embodiment of the radioactive article moving device according to the present invention.

FIG. 6 is a longitudinal sectional view showing a radioactive article moving device according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... High dose radioactive article, 2 ... Hanging container, 3 ... Hanging rope, 4 ... Shielding cap, 5 ... Crane hook, 6 ... Hanging rope opening, 7 ... Hanging ring, 8 ... Crane rope, 9 ... Mesh , 10 ... pool water, 11 ... spiral opening,
12 ... Large transport cask, 13 ... Transport cask lid, 14 ... Mating part, 15 ... Small transport cask.

Claims (4)

[Claims] 1. A container for storing a high-dose radioactive article, a suspension rope for suspending the container, a shielding cap having an opening for the suspension rope through which the suspension rope is inserted, and covering the container from above, A radioactive article moving device, comprising: a hanging rope for hanging a shielding cap. 2. The radioactive article moving device according to claim 1, wherein the hanging rope opening is formed in a meandering shape. 3. The radioactive article moving device according to claim 1, wherein a water outflow member for discharging the water inside is provided on a bottom surface or a side surface of the container. 4. A cask for storing the shielding cap,
2. The radioactive article moving device according to claim 1, further comprising a cask fitted with a lower end of the shielding cap. 3.