JPH0727897A - Radioactive material transportation vessel - Google Patents

Abstract

PURPOSE:To prevent cracking in a shielding body and enable radiation shielding for a long period by arranging a shielding plate between a sealed body and the shielding body for suppressing the temperature rise of the shielding body. CONSTITUTION:The radiation from a radioactive body is blocked by a concreat shielding body 1. When radiation heat is emitted from the radioactive body, air in an annular thermal insulation space 6 between a sealed body 2 and the shielding body 1 is heated to rise and discharged out of the shielding body 1 through a heat discharge hole 10. And fresh air is taken in through an air intake 9 by the natural convection and heat is removed. As a shielding plate 7 is provided in the insulation space 6, the radiation heat from the radioactive body is blocked by the shielding plate 7, reduced and then transfered to the inner surface 1a of the shielding body 1. By this, the temperature rise of the shielding body 1 can be suppressed, and therefore cracking in the shielding body is prevented and resultingly radiation can be blocked for a long period.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a container for transporting radiation objects.

[0002]

2. Description of the Related Art A conventional container for transporting a radiation object (for example, a dry storage cask) is shown in FIG. This has an inner sealing body 31 that hermetically seals the radiation object 30, and an outer concrete shield 32 that shields the radiation from the radiation object 30, and the outer peripheral surface of the sealing body 31 and the shield 32. A heat insulating space 33 is provided between the inner peripheral surface and the heat insulating space 33, and an intake port 34 formed in the lower portion of the shield 32 and a heat radiating port 35 formed in the upper portion of the shield 32 communicate with each other through the heat insulating space 33. There is.

In this container for transporting radiation objects, the air entering from the intake port 34 is heated by the radiant heat from the radiation object 30 and radiated from the heat radiation port 35 by natural convection.

[0004]

In the conventional radiation object transport container, the heat transmitted from the radiation object 30 to the sealing body 31 is radiated to the outside from the heat insulating space 33 through the heat radiation port 35. However, convection in the heat insulating space 33 alone does not sufficiently dissipate heat, so that the temperature of the shield 32 rises. Then, since the shield 32 is made of concrete and is inferior in heat resistance, there is a problem that cracks occur and the radiation cannot be shielded sufficiently.

Therefore, the present invention aims to provide a container for transporting a radiation object which can solve the above problems.

[0006]

Means for solving the problems of the present invention is to provide a sealing body for sealing a radiation object,
A concrete shield for shielding the radiation from the radiation object is installed via a heat insulating space, and an intake port communicating with the heat insulating space is formed at the bottom of the shield and at the top of the shield. A heat dissipation port communicating with the heat insulating space is formed, and a heat shield plate for reducing transfer of radiant heat from the radiation object to the shield is provided in the heat insulating space.

[0007]

In the above structure, the radiation emitted from the radiation object is shielded by the concrete shield. Also,
When radiant heat is emitted from the radiation object, the air in the adiabatic space heats up and rises, is released from the heat dissipation port to the outside of the shield, and natural convection draws in new air through the air intake port to dissipate heat. The radiant heat emitted from the radiation object is reduced by the heat shield plate arranged in the heat insulating space and then transmitted to the shield body to suppress the temperature of the shield body from becoming high.

[0008]

Embodiments of the container for transporting a radiation object according to the present invention will be described below with reference to the drawings. A container for transporting a radiation object according to an embodiment of the present invention has an interior space 3 for containing a copper sealing body 2 that seals a radiation object inside a cylindrical shield 1 made of concrete. 2 is interior space 3
Is fixed to the bottom surface of the interior space 3, and a cask liner 4 is arranged around the entire inner wall surface of the interior space 3.
Is closed by.

An annular space between the outer peripheral surface 2a of the sealing body 2 and the inner peripheral surface 1a of the shield 1 serves as a heat insulating space 6 for insulating the radiant heat from the radiation object.
A cylindrical iron heat shield plate 7 is disposed in the inside of the shield body 2. The heat shield plate 7 is fixed to the cask liner 4 via a mounting tool 11, and the outer peripheral surface 2a of the sealing body 2 and the shield body 1 are The sealing body 2 is externally fitted so that the shielding surface 7a is located at the center of the peripheral surface 1a.

At a plurality of locations below the side wall 8 of the shield 1,
Intake ports 9 communicating with the heat insulating space 6 are formed, and heat radiating ports 10 communicating with the heat insulating space 6 are formed at a plurality of locations on the upper side wall 8 of the shield 1.

In the above structure, the radiation emitted from the radiation object is shielded by the concrete shield 1.
By the way, when radiant heat is emitted from the radiation object, the air A in the heat insulating space 6 is heated and rises, and is discharged to the outside of the shield 1 from the heat radiation port 10, and along with this, new air A is taken in by natural convection. The air is taken in from 9 to release heat.

By the way, since the heat shield plate 7 is arranged in the heat insulating space 6, the radiant heat emitted from the radiation object is
After being shielded by the heat shield plate 7 and reduced, it is transmitted to the inner peripheral surface 1 a of the shield 1. As a result, it is possible to prevent the temperature of the shield 1 from becoming high, and thus the shield 1
Since it is possible to prevent cracks from occurring, the shield 1 can shield the radiation from the radiation object for a long period of time.

FIG. 3 shows the temperature emitted to the shield 1 when the heat shield 7 is provided as in the present invention. The temperature emitted to the shield 1 by providing the heat shield 7 is shown in FIG. Is lower than that in the case where the heat shield plate 7 is not provided as shown in FIG. 4, and the heat quantity can be reduced by 3% to 5%.

Thus, by disposing the heat shield plate 7 between the outer peripheral surface 2a of the sealing body 2 and the inner peripheral surface 1a of the shield 1, the amount of heat emitted from the radiation object is reduced and shielded. Since it is transmitted to the body 1, it is possible to prevent the shield 1 from reaching a high temperature, prevent the shield 1 from being cracked, and shield the radiation emitted from the radiation object for a long period of time.

The present invention is not limited to the above embodiment, but as shown in FIG. 5, the heat insulating plate 7 is provided with a through hole formed in the inner peripheral surface 1a of the shield 1 so as to be inclined upward, and the heat insulating space 6 It may be configured to clear the air flow therein. Also in this case, the radiant heat from the radiation object can be shielded by the heat shield plate 7 as in the above embodiment.

Further, the temperature rise of the shield 1 can be suppressed by coating the heat shield 7 with a paint that reduces the radiant heat emitted from the radiation object.

[0017]

As is apparent from the above description, according to the present invention, by disposing a heat shield plate between the sealing body and the shield body, the amount of heat emitted from the radiation object is reduced and shielded. As it is transmitted to the body, it prevents the shield from reaching high temperature, thus preventing the shield from cracking.
The radiation emitted from the radiation object can be shielded for a long time.

[Brief description of drawings]

FIG. 1 is an overall sectional view of a container for transporting a radiation object showing an embodiment of the present invention.

FIG. 2 is likewise a simplified cross-sectional view of a main part.

FIG. 3 is a temperature change diagram showing the temperature emitted to the shield when the radiation object transport container is provided with a heat shield plate.

FIG. 4 is a temperature change diagram showing the temperature emitted to the shield when the radiation object transport container is not provided with a heat shield plate.

FIG. 5 is a cross-sectional view of essential parts of a container for transporting a radiation object showing another embodiment.

FIG. 6 is a partially cutaway perspective view of a conventional container for transporting a radiation object.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield 2 Sealing 3 Interior space 4 Caskliner 6 Insulating space 7 Heat shield 8 Side wall 9 Intake port 10 Radiating port

Claims (1)

[Claims] 1. A hermetically sealed body for enclosing a radiation object is provided inside a concrete shield for shielding radiation from the radiation object via a heat insulating space, and communicates with a heat insulating space below the shield. And a heat dissipation port communicating with the heat insulating space are formed in the upper part of the shield, and heat shielding for reducing transfer of radiant heat from the radiation object to the shield to the heat insulating space. A container for transporting a radiation object, which is provided with a plate.