JPH10282291A - Device for storing spent nuclear fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To store with high cooling effect a spent nuclear fuel which is housed in a canister attached with an open/close lid that is designed in consideration of reuse of spent nuclear fuel. SOLUTION: This storage device is designed to cool by an air flowing in the outside of a housing tube 12 a canister 22, in which a spent nuclear fuel 4 is inserted into a vessel body 25 provided with a flange 24 on its upper end outer part and it is sealed by fixing an open/close lid 27 to the flange 24 with bolts 28, by inserting it into the housing tube 12 provided to a storage cell 11. A heat radiation fin 29 is fitted to the outer circumferential surface of the vessel body 25 of the canister 22 in a manner that it is in contact with the inner surface of the housing tube 12 and is inserted thereinto, thereby conducting a heat from the canister 22 to the housing tube 12 through the heat radiation fin 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spent nuclear fuel storage device for storing spent nuclear fuel from a nuclear reactor such as a nuclear power plant in a stable state.

[0002]

2. Description of the Related Art Spent nuclear fuel generated in a nuclear reactor such as a nuclear power plant is housed in a dedicated hermetically sealed container, and stored and stored in a spent nuclear fuel storage device.

Conventionally, spent nuclear fuel is stored in a storage device,
In order to store the spent nuclear fuel, first, the used nuclear fuel is hermetically contained in a sealed container called a canister 1 as shown in FIGS.

In the canister 1 shown in FIGS. 7 and 8, a spent nuclear fuel 4 composed of a fuel assembly supported by a fuel assembly basket 3 is inserted into a container body 2 having an open upper end. The opening of the main body 2 is closed with a container lid 5 and the outer periphery of the container lid 5 is integrally connected to the container main body 2 by welding 6 so as to be sealed. A locking projection 7 is provided on the upper surface of the container lid 5 so that the canister 1 can be transported by a crane or the like.

[0005] As a spent nuclear fuel storage device for storing the canister 1 in which the spent nuclear fuel 4 is sealed and housed, a structure as shown in FIGS. 9 and 10 has been proposed.

A spent nuclear fuel storage device 8 shown in FIGS. 9 and 10 has an upper handling chamber 10 defined by a partition wall 9.
And lower storage cells 11. The upper ends of a number of storage tubes 12 whose lower ends extend into the storage cells 11 are fixed to the partition wall 9.

As described above, the canister 1 in which the used nuclear fuel 4 is sealed and accommodated in another room (not shown) is placed in the handling room 10 of the used nuclear fuel storage device 8 by a transfer device 13 such as a crane shown in FIG. 10, the canister 1 is hung down in the storage tube 12 and inserted into the storage tube 12 so as to be stacked, and the upper end opening of the storage tube 12 is closed by the storage tube cover 14.

A ventilation pipe 16 is formed on the outer side in the circumferential direction of the storage pipe 12 so as to form an air passage 15 at a predetermined interval. The canister 1 accommodated therein is cooled through the inside 12, and the spent nuclear fuel 4 sealed and accommodated inside the canister 1 is further cooled.

[0009] In FIG. 9, air 17 taken in from an air inlet 18 provided at the upper side of the handling chamber 10 is shown.
Is connected to the storage cell 1 via a cooling air intake shaft 19.
1 and the ventilation pipe 16 and the storage pipe 12 shown in FIG.
After the spent nuclear fuel 4 contained in the canister 1 is cooled by flowing upward through the air passage 15 between the canister 1, the upper air outlet from the upper side of the storage cell 11 through the cooling air outlet shaft 20 21 to be discharged to the outside.

In the spent nuclear fuel storage device 8, the spent nuclear fuel 4 sealed in the canister 1 is stored.
Is transmitted from the canister 1 to the storage pipe 12, and the heat transmitted to the storage pipe 12 is transmitted to the ventilation pipe 16.
It is removed by being cooled by the air 17 flowing upward in the air passage 15 between the air passage 15 and the housing pipe 12.

On the other hand, the conventional nuclear fuel storage device 8
Is configured on the assumption that the spent nuclear fuel 4 is stored for a long period of time until the heat generated from the spent nuclear fuel 4 decreases to a predetermined value. In recent years, however, as described above, It is becoming possible to take out the spent nuclear fuel 4 stored in the spent nuclear fuel storage device 8 and store it assuming reuse.

To this end, it has been considered to provide a canister 22 having a structure that can be opened and closed as shown in FIGS.

The canister 22 shown in FIGS.
Container main body 2 provided with flange 24 outside upper end opening 23
5 is provided, and an opening / closing lid 27 provided with an airtight O-ring 26 is placed on the flange 24 and fixed with bolts 28. With this configuration, the spent nuclear fuel 4 Can be sealed inside.

The canister 22 having the opening / closing lid 27
When taking out the used nuclear fuel 4 hermetically sealed therein and using it again, after removing the canister 22 from the storage tube 12, the bolt 28 is loosened and the opening / closing lid 27 is removed to remove the used nuclear fuel 4. 4 can be easily taken out from the canister 22.

[0015]

However, FIG. 11 and FIG.
2, an open / close canister 22 provided with a flange 24 and capable of being opened / closed by an open / close lid 27.
When the inserted nuclear fuel 4 is inserted into the storage tube 12, a large space L is formed between the storage tube 12 and the container main body 25 due to the presence of the flange 24.
The heat transmitted to the container main body 25 of the canister 22 is very difficult to be transmitted to the storage tube 12, and therefore, there is a problem that the cooling effect of the spent nuclear fuel 4 is significantly reduced.

The present invention has been made in view of such circumstances, and has a high cooling effect on spent nuclear fuel contained in a canister with an open / close lid which is stored in consideration of reuse of spent nuclear fuel. It is an object of the present invention to provide a spent nuclear fuel storage device that can be stored with a nuclear fuel.

[0017]

According to the first aspect of the present invention, spent nuclear fuel is inserted into a container body having a flange on the upper end outside, and an opening / closing lid is fixed on the flange with a bolt to hermetically accommodate it. A spent nuclear fuel storage device, wherein the canister is inserted into a storage tube provided in a storage cell and is cooled by air flowing outside the storage tube, the outer peripheral surface of a container body of the canister. And a radiation fin adapted to be inserted in contact with the inner surface of the storage tube.

According to a second aspect of the present invention, the radiating fins are radial fins extending radially from the axial center of the canister and extending along the axial direction of the canister. 2. The spent nuclear fuel storage device according to claim 1, further comprising clamping fins attached so as to be in contact with both side surfaces of said fin.

According to the first aspect of the present invention, since the opening / closing canister having the flange is provided on the outer peripheral surface of the container body with a radiation fin which can be inserted in contact with the inner surface of the storage tube, the canister is used. The heat transmitted from the spent nuclear fuel to the canister is directly and efficiently transmitted to the storage pipe by the heat transfer by the radiation fins, so that the cooling effect of the spent nuclear fuel can be significantly enhanced.

According to the second aspect of the present invention, the holding tube is provided on the inner surface thereof with the holding fin which comes into contact with the radial fin provided on the outer peripheral surface of the container body of the canister. The heat transfer performance can be further enhanced by contact with the fins, and thus the cooling effect of the spent nuclear fuel can be further enhanced.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment according to the first aspect of the present invention. In a canister 22 constructed in the same manner as in FIGS. A radiating fin 29 that can be inserted in contact with the inner surface of the storage tube 12 is integrally attached.

The radiation fins 29 shown in FIGS. 1 and 2 are arranged radially from the axis of the canister 22 and radially from the canister 2.
A plurality of radial fins 2 extending along the axial direction 2
9a shows a case where the configuration is made.

FIG. 3 shows another example of the radiating fins 29. An annular fin 29b which can be inserted into the outer peripheral surface of the container body 25 of the canister 22 in contact with the inner surface of the storage tube 12 is shown. Are provided at predetermined intervals in the axial direction of the canister 22.

FIG. 4 shows still another example of the radiating fins 29. The radiating fins 29 have a spiral shape which can be inserted into the outer peripheral surface of the container body 25 of the canister 22 in contact with the inner surface of the storage tube 12. The case where the fin 29c is provided is shown.

Next, the operation of the above embodiment will be described.

As shown in FIG. 1 to FIG.
Is provided on the outer peripheral surface of the container body 25 with a radiation fin 29 formed of a radial fin 29a, an annular fin 29b, or a spiral fin 29c which can be inserted in contact with the inner surface of the storage tube 12. The heat generated from the spent nuclear fuel 4 which is sealed and accommodated in the canister 22 is directly and effectively transmitted from the canister 22 to the storage tube 12 by heat transfer by the radiation fins 29, and the ventilation tube 16 and the storage tube 12 Is cooled by the air 17 flowing upward in the air passage 15 (see FIG. 10), so that the cooling effect of the spent nuclear fuel 4 can be significantly enhanced.

FIGS. 5 and 6 show an embodiment according to the second aspect of the present invention. Similar to FIGS. 1 and 2, the outer peripheral surface of the container main body 25 of the canister 22 has a radial shape. In the configuration in which the radiation fins 29 composed of the fins 29 a are attached, the radial fins 2
Nipping fins 30, 31 contacting both side surfaces of 9a
Is attached.

In the embodiment shown in FIGS. 5 and 6, as described above, the radiation fins 29 are provided on the outer peripheral surface of the container body 25 of the canister 22 so as to be able to be inserted in contact with the inner surface of the storage tube 12. As a result, the heat transfer performance from the canister 22 to the storage tube 12 can be improved, and at the same time, the heat transfer performance is further improved by the contact between the radiating fins 29 and the holding fins 30, 31. The effect of cooling the spent nuclear fuel 4 can be further enhanced.

It should be noted that the present invention is not limited only to the above-described embodiment, and that the shapes of the radiating fins and the holding fins can be variously changed. Of course, various changes can be made.

[0031]

According to the first aspect of the present invention, the outer peripheral surface of the container body of the openable canister having the flange is provided with:
By providing a radiation fin that can be inserted in contact with the inner surface of the storage tube, the heat transmitted from the spent nuclear fuel to the canister is directly and efficiently transmitted to the storage tube by the heat transfer by the radiation fin. There is an effect that the cooling effect of spent nuclear fuel can be significantly increased.

According to the second aspect of the present invention, the holding fin is provided on the inner surface of the storage tube so as to contact the radial fin provided on the outer peripheral surface of the container body of the canister. The heat transfer performance can be further enhanced by the contact between the fuel and the holding fins, so that the cooling effect of the spent nuclear fuel can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a cut-away side view showing an embodiment of the invention described in claim 1;

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a sectional side view showing another example of the embodiment of the invention described in claim 1;

FIG. 4 is a cut-away side view showing still another example of the embodiment of the invention described in claim 1;

FIG. 5 is a sectional side view showing an embodiment of the invention described in claim 2;

6 is a view in the direction of arrows VI-VI in FIG. 5;

FIG. 7 is a cut-away side view showing an example of a conventional canister.

8 is a view in the direction of arrows VIII-VIII in FIG. 7;

FIG. 9 is a longitudinal sectional view showing an example of the entire spent nuclear fuel storage device.

FIG. 10 is a sectional view showing details of a portion X in FIG. 9;

FIG. 11 is a cut-away side view showing an example of an openable canister having a conventional flange.

FIG. 12 is a view taken in the direction of arrows XII-XII in FIG. 11;

[Explanation of symbols]

 REFERENCE SIGNS LIST 4 Spent nuclear fuel 8 Spent nuclear fuel storage device 9 Partition wall 11 Storage cell 12 Storage pipe 14 Storage pipe lid 17 Air 22 Canister 24 Flange 25 Container body 27 Opening / closing lid 28 Bolt 29 Radiation fin 29a Radial fin 30, 31 Holding fin

Claims (2)

[Claims] A storage cell is provided with a canister in which spent nuclear fuel is inserted into a container body having a flange at an upper end outside, and an opening / closing lid is fixed on the flange with a bolt and hermetically sealed. A used nuclear fuel storage device that is inserted into a storage tube to cool the outside of the storage tube by flowing air, and may be inserted into an outer peripheral surface of a container body of the canister in contact with an inner surface of the storage tube. A spent nuclear fuel storage device provided with a radiation fin as described above. 2. The radiation fin is a radial fin extending radially from the axial center of the canister and along the axial direction of the canister, and is in contact with the inner surface of the storage tube and both side surfaces of the radial fin. 2. The spent nuclear fuel storage device according to claim 1, further comprising a holding fin mounted as described above.