KR20130111040A

KR20130111040A - Transport or storage concrete cask for spent nuclear fuel

Info

Publication number: KR20130111040A
Application number: KR1020120033516A
Authority: KR
Inventors: 이경구; 성기열; 김형진; 김태만; 김아름
Original assignee: 한국원자력환경공단
Priority date: 2012-03-30
Filing date: 2012-03-30
Publication date: 2013-10-10
Also published as: KR101333066B1

Abstract

The present invention relates to a concrete container for transporting or storing spent fuel, and embedding a heat transfer medium in the wall of the cask to promote heat dissipation through the cask wall, and smooth the air flow around the basket so as to be contained in the basket assembly. The aim is to further promote cooling and heat release of spent fuel. In the concrete container of the present invention for achieving the above object, in the concrete container for spent fuel transport or storage containing a basket containing spent fuel in the interior of the cask is formed upper and lower air passage, the cask is An inner shell of a metal material forming a cavity in which the basket is accommodated; An outer shell made of a metal material to surround the outside of the inner shell at a predetermined interval to form an outer surface of the cask; A concrete shielding material provided between the inner shell and the outer shell to form a thick wall; And a metal structure disposed between the inner shell and the outer shell and including a plurality of horizontal members and embedded in the concrete shielding material, wherein the lower air access path comprises: a communication path vertically communicating with the cavity; And a plurality of entrances and exits through which external air is introduced and connected to the cavity through the communication path.

Description

Concrete container for transport or storage of spent fuel {TRANSPORT OR STORAGE CONCRETE CASK FOR SPENT NUCLEAR FUEL}

The present invention relates to a concrete container for transporting or storing spent fuel, and more particularly, to increase heat conductivity through a cask wall, and to smoothly flow the spent fuel by smoothly flowing air in and around the basket assembly. A concrete container for transporting or storing spent fuel can be cooled and discharged.

Nuclear fuel that has been burned after a predetermined period of time in a nuclear power plant is called spent fuel. The spent fuel is cooled and transported to a reprocessing facility or storage. Since spent fuel is a radioactive material that emits a large amount of radiation and decay heat, it can be safely protected against external shocks in order to transport or store it. In addition, there is a need for a dedicated container made of a structure capable of shielding radiation and releasing heat of collapse smoothly.

A conventional spent fuel transport or storage container is composed of a cask having an accommodating space therein and a basket assembly accommodated in the cask, which is divided into a metal container and a concrete container according to the main material of the cask. Among them, the concrete container has a cask structure provided with a cavity inside a thick wall of concrete as a shielding material, and since concrete has poor thermal conductivity, only the thermal conductivity through the wall of the cask is generated from spent fuel contained therein. There is a problem that the discharge of the heat is not made smoothly.

In order to solve this problem, the concrete container is usually provided with an air inlet for communicating the cavity with the outside has an air-cooled structure in which the air introduced from the outside absorbs the heat of the spent fuel contained in the cavity to be discharged to the outside. However, the conventional concrete container has a problem that the heat dissipation and cooling of the spent fuel is not made efficiently due to poor air flow inside.

Meanwhile, the basket assembly is a structure for maintaining a plurality of baskets containing spent fuel at predetermined intervals, and the conventional basket assembly has a lattice structure having a plurality of channels into which the entire basket is inserted and accommodated. Accordingly, the conventional basket assembly has a problem that the cooling and heat dissipation effect of the spent fuel is poor because the air flow around the basket is not smooth.

The present invention is to provide a concrete container for spent fuel transport or storage to improve the problems as described above, to embed heat transfer medium in the wall of the cask to facilitate heat dissipation through the cask wall. There is a purpose.

It is also an object of the present invention to provide a concrete container for spent fuel transport or storage that can facilitate the flow of air around the basket to further promote cooling and heat release of spent fuel contained in the basket assembly.

In order to achieve the above object, the present invention is a concrete container for spent fuel transport or storage in which a basket containing spent fuel is accommodated in a cask having upper and lower air access passages, wherein the cask has An inner shell of a metal material forming a cavity in which the basket is accommodated; An outer shell made of a metal material to surround the outside of the inner shell at a predetermined interval to form an outer surface of the cask; A concrete shielding material provided between the inner shell and the outer shell to form a thick wall; And a metal structure disposed between the inner shell and the outer shell and including a plurality of horizontal members and embedded in the concrete shielding material, wherein the lower air access path comprises: a communication path vertically communicating with the cavity; And a plurality of entrances and exits through which external air is introduced and connected to the cavity through the communication path.

Preferably, in the present invention, the metal structure is characterized in that made of a reinforced structure.

Preferably, in the present invention, a plurality of spacers are formed in the cavity of the cask to form an air passage between the basket assembly, and more preferably, the spacer is an inner circumferential surface of the inner shell. And a side spacer disposed vertically long to form an air passage in a vertical direction, and a bottom spacer disposed radially on a bottom surface of the inner shell to form a radial air passage.

In the present invention, preferably, a plurality of storage members accommodated in the cask and provided with a plurality of storage ports into which the basket is inserted are coupled to be spaced apart from each other by a predetermined interval to store the baskets in a predetermined arrangement. It further comprises a basket assembly.

In the present invention, preferably, the containment member is characterized in that the ventilation hole is formed to communicate the divided both spaces.

Preferably, in the present invention, at least one side of the upper and lower portions of the basket is characterized in that the ventilation groove is formed to enable the inflow and outflow of air.

In the present invention, preferably, the basket assembly further includes a canister shell for shielding the outside from the inside.

Preferably, in the present invention, the basket is a rectangular enclosure, and a neutron absorber is further laminated on the outer wall of the enclosure.

According to the present invention configured as described above has the following effects.

(1) The inner shell and outer shell of high thermal conductivity metal are combined inside and outside the cask wall made of concrete shielding material, and a metal structure having high thermal conductivity is embedded between the inner shell and the outer shell. As a result, the heat transfer of the spent fuel contained in the cask is facilitated by promoting heat transfer through the walls of the cask, thereby making it more efficient.

(2) The basket is arranged by the storage members spaced apart from each other, so that heat generated from the spent fuel can be more efficiently dissipated by heat conduction through the storage members and convection of air through the spaces between the storage members. It has the effect of cooling.

(3) By forming a vent hole in the containment member to facilitate air communication in both spaces partitioned by the containment member, and by forming a vent groove in the basket to facilitate the flow of air into and out of the basket, There is an effect that can further improve the heat dissipation and cooling effect of spent fuel.

1 is a front sectional view showing an embodiment of a concrete container for spent fuel transport or storage according to the present invention,
FIG. 2 is a cross sectional plan view taken along line AA in FIG. 1;
3 is a front sectional view of the cask of FIG. 1;
4 is a cross-sectional plan view in the BB direction of FIG. 3;
5 is a cross-sectional plan view in the CC direction of FIG. 3;
6 is a sectional view taken along the line DD of FIG. 3;
7 is a front sectional view of the basket assembly in the cask shown in FIG.
8 is a front view showing a coupling structure of the containment member and the support rod in the basket assembly shown in FIG.
9 is a cross-sectional plan view of the basket assembly shown in FIG.
10 is a perspective view of the basket in the basket assembly shown in FIG.
11 is a plan sectional view of the basket shown in FIG. 10.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

The following specific structures or functional descriptions are merely illustrated for the purpose of describing embodiments in accordance with the inventive concept, and embodiments according to the inventive concept may be embodied in various forms and may be described in detail herein. It should not be construed as limited to the examples.

Embodiments in accordance with the concepts of the present invention can be variously modified and have a variety of forms, specific embodiments will be illustrated in the drawings and described in detail herein. However, it should be understood that the embodiments according to the concept of the present invention are not intended to limit the present invention to specific modes of operation, but include all modifications, equivalents and alternatives falling within the spirit and scope of the present invention.

The terms first and / or second etc. may be used to describe various components, but the components are not limited to these terms. The terms are used only for the purpose of distinguishing one component from other components, for example, without departing from the scope of the rights according to the inventive concept, and the first component may be referred to as a second component and similarly The second component may also be referred to as the first component.

When a component is referred to as being "connected" or "connected" to another component, it is to be understood that the component may be directly connected or connected to the other component, but other components may exist in between. something to do. On the other hand, when any component is said to be "directly connected" or "directly contacted" to another component, it should be understood that no other component exists in the middle. Other expressions for describing relationships between components, such as "between" and "immediately between" or "adjacent to" and "directly adjacent to", should likewise be interpreted.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. The terms "comprise" or "having" herein are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof that is implemented, and that one or more other features or numbers, It is to be understood that it does not exclude in advance the possibility of the presence or addition of steps, actions, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning of the context in the relevant art and, unless explicitly defined herein, are to be interpreted as ideal or overly formal Do not.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

As shown in Figure 1 and 2, the spent fuel transport or storage concrete container of the present invention is a basket assembly 200 is accommodated inside the cask 100, each used in the basket assembly 200 It has a structure in which a plurality of baskets 230 in which the nuclear fuel is contained are accommodated.

3 to 6, the cask 100 is formed in a cylindrical shape with a cavity 109 in which the basket assembly 200 is accommodated, and the basket assembly 200 thereon. It is composed of a cask body 110 having an entrance and exit and a cask lid 120 coupled to an upper portion of the cask body 110 to close and close the entrance.

The cask body 110 has a structure in which a concrete shielding material 130 is embedded between an inner shell 101 and an outer shell 102 made of a metal material, for example, steel or cast iron. . Such a structure may be manufactured by pouring concrete between the inner shell 101 and the outer shell 102, which are manufactured to form the outer shape of the cask 100, and curing the cask 100. The inner shell 101 and the outer shell 102 may be overlaid on the surface of the concrete shield 130.

A metal structure 131 is embedded in the concrete shielding material 130. The metal structure 131 may be made of a reinforcing bar structure that is typically used for reinforcing-concrete structures. In the present invention, the metal structure 131 is not only a function of increasing the structural strength, but also the heat released from the spent fuel contained in the interior of the cask 100, the inner shell 101 side to the outer shell 102 side quickly It acts as a heat transfer medium. To this end, the metal structure 131 preferably includes a plurality of horizontal members 132 disposed along the radial direction of the cask 100. The horizontal member 132 is more preferable in terms of heat conduction efficiency is installed so that both ends are as close to or in contact with the inner shell 101 and the outer shell 102, respectively.

The lower air access paths 103 and 104 are provided below the cask body 110 to allow air communication between the inside of the cavity 109 and the outside of the cask 100. Typically, since the inside of the cavity 109 forms an upward flow while the air is heated, the lower air access passages 103 and 104 function as a passage passage of air. The lower air access paths 103 and 104 are formed in a shape in which a plurality of entrances and exits 103 formed in a radial direction are connected to the cavity 109 through the communication path 104, and the communication path 104 is the cavity 109. Is in vertical communication with. As shown in FIG. 3, the communication path 104 is formed at an upper end of a predetermined height from the lower end surface of the cask body 110 and has a diameter smaller than that of the cavity 109. In addition, the positions of the plurality of entrances and exits 103 are formed in contact with the lowermost end of the cask body 110 at a position lower than the communication path 104 to allow the inflow of outside air.

On the inner wall surface of the cavity 109 of the cask body 110, that is, the inner wall surface of the inner shell 101, a plurality of side spacers 105 may be formed in the air passage 106 between the basket assembly 200. And a bottom spacer 108 is installed. That is, a relatively long rod-shaped side spacer 105 is disposed vertically long on the inner circumferential surface of the inner shell 101 to form an air passage in the vertical direction, and a relatively short on the bottom surface of the inner shell 101. A bottom spacer 108 in the form of a rod is disposed radially about the communication path 104 to form a radial air passage.

The cask lid 120 is provided with an upper air access path 121. As described above, since an upward flow of air is generally formed inside the cavity 109, the upper air access passage 121 functions as an outlet passage of air. The upper air access passage 121 is also formed in a shape in which a plurality of entrances and exits 121 formed in a radial direction similar to the lower air access passage are connected to the cavity 109 through a central communication passage. Concrete shielding materials 133 and 134 are provided inside and outside the cask lid 120 in correspondence with the upper air access path 121, and a metal cover is also provided outside the concrete shielding materials 133 and 134. Ash 123 is covered.

Meanwhile, in the illustrated embodiment, the upper air access passage 121 is illustrated in the cask lid 120, but is not limited thereto. The upper air access passage 121 may be disposed on the cask body 110. May be formed.

A configuration of the basket assembly 200 will be described with reference to FIGS. 7 to 11.

The basket assembly 200 constitutes an assembly in which a plurality of storage members 210 are spaced apart by a predetermined interval through the support rod 220, and the plurality of baskets 230 are stored through the storage member 210. Has a structure. In addition, the basket assembly 200 may have a structure housed inside the canister shell 201.

The containment member 210 may be formed in various forms according to the shape of the cavity 109 of the basket assembly 200 including the disk form shown. The storage member 210 has a plurality of receiving openings 212 into which the basket 230 is inserted are arranged at predetermined intervals, and a plurality of coupling holes 213 into which the support rod 220 is inserted are radially outer portions. Is formed. In addition, a plurality of ventilation holes 211 are formed to enable air communication between the two spaces partitioned by the containment member 210.

As shown in detail in FIGS. 10 and 11, the basket 230 has a body 233 having a rectangular shape having a long vertical shape to accommodate spent fuel therein, and an outer wall of the body 233. It consists of a neutron absorber 235 attached to the surface. A plurality of vent grooves 231 and 232 are formed at upper and lower ends of the body 233 to allow air to flow in and out. The neutron absorber 235 has a structure in which a neutron absorber 235b is stacked inside the cover plate 235a. In the present invention, the neutron absorber may be provided by a compound or an alloy containing boron, and preferably, a powder of a boron compound such as B ₄ C may be filled.

The canister shell 201 is coupled to the support rod 220 and surrounds the structure of the containment member 210 in which the basket 230 is accommodated to shield the outside, and is formed in a cylindrical shape corresponding to the cavity 109. The lid 203 and the bottom plate 202 are coupled to the opened upper and lower portions, respectively.

The cask of the present invention configured as described above can more quickly release the heat of the received spent fuel through air flow and heat conduction.

That is, by way of example, the outside air introduced into the cavity 109 through the lower air access passages 103 and 104 moves upward through the air passage 106 around the basket assembly 200. Absorbs heat generated from the spent fuel contained in the basket assembly 200 and is discharged to the outside through the upper air access passage 121, so that rapid cooling and heat dissipation is achieved by the flow of air. At this time, since the plurality of storage members 210 made of a plate shape serves as a heat radiation fin to diffuse heat and increase the heat radiation area, heat and cooling of the heat can be made more quickly. In particular, since the outside air introduced into the interior through the plurality of entrances and exits 103 moves upward along the communication path 104 and flows into the cavity 109, the basket assembly 200 has the air passage 106. In addition to the side () is formed, the bottom of the communication path 104 is formed is exposed to the outside air to increase the overall air contact area can further improve the efficiency of cooling and heat dissipation. In particular, the air heated by the bottom surface of the basket assembly 200 mounted in the cavity 109 can be efficiently vertically moved through the air passage 106 around the basket assembly 200.

In addition, the ventilation hole 211 is formed in the containment member 210 to facilitate air communication between the spaces on both sides of the containment member 210, and the ventilation grooves 231 and 232 are formed in the basket 230. Since the inflow and outflow of air into the basket 230 can be made smoothly, the heat radiation and cooling effect by the air can be further improved.

In addition, although the concrete shielding material 130 has a low thermal conductivity, the inner shell 101 and the outer shell 102 of a metal material having a high thermal conductivity are installed inside and outside the concrete shielding material 130, and the inner shell Since the metal structure 131 having a high thermal conductivity is embedded between the 101 and the outer shell 102, the thermal conductivity from the inner shell 101 to the outer shell 102 is applied to the metal structure 131. This can be achieved quickly, and thus smooth heat dissipation can be achieved even through the wall of the cask 100.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

100: cask 101: inner shell
102: outer shell 103, 104: lower air access route
105: side spacer 108: bottom spacer
110: cask body 120: cask lid
121: upper air access road 130, 133, 134: concrete shielding material
131: metal structure 200: basket assembly
201: canister shell 210: containment member
211 ventilation hole 212 storage port
220: support rod 230: basket
231, 232: ventilation groove 235: neutron absorber

Claims

In a concrete container for spent fuel transport or storage containing a basket containing spent fuel in the interior of the cask, the upper and lower air access passages,
The cask is,
An inner shell made of a metal material forming a cavity in which the basket is accommodated;
An outer shell made of a metal material to surround the outside of the inner shell at a predetermined interval to form an outer surface of the cask;
A concrete shielding material provided between the inner shell and the outer shell to form a thick wall; And
Located between the inner shell and the outer shell and includes a plurality of horizontal members and includes a metal structure embedded in the concrete shielding material,
The lower air access passage,
A communication path in vertical communication with the cavity; And
A spent fuel transportation or storage concrete container including a plurality of entrances and communicating with the communication path to allow the outside air to enter.

The concrete container for spent fuel transportation or storage according to claim 1, wherein the metal structure is made of a reinforced structure.

The concrete container for spent fuel transportation or storage according to claim 1, wherein a plurality of spacers are formed in the cavity of the cask to form an air passage between the basket assembly.

The method of claim 3,
The spacer includes a side spacer disposed vertically long on the inner circumferential surface of the inner shell to form a vertical air passage and a bottom spacer disposed radially on a bottom surface of the inner shell to form a radial air passage. Concrete container for spent fuel transport or storage.

The method of claim 1,
The spent fuel contained in the cask, the plurality of containment members having a plurality of receiving openings into which the basket is inserted are coupled to be spaced apart from each other by a predetermined interval, further comprising a basket assembly for storing the basket to form a predetermined arrangement Concrete container for transport or storage.

The method of claim 5,
The containment member is a concrete container for spent fuel transport or storage, characterized in that the ventilation hole is formed to communicate the two spaces partitioned.

The method of claim 5,
A concrete container for spent fuel transport or storage, characterized in that the ventilation groove is formed to allow the inflow and outflow of air on at least one side of the upper and lower portions of the basket.

The method of claim 5,
A concrete container for spent fuel transport or storage further comprising a canister shell housing the basket assembly therein to shield the outside.

2. The concrete container for spent fuel transportation or storage according to claim 1, wherein the basket is a rectangular enclosure, and an neutron absorber is further stacked on an outer wall of the enclosure.