JPH0868890A - Spent fuel storage rack and spent fuel storage facility - Google Patents

Abstract

(57) [Summary] [Purpose] The lower support plate is not required, the seismic resistance and cooling efficiency of the equipment are improved, and the spent fuel storage cells can be easily attached and detached.
Provided are a spent fuel storage rack having a reduced center distance of stored fuel and an increased storage capacity, and a spent fuel storage facility including the rack. [Structure] The spent fuel storage rack 56 is a first rectangular cylinder.
(Spent fuel storage cell) 3 and second prism 53 having an inner size slightly larger than that of the first prism 3 and arranged in a checkered pattern
A member (not shown) for connecting and fixing the corner portions of the second rectangular cylinder 53, a columnar member 55 having a length reaching the floor arranged at a position determined in consideration of earthquake resistance conditions, In order to arrange and fix the first rectangular tube 3 in the space defined by the inner surface or the outer surface of the rectangular tube 53 (and the columnar member 55), the first
The storage cell fixing member 52 is inserted into the gap between the outer surface of the rectangular tube 3 and the inner surface or the outer surface of the second rectangular tube 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spent fuel storage rack and a spent fuel storage for vertically storing a spent fuel generated in a nuclear power plant equipped with a reactor such as a pressurized water reactor. The present invention relates to a facility, and more particularly to a structure of a spent fuel storage rack capable of realizing a spent fuel storage facility capable of storing spent fuel at a high density by reducing a center distance between adjacent stored fuels having high earthquake resistance.

[0002]

2. Description of the Related Art Spent fuel assemblies generated in a power plant equipped with a nuclear reactor such as a pressurized water reactor are used for storing spent fuel in a nuclear power plant until they are delivered to a reprocessing plant. It is stored while being cooled in a pool or spent fuel storage facility. Spent fuel assemblies are stored in a spent fuel storage rack located at the bottom of the spent fuel storage pool. The spent fuel assemblies are inserted and stored in the spent fuel storage cells one by one in order to maintain their subcriticality. The characteristics of the materials that make up the spent fuel storage cells and the neutron absorption effect of water Therefore, it is necessary to hold them vertically while maintaining an interval of a predetermined value or more determined in consideration of the above.

A conventional spent fuel storage rack has a structure in which spent fuel storage cells are vertically supported by a first support member and a second support member, as described in, for example, Japanese Patent Application Laid-Open No. 60-170796. It has been known. That is, the spent fuel storage rack includes a large number of spent fuel storage cells made of stainless steel or the like, a first support member,
The second support member. The first support member and the second support member of the spent fuel storage rack are orthogonal to each other, and are fixed to the embedded hardware of the concrete wall of the spent fuel storage pool by an appropriate method. The spent fuel storage cell is sequentially inserted between the first support member and the second support member, and attached to these support members by welding.

On the other hand, as described in Japanese Utility Model Publication No. 60-72595, there is known a structure in which a spent fuel storage cell is supported by an upper rack supporting plate and a lower rack supporting plate. The upper and lower rack support plates are welded to the embedded hardware of the concrete wall of the pool. The spent fuel storage cells are sequentially inserted into the upper rack supporting plate and the lower rack supporting plate, and attached to these rack supporting plates by welding.

[0005]

In the above-mentioned prior art, the upper and lower support members are made of a combination or plate of shaped steel, and further fixed to the wall in a cantilever manner to support the fuel storage cell. Therefore, there is a problem that the seismic resistance is low, and if the upper and lower support members have a strong structure in terms of seismic design, the constituent members become large and the center distance of the stored fuel cannot be reduced. there were.

That is, in these spent fuel storage racks according to the prior art, the support member constitutes a space for holding the fuel storage cell by the combination of the shape steels, while the rack support plate has its own fuel storage cell. Are provided with a large number of holes. A space for holding the fuel storage cells occupying in the support member or the rack support plate when the fuel storage cells are brought close to each other in order to reduce the center distance of the stored fuel inserted into each spent fuel storage cell. Is relatively large, and the amount of supporting members or rack supporting plates that ensure the supporting function is reduced. Support members and rack support plates require a strong structure in terms of seismic design,
In the above conventional technology, when the distance between the centers is reduced,
It was not possible to maintain sufficient seismic strength.

Further, since the upper and lower supporting members and the rack supporting plate are provided, the cooling water flow passage is narrow and the cooling efficiency of the fuel storage pool water is not good.

Further, since the spent fuel storage cell is attached to the support member or the rack support plate by welding, it is difficult to perform maintenance or modification after the installation.

An object of the present invention is to provide a fuel storage cell support structure having a simple structure, light weight, high seismic strength, and capable of reducing the center distance of stored fuel while improving the seismic resistance of a spent fuel storage rack. And a spent fuel storage facility having the storage rack.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a spent fuel storage rack for storing and storing spent fuel generated in a nuclear power plant, in which each spent fuel is internally stored. The first square cylinder (spent fuel storage cell) to be stored in the second square cylinder, the second square cylinder having an inner size slightly larger than the outer shape of the first square cylinder and arranged in a checkered pattern, and the corner of the second square cylinder. A member for connecting and fixing the parts to each other, and an outer surface of the first prism and an inner surface of the second prism for inserting and fixing the first prism into a space defined by the inner surface or the outer surface of the second prism. The present invention proposes a spent fuel storage rack having a storage cell fixing member that is inserted into a gap between the outer surface and the outer surface.

In order to achieve the above-mentioned object, the present invention also relates to a spent fuel storage rack for storing and storing spent fuel generated in a nuclear power plant, wherein the spent fuel is arranged at predetermined intervals. First to store each body inside
The columns of the square tubes (spent fuel storage cells) and the first square tubes having an inner dimension slightly larger than the outer shape of the first square tubes are arranged in the checkered pattern with the first spacing from the first square tubes offset in the row direction. A row of second rectangular cylinders, a member for connecting and fixing the corners of the first rectangular cylinder and the second rectangular cylinder arranged in a checkered pattern, and the inside of the second rectangular cylinder and the first rectangular cylinder and the first rectangular cylinder. The first rectangular tube inserted into the space defined by the rectangular tube and the second rectangular tube or the first rectangular tube.
A gap between the outer surface of the first rectangular tube and the inner surface of the second rectangular tube inserted to insert and fix the first rectangular tube into the space defined by the rectangular tube and the second rectangular tube, or the inserted first tube. The present invention proposes a spent fuel storage rack having a storage cell fixing member that is inserted into a gap between a one-sided cylinder and a checkered first square cylinder.

The first prism holds the spent fuel vertically.
The second prism, which has a length necessary for storage, vertically sits on the floor of the spent fuel storage pool and supports the first prism at a position slightly lower than the upper end of the spent fuel to be stored. Therefore, it has a structure and a length required to be supported in a cantilever shape from the wall surface of the spent fuel storage pool and to support the first rectangular cylinder with sufficient seismic strength through the storage cell fixing member.

In any of the above cases, at least one of the first square tubes (spent fuel storage cells) is a square tube having a bottom portion with a seat plate 100 for holding spent fuel for a boiling water reactor. can do.

At least one of the first rectangular cylinder and the second rectangular cylinder is either austenitic stainless steel or boron-added stainless steel obtained by adding boron having a neutron absorbing effect to austenitic stainless steel.

More specifically, the storage cell fixing member is a wedge-shaped fixing member, a plurality of wedge-shaped fixing members, a corrugated plate-shaped fixing member, a corrugated fixing member, a fixing member having a coil-shaped member, and an arc-shaped plate-shaped member. It is either a fixed member having a member, a fixed member having a movable jack structure, or a member having a fixed jack.

The storage cell fixing member inserted into the gap for fixing the first rectangular cylinder is welded or bolted to the second rectangular cylinder or the first rectangular cylinder in advance before assembling the spent fuel storage rack. It can be attached by mechanical means.

In order to achieve the above object, the present invention further provides any one of the above-mentioned spent fuel storage racks, a pool for storing the spent fuel storage rack and the spent fuel, and a spent fuel storage rack. It proposes a spent fuel storage facility including a member fixed to a wall of a pool.

[0018]

[Function] When the second rectangular cylinders are arranged in a checkerboard pattern to form a square lattice, seismic / shear resistant walls are formed in two directions in which the respective sides of the second rectangular cylinders are orthogonal to each other, and the horizontal and vertical directions during an earthquake It exhibits high strength and rigidity against force. When the spent fuel storage cell, which is the first prism, is installed in the support member formed by the second prism, a spent fuel storage rack having a simple structure, light weight, and high earthquake resistance can be obtained.

The rows of the first rectangular cylinders arranged at a predetermined interval to store the spent fuel inside one by one and the first rectangular cylinders arranged at the predetermined intervals are arranged in a checkered pattern while being shifted in the row direction. When the set of the second rectangular cylinder and the row of the second rectangular cylinder is a square lattice, the sides of the first rectangular cylinder and the second rectangular cylinder are also orthogonal to each other.
It becomes an earthquake-resistant / shear-resistant wall in the direction and exhibits high strength and rigidity against horizontal and vertical forces during an earthquake. Further, when the spent fuel storage cell, which is the first prism, is installed in the support member formed by the first prism and the second prism, the spent fuel storage rack having a simple structure, light weight, and high earthquake resistance is installed. Is obtained. In this case, since the number of the second rectangular cylinders is about half, the weight of the supporting member for the spent fuel storage cell can be reduced.

In any case, the length of the first prism is the length required to vertically hold and store the spent fuel, and the length of the second prism is on the floor of the spent fuel storage pool. It is held in a cantilever shape from the wall surface of the spent fuel storage pool to support the first prism at a position slightly lower than the upper end of the spent fuel that is vertically seated and stored, and a storage cell fixing member is provided. The structure and length are required to support the first rectangular cylinder inserted through the plate with sufficient seismic strength.

The above-mentioned structure is basically intended for a spent fuel storage facility from a pressurized water reactor, but
If at least one of the square tubes (spent fuel storage cells) is made into a square tube having a seat plate 100 for holding spent fuel for a boiling water reactor at the bottom, the square tubes (spent fuel storage cells) can be used as they are from the boiling water reactor. Applicable to spent fuel storage equipment.

The first rectangular cylinder and the second rectangular cylinder are respectively
If any of the boron-added stainless steel added boron having a neutron absorption effect to austenitic stainless steel or austenitic stainless steel, for example, if austenitic stainless steel is selected,
An inexpensive support member can be constructed, and when the first and second square cylinders are made of boron-added stainless steel, the pitch between adjacent spent fuels can be reduced, so that the same capacity of spent fuel can be stored. More spent fuel can be stored in the pool.

It has a wedge-shaped fixing member, a plurality of wedge-shaped fixing members, a corrugated plate-shaped fixing member, a corrugated fixing member, a fixing member having a coil-shaped member, a fixing member having an arched plate-shaped member, and a movable jack structure. When the storage cell fixing member, which is either a fixing member or a member having a fixed jack, is inserted into the gap formed by the outer surface of the first prism and the inner surface or outer surface of the second prism, the first prism is seismic-resistant. It is possible to hold it with sufficient strength.

When the storage cell fixing member to be inserted into the gap for fixing the first rectangular cylinder is attached to the second rectangular cylinder or the first rectangular cylinder in advance by welding or by mechanical means such as bolting,
Work time can be shortened when the spent fuel storage rack is installed locally.

A spent fuel storage facility comprising any of the above-mentioned spent fuel storage racks, a pool for storing the spent fuel storage rack and the spent fuel, and a member for fixing the spent fuel storage rack to the wall of the pool. With the above construction, it is possible to reduce the center distance of the stored fuel by improving the seismic resistance of the spent fuel storage rack with a simple structure and being lightweight and having a large earthquake resistance.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spent fuel storage rack according to the present invention and a spent fuel storage facility equipped with this storage rack will be described below with reference to FIGS. Before that, in order to help understanding of the present invention, FIGS.
With reference to, an outline and problems of the structure of the conventional spent fuel storage rack will be described.

Spent fuel assemblies generated in a power plant equipped with a pressurized water reactor are stored while being cooled in a spent fuel storage pool provided in the nuclear power plant until being transported to a reprocessing plant. To be done. Spent fuel assemblies are stored in a spent fuel storage rack located at the bottom of the storage pool. In order to maintain the subcriticality of the spent fuel assembly, one fuel storage cell is provided for each spent fuel assembly, the characteristics of the material forming the spent fuel storage cell, the neutron absorption effect of water, etc. Therefore, it is necessary to hold them vertically while maintaining a space equal to or larger than a predetermined value determined in consideration.

FIG. 19 is a perspective view showing the structure of a conventional spent fuel storage rack 8 in which spent fuel storage cells are vertically supported by the first support member 4 and the second support member 5. The spent fuel storage rack 8 includes a large number of spent fuel storage cells 3 made of stainless steel and the like, and a first support member 4
And a second support member 5. The first support member 4 and the second support member 5 of the spent fuel storage rack 8 are orthogonal to each other and are fixed to the embedded metal 7 of the concrete wall 6 of the spent fuel storage pool 1 by an appropriate method. The spent fuel storage cell 3 includes a first supporting member 4 and a second supporting member 5.
Between the support members 4 and 5 by welding.

FIG. 20 is a perspective view showing the structure of a conventional spent fuel storage rack 11 in which the spent fuel storage cells 3 are vertically supported by the upper rack support plate 9 and the lower rack support plate 10. The spent fuel storage cells 3 of the spent fuel storage rack 11 are supported by the upper rack support plate 9 and the lower rack support plate 10. These rack support plates 9 and 10 are attached to the concrete wall 6 of the pool 1.
It is fixed to the embedded metal 7 by welding. The spent fuel storage cell 3 is sequentially inserted into the upper rack support plate 9 and the lower rack support plate 10 and attached to these rack support plates 9 and 10 by welding.

In these spent fuel storage racks 8 or 11 according to the prior art, the support members 4 and 5 form a space for holding the fuel storage cells 3 by a combination of shaped steels, and the rack support plates 9 and 10 are provided. Each has a large number of holes for holding the fuel storage cells 3. Although not shown here, the center-to-center distance 12 of the stored fuel 50 inserted and stored in each spent fuel storage cell 3 (see FIG.
If the fuel storage cells 3 are brought close to each other in order to reduce the size of the fuel storage cells 3, the space for holding the fuel storage cells 3 in the support members 4, 5 or the rack support plates 9, 10 increases,
The amount of supporting members or rack supporting plates that ensure the supporting function is reduced. Support members 4, 5 and rack support plates 9, 10
Requires a strong structure in terms of seismic design, but in the above-mentioned conventional technology, even if the center-to-center distance 12 is reduced, it is not possible to maintain sufficient seismic strength. Further, since there are the upper and lower two-stage support members 4 and 5 and the rack support plates 9 and 10, there is a problem that the cooling water flow path is narrow and the cooling efficiency of the fuel storage pool water is not good. Furthermore, since the spent fuel storage cell 3 is attached to the support members 4,5 and the rack support plates 9 and 10 by welding, it is difficult to perform maintenance and modification after the installation.

According to the embodiment of the spent fuel storage rack and the spent fuel storage facility of the present invention described below,
It is possible to improve the earthquake resistance of the storage rack, reduce the center distance of the stored fuel, and increase the storage density of the spent fuel.

FIG. 1 is a perspective view showing a structure of an embodiment of a spent fuel storage rack according to the present invention, and FIG. 2 is a perspective view showing a state of assembling the spent fuel storage rack of the embodiment of FIG. FIG. 3 is a side view showing a state where spent fuel is stored in the spent fuel storage rack of the embodiment of FIG.

Spent fuel storage rack 5 of the embodiment of FIG.
Reference numeral 6 denotes a first rectangular tube, that is, the spent fuel storage cells 3, and a second rectangular tube, that is, a rectangular cross-section tube 53 arranged in a checkered pattern.
And a member (see FIGS. 8 and 9 described later) for connecting and fixing the second rectangular tubes 53 to each other, and a storage cell fixing member 52.

First square cylinder, ie, spent fuel storage cell 3
Is installed in the spent fuel storage pool 1 and vertically holds and stores the spent fuel 50 which is vertically seated on the floor 2 of the spent fuel storage pool 1. The plurality of second rectangular tubes, that is, the rectangular cross-section tubes 53, are positioned slightly lower than the upper end of the spent fuel 50 stored in the spent fuel storage cell 3,
It is held on the wall surface 51 of the spent fuel storage pool 1 so as to support the spent fuel storage cell 3. The plurality of second rectangular cylinders 53 have a structure and length capable of supporting the spent fuel storage cells 3 with sufficient seismic strength, and are fixed to each other in a checkered pattern.

As shown in FIG. 2, the storage cell fixing member 52 serves to fix the spent fuel storage cell 3 inserted in the second rectangular cylinder 53 in the second rectangular cylinder 53 so as to fix the spent fuel storage cell 3. The cell 3 and the second rectangular tube 53 are fitted into the gap from above. Further, when the storage cell fixing member 52 is attached to the first square tube 3 or the second square tube 53 in advance by welding or by mechanical means such as bolt tightening, work for installing the spent fuel storage rack 56 on site You can save time.

The second rectangular cylinder at the position determined in consideration of the seismic resistance condition of the plant has a length that reaches the floor 2, and other second cylinders are used.
Columnar member 5 that supports the rectangular tube and the storage cell fixing member 52, etc.
It is desirable to provide 5.

FIG. 4 is a view showing the structure of the spent fuel storage rack of the embodiment shown in FIG. 1 at the height of the rectangular section pipe. When the rectangular cross-section tubes, that is, the corner portions of the second rectangular cylinder 53 are connected and arranged, as shown in FIG. 4, each side of the second rectangular cylinder 53 has a structure in which the sides are arranged substantially in one line in two orthogonal directions. . The side arranged in one row forms an earthquake-resistant / shear-resistant wall as the entire installation portion of the second rectangular cylinder 53, and the seismic-resistant shear wall hangs horizontally and / or on the installation portion of the second rectangular cylinder 53 during an earthquake. Since it receives vertical force, it is possible to obtain a spent fuel storage rack that is lightweight, has high strength and rigidity, and has excellent earthquake resistance.

Further, if the diameter of the rectangular cross-section tube 53 forming this portion is reduced by taking advantage of the structural characteristics of the entire installation portion of the second rectangular cylinder 53 having excellent earthquake resistance, it is held there. The fuel storage cells 3 can be made closer to each other, and the storage density of the spent storage fuel 50 can be increased while maintaining high strength and high earthquake resistance.

Here, if the spent fuel storage cell 3 is replaced with a spent fuel storage cell formed of a material having a neutron absorption effect, for example, boron-added stainless steel, without changing the structure of the second rectangular cylinder 53 or the like, It is possible to obtain a spent fuel storage facility capable of storing high burnup fuel. If the spent fuel storage cell 3 is made of a material having a neutron absorption effect, the structure of the installation part of the second prism 53 is changed, and the center distance 12 of the spent stored fuel 50 is reduced, the storage pool 1 The storage capacity of the spent storage fuel 50 can be increased without changing the shape or size of the body.

FIG. 5 is a perspective view showing a structure of an example of a spent fuel storage cell provided with a lower structure capable of stably holding a fuel assembly for a boiling water nuclear reactor vertically, and FIG.
FIG. 3 is a diagram showing a structure at a height of a second rectangular cylinder 53 of a spent fuel rack when the spent fuel storage cell 101 of FIG. is there.

1 to 4 are examples of a spent fuel storage rack and a spent fuel storage facility for storing spent fuel assemblies generated in a power plant equipped with a pressurized water reactor. However, in the embodiment of FIGS. 5 and 6, the seat plate 100 capable of stably holding the fuel assembly for the boiling water reactor vertically is provided in the lower portion of the spent fuel storage cell 3 and is used. An example is shown in which a spent fuel storage cell 101 having a cross-sectional dimension of the fuel storage cell 3 that is suitable for stably holding a fuel assembly for a boiling water reactor is adopted and installed in a partial storage region. There is.

Employing this spent fuel storage cell 101, each implementation of a spent fuel storage rack for a pressurized water reactor and a spent fuel storage facility with this storage rack as described herein. Similar to the example, a spent fuel storage rack for a boiling water reactor and a spent fuel storage facility equipped with this storage rack can be realized. This modification to the spent fuel storage cell 101 can be applied to other embodiments described below.

FIG. 7 shows a case where the spent fuel storage rack 56 according to the present invention is combined with the lower support plate 150 so that the spent fuel 50 can be applied to a plant having extremely severe seismic conditions. It is a side view which shows the condition which is storing. Lower support plate 150 of this embodiment
20 performs the same function as the conventional lower rack support plate 10 shown in FIG. 20, but does not have the conventional upper rack support plate 9 shown in FIG. Cooling efficiency of pool water is relatively good.

FIG. 8 is a view showing the structure of an embodiment in which the corner portions of the second rectangular tube 53 are connected via spacers 200 in order to arrange the second rectangular tube rectangular cross-section tubes 53 in a checkerboard pattern. is there. Since the corner portions of the second rectangular cylinder 53 are round, in order to fix the second rectangular cylinders 53 to each other while maintaining a predetermined pitch,
Spacer 200 is required.

FIG. 9 is a diagram showing the structure of an embodiment in which L-shaped members are attached near the corners of the second rectangular cylinders (rectangular cross-section tubes) 53 so as to be arranged in a checkered pattern and connected. . Instead of the spacer 200 of FIG. 8, the L-shaped member 2 of FIG.
01 may be adopted.

10 to 17 show that, in each embodiment of the spent fuel storage rack according to the present invention, the spent fuel storage cells 3, 101 (FIG. 5) can be easily attached and detached to and supported by the second rectangular cylinder 53. Fixing members 52, 102 capable of (Fig. 6)
It is a perspective view showing the concrete shape of.

The used fuel storage cell fixing member 2 of FIG.
The vertical cross-section 50 has a single-step wedge shape.

The used fuel storage cell fixing member 2 of FIG.
51 has a wedge-shaped cross-section in the vertical direction.

The used fuel storage cell fixing member 2 of FIG.
52 is a plate whose longitudinal cross-sectional shape is corrugated.

The used fuel storage cell fixing member 2 of FIG.
The vertical cross-sectional shape of 53 is corrugated.

The used fuel storage cell fixing member 2 of FIG.
54 has a coil-shaped member 256 between the member 254 on the spent fuel storage cell 3 or 101 side and the member 255 on the second rectangular tube 53 side. The coiled member 256 is
Made of spring or shape memory alloy.

The used fuel storage cell fixing member 2 of FIG.
The member 59 has an arcuate plate member 258 between the member 254 on the spent fuel storage cell 3 or 101 side and the member 255 on the second rectangular tube 53 side. The arcuate plate member 258 is made of a spring or a shape memory alloy.

The used fuel storage cell fixing member 2 of FIG.
61 has a movable jack structure 260 between a member 254 on the side of the spent fuel storage cell 3 or 101 and a member 255 on the side of the second rectangular cylinder 53.

The used fuel storage cell fixing member 2 of FIG.
63 has a fixed jack structure 262 between a member 254 on the side of the spent fuel storage cell 3 or 101 and a member 255 on the side of the second rectangular cylinder 53.

As shown in FIGS. 16 and 17, the jack structure 2
When 60 and 262 are adopted, there is an advantage that it is possible to flexibly cope with the gaps of various sizes between the first rectangular tube 3 or 101 and the second rectangular tube 53.

FIG. 18 is a view showing the structure of an embodiment of the spent fuel storage rack according to the present invention in which the first rectangular cylinder and the second rectangular cylinder are alternately arranged in a checkerboard pattern and the corner portions are directly joined. Is. In the present embodiment, the spacers 200 for joining the corner portions of the rectangular cross-section pipes are interposed and connected between the first rectangular tube 3a and the second rectangular tube 53, and they are fixedly joined. The first rectangular cylinders 3a and the second rectangular cylinders 53 are arranged alternately and have a checkered pattern. A region surrounded by another first rectangular cylinder 3 loaded via the fixing member 52 in the second rectangular cylinder 53, and the first rectangular cylinder 3a and the second rectangular cylinder 53 arranged in a checkered pattern. Another first square cylinder 3 loaded via the fixing member 52 is arranged between the first square cylinder 3a and the first square cylinder 3a, and the stored fuel 50 is stored in the first square cylinders 3 and 3a. A spent fuel storage rack is illustrated.

According to the embodiment shown in FIG. 18, since the number of the second rectangular cylinders 53 is reduced to about half, the weight can be remarkably reduced. Also,
Since the first rectangular tube 3a and the second rectangular tube 53 are firmly joined via the spacer 200 for joining the corner portions of the rectangular cross-section tube, excellent vibration resistance is provided.

For the first rectangular cylinders 3 and 3a and the second rectangular cylinder 53, austenitic stainless steel and boron-added stainless steel can be used in any combination. Also, FIG.
Similar to the embodiment described above, the second rectangular cylinder 53 can be held in a cantilever shape from the wall surface of the spent fuel storage pool, and as the fixing member 52, the structure shown in FIGS.

According to the embodiment of the present invention, a spent fuel storage rack having high seismic resistance, good cooling efficiency of stored spent fuel, and light weight as a whole can be obtained.

Further, since the spent fuel storage cells 3, 101 can be exchanged relatively easily even after the storage rack is once installed, the spent fuel storage cells 3, 10 made of different materials can be exchanged.
When it is replaced with 1, it becomes possible to provide a spent fuel storage facility capable of storing high burnup fuel.

Further, by using the spent fuel storage cell 101 whose shape is partially changed, the spent fuel generated not only in the nuclear power plant having the pressurized water reactor but also in the nuclear power plant having the boiling water reactor is used. It becomes possible to store.

[0062]

In the spent fuel storage rack according to the present invention, a plurality of rectangular cross-section pipes having the length determined in consideration of the seismic condition, that is, the second rectangular cylinders are combined and fixed in a checkered pattern. Since it is used as the supporting member for the fuel storage cell, the lower supporting member or the lower supporting plate is not required, and it is possible to improve the cooling efficiency while ensuring the earthquake resistance of the spent fuel storage facility.

In particular, when a columnar member having a length reaching the floor from the position of the supporting member is arranged at a position determined in consideration of the seismic resistance condition of the plant, the supporting member is supported and the lower supporting member or the lower supporting plate is unnecessary. Therefore, it is possible to improve the cooling efficiency while further improving the earthquake resistance of the spent fuel storage facility.

Since the plurality of rectangular cylinders forming the support member are arranged in a checkered pattern, the weight of the spent fuel storage facility can be reduced.

By adopting a structure in which the cell fixing member is fitted between the support member and the spent fuel storage cell, the spent fuel storage cell can be easily detachably attached and supported from the support member, and maintenance can be performed. It will be easier.

If the spent fuel storage cell is composed of a tube having a neutron absorption effect, it is possible to realize a facility capable of storing high burnup fuel without changing the structure of the support member.

When the structure of the support member of the spent fuel storage cell is changed to reduce the center distance of the spent fuel storage cell, the storage density of the spent fuel in the spent fuel storage facility is increased and the capacity of the storage facility is increased. Can be increased.

When a structure capable of stably holding vertically the fuel assembly for a boiling water reactor is provided at the bottom of each spent fuel storage cell, the spent fuel generated in a nuclear power plant having a boiling water reactor can be A storage facility can be realized.

The support member formed by combining and fixing the spent fuel storage racks in a checkered pattern,
When used in combination with the lower support plate, the rack's seismic resistance is further improved, and it can be applied to plants with extremely severe seismic conditions.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of an embodiment of a spent fuel storage rack according to the present invention.

FIG. 2 is a perspective view showing a state in which the spent fuel storage rack of the embodiment of FIG. 1 is assembled.

FIG. 3 is a side view showing a state where spent fuel is stored in the spent fuel storage rack of the embodiment of FIG.

FIG. 4 is a diagram showing the structure of the spent fuel storage rack of the embodiment of FIG. 1 at the height of a rectangular cross-section tube.

FIG. 5 is a perspective view showing a structure of an example of a spent fuel storage cell provided with a lower structure capable of stably holding a fuel assembly for a boiling water reactor vertically.

6 is a view showing a structure at a height of a supporting member of a spent fuel rack when the spent fuel storage cell of FIG. 5 is adopted as a part of a storage area and fixed to a supporting member by a fixing member.

FIG. 7 shows a situation in which spent fuel is stored in a spent fuel storage rack of an embodiment in which the spent fuel storage rack according to the present invention is combined with a lower support plate to be applied to a plant having extremely severe seismic conditions. It is a side view shown.

FIG. 8 is a diagram showing a structure of an embodiment in which corner portions are connected to each other through spacers in order to arrange the second rectangular cylinders (rectangular cross-section tubes) in a checkerboard pattern.

FIG. 9 is a diagram showing a structure of an embodiment in which an L-shaped member is attached and connected in the vicinity of a corner portion of the second rectangular cylinder (rectangular cross-section tube) so as to be arranged in a checkered pattern.

FIG. 10 is a view showing a used fuel storage cell fixing member having a one-step wedge-shaped vertical cross-section.

FIG. 11 is a view showing a used fuel storage cell fixing member having a wedge-shaped vertical cross-section.

FIG. 12 is a view showing a used fuel storage cell fixing member made of a corrugated plate having a vertical cross-sectional shape.

FIG. 13 is a view showing a used fuel storage cell fixing member having a corrugated vertical cross-sectional shape.

FIG. 14 is a view showing a used fuel storage cell fixing member having a coiled member between a member on the spent fuel storage cell side and a member on the support member side.

FIG. 15 is a view showing a used fuel storage cell fixing member having an arcuate plate-shaped member between the used fuel storage cell side member and the support member side member.

FIG. 16 is a view showing a used fuel storage cell fixing member having a movable jack structure between the used fuel storage cell side member and the support member side member.

FIG. 17 is a view showing a spent fuel storage cell fixing member having a fixed jack structure between a member on the spent fuel storage cell side and a member on the support member side.

FIG. 18 is a view showing a structure of an embodiment of a spent fuel storage rack in which first rectangular cylinders and second rectangular cylinders are alternately arranged in a checkerboard pattern, and corner portions are directly joined to each other.

FIG. 19 is a perspective view showing a structure of an example of a conventional spent fuel storage rack in which spent fuel storage cells are vertically supported by a first support member and a second support member.

FIG. 20 is a perspective view showing the structure of an example of a conventional spent fuel storage rack in which spent fuel storage cells are vertically supported by an upper rack support plate and a lower rack support plate.

[Explanation of symbols]

 1 Spent Fuel Storage Pool 2 Bottom of Storage Pool 3 First Square Tube (Spent Fuel Storage Cell) 4 1st Support Member 5 2nd Support Member 6 Concrete Wall 7 Embedded Hardware 8 Conventional Spent Fuel Storage Rack 9 Upper Rack Support Plate 10 Lower rack support plate 11 Conventional spent fuel storage rack 12 Center distance of stored fuel 50 Stored fuel 51 Spent fuel storage pool wall 52 Spent fuel storage cell fixing member 53 Second prism (rectangular section tube) 55 Columnar member that supports the supporting member 56 Spent fuel storage rack 100 of the present invention 100 Seat plate 101 Spent fuel storage cell 102 Spent fuel storage cell fixing member 150 Lower support plate 200 Spacer 201 L-shaped member 250 Spent fuel storage cell fixing member 251 Used fuel storage cell fixing member 252 Used fuel storage cell fixing Material 253 Spent fuel storage cell fixing member 254 Spent fuel storage cell side member 255 Support member side member 256 Coil member 257 Spent fuel storage cell fixing member 258 Bow plate member 259 Spent fuel storage cell fixing member 260 Movable jack structure 261 Spent fuel storage cell fixing member 262 Fixed jack structure 263 Spent fuel storage cell fixing member

Front Page Continuation (72) Inventor Yasuyasu Yamanaka 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Takashi Matsumoto 3-1-1, Saiwaicho, Ibaraki No. Hitachi Co., Ltd. Hitachi Factory (72) Inventor Shozo Saito 3-1-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Co., Ltd. Hitachi Factory

Claims (8)

[Claims] 1. A spent fuel storage rack for storing and storing spent fuel generated in a nuclear power plant, wherein a first rectangular cylinder for accommodating the spent fuel inside one by one.
(A spent fuel storage cell), a second rectangular cylinder having an inner dimension slightly larger than the outer shape of the first rectangular cylinder and arranged in a checkerboard pattern, and the corner portions of the second rectangular cylinder are connected to each other. A member to be fixed and an outer surface of the first prism and an inner surface or an outer surface of the second prism for inserting and fixing the first prism into a space defined by an inner surface or an outer surface of the second prism. And a storage cell fixing member which is inserted into a gap between the storage tank and the storage cell fixing member. 2. A spent fuel storage rack for storing and storing spent fuel generated in a nuclear power plant, wherein a first rectangular cylinder arranged at predetermined intervals to store the spent fuel inside one by one ( The columns of (spent fuel storage cells) and the first rectangular cylinders having an inner size slightly larger than the outer shape of the first rectangular cylinders and arranged at the predetermined intervals are arranged in a checkered pattern while being shifted in the row direction. A row of second rectangular cylinders, a member for connecting and fixing corners of the first rectangular cylinder and the second rectangular cylinder arranged in a checkered pattern, and inside the second rectangular cylinder and the first rectangular cylinder A first square tube inserted into a space defined by the second square tube and the second square tube; and a second square tube, or a space defined by the first square tube and the second square tube. An outer surface of the inserted first rectangular cylinder and the second corner for inserting and fixing the first rectangular cylinder. A spent fuel storage rack comprising: a storage cell fixing member that is inserted into a gap between the inner surface of the cylinder or the gap between the inserted first rectangular cylinder and the checkered first rectangular cylinder. 3. The spent fuel storage rack according to claim 1 or 2, wherein the first prism has a length required to vertically hold and store the spent fuel, and A square tube sits vertically on the floor of the spent fuel storage pool and is a wall surface of the spent fuel storage pool for supporting the first square tube at a position slightly lower than the upper end of the spent fuel stored. Fuel storage rack having a structure and a length required to support the first rectangular cylinder with sufficient seismic strength via the storage cell fixing member. . 4. The spent fuel storage rack according to any one of claims 1 to 3, wherein at least one of the first rectangular cylinders (spent fuel storage cells) is a boiling water reactor. A spent fuel storage rack, which is a rectangular tube having a seat plate 100 for holding spent fuel for use in the bottom thereof. 5. The spent fuel storage rack according to any one of claims 1 to 4, wherein at least one of the first rectangular cylinder and the second rectangular cylinder is
A spent fuel storage rack, which is either an austenitic stainless steel or a boron-added stainless steel containing boron added to austenitic stainless steel, which has a neutron absorbing effect. 6. The spent fuel storage rack according to any one of claims 1 to 5, wherein the storage cell fixing member is a wedge-shaped fixing member, a plurality of wedge-shaped fixing members, and a corrugated plate-shaped fixing member. Use of any one of a member, a corrugated fixing member, a fixing member having a coil-shaped member, a fixing member having an arched plate member, a fixing member having a movable jack structure, and a member having a fixed jack. Spent fuel storage rack. 7. The spent fuel storage rack according to any one of claims 1 to 6, wherein the storage cell fixing member is provided with the second rectangular cylinder prior to assembly of the spent fuel storage rack. Alternatively, a spent fuel storage rack, which is previously attached to the first rectangular cylinder by welding or by mechanical means. 8. The spent fuel storage rack according to any one of claims 1 to 7, a pool for storing the spent fuel storage rack and the spent fuel, and the spent fuel storage rack. And a member for fixing the above to the wall of the pool.