JP5913036B2 - Damaged fuel storage rack - Google Patents

Description

  The present invention relates to a damaged fuel storage rack for storing damaged fuel.

  In general, in a nuclear power plant, spent fuel taken out of the core after operating the reactor for a certain period of time is stored in a fuel storage rack that can be stably stored for a period until the reprocessing, and the nuclear power plant. The decay heat removal is performed by immersing the fuel storage rack stored in the internal fuel storage pool and cooling it. Here, the fuel storage rack that can be stably stored refers to a fuel storage rack that is designed in advance in consideration of the shape of the fuel, the amount of uranium, the reactivity, and the like.

  The fuel storage rack used at this time was designed for healthy spent fuel, so that it maintains the same shape as healthy spent fuel, although there are healthy spent fuel and pinholes. It was possible to store the damaged fuel (see, for example, Patent Document 1).

  On the other hand, fuel that has undergone significant damage due to core melting or the like has a high possibility that the shape of the fuel is significantly deformed. Even when a damaged fuel having such a deformed shape is taken out of the core, there has been no fuel storage rack that is considered to be stably accommodated and stored and cooled.

JP 2001-108788 A

  When taking out damaged fuel, it is conceivable that the damaged fuel is crushed and stored in a canister, and the canister is stored in a fuel storage rack and stored in a fuel storage pool. Since it is difficult to predict the shape, uranium amount, reactivity, etc. of damaged fuel in advance, it is necessary to determine the size of the damaged fuel to be crushed flexibly on site and store it. In this case, since there is a capacity limit of the fuel storage pool, it is considered necessary to efficiently store the damaged fuel to some extent, but a fuel storage rack that satisfies such a situation has not been considered.

  Therefore, the present invention has been made in consideration of the above-described problems, and provides a damaged fuel storage rack that can flexibly handle storage work at a work site.

A damaged fuel storage rack according to an embodiment of the present invention is a rectangular parallelepiped damaged fuel storage rack capable of storing a plurality of canisters containing damaged fuel, and includes a base having a rectangular surface and four corners of the rectangular surface of the base. And at least four structural strength materials that are vertically connected to the base and a plurality of frames that can be installed horizontally to the base at a plurality of height positions of the structural strength material A plurality of cells provided to divide a plane plane space provided in the frame plate and horizontally in the base of the frame plate in order to store a plurality of canisters. At least one of the above is characterized in that the side surface of the canister is supported when the canister is stored .

  ADVANTAGE OF THE INVENTION According to this invention, the damaged fuel storage rack which can respond to a storage operation | work flexibly in a work site can be provided.

The perspective view of the damaged fuel storage rack of 1st Embodiment. The top view of the frame board 5. FIG. The figure which shows the example of attachment of the frame board 5 The figure which shows the example of attachment of the supporting member 6 The figure explaining the adjuster mechanism 8 of the supporting member 6 The figure which shows the example which bolted the supporting member 6 and the frame board 5 The perspective view of the damaged fuel storage rack of 2nd Embodiment. The perspective view of the damaged fuel storage rack of 3rd Embodiment. The perspective view of the damaged fuel storage rack of 4th Embodiment.

Hereinafter, an embodiment of a damaged fuel storage rack will be described with reference to the drawings.
[First Embodiment]
FIG. 1 shows a damaged fuel storage rack 1 of the present embodiment.

  The damaged fuel storage rack 1 is a rectangular parallelepiped shape capable of storing a plurality of canisters containing damaged fuel, and is joined to a rectangular base 2 and four corners of the rectangular surface of the base 2, and is perpendicular to the rectangular surface. Four structural strength members 3 serving as pillars in the direction, a plurality of reinforcing members 4 (plate 4a and brace 4b in the figure) that join between at least two adjacent structural strength materials, and above the rectangular surface of the base 2 At least a part of the plurality of cells provided to divide the space into a plurality of parts in the vertical direction and store a plurality of canisters supports the side surface of the canister when the canister is stored, and the structural strength material A plurality of frame plates 5 that can be installed freely at a plurality of height positions are provided.

  Here, although not shown, the base 2 may be fixed by a foundation bolt installed in the fuel storage pool, but a support member such as a foundation bolt cannot be obtained or an existing support member cannot be used in terms of strength. May be a sliding bearing. The structural strength material 3 is shown here as a square tube, but is not limited thereto. In addition, the structural strength material 3 is four here, but may be four or more. The reinforcing member 4 is shown here as a plate 4a and a brace 4b, but is not limited thereto.

  FIG. 2 shows a standard cross-sectional shape of the frame plate 5. The frame plate 5 includes a structural material portion 5a formed of a member such as stainless steel or corrosion-resistant aluminum alloy steel, a storage cell portion 5b that is a space for holding a canister that is a container for containing damaged fuel, and a fuel storage rack. And a notch 5d for dodging the structural strength material 3 with the same outer dimensions as the base 2. The frame plate 5 is installed on the damaged fuel storage rack 1 with a sling or the like attached to the storage cell portion 5b or the space portion 5c. The storage cell portion 5b is formed in advance so as to match the canister outer dimensions, but the frame plate 5 having the inner dimensions of several types of storage cell portions 5b so as to correspond to the several canister outer dimensions in advance. May be prepared, and the frame plate 5 may be selected and installed as necessary at the site.

  FIG. 3 shows an example of a structure for enabling the frame plate 5 to be installed on site.

  The support member 6 is installed at a predetermined position of the structural strength material 3 and supports the frame plate 5 in the vertical direction. The support member 6 has a hook shape as shown in FIG. The support member 6 is inserted and installed in the hole 7 provided at the position of the structural strength material 3 corresponding to the height of the canister that is assumed to be used in advance. Since only the installation of the frame plate 5 on the support member 6 causes rattling, the frame plate 5 may be fixed by installing and stretching an adjuster mechanism 8 as shown in FIG. 5, for example. By doing in this way, it can prevent that the frame board 5 floats by the vertical direction load by an earthquake etc.

  The adjuster mechanism 8 shown in the figure has a structure in which the wedge 8c is pushed in by turning and tightening a nut 8b welded to the screw 8a, and the block 8d is expanded. In addition, as shown in FIG. 6, a base 9 b provided with a long hole 9 a is installed in the space portion 5 c of the outer peripheral portion of the frame plate 5, and a through hole 9 c and a nut 9 d are also installed in the support member 6. The bolt 5e may be tightened after the frame plate 5 is installed to fix the frame plate 5 and the support member 6.

  In the present embodiment, the structure in which the frame plate 5 is installed at three places in the height direction is shown, but two or less places may be used if not necessary. When installing the frame plates 5 at three or more locations, the plurality of upper frame plates 5 may be connected in the height direction with long bars or the like. In this case, the installation time can be shortened.

  1 shows a structure in which the structural strength material 3 is joined to the base 2 and the structural strength material 3 is joined by a reinforcing member 4 such as a plate or a brace. Instead, the structural strength material 3 has the same height. The frame may be formed on the base with the large plate without using the large plate or using the structural strength material 3.

  According to the present embodiment configured as described above, the seismic strength of the entire damaged fuel storage rack is secured by the structural strength members 3 at the four corners, and the horizontal load of the stored item is supported by the frame plate 5. Further, the support member 6 supports a vertically downward load of the frame plate 5, and the horizontal load of the frame plate 5 is supported by the structural strength material 3.

  Moreover, according to this embodiment, the frame board which has several kinds of storage cell internal shapes prepared beforehand can be selected arbitrarily locally. Thereby, it is possible to install the frame plate 5 from above even after the damaged fuel storage rack 1 is installed in the fuel storage pool, and to install a frame plate that can hold the storage cell according to the situation (necessary). it can.

  Furthermore, according to the present embodiment, the frame plate 5 can be additionally installed by access from above at a height position prepared in advance so that the support member 6 can be installed. Even after installation, the frame plate 5 can provide appropriate support depending on the stored canister height.

And since the damaged fuel storage rack of this embodiment can be made into the substantially same external shape, many damaged fuel storage racks can be densely arrange | positioned in a fuel pool.
[Second Embodiment]
FIG. 7 shows a second embodiment.

The damaged fuel storage rack of the present embodiment is attachable to the damaged fuel storage rack of the first embodiment and further to one cell of the frame plate 5 and has a size that fits the outer peripheral size of the canister. A grid plate 10 is provided.

  The lattice plate 10 has a width equivalent to the inner dimension of the storage cell portion 5 b of the frame plate 5.

  A part of the end portion of the lattice plate 10 is provided with a protruding portion 10a for riding on the structural member 5a of the frame plate 5 to prevent dropping. The structural material 5a is provided with slits (not shown) that fit into the thickness of the members of the lattice plate 10, and the lattice plate 10 is installed so as to fit into the slits so that the lattice plate 10 does not rotate. ing.

In addition, although the grid plate 10 in which the storage cell units 5b are equally arranged is shown in the drawing, the dimensions of the storage cell unit 5b and the grid plate 10 are determined according to the size of the canister expected to be used. do it. Moreover, you may join the lattice board 10 and the frame board 5 by welding etc. as needed.
In addition to the effects of the first embodiment described above, the present embodiment configured as described above can further divide the storage cell portion 5b of the frame plate 5 at the site, and the assumption in advance at the site Even if different canisters are used, it is possible to respond more flexibly. In addition, when storing a high reactivity canister locally, it can also be used for the purpose of expanding the storage pitch, and it becomes possible to easily maintain subcriticality.

[Third Embodiment]
FIG. 8 shows a damaged fuel storage rack of the third embodiment. The damaged fuel storage rack of the third embodiment is installed in a space further divided by cells with respect to the damaged fuel storage rack of the first embodiment or the second embodiment, and is at least a metal. A square tube made of a material or a neutron absorber is provided.

  The square tube 11 is installed in order to maintain subcriticality according to the reactivity of the stored product. In this figure, the larger one of the square tubes is a square tube 11a, and the smaller one is a square tube 11b. However, the square tube 11a is held without the grid 10 for dividing shown in the second embodiment. The square tube 11b is provided with a lattice 10 and held.

  The square tubes 11a and 11b may be installed together when the damaged fuel storage rack 1 is assembled on site, but can be additionally installed from above after the damaged fuel storage rack 1 is installed in the fuel storage pool. It is. Furthermore, what is necessary is just to install only in the required storage cell part 5b according to the reactivity of the store thing to be stored.

  The rectangular tubes 11a and 11b are manufactured from stainless steel, corrosion-resistant aluminum alloy steel, alloy steel obtained by adding high-concentration boron to these metals, metal materials containing boron carbide or sintered, and depending on the reactivity of the stored canister. Use a suitable material.

  According to the present embodiment configured as described above, the neutron absorption effect corresponding to the material of the square tube 11 can be obtained by installing the square tube 11 on the outer periphery of the storage cell 5b. In particular, as compared with the second embodiment, when storing a canister having a high reactivity, it is not necessary to use a storage cell to increase the storage pitch, and a stronger neutron absorption effect can be obtained.

  In addition, since the installation of the square tube 11 in the damaged fuel storage rack 1 can be performed after the damaged fuel storage rack 1 is installed in the fuel storage pool, the canister is stored in the damaged fuel storage rack in advance. Unlike the plan, it is also effective when it is necessary to store a highly reactive store next to it.

[Fourth Embodiment]
FIG. 9 shows a fourth embodiment. In the damaged fuel storage rack of the fourth embodiment, the canister 13 lower than the length of the structural strength material is further stored in the upper space after any of the first to third embodiments is stored. It is provided with an additional base that can be attached to store the battery.

  The additional base 12 has a chair-like structure including a plate 12a and legs 12b. The area above the plate 12a is an enlarged storage space. Two legs 12b, which are arranged in two at approximately four corners below the plate 12a, are seated on the base 2 through the space 5c on the outer peripheral edge of the frame plate 5. Although the leg 12b should just be a structural strength material, what was comprised with the square tube is illustrated here. If there are multiple types of canisters 13 having a low height and there are differences in the height dimensions, a plurality of structural materials having different lengths are prepared in advance, and bolts between several selected structural materials are used. It is good also as a structure which connects by and adjusts the height of the leg 12b.

  A plate of a size that passes through the space 5c in the outer peripheral portion of the frame plate 5 may be installed on the seating surface of the leg 12b on the base 2 so as to reduce the surface pressure. Here, an example in which the number of legs 12b is eight is shown, but the number of legs 12b can be increased or decreased in consideration of various conditions such as a surface pressure applied to the base 2.

  Such an additional base 12 is used when a canister 13 having a relatively low height is stored in a damaged fuel storage rack. After the additional base 12 is installed, another canister 13 is installed above the plate 12a. Can do.

  According to the present embodiment, the fuel storage pool limited in plan can be used in the height direction, and the storage capacity can be increased. Further, since the additional base 12 does not protrude outside the damaged fuel storage rack, the damaged fuel storage rack can be densely installed.

  It should be noted that the present invention is not limited to the above embodiments as they are, and can be implemented in various forms other than the above-described embodiments in the implementation stage without departing from the spirit of the invention. Various omissions, additions, replacements, and changes can be made. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1 ... damaged fuel storage rack, 2 ... base, 3 ... structural strength material,
4 ... reinforcement member, 4a ... plate, 4b ... brace,
5 ... frame plate, 5a ... structural material, 5b ... storage cell part,
5c: space, 5d: notch, 6 ... support member, 7 ... hole,
8 ... Adjuster mechanism, 8a ... Screw, 8b ... Nut, 8c ... Wedge,
8d ... block, 9a ... long hole, 9b ... pedestal, 9c ... through hole,
9d ... nut, 9e ... bolt
10 ... Lattice plate, 11, 11a, 11b ... Square tube, 12 ... Additional base,
12a ... board, 12b ... leg, 13 ... canister

Claims (4)

A rectangular parallelepiped damaged fuel storage rack capable of storing a plurality of canisters containing damaged fuel,
A base having a rectangular surface, and at least four structural strength materials which are respectively joined to four corners of the rectangular surface of the base and serve as vertical columns with respect to the base;
A plurality of reinforcing members for joining between at least two adjacent structural strength materials;
A plurality of frame plates that can be installed horizontally to the base at a plurality of height positions of the structural strength material; and
In order to store a plurality of the canisters, a plurality of cells provided in the frame plate and provided in the base of the frame plate so as to divide a horizontal plane space into a plurality of cells,
A damaged fuel storage rack, wherein at least one of the plurality of cells supports a side surface of the canister when the canister is stored .   2. The damaged fuel storage rack according to claim 1, further comprising a lattice plate that can be attached to one cell of the frame plate and has a size that fits an outer peripheral size of the canister.   3. The damaged fuel storage rack according to claim 1 or 2, further comprising a square tube made of at least a metal material or a neutron absorber, which is installed in a space divided by cells.   4. An additional base which can be attached to store another canister in the upper space after storing a canister lower than the length of the structural strength material is further provided. Damaged fuel storage rack.

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