JP2019158398A - Spent fuel storage container - Google Patents

Abstract

To secure strength of a basket plate while reducing weight of the basket plate, and form a water gap which is excellent in drainage performance and which can be manufactured easily and economically.SOLUTION: A spent fuel storage container includes a storage container body 10, and a basket 12 which is provided in the storage container body 10 and in which a plurality of section parts 11 for sectioning and storing spent fuel assemblies 100 one by one are provided. The basket 12 is constituted by assembling the plurality of basket plates 20 in a lattice shape. The basket plate 20 is constituted by a pair of plates 21, 22 oppositely arranged by forming a water gap 25 opening in an axial direction of the storage container body 10. A reinforcement member 30 extending in the axial direction of the storage container body 10 is arranged in the water gap 25.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a spent fuel storage container used for transporting and storing spent fuel assemblies generated from a nuclear power plant, and particularly suitable for transporting and storing spent fuel in a pressurized water reactor (PWR). The present invention relates to a new spent fuel storage container.

  The fuel that has been used for a certain period in the reactor core of the nuclear power plant facility is taken out of the core and temporarily stored in a fuel pit for storing the spent fuel assembly. The spent fuel assembly cooled for a predetermined period is finally carried to a reprocessing plant where it is reprocessed, uranium and plutonium are taken out, and used as resources.

As a method for managing and storing spent fuel assemblies inside or outside the nuclear power plant site, there are dry storage methods such as metal cask storage, concrete cask storage and vault storage, and wet storage methods such as a water pool.
When considering the storage cost, safety when the power supply is lost, and long-term storage stability, a dry storage system that can be cooled by air without using a power supply is advantageous. Among the dry storage systems, what is currently put to practical use in Japan is a metal cask storage system in which spent fuel is stored in a metal cask.

  A metal cask has a lattice basket in a cylindrical container, and a spent fuel assembly is inserted into each lattice and sealed with a double lid. The basket is made of a material containing a neutron absorber, and when the spent fuel assembly is loaded in the basket, it absorbs neutrons generated from the spent fuel assembly sufficiently and is subcritical. Designed to ensure. The spent fuel assembly generates decay heat, but the internal heat is transferred to the surface of the metal cask through the basket. Heat is released from the surface of the metal cask by radiation heat radiation to the surroundings and cooling by natural convection of air. In addition, the metal cask has a sufficient structural strength so as not to break even with a high impact load that is received in the event of a drop during transportation.

  A fuel assembly used in a pressurized water reactor (PWR) is wider than a fuel assembly in a boiling water reactor (BWR). For this reason, if the spent fuel assemblies of the pressurized water reactor (PWR) loaded in the basket in water are too close to each other, it may become critical. Therefore, it is necessary to dispose the spent fuel assembly of the pressurized water reactor (PWR) at a distance between adjacent fuel assemblies as compared to the spent fuel assembly of the boiling water reactor (BWR). is there. Hereinafter, this interval is referred to as a water gap.

  There are roughly two types of baskets for storing spent fuel assemblies of a pressurized water reactor (PWR). One is a basket composed of a plurality of square pipes spaced apart as disclosed in Patent Document 1, for example, and the other is disclosed in Patent Document 2. A basket is formed by inserting a hollow basket plate having a notch (slit) at right angles.

  In the latter case, since baskets are manufactured by sequentially stacking basket plates, it is easy to manufacture baskets with high spacing accuracy.

  Further, a basket structure disclosed in Patent Documents 3 and 4 is also known. In the basket structure of Patent Document 3, an aluminum alloy plate having a high thermal conductivity and including a neutron absorber is disposed as a basket plate near the center, and a stainless steel plate including a neutron absorber is disposed as a basket plate in the periphery. .

  Patent Document 4 describes a technique for forming a water gap by inserting a spacer between a square pipe and a square pipe as a basket structure for a spent fuel assembly of a pressurized water reactor (PWR). .

JP 2001-108788 A Japanese Patent Laid-Open No. 2006-200939 JP 2006-105741 A JP-A-2005-283135

  In Patent Document 2, when a spent fuel assembly of a pressurized water reactor (PWR) that is heavier and wider than a spent fuel assembly of a boiling water reactor (BWR) is targeted, the basket plate is made thicker. It is necessary to construct and give the basket enough strength. For this reason, there existed a subject that the weight of a spent fuel storage container increased. Moreover, in patent document 2, the hollow part of a basket plate acts as a water gap. Since this hollow portion is open in a direction perpendicular to the axial direction of the container, it takes time to discharge water when discharging the water after loading the spent fuel assembly in the basket in the fuel pit. There was a possibility.

In Patent Document 3, a spent fuel assembly of a boiling water reactor (BWR) is targeted, and a spent fuel assembly of a pressurized water reactor (PWR) that is heavier and wider than this is targeted. The basket plates need to be thick. For this reason, since the process of the slit of a fitting part becomes difficult, there existed a subject that it became expensive.
It is also possible to produce a basket plate having a hollow portion by forming an aluminum alloy plate by extrusion, but since the aluminum alloy plate has a lower strength than steel, each plate is thickened to ensure strength. Need to form. For this reason, the amount of material and the processing cost increase compared to the case where steel is used, and the cost becomes high. Moreover, since a stainless steel plate is difficult to extrude, it is difficult to manufacture.

  Further, in Patent Document 4, a support member is inserted in the center of the four square pipes to hold the square pipes and spacers, and the structure is such that the square pipes and spacers are positioned at the same time. Therefore, there is a problem that assembly is difficult. In addition, it is necessary to manufacture a large square pipe for storing the spent fuel assembly, which increases processing costs. Moreover, when forming a water gap with the basket plate of a board | plate material, there also existed a subject that a board | plate material became thick for ensuring intensity | strength.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a spent fuel storage container in which a basket can be easily manufactured and a water gap can be formed economically.

  A spent fuel storage container according to the present invention includes a storage container main body, and a basket provided in the storage container main body and provided with a plurality of partition portions for partitioning and storing spent fuel assemblies one by one. The basket is configured by assembling a plurality of basket plates in a lattice shape, and the basket plates form a pair of plates opposed to each other by forming a water gap that opens in the axial direction of the storage container body. A reinforcing member extending in the axial direction of the storage container body is disposed in the water gap.

  According to the present invention, it is possible to obtain a spent fuel storage container in which a basket can be easily manufactured and a water gap can be formed economically.

1 is a partially cut perspective view showing a schematic structure of a spent fuel storage container according to a first embodiment of the present invention. It is a model cross-sectional view of a spent fuel storage container. It is an expansion perspective view which shows a part of structure of a basket. It is a model cross-sectional view of the spent fuel storage container which concerns on 2nd Embodiment of this invention. It is a model cross-sectional view of the spent fuel storage container which concerns on 3rd Embodiment of this invention. It is a model cross-sectional view of the spent fuel storage container which concerns on 4th Embodiment of this invention. It is an expansion perspective view which shows a part of structure of the basket of the spent fuel storage container which concerns on 4th Embodiment of this invention. It is a model expanded horizontal sectional view which shows a part of structure of the basket of the spent fuel storage container which concerns on 5th Embodiment of this invention. It is an expansion perspective view which shows arrangement | positioning with the reinforcing member and positioning plate of the spent fuel storage container which concern on 5th Embodiment of this invention. It is a model expanded horizontal sectional view which shows a part of structure of the basket of the spent fuel storage container which concerns on 6th Embodiment of this invention. It is a model expanded horizontal sectional view which shows a part of structure of the basket of the spent fuel storage container which concerns on 7th Embodiment of this invention. It is a model expanded horizontal sectional view which shows a part of structure of the basket of the spent fuel storage container which concerns on 8th Embodiment of this invention. It is a model expanded horizontal sectional view which shows a part of structure of the basket of the spent fuel storage container which concerns on 9th Embodiment of this invention. It is a model expanded horizontal sectional view which shows a part of structure of the basket of the spent fuel storage container which concerns on 10th Embodiment of this invention. It is a model expanded horizontal sectional view which shows the fixation structure of the basket of the spent fuel storage container which concerns on 11th Embodiment of this invention. It is a model expanded horizontal sectional view which shows the other fixing structure of the basket of the spent fuel storage container which concerns on 11th Embodiment of this invention. It is a model perspective view which shows the reinforcement member used for the spent fuel storage container which concerns on 12th Embodiment of this invention. It is a model perspective view which shows the modification of the reinforcement member used for the spent fuel storage container which concerns on 12th Embodiment of this invention.

  Hereinafter, embodiments of a spent fuel storage container according to the present invention will be described with reference to the drawings. In each embodiment, the same code | symbol is attached | subjected to the same part and the overlapping description is abbreviate | omitted. In the following embodiments, a case will be described in which the fuel assembly stored in the spent fuel storage container of the present invention is a spent fuel assembly of a pressurized water reactor (PWR). Note that hatching indicating a cross section is omitted in some drawings.

(First embodiment)
First, the overall configuration of the spent fuel storage container 1 will be described with reference to FIG. The spent fuel storage container (cask) 1 is used for storing or transporting the spent fuel assembly 100. The spent fuel storage container 1 includes a basket 12 provided with a plurality of compartments 11 for loading a spent fuel assembly 100 inside a storage container main body (inner cylinder) 10.

The storage container body 10 has a function of shielding γ rays generated from the spent fuel assembly 100. The storage container body 10 is, for example, a cylindrical container made of alloy steel. An outer cylinder 13 is disposed on the outer periphery of the side surface of the storage container body 10. The storage container body 10 and the outer cylinder 13 are connected by heat transfer fins 14 that also serve as heat transfer paths.
Further, a neutron shielding material 15 is filled in the space surrounded by the storage container body 10, the outer cylinder 13, and the heat transfer fins 14. In this embodiment, a resin is used as the neutron shielding material 15. As a result, neutrons generated from the spent fuel assembly 100 are shielded. The neutron shielding material 15 is made of, for example, a resin containing boron having high neutron absorption capability.

  The upper opening of the storage container body 10 is closed from the inside by a primary lid 16, a secondary lid 17 and a tertiary lid 18. Each lid is attached by a bolt (not shown).

  Next, the basket 12 will be described. As shown in FIGS. 2 and 3, the basket 12 includes a plurality of partition portions 11 for storing the spent fuel assemblies 100 one by one by assembling a plurality of plate-like basket plates 20 in a lattice shape. Forming. Each partition 11 is provided with a rectangular cylindrical opening in plan view (as viewed from the axial direction of the storage container body 10), and has a size capable of storing the spent fuel assembly 100.

  The basket plate 20 includes a pair of plates 21 and 22. The pair of plates 21 and 22 are flat metal plates, and are opposed to each other so as to form a water gap 25 that opens in the axial direction of the storage container body 10. The water gap 25 is located between the adjacent spent fuel assemblies 100 and outside the outermost spent fuel assembly 100 to ensure subcriticality.

  The overall length of each basket plate 20 in the longitudinal direction is set to a length that contacts the inner surface 10 a of the storage container body 10 or a length that does not contact the inner surface 10 a of the storage container body 10. The material of the basket plate 20 is preferably a material having high strength and / or high thermal conductivity. In this embodiment, the basket plate 20 is formed of boron-containing stainless steel, but may be formed of boron-containing aluminum alloy. Further, the materials may be changed between the adjacent plates 21 and 22. For example, the plate 21 made of boron-containing stainless steel and the plate 22 made of an aluminum alloy may be arranged next to each other. It is also possible to arrange the plate 21 made of carbon steel and the plate 22 made of an aluminum alloy or a boron-containing aluminum alloy next to each other.

  As shown in FIG. 3, assembling cuts 26 and 26 are formed at predetermined positions on the upper and lower portions of each pair of plates 21 and 22. The cuts 26 are formed at both ends in the longitudinal direction of the pair of plates 21 and 22. Each notch 26 extends in the axial direction of the storage container body 10 and has a width that allows the corresponding plates 21 and 22 to be inserted during assembly. When the basket 12 is created, the basket plates 20 are fitted to each other by inserting them so as to be perpendicular to each other so that the notches 26 of the plates 21 and 22 match in the vertical direction. Then, the basket plates 20 are sequentially stacked in the axial direction of the storage container body 10 and assembled so that the whole becomes a lattice shape.

  A hollow reinforcing member 30 is disposed in the water gap 25 formed between the pair of plates 21 and 22. The reinforcing member 30 is disposed along substantially the entire vertical direction of the water gap 25 along the axial direction of the storage container body 10. The reinforcing member 30 has a cylindrical cross section. As the material of the reinforcing member 30, like the basket plate 20, a material having high strength and / or high thermal conductivity is preferable. For example, the reinforcing member 30 can be formed of boron-containing stainless steel.

  The reinforcing member 30 is disposed in the water gap 25 along the axial direction of the storage container body 10 so that the cylindrical opening is positioned at the opening of the water gap 25. The reinforcing member 30 is disposed in the water gap 25 by being inserted from the opening of the water gap 25 at the upper end of the basket 12 toward the bottom of the storage container body 10 after the basket 12 is formed. Such a reinforcing member 30 is inserted into the water gap 25 without being fixed, and is not integrated with the basket plate 20. For this reason, the basket 12 can be formed without using welding.

  The reinforcing member 30 is disposed in the water gap 25 with a predetermined gap with respect to the plates 21 and 22. Thereby, the thermal stress by the difference in the temperature change of a mutual member is suppressed low. The reinforcing member 30 may be disposed so as to be in contact with at least one of the plates 21 and 22 or may be partially fixed to the plates 21 and 22 by welding or the like. Further, although the reinforcing member 30 is disposed at the center portion in the longitudinal direction of the water gap 25, the present invention is not limited to this, and the water gap 25 may be disposed in the vicinity of the end portion.

  The reinforcing member 30 is not limited to a cylindrical cross section, and may be an elliptical one. The reinforcing member 30 is preferably hollow from the viewpoint of weight reduction, but may be solid. In FIG. 2, the reinforcing members 30 are disposed in all the water gaps 25. However, the present invention is not limited to this, and the number of the reinforcing members 30 can be reduced if the strength of the basket plate 20 can be secured.

  Such a reinforcing member 30 has a function of transmitting the load received from the spent fuel assembly 100 from, for example, one plate 21 to the other plate 22. Thus, the load from the spent fuel assembly 100 can be substantially supported by the two plates 21 and 22. Therefore, it is possible to improve the strength of the basket 12 while suppressing an increase in the thickness of the basket plate 20. In addition, it is possible to easily manufacture the water gap 25 with an inexpensive and high strength member (such as steel).

In the spent fuel storage container 1 of the present embodiment described above, in the basket 12 formed by fitting the basket plate 20 of the plate material, the basket plate 20 is formed by a pair of plates 21 and 22, and between the plates 21 and 22. Since the reinforcing member 30 is disposed in the formed water gap 25, the strength can be ensured with little increase in the plate thickness. Further, the water gap 25 can be easily formed in the process of fitting the plates 21 and 22 in a lattice shape, and the basket 12 having a guaranteed strength can be constructed by inserting the reinforcing member 30 into the water gap 25. Therefore, the water gap 25 can be formed easily and economically with the basket 12.
Further, since the increase in the plate thickness is small, the cutting 26 can be easily processed, and the cost can be reduced, which is economical.

  Further, since the water gap 25 is opened in the axial direction of the storage container body 10, the water discharge performance after the spent fuel assembly 100 is loaded on the basket 12 in the fuel pit is excellent.

  When the spent fuel storage container 1 is stored upright as shown in FIG. 1 after the spent fuel assembly 100 is loaded, the water gap 25 opens in the vertical direction (the axial direction of the storage container body 10). is doing. For this reason, the effect of natural convection of gas inside the storage container body 10 can be used, and improvement in heat removal performance can be expected.

(Second Embodiment)
The spent fuel storage container of the second embodiment will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view of a spent fuel storage container according to the second embodiment of the present invention. This embodiment is different from the first embodiment in that a hollow reinforcing member 31 having a rectangular cross section is used.

  As shown in FIG. 4, the reinforcing member 31 is disposed in the water gap 25 along the axial direction of the storage container body 10 so that the opening of the square tube is positioned at the opening of the water gap 25. The reinforcing member 31 is disposed in the water gap 25 by being inserted from the opening of the water gap 25 at the upper end of the basket toward the bottom of the storage container body 10 after the basket 12 is formed. Also in this embodiment, the reinforcing member 31 is inserted into the water gap 25 without being fixed, and is not integrated with the basket plate 20. For this reason, the basket 12 can be formed without using welding.

  The reinforcing member 31 is disposed in the water gap 25 with a predetermined gap with respect to the plates 21 and 22 and has a predetermined play. The reinforcing member 31 may be disposed so as to be in contact with at least one of the plates 21 and 22 or may be partially fixed to the plates 21 and 22 by welding or the like. Further, although the reinforcing member 31 is disposed in the center portion in the longitudinal direction of the water gap 25, the present invention is not limited to this, and the water gap 25 may be disposed in the vicinity of the end portion.

  The reinforcing member 31 is not limited to a rectangular tube-shaped cross section, and may be a trapezoidal tube-shaped member. The reinforcing member 31 is preferably hollow from the viewpoint of weight reduction, but may be solid. In FIG. 4, the reinforcing members 31 are disposed in all the water gaps 25. However, the present invention is not limited to this, and the number of the reinforcing members 31 can be reduced if the strength of the basket plate 20 can be secured.

  Further, the reinforcing member 30 described in the first embodiment may be added to one water gap 25, or two kinds of reinforcing members 30, 31 may be arranged in the entire basket 12. It may be configured.

  Also according to the second embodiment, the same operational effects as those of the first embodiment described above can be obtained. Furthermore, since the reinforcing member 31 has a rectangular tube shape, it is possible to receive a load generated on the reinforcing member 31 from the basket plate 20 on a wider surface. For this reason, the amount of deflection of the basket plate 20 can be reduced.

(Third embodiment)
The spent fuel storage container of the third embodiment will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view of a spent fuel storage container according to a third embodiment of the present invention. This embodiment is a modification of the second embodiment, and a positioning plate 31 a for positioning the reinforcing member 31 is disposed in the water gap 25.

The positioning plate 31a has a cross-sectional hat shape. The positioning plate 31 a includes a positioning protrusion 31 b that extends in the axial direction of the storage container body 10 and protrudes in a direction orthogonal to the axial direction of the storage container body 10, that is, in the short direction of the water gap 25. I have. The reinforcing member 31 is held and positioned inside the protruding portion 31b.
Here, the size of the protrusion 31b in the short direction of the water gap 25 is set to be equal to or smaller than the width of the water gap 25 in the short direction. That is, the dimension is set so that the protruding portion 31 b itself does not act as a member corresponding to the reinforcing member between the plates 21 and 22. Further, the size of the protruding portion 31 b in the longitudinal direction of the water gap 25 is set larger than the size of the reinforcing member 31 in the longitudinal direction.

  The positioning plate 31 a is disposed in the water gap 25 by being inserted together with the reinforcing member 31 from the opening of the water gap 25 at the upper end of the basket 12 toward the bottom of the storage container body 10 after the basket 12 is formed. Such a positioning plate 31 a is inserted without being fixed in the water gap 25, and is not integrated with the basket plate 20. For this reason, the basket 12 can be formed without using welding.

In the present embodiment, the positioning plate 31a for the rectangular tube-shaped reinforcing member 31 has been described. However, the shape of the reinforcing member and the shape of the protruding portion 31b of the positioning plate 31a are not limited. Further, the number and arrangement of the reinforcing members 31 and the positioning plates 31a and the number and formation positions of the protruding portions 31b in the water gap 25 are not limited.
Also in this embodiment, the reinforcing members 31 are disposed in all the water gaps 25. However, the present invention is not limited to this, and the number of the reinforcing members 31 can be reduced if the strength of the basket plate 20 can be ensured.

According to the third embodiment as well, in addition to the operational effects of the second embodiment described above, the reinforcing member 31 can be held at an arbitrary position within the water gap 25 by the positioning plate 31a.
The positioning plate 31a does not need to be disposed in the entire axial direction of the storage container body 10 in the basket 12, and may be configured to be disposed at a predetermined interval in the axial direction. In this case, it is preferable to fix the positioning plate 31 a having an arbitrary size in the axial direction to the reinforcing member 31 with an interval in the axial direction of the reinforcing member 31.

(Fourth embodiment)
The spent fuel storage container of the fourth embodiment will be described with reference to FIGS. FIG. 6 is a schematic cross-sectional view of a spent fuel storage container according to a fourth embodiment of the present invention. FIG. 7 is an enlarged perspective view showing the arrangement of the reinforcing member and the positioning plate. The present embodiment is a modification of the second embodiment, and a positioning plate 32 for positioning the reinforcing member 30 is disposed in the water gap 25.

The positioning plate 32 has a cross-sectional wave shape. The positioning plate 32 has a protruding portion 32b that extends in the axial direction of the storage container body 10 and protrudes in a curved shape in a direction orthogonal to the axial direction of the storage container body 10, that is, in the short direction of the water gap 25. I have. The reinforcing member 30 is held and positioned inside the protruding portion 32b.
Here, the size of the protrusion 32b in the short direction of the water gap 25 is set to be equal to or smaller than the width of the water gap 25 in the short direction. That is, the dimension is set so that the protrusion 32b itself does not act as a member corresponding to the reinforcing member between the plates 21 and 22. Further, the size of the protruding portion 32b in the longitudinal direction of the water gap 25 is set to a size that can accommodate the reinforcing member 31 inside thereof.

  The positioning plate 32 is disposed in the water gap 25 by being inserted together with the reinforcing member 30 from the opening of the water gap 25 at the upper end of the basket 12 toward the bottom of the storage container body 10 after the basket 12 is formed. Such a positioning plate 32 is inserted into the water gap 25 without being fixed, and is not integrated with the basket plate 20. For this reason, the basket 12 can be formed without using welding.

In the present embodiment, the positioning plate 32 for the cylindrical reinforcing member 30 has been described. However, the shape of the reinforcing member and the shape of the protruding portion 32b of the positioning plate 32 are not limited. Further, the number and arrangement of the reinforcing members 30 and the positioning plates 32 and the number and formation positions of the protrusions 32b in the water gap 25 are not limited.
Also in this embodiment, the reinforcing members 30 are arranged in all the water gaps 25, but the present invention is not limited to this, and the number of the reinforcing members 30 can be reduced if the strength of the basket plate 20 can be secured.

According to the fourth embodiment, in addition to the operation and effect of the second embodiment, the reinforcing member 30 can be held at an arbitrary position within the water gap 25 by the positioning plate 32.
Further, since the positioning plate 32 has a cross-sectional wave shape, it is easy to disperse the load when receiving the load.
The positioning plate 32 does not have to be disposed in the entire basket 12 in the axial direction of the storage container body 10 and may be configured to be disposed at a predetermined interval in the axial direction. In this case, a positioning plate 32 having an arbitrary size in the axial direction may be fixed to the reinforcing member 30 with an interval in the axial direction of the reinforcing member 30.

(Fifth embodiment)
The spent fuel storage container of the fifth embodiment will be described with reference to FIGS. FIG. 8 is a schematic enlarged cross-sectional view showing a part of the configuration of the spent fuel storage container basket according to the fifth embodiment of the present invention. FIG. 9 is an enlarged perspective view showing the arrangement of the reinforcing member and the positioning plate. The present embodiment is a modification of the fourth embodiment, and is arranged in the water gap 25 by alternately changing the direction of the protrusions 32b of the positioning plate 32 in the axial direction X1 of the reinforcing member 30.

  A plurality of positioning plates 32 are stacked in the axial direction X1 of the reinforcing member 30. The positioning plates 32 are alternately stacked so that the protruding directions of the protruding portions 32b adjacent to each other in the axial direction X1 are different by 180 degrees. Accordingly, the reinforcing member 30 is held and positioned in both the short and long directions of the water gap 25 by the plurality of protruding portions 32b protruding alternately along the axial direction X1.

  After the formation of the basket 12, the positioning plate 32 is inserted into the water gap 25 by changing its direction together with the reinforcing member 30 from the opening of the water gap 25 at the upper end of the basket 12 toward the bottom of the storage container body 10. Also in this embodiment, the positioning plate 32 is inserted into the water gap 25 without being fixed, and is not integrated with the basket plate 20. For this reason, the basket 12 can be formed without using welding.

In the present embodiment, the positioning plate 32 for the cylindrical reinforcing member 30 has been described. However, the shape of the reinforcing member and the shape of the protruding portion 32b of the positioning plate 32 are not limited. Further, the number and arrangement of the reinforcing members 30 and the positioning plates 32 and the number and formation positions of the protrusions 32b in the water gap 25 are not limited.
Also in this embodiment, the reinforcing members 30 are arranged in all the water gaps 25, but the present invention is not limited to this, and the number of the reinforcing members 30 can be reduced if the strength of the basket plate 20 can be secured.

  In the fifth embodiment, in addition to the effects of the fourth embodiment described above, the reinforcing member 30 can be positioned and held in the water gap 25 in both the short direction and the long direction.

(Sixth embodiment)
With reference to FIG. 10, the spent fuel storage container of 6th Embodiment is demonstrated. FIG. 10 is a schematic enlarged cross-sectional view showing a part of the configuration of the spent fuel storage container basket according to the sixth embodiment of the present invention. In the present embodiment, a positioning plate 33 having a substantially H-shaped cross section is disposed in the water gap 25.

  A pair of positioning plates 33 are arranged on both sides in the longitudinal direction of the reinforcing member 31 in the water gap 25, and the reinforcing members 31 are held and positioned from both longitudinal sides of the water gap 25.

  The positioning plate 33 is inserted into the water gap 25 from the opening of the water gap 25 at the upper end of the basket 12 toward the bottom of the storage container body 10 after the basket 12 is formed. Also in the present embodiment, the positioning plate 33 is inserted into the water gap 25 without being fixed, and is not integrated with the basket plate 20. For this reason, the basket 12 can be formed without using welding.

  Here, the size of the positioning plate 33 in the short direction of the water gap 25 is set smaller than the width of the water gap 25 in the short direction. That is, the dimension is set so that the positioning plate 33 itself does not act as a member corresponding to the reinforcing member between the plates 21 and 22. Further, the size of the positioning plate 33 in the longitudinal direction of the water gap 25 is set to be smaller than the size in the longitudinal direction of the space formed on both sides of the reinforcing member 31 in the longitudinal direction.

  When the size of the positioning plate 33 in the short direction of the water gap 25 is set to be equal to or larger than the width and dimensional tolerance of the reinforcing member 31, the positioning plate 33 is It can function as a reinforcing member. That is, by using such a positioning plate 33, the reinforcing member 31 can be positioned and further reinforcement between the plates 21 and 22 can be achieved.

In addition, although this embodiment demonstrated as the positioning plate 33 with respect to the square cylinder-shaped reinforcement member 31, it does not limit about the shape of a reinforcement member. Further, the number and arrangement of the reinforcing members 30 and the positioning plates 33 in the water gap 25 are not limited.
Also in this embodiment, the reinforcing members 31 are disposed in all the water gaps 25. However, the present invention is not limited to this, and the number of the reinforcing members 31 can be reduced if the strength of the basket plate 20 can be ensured.

  In such a 6th embodiment, the same operation effect as an operation effect of an above-mentioned 2nd embodiment is acquired. Further, the positioning plate 33 can be used as a reinforcing member.

(Seventh embodiment)
The spent fuel storage container of the seventh embodiment will be described with reference to FIG. FIG. 11 is a schematic enlarged cross-sectional view showing a part of the configuration of a spent fuel storage container basket according to a seventh embodiment of the present invention. In the present embodiment, a plurality of reinforcing members 30 are arranged in the water gap 25.

  A plurality of reinforcing members 30 are arranged in the longitudinal direction of the water gap 25. In this embodiment, a plurality of cylindrical reinforcing members 30 are used. However, the rectangular cylindrical reinforcing member 31 of the second, third and sixth embodiments and the positioning plate having a substantially H-shaped cross section of the sixth embodiment. 33 can be used as a reinforcing member, and a combination thereof is also possible.

  Also according to the seventh embodiment, the same effects as those of the first embodiment can be obtained. Furthermore, it becomes possible to make the reinforcing member 30 stand by itself without processing such as welding or grooves, and a positioning structure is not necessary.

(Eighth embodiment)
With reference to FIG. 12, the spent fuel storage container of 8th Embodiment is demonstrated. FIG. 12 is a schematic enlarged cross-sectional view showing a part of the structure of the spent fuel storage container basket according to the eighth embodiment of the present invention. In the present embodiment, the heat transfer plate 27 is disposed on the side surface of the basket plate 20.

Similar to the basket plate 20, the heat transfer plate 27 is provided by fitting. The heat transfer plate 27 is preferably disposed on the side surface opposite to the side surface of the water gap 25. Thereby, the decay heat generated from the spent fuel assembly 100 can be efficiently transmitted to the outside of the spent fuel storage container 1 by the heat transfer plate 27 closest to the spent fuel assembly 100. The heat transfer plate 27 is preferably made of a material having a high thermal conductivity (for example, a material such as an aluminum alloy). Moreover, you may use the neutron shielding material which added neutron absorbers, such as boron, or the heat-transfer board 27 formed by joining a neutron shielding material to the side surface.
In the present embodiment, the heat transfer plates 27 are arranged on the side surfaces of all the basket plates 20 as an example. However, the arrangement positions of the heat transfer plates 27 need to be on the side surfaces of all the basket plates 20. There may be any position. For example, in FIG. 12, the heat transfer plate 27 may be disposed on the side surface of the plate 21, and the heat transfer plate 27 may not be disposed on the side surface of the plate 22.

  Also according to the eighth embodiment, the same operational effects as those of the fourth embodiment described above can be achieved. Furthermore, the decay heat generated from the spent fuel assembly 100 can be efficiently transmitted to the outside of the spent fuel storage container 1 through the heat transfer plate 27.

(Ninth embodiment)
The spent fuel storage container of the ninth embodiment will be described with reference to FIG. FIG. 13 is a schematic enlarged cross-sectional view showing a part of the structure of the spent fuel storage container basket according to the ninth embodiment of the present invention. In the present embodiment, two or more different materials are used for the basket plate 20.

  Of the basket plate 20, the plate 21 and the plate 22 are formed of different materials. By adopting such a configuration, for example, one of the plates 21 can be provided with a neutron absorption function (neutron shielding function), and the other plate 22 can be provided with a heat transfer function. it can.

  Also according to the ninth embodiment, the same operational effects as those of the fourth embodiment can be obtained. Furthermore, the function of the basket plate can be divided into a neutron absorption function and a heat transfer function.

(10th Embodiment)
With reference to FIG. 14, the spent fuel storage container of 10th Embodiment is demonstrated. FIG. 14 is a schematic enlarged cross-sectional view showing a part of the structure of the spent fuel storage basket according to the tenth embodiment of the present invention. In the present embodiment, the thickness of the basket plate 20 is varied.

  In the basket plate 20, the plate 21b and the plate 22b are formed with different plate thicknesses. For example, one plate 21b is made thinner than the other plate 22b. The water gap 25 has the same size as that in the above embodiment.

  Also according to the tenth embodiment, the same operational effects as those of the fourth embodiment described above can be achieved. Furthermore, if the structural strength of the basket 12 can be ensured, the inner diameter of the storage container body 10 can be reduced by reducing the thickness of the other plate 21b. Thereby, the weight and cost of the spent fuel storage container 1 can be reduced.

(Eleventh embodiment)
The spent fuel storage container of the eleventh embodiment will be described with reference to FIGS. 15 and 16. FIG. 15 is a schematic enlarged cross-sectional view showing a structure for fixing a spent fuel storage container basket according to an eleventh embodiment of the present invention. FIG. 16 is a schematic enlarged cross-sectional view showing another fixing structure of the spent fuel storage container basket according to the eleventh embodiment. In the present embodiment, the end portion of the basket plate 20 is held on the inner surface 10 a of the storage container body 10.

  The inner surface 10 a of the storage container body 10 is provided with a plurality of grooves 35 extending in the axial direction of the storage container body 10. Each groove portion 35 is formed at a position corresponding to the end portion of each plate 21, 22 and has a groove width larger than the plate thickness of the plates 21, 22. The end portions of the plates 21 and 22 can be inserted and held in the respective groove portions 35.

  As shown in FIG. 16, the basket plate 20 provided with the heat transfer plate 27 on the side surface is configured to insert and hold only the end portions of the plates 21 and 22 not including the heat transfer plate 27 in the groove portion 35. . By doing so, most of the generated load can be received by the basket plate 20.

  Also according to the eleventh embodiment, the same operational effects as those of the fourth or eighth embodiment described above can be achieved. Further, since the fitting and fixing of the basket plate 20 is easy, the manufacturability of the basket 12 is improved. Further, in the basket plate 20 provided with the heat transfer plate 27 on the side surface, since the basket plate 20 receives most of the generated load, it is not necessary to configure the heat transfer plate 27 as a strength member, and the cost can be reduced.

(Twelfth embodiment)
The spent fuel storage container of the twelfth embodiment will be described with reference to FIGS. 17 and 18. FIG. 17 is a schematic perspective view showing a reinforcing member used in the spent fuel storage container according to the twelfth embodiment of the present invention. FIG. 18 is a schematic perspective view showing a modification of the reinforcing member used in the spent fuel storage container according to the twelfth embodiment of the present invention. In the present embodiment, holes 36 and 37 are formed in the reinforcing member 30.

  In the reinforcing member 30 shown in FIG. 17, a vertically long hole 36 is formed in the lower peripheral wall along the axial direction. The hole portion 36 penetrates the lower peripheral wall and communicates the inner space of the reinforcing member 30 and the outer space of the reinforcing member 30.

  In the reinforcing member 30 shown in FIG. 18, a vertically long slit-shaped hole portion 37 is formed on the lower peripheral wall along the axial direction. Similarly, the hole portion 37 penetrates the lower peripheral wall and communicates the inner space of the reinforcing member 30 and the outer space of the reinforcing member 30.

According to the twelfth embodiment, the water accumulated in the water gap 25 after the spent fuel assembly 100 is loaded is easily discharged by the holes 36 and 37.
It is possible to provide a plurality of holes 36 and 37 in the circumferential direction or a plurality of holes in the axial direction.
Similar holes 36 and 37 may be provided for the basket plate 20. Also in this case, the water accumulated in the water gap 25 after the spent fuel assembly 100 is loaded is easily discharged.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
For example, in each of the above-described embodiments, the reinforcing member 30 and the like may be disposed in a state of being inclined with respect to the axial direction of the storage container body 10 in the water gap 25.

  Further, the reinforcing member 30 or the like may be formed in a substantially C-shaped cross section.

  Further, the heat transfer plate 27 may be provided on both side surfaces of the plates 21 and 22.

  Furthermore, the reinforcing member 30 and the like are not limited to those integrated in the axial direction, and may be configured by being divided in the axial direction.

  The present invention can also be applied to a spent fuel storage container that stores a spent fuel assembly of a boiling water reactor (BWR).

DESCRIPTION OF SYMBOLS 1 Used fuel storage container 10 Storage container main body 11 Partition part 20 Basket plate 21,22 Plate 25 Water gap 30 Reinforcement member 31 Reinforcement member 31a Positioning plate 31b Protrusion part 32 Positioning plate 32b Protrusion part 33 Positioning plate 36,37 Hole part 100 Spent fuel assembly

Claims (15)

A storage container body;
A basket provided in the storage container main body, and provided with a plurality of partition portions for partitioning and storing spent fuel assemblies one by one,
The basket is configured by assembling a plurality of basket plates in a lattice shape,
The basket plate is composed of a pair of plates that are opposed to each other by forming a water gap that opens in the axial direction of the storage container body,
A spent fuel storage container, wherein a reinforcing member extending in the axial direction of the storage container body is disposed in the water gap.   2. The spent fuel storage container according to claim 1, wherein the reinforcing member has a cylindrical cross section, an elliptical cylindrical cross section, a square cylindrical cross section, or a trapezoidal square cylindrical cross section.   Both the reinforcing member having a cylindrical cross section or an elliptical cylindrical cross section and the reinforcing member having a square cylindrical cross section or a trapezoidal square cylindrical cross section are disposed in the water gap. The spent fuel storage container according to claim 1. A positioning plate that positions the reinforcing member at a predetermined position of the water gap is disposed in the water gap,
The positioning plate includes a positioning protrusion that extends in an axial direction of the storage container body and protrudes in a direction orthogonal to the axial direction of the storage container body. Spent fuel storage container as described in 1. The positioning plate is composed of a divided plate divided into a plurality of parts in the axial direction of the storage container body,
The spent fuel storage container according to claim 4, wherein the divided plates adjacent in the axial direction are arranged such that the protruding directions of the protruding portions are different from each other. A positioning plate that positions the reinforcing member at a predetermined position of the water gap is disposed in the water gap,
2. The spent fuel storage container according to claim 1, wherein the positioning plate extends in an axial direction of the storage container body and has a substantially H-shaped cross section.   The spent fuel storage container according to claim 1, wherein a plurality of the reinforcing members are arranged in at least one of the water gaps.   The spent fuel storage container according to claim 1, wherein a heat transfer plate is provided on at least one of the pair of plates.   The spent fuel storage container according to claim 1, wherein the basket plate is made of two or more kinds of materials.   The spent fuel storage container according to claim 1, wherein the pair of plates are made of different materials.   The spent fuel storage container according to claim 1, wherein the pair of plates have different plate thicknesses.   2. The spent fuel storage container according to claim 1, wherein the pair of plates is made of a neutron shielding material or a material to which a neutron shielding material is added.   The spent fuel storage container according to claim 1, wherein the reinforcing member is made of a neutron shielding material or a material to which a neutron shielding material is added.   The spent fuel storage container according to claim 8, wherein the heat transfer plate is made of a neutron shielding material or a material to which a neutron shielding material is added.   The spent fuel storage container according to claim 1, wherein a hole is formed in at least one of the reinforcing member and the pair of plates.

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