JP2016183879A - Fuel assembly storage method and cask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel assembly storage method capable of suppressing the occurrence of erroneous storage in zone loading.SOLUTION: A fuel assembly storage method includes: a step of determining first cells for storing first fuel assemblies and second cells for storing second fuel assemblies among a plurality of cells provided in a basket of a cask; a step of putting first marks for indicating the first cells at least at a part of each periphery of the first cells; and a step of storing the first fuel assemblies in the first cells on the basis of the first marks, so as to store the second fuel assemblies in the second cells.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel assembly storage method and a cask.

  Spent fuel assemblies generated in a nuclear power plant are stored in a storage rack provided in a fuel storage pool in the nuclear power plant, cooled for a certain period, and then stored in a cask for storage or transportation. . The cask has a basket provided with a plurality of cells, and the fuel assembly is stored in the cells of the basket. Patent Document 1 discloses a technique for storing a fuel assembly in a cask using an insertion guide. Patent Documents 2 and 3 disclose techniques for determining the storage position of a fuel assembly according to the cooling period or type of the fuel assembly. Patent Document 4 discloses a technique related to a fuel exchange operation in the core.

JP-A-63-066499 Japanese Patent Laid-Open No. 07-260991 JP 2012-111284 A Japanese Patent Laid-Open No. 05-040196

  A method for determining a storage position of a fuel assembly in a cask according to the cooling period or type of the fuel assembly and storing the fuel assembly in the determined storage position as disclosed in Patent Documents 2 and 3 Is called zone loading. In zone loading, a cell for storing a predetermined fuel assembly is determined in advance, and the predetermined fuel assembly is stored in the determined cell. If the fuel assembly is erroneously stored (erroneously stored) in a cell other than a predetermined cell due to a human error, the significance of zone loading is impaired.

  It is an object of the present invention to provide a fuel assembly storage method and cask that can suppress the occurrence of erroneous storage during zone loading.

  The present invention includes a step of determining a first cell in which a first fuel assembly is stored and a second cell in which a second fuel assembly is stored among a plurality of cells provided in a basket of a cask; Attaching a first mark indicating the first cell to at least a part of the periphery of one cell; and storing the first fuel assembly in the first cell based on the first mark; and And a step of storing the second fuel assembly, and a method of storing the fuel assembly.

  According to the present invention, in zone loading, the first and second cells in which the first and second fuel assemblies are to be stored are determined, and the first mark indicating the first cell is attached to the first cell. Thus, the worker who performs the storage operation can visually confirm the first cell in which the first fuel assembly is to be stored. Thereby, generation | occurrence | production of a human error is suppressed and the 1st, 2nd fuel assembly is reliably accommodated in each of the 1st, 2nd cell. Therefore, occurrence of erroneous storage during zone loading is suppressed.

  In the present invention, the first mark may be provided on an upper surface of the basket around the first cell.

  In many cases, an operator who performs the storage work visually observes the cask from above. Therefore, by providing the first mark on the upper surface of the basket, the operator can visually recognize the first mark smoothly.

  In the present invention, a plate member having an opening corresponding to the cell may be placed on the basket, and the first mark may be provided on the plate member.

  By placing the plate member with the first mark on the basket and performing the storing operation, erroneous storage can be suppressed without attaching the first mark to the basket. Since the plate member has an opening corresponding to the cell, the first and second fuel assemblies can be accommodated in the first and second cells through the opening. After the storing operation, the plate member can be removed from the basket and used again and again.

  The present invention may include a step of positioning the basket and the plate member with a positioning member provided on the plate member.

  The positioning operation is performed smoothly by positioning the basket and the plate member using the positioning member to suppress the positional deviation between the cell and the opening of the plate member.

  In the present invention, the first mark may include a number associated with the first fuel assembly.

  By attaching a number associated with the first fuel assembly as the first mark, the predetermined first fuel assembly can be reliably stored in the determined first cell. Further, even after the first fuel assemblies are stored in the first cells, which first fuel assemblies are stored in which first cells can be managed using numbers.

  In the present invention, the first mark may include a colored portion provided around the first cell.

  By adopting the colored portion as the first mark, it is possible to appeal to the operator's vision and to effectively prevent human error.

  In the present invention, the colored portion may be colored with a retroreflective coating.

  Since the storage operation is performed in a state where the cask is installed in the fuel storage pool, the operator may have difficulty in visually recognizing the first mark. By coloring the colored portion with the retroreflective coating material, if the first mark is irradiated with a light or the like, the operator can sufficiently visually recognize the first mark.

  In the present invention, the first mark may include a light emitter.

  As described above, since the storage work is performed with the cask installed in the fuel storage pool, it may be difficult for the operator to check the first mark. When the first mark includes the illuminant, the worker can sufficiently view the first mark of the cask installed in the fuel storage pool.

  In the present invention, the method includes a step of attaching a second mark indicating the second cell to at least a part of the periphery of the second cell, and based on the first and second marks, the first and second cells The first and second fuel assemblies may be stored.

  The operator can distinguish between the first cell and the second cell only by attaching the first mark to the first cell. By adding the second mark to the second cell in addition to the first mark, the operator can more reliably distinguish the first cell from the second cell.

  The present invention includes a step of determining a first cell in which a first fuel assembly is stored and a second cell in which a second fuel assembly is stored among a plurality of cells provided in a basket of a cask, and a plate member Placing the first fuel assembly in the basket, closing the second cell, housing the first fuel assembly in the first cell, retracting the plate member from the basket, and the second And a step of storing the second fuel assembly in a cell.

  According to the present invention, in zone loading, the first and second cells in which the first and second fuel assemblies are to be stored are determined, and the plate member created based on the zone loading is placed on the basket. By closing the second cell, the operator can reliably store the first fuel assembly in the first cell that is not closed without erroneously storing the first fuel assembly in the second cell. . After the first fuel assembly is stored in the first cell, the operator can reliably store the second fuel assembly in the second cell by withdrawing the plate member from the basket. When the second fuel assembly is stored in the second cell, since the first fuel assembly is already stored in the first cell, the operator does not erroneously store the second fuel assembly in the first cell. , And can be stored in the second cell. Thereby, the occurrence of a human error is suppressed, and the occurrence of erroneous storage during zone loading is suppressed.

  The present invention provides a first cell in which storage of the first fuel assembly is determined, a basket provided with a second cell in which storage of the second fuel assembly is determined, and a periphery of the first cell. A cask provided at least in part and including a first mark indicating the first cell is provided.

  According to the present invention, occurrence of erroneous storage during zone loading is suppressed.

  In the present invention, the first mark may include a number associated with the first fuel assembly.

  Accordingly, occurrence of erroneous storage is suppressed, and which first fuel assembly is stored in which first cell can be managed using the number.

  In the present invention, the first mark may include a colored portion provided around the first cell.

  Thereby, it can appeal to an operator's vision and a human error can be prevented effectively.

  In the present invention, the colored portion may be colored with a retroreflective coating.

  Thereby, the operator can fully visually recognize the first mark by irradiating the first mark with a light or the like.

  In the present invention, the first mark may include a light emitter.

  Thereby, the operator can fully visually recognize the first mark.

  In this invention, you may provide the 2nd mark which is provided in at least one part of the circumference | surroundings of the said 2nd cell, and shows the said 2nd cell.

  Thereby, the operator can distinguish a 1st cell and a 2nd cell more reliably.

  ADVANTAGE OF THE INVENTION According to this invention, the storage method and cask of a fuel assembly which can suppress generation | occurrence | production of incorrect storage in zone loading are provided.

FIG. 1 is a longitudinal sectional view showing an example of a cask according to the first embodiment. FIG. 2 is a horizontal sectional view showing an example of the cask according to the first embodiment. FIG. 3 is a plan view of the cask basket according to the first embodiment as viewed from above. FIG. 4 is a flowchart illustrating an example of a fuel assembly storage method according to the first embodiment. FIG. 5 is a diagram schematically illustrating an example of a method for storing a fuel assembly according to the first embodiment. FIG. 6 is a view showing a modification of the basket according to the first embodiment. FIG. 7 is a plan view of the cask basket according to the second embodiment as viewed from above. FIG. 8 is a view showing a modification of the basket according to the second embodiment. FIG. 9 is a plan view of the cask basket according to the third embodiment as viewed from above. FIG. 10 is a partially broken perspective view showing the plate member according to the fourth embodiment. FIG. 11 is a flowchart illustrating an example of a fuel assembly storage method according to the fourth embodiment. FIG. 12 is a diagram schematically illustrating an example of a fuel assembly storage method according to the fourth embodiment. FIG. 13 is a view showing a modification of the plate member according to the fourth embodiment. FIG. 14 is a view showing a modification of the plate member according to the fourth embodiment. FIG. 15 is a diagram illustrating an example of a plate member according to the fifth embodiment. FIG. 16 is a flowchart illustrating an example of a fuel assembly storage method according to the fifth embodiment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. The components of each embodiment described below can be combined as appropriate. Some components may not be used.

<First Embodiment>
A first embodiment will be described. FIG. 1 is a longitudinal sectional view showing an example of a cask 11 according to the present embodiment. FIG. 2 is a horizontal sectional view showing an example of the cask 11 according to the present embodiment. As shown in FIGS. 1 and 2, the cask 11 includes a trunk portion 12, a lid portion 13, and a basket 14.

  The body 12 includes a cylindrical body 21, a bottom 23 that covers the lower portion of the body 21, an outer cylinder 25 disposed around the body 21, and a trunnion 30 that is fixed to the outer peripheral surface of the body 21 And a heat transfer fin 26 provided between the trunk body 21 and the outer cylinder 25, and a resin 27 provided between the trunk body 21 and the outer cylinder 25.

  The trunk body 21 and the bottom portion 23 are forged products made of carbon steel having a γ-ray shielding function. The trunk body 21 and the bottom 23 are welded or integrally formed. An opening 22 is provided in the upper part of the trunk body 21, and a cavity 24 is provided in the trunk body 21.

  A gap is formed between the outer peripheral surface of the trunk body 21 and the inner peripheral surface of the outer cylinder 25, and a plurality of heat transfer fins 26 are provided in the gap. The heat transfer fins 26 are made of copper or steel, and a plurality of heat transfer fins 26 are provided at intervals in the circumferential direction of the trunk body 21. The heat transfer fins 26 are welded to the trunk main body 21 and the outer cylinder 25, and transmit heat of the trunk main body 21 to the outer cylinder 25. The resin 27 is a neutron shield containing a boron compound, and is filled in the gap between the trunk body 21 and the outer cylinder 25.

  Further, the body 12 includes a bottom plate 28 that faces the lower surface of the bottom 23 via a gap, and a resin (neutron shield) 29 that fills the gap between the bottom 23 and the bottom plate 28.

  The lid portion 13 includes a primary lid 31, a secondary lid 32, and a tertiary lid 33. The primary lid 31, the secondary lid 32, and the tertiary lid 33 are detachable from the trunk body 21. The primary lid 31 is provided so as to close the opening 22. The secondary lid 32 is disposed outside the primary lid 31 with respect to the cavity 24. The tertiary lid 33 is disposed outside the secondary lid 32 with respect to the cavity 24.

  The primary lid 31 has a resin (neutron shield) on the secondary lid 32 side, and shields radiation (γ rays). Further, the primary lid 31 maintains the negative pressure of the cavity 24 and prevents the gas in the cavity 24 from leaking. The secondary lid 32 has a pressure monitoring boundary pressurized against the atmosphere with the primary lid 31, prevents gas leakage from the primary lid 31, and ensures the pressure on the cavity 24 side. The tertiary lid 33 protects the secondary lid 32 from external impacts.

  The trunk body 21 includes first, second, and third step portions 41, 42, and 43 provided on the inner peripheral portion of the opening 22. The first step portion 41 has a first seat surface portion 41a. The second step portion 42 includes a second seat surface portion 42 a that is disposed on the outer side of the first step portion 41 with respect to the opening 22. The third step portion 43 has a third seat surface portion 43 a that is disposed outside the second step portion 42 with respect to the opening 22. A plurality of screw holes 41 b are formed in the first seat surface portion 41 a at equal intervals in the circumferential direction of the trunk body 21. A plurality of screw holes 42 b are formed in the second seat surface portion 42 a at equal intervals in the circumferential direction of the trunk body 21. A plurality of screw holes 43 b are formed in the third seat surface portion 43 a at equal intervals in the circumferential direction of the trunk body 21.

  The primary lid 31 is fitted into the first step portion 41 and is in close contact with the first seat surface portion 41a. The primary lid 31 passes through the primary lid 31 and is fixed to the first step portion 41 of the trunk body 21 by a bolt 51 that is coupled to the screw hole 41b. The secondary lid 32 fits into the second step portion 42 and is in close contact with the second seat surface portion 42a. The secondary lid 32 passes through the secondary lid 32 and is fixed to the second step portion 42 of the trunk body 21 by a bolt 52 that is coupled to the screw hole 42b. The tertiary lid 33 is fitted into the third step portion 43 and is in close contact with the third seat surface portion 43a. The tertiary lid 33 passes through the tertiary lid 33 and is fixed to the third step portion 43 of the trunk body 21 by a bolt 53 that is coupled to the screw hole 43b.

  Next, the basket 14 will be described. FIG. 3 is a plan view of the basket 14 of the cask 11 according to this embodiment as viewed from above. As shown in FIGS. 1, 2, and 3, the basket 14 is disposed in the cavitdy 24. The basket 14 is made of stainless steel or aluminum alloy. The basket 14 has a plurality of cells in which spent fuel assemblies are stored. A cell is a space (chamber) in which a fuel assembly is stored. An opening is provided at the upper end of the cell. An upper surface 65 of the basket 14 is disposed around the opening of the cell. The fuel assembly is inserted inside the cell through the opening of the cell.

  A plurality of fuel assemblies having different burnups are stored in the cask 11. In the present embodiment, the first fuel assembly 101 having the first burnup and the second fuel assembly 102 having the second burnup lower than the first burnup are stored in the cask 11 as the fuel assemblies. .

  In the basket 14, a cell in which the first fuel assembly 101 is stored and a cell in which the second combustion assembly 102 is stored are determined in advance. In the following description, the cell in which the storage of the first fuel assembly 101 is determined is appropriately referred to as a first cell 61, and the cell in which the storage of the second fuel assembly 102 is determined is appropriately the second cell 62. Called. The first fuel assembly 101 is housed inside the first cell 61 through the opening 61 </ b> K at the upper end of the first cell 61. The second fuel assembly 102 is accommodated inside the second cell 62 through the opening 62 </ b> K at the upper end of the second cell 62.

  The radiation dose emitted from the first combustion assembly 101 is higher than the radiation dose emitted from the second combustion assembly 102. The first cell 61 is set at the center of the cask 11, and the second cell 62 is set around the first cell 61.

  As shown in FIG. 3, a first mark 71 indicating the first cell 61 and a second mark 72 indicating the second cell 62 are provided on the upper surface 65 of the basket 14. The first mark 71 is provided in a partial region of the upper surface 65 around the opening 61 </ b> K of the first cell 61. The second mark 72 is provided in a partial region of the upper surface 65 around the opening 62 </ b> K of the second cell 62.

  The first mark 71 is a number associated with the first fuel assembly 101, and the second mark 72 is a number associated with the second fuel assembly 102. In the example illustrated in FIG. 3, as the first mark 71, “No. 5”, “No. 6”, “No. 7”, “No. Numbers (characters) of “10”, “No. 11”, “No. 12”, “No. 15”, “No. 16”, “No. 17” are given. As the second mark 72, “No. 1”, “No. 2”, “No. 3”, “No. 4”, “No. 8” are formed on a part of the upper surface 65 around the second cell 62. ”,“ No. 9 ”,“ No. 13 ”,“ No. 14 ”,“ No. 18 ”,“ No. 19 ”,“ No. 20 ”,“ No. 21 ”are attached with numbers (characters). Has been.

  In plan view, the first and second cells 61 and 62 are quadrangular, and include a first side H1, a second side H2 that faces the first side H1, a first end of the first side H1, and a second side H2. And a fourth side H4 that connects the other end of the first side H1 and the other end of the second side H2 and faces the third side H3. The first and second marks 71 and 72 are provided along the first side H1 in a partial region of the upper surface 65 including the first side H1 of the first and second cells 61 and 62. The shape in plan view is a shape in a plane orthogonal to the central axis of the trunk body 21 of the cask 11.

  The first and second marks 71 and 72 are formed by carving the upper surface 65. In the present embodiment, the upper surface 65 is irradiated with laser light, and a part of the upper surface 65 is carved by the laser light, whereby the first and second marks 71 and 72 are formed.

  Next, a method for housing the first and second fuel assemblies 101 and 102 according to the present embodiment in the cask 11 will be described. FIG. 4 is a flowchart illustrating an example of a storage method according to the present embodiment.

  Zone loading design is performed. Zone loading refers to determining the storage position of the fuel assembly in the cask 11 according to the burnup, cooling period, or type of the fuel assembly, and storing the fuel assembly in the determined storage position. .

  In the zone loading, first, among the plurality of cells provided in the basket 14 of the cask 11, the first cell 61 in which the first fuel assembly 101 is stored and the second cell 62 in which the second fuel assembly 102 is stored. Is performed (step SA10). In the present embodiment, among the plurality of cells, nine cells in the central portion of the cask 11 are determined as the first cell 61, and 12 cells around the first cell 61 are determined as the second cell 62. The

  The first mark 71 indicating the first cell 61 is attached to at least a part of the periphery of the opening 61K of the first cell 61, and the second cell 62 is illustrated in at least a part of the periphery of the opening 62K of the second cell 62. Processing for attaching the second mark 72 is performed (step SA20). In the present embodiment, “No. 5”, “No. 6”,... As “first mark 71” are formed on a part of the upper surface 65 around the opening 61K of each of the nine first cells 61. No. 17 ”is formed, and a second mark 72 is provided as a second mark 72 on a part of the upper surface 65 around the opening 62K of each of the twelve second cells 62 as“ No. 1 ”,“ No. 2 ”. ", No. 21" is formed.

  The first and second marks 71 and 72 are numbers associated with the first and second fuel assemblies 101 and 102. Each of the plurality of first fuel assemblies 101 is assigned a number (“No. 5”, “No. 6”,... “No. 17”) corresponding to the first mark 71, and the plurality of second fuel assemblies 101. Each of the bodies 102 is given a number (“No. 1”, “No. 2”,... “No. 21”) corresponding to the second mark 72.

  Next, based on the first mark 71 and the second mark 72, a process of storing the first fuel assembly 101 in the first cell 61 and storing the second fuel assembly 102 in the second cell 62 is performed. (Step SA30).

  FIG. 5 is a schematic diagram for explaining a process of storing the first and second fuel assemblies 101 and 102 in the first and second cells 61 and 62. A cask 11 having a basket 14 provided with first and second marks 71 and 72 is installed in a cask pit in the fuel storage pool. The operation of storing the first and second fuel assemblies 101 and 102 in the first and second cells 61 and 62 is performed by a worker WM outside the fuel storage pool. The worker WM operates a transfer device (not shown) to store the first and second fuel assemblies 101 and 102 stored in the storage rack one by one in the first and second cells 61 and 62. .

  The worker WM refers to an instruction sheet such as a work procedure manual and performs a work of storing the first and second fuel assemblies 101 and 102 in the cask 11. The instruction sheet describes zone loading design information. In the present embodiment, the first fuel assembly 101 with the numbers (“No. 5”, “No. 6”,... “No. 17”) corresponding to the first mark 71 is assigned to the first cell 61. The second fuel assembly 102 that is stored and numbered (“No. 1”, “No. 2”,... “No. 21”) corresponding to the second mark 72 is stored in the second cell 62. Instructions indicating are described in the instructions.

  The worker WM operates the transfer device, takes out the first fuel assembly 101 from the storage rack, and starts the operation of storing the first fuel assembly 101 in the first cell 61. The worker WM visually checks the first mark 71 and confirms the position of the first cell 61 in which the first fuel assembly 101 is to be stored. Since the first mark 71 is provided along with the first cell 61, the worker WM can reliably store the first fuel assembly 101 in the first cell 61. Further, since the first mark 71 is a number associated with the first fuel assembly 101, the worker WM, for example, selects the first fuel assembly 101 with the number "No. 5" It can be securely stored in the “No. 5” first cell 61.

  A plurality of first fuel assemblies 101 are stored in the first cell 61 one by one, and a plurality of second fuel assemblies 102 are stored in the second cell 62 one by one in the same procedure as described above.

  After the first and second fuel assemblies 101 and 102 are accommodated in the first and second cells 61 and 62, the opening 22 is closed by the lid 13.

  As described above, according to the present embodiment, the first and second cells 61 and 62 in which the first and second fuel assemblies 101 and 102 are to be accommodated in the zone loading are determined, and the designed zone loading is performed. Based on the first and second marks 71 and 72 indicating the first and second cells 61 and 62 attached to the first and second cells 61 and 62, the worker WM performing the storing operation The first and second cells 61 and 62 in which the first and second fuel assemblies 101 and 102 should be accommodated can be confirmed through vision. As a result, the occurrence of human error is suppressed, the first and second fuel assemblies 101 and 102 are securely stored in the first and second cells 61 and 62, respectively, and the occurrence of erroneous storage during zone loading is suppressed. The

  In the present embodiment, the first and second marks 71 and 72 are provided in at least a part of the upper surface 65 of the basket 14 around the openings 61K and 62K. As described with reference to FIG. 5, the worker WM who carries out the storage work looks at the cask 11 from above, so that the first and second marks 71 and 72 are provided on the upper surface 65 of the basket 14. The worker WM can visually recognize the first and second marks 71 and 72 smoothly.

  In the present embodiment, the first and second marks 71 and 72 include numbers associated with the first and second fuel assemblies 101 and 102. By assigning numbers as the first and second marks 71 and 72, the predetermined first and second fuel assemblies 101 and 102 are reliably stored in the determined first and second cells 61 and 62. Further, by using the associated numbers, any of the first and second cells 61 and 62 after the first and second fuel assemblies 101 and 102 are stored in the first and second cells 61 and 62 can be used. It is possible to smoothly manage which first and second fuel assemblies 101 and 102 are housed.

  In the present embodiment, the first and second marks 71 and 72 are formed by carving the upper surface 65. The first and second marks 71 and 72 may be formed by applying paint on the upper surface 65. By forming the first and second marks 71 and 72 with colored paints, it is possible to appeal to the visual sense of the worker WM and to effectively prevent human error. The paint may be a retroreflective paint. Retroreflective refers to the property that light emitted from a light source returns to its original location after reflection. The retroreflective coating is a coating containing a material having retroreflectivity. By using the retroreflective paint as the paint, if the first and second marks 71 and 72 are irradiated with light or the like with the light emitted from the light source, the worker WM can change the first and second cask 11 in the fuel storage pool. The second marks 71 and 72 can be sufficiently visually recognized.

(Modification of the first embodiment)
In the present embodiment, both the first mark 71 attached to the first cell 61 and the second mark 72 attached to the second cell 62 are provided. As shown in FIG. 6, the second mark 72 may be omitted. Even if the second mark 72 is omitted, by providing the first mark 71, the worker WM can distinguish between the first cell 61 and the second cell 62 based on the first mark 71. Note that the second mark 72 may be provided and the first mark 71 may be omitted.

Second Embodiment
A second embodiment will be described. FIG. 7 is a plan view showing an example of the basket 14A according to the present embodiment. The basket 14 </ b> A has a first mark 71 </ b> A indicating the first cell 61 and a second mark 72 </ b> A indicating the second cell 62. The first mark 71A includes a first colored portion 71A provided around the first cell 61, and the second mark 72A includes a second colored portion 72A provided around the second cell 62. The first colored portion 71A is provided in the first region 73 of the upper surface 65 surrounding the opening 61K of the first cell 61. The second colored portion 72A is provided in the second region 74 of the upper surface 65 surrounding the opening 62K of the second cell 62. The entire first region 73 is colored with the first color. The entire second region 74 is colored with a second color different from the first color. The first colored portion 71A is, for example, red, and the second colored portion 72A is, for example, blue.

  The first and second colored portions 71A and 72A are formed by applying paint to the first and second regions 73 and 74 of the upper surface 65 of the basket 14A. In the present embodiment, the first and second coloring portions 71A and 72A are colored with a retroreflective coating.

  As described above, according to the present embodiment, by adopting the first and second coloring portions 71A and 72A as the first and second marks 71A and 72A, it is possible to appeal to the visual sense of the worker WM, Human error can be effectively prevented.

  Further, by using a retroreflective paint as a paint, if the first and second marks 71A and 72A of the cask 11 in the fuel storage pool are irradiated with a light or the like from the outside of the fuel storage pool, the worker WM The first and second marks 71A and 72A can be sufficiently visually recognized.

(Modification of the second embodiment)
In addition, as shown in FIG. 8, 71 A of 1st coloring parts may be provided and 72 A of 2nd coloring parts may be abbreviate | omitted. Even if the second coloring portion 72A is omitted, the worker WM can distinguish between the first cell 61 and the second cell 62 based on the first coloring portion 71A. Note that the second coloring portion 72A may be provided, and the first coloring portion 71A may be omitted.

<Third Embodiment>
A third embodiment will be described. FIG. 9 is a plan view showing an example of the basket 14B according to the present embodiment. The basket 14 </ b> B has a first mark 71 </ b> B indicating the first cell 61 and a second mark 72 </ b> B indicating the second cell 62. The first mark 71B includes a first light emitter 71B provided around the first cell 61, and the second mark 72B includes a second light emitter 72B provided around the second cell 62. A plurality of the first light emitters 71B are provided in the first region 73B of the upper surface 65 surrounding the opening 61K of the first cell 61. A plurality of the second light emitters 72B are provided in the second region 74B of the upper surface 65 surrounding the opening 62K of the second cell 62. The first light emitter 71B emits first color light. The second light emitter 72B emits second color light different from the first color light. The first light emitter 71B includes, for example, a red LED that emits red light, and the second light emitter 72B includes, for example, a blue LED that emits blue light.

  As described above, according to the present embodiment, by adopting the first and second light emitters 71B and 72B as the first and second marks 71B and 72B, it is possible to appeal to the vision of the worker WM, Human error can be effectively prevented. In addition, the cask 11 is installed in the fuel storage pool, and even when it is difficult for the worker WM to visually recognize the basket 14B, the worker WM can set the first and second landmarks 71B, 71B, 72B and the 1st, 2nd cells 61 and 62 can fully be visually recognized.

  In the present embodiment, one of the first light emitter 71B and the second light emitter 72B may be omitted.

<Fourth embodiment>
A fourth embodiment will be described. FIG. 10 is a perspective view in which a part of the plate member 80 according to the present embodiment is broken.

  In the present embodiment, a plate member 80 as shown in FIG. 10 is used in the storing operation. The plate member 80 has a first opening 81 corresponding to the first cell 61 and a second opening 82 corresponding to the second cell 62. The plate member 80 includes a disk portion 801 installed on the upper surface 65 of the basket 14 and a flange portion 802 installed on the first seat surface portion 41a. When the disc portion 801 of the plate member 80 is placed on the upper surface 65 of the basket 14, the first cell 61 and the first opening 81 coincide with each other, and the second cell 62 and the second opening 82 coincide with each other. A plate member 80 is created.

  The plate member 80 has a first mark 71 indicating the first cell 61 and a second mark 72 indicating the second cell 62. The first mark 71 is provided on the upper surface of the disc portion 801 so as to be attached to the first opening 81. The second mark 72 is provided on the upper surface of the disk portion 801 so as to be attached to the second opening 82. As in the first embodiment, numbers “No. 5”, “No. 6”,... “No. 17” are formed as the first mark 71, and “No. 1” is formed as the second mark 72. , “No. 2”,... “No. 21” are formed. The first and second marks 71 and 72 may be formed by carving the disc portion 801, or may be formed by applying paint (including retroreflective paint) to the disc portion 801.

  Next, a method for housing the first and second fuel assemblies 101 and 102 according to the present embodiment in the cask 11 will be described. FIG. 11 is a flowchart illustrating an example of a storage method according to the present embodiment.

  Zone loading is designed, and the first and second cells 61 and 62 in which the first and second fuel assemblies 101 and 102 are stored are determined (step SB10).

  Based on the designed zone loading, the plate member 80 is created (step SB20). First and second openings 81 and 82 corresponding to the first and second cells 61 and 62 are formed in the plate member 80. The plate member 80 has first and second marks 71 and 72 indicating the first and second cells 61 and 62 attached to the first and second openings 81 and 82.

  Next, the plate member 80 is placed on the basket 14 (step SB30). FIG. 12 is a side sectional view schematically showing an example of the storage method according to the present embodiment. As shown in FIG. 12, the flange portion 802 of the plate member 80 is supported by the first seat surface portion 41 a, and the disc portion 801 is placed on the basket 14. In the present embodiment, the plate member 80 includes a positioning member 83 that positions the plate member 80 and the basket 14. The positioning member 83 includes a protrusion that protrudes downward from the lower surface of the flange portion 802. As shown in FIG. 12, the positioning member 83 is disposed in the screw hole 41b (concave portion) provided in the first seat surface portion 41a in a state where the flange portion 802 is installed on the first seat surface portion 41a. A plurality of positioning members 83 and screw holes 41b are provided. The plate member 80 and the basket 14 are positioned by arranging the plurality of positioning members 83 in the plurality of screw holes 41b. The plate member 80 and the basket 14 are positioned so that the first cell 61 and the first opening 81 coincide with each other, and the second cell 62 and the second opening 82 coincide with each other.

  When the first cell 61 and the first opening 81 coincide with each other, the first mark 71 is provided in at least a part of the periphery of the opening 61K of the first cell 61. By matching the second cell 62 and the second opening 82, the second mark 72 is provided in at least a part of the periphery of the opening 62 </ b> K of the second cell 62.

  Next, based on the first mark 71 and the second mark 72, the first fuel assembly 101 is stored in the first cell 61, and the second fuel assembly 102 is stored in the second cell 62 (step SB40). .

  The worker WM stores the first fuel assembly 101 in the first cell 61 via the first opening 81 and the second combustion assembly 102 via the second opening 82 using the transfer device. 62. The worker WM visually checks the first mark 71 and confirms the position of the first cell 61 in which the first fuel assembly 101 should be stored, and then stores the first combustion assembly 101. Since the first mark 71 provided around the first opening 81 is disposed so as to be attached to the first cell 61, the worker WM visually observes the first mark 71, thereby the first fuel assembly. 101 can be securely stored in the first cell 61. Similarly, since the second mark 72 provided around the second opening 82 is disposed so as to be incidental to the second cell 62, the worker WM looks at the second mark 72 to check the second mark 72. The fuel assembly 102 can be reliably stored in the second cell 62.

  After completion of the storing operation, the plate member 80 is withdrawn from the cask 11. After the plate member 80 is retracted, the opening 22 is closed with the lid 13.

  As described above, according to the present embodiment, the plate member 80 with the first and second marks 71 and 72 is placed on the basket 14 to perform the storing operation, thereby suppressing erroneous storage. can do. According to this embodiment, it is not necessary to attach the first and second marks 71 and 72 to the basket 14. After the storing operation, the plate member 80 can be withdrawn from the cask 11 and used many times.

  Further, according to the present embodiment, the positioning of the basket 14 and the plate member 80 is performed by the positioning member 83 provided on the plate member 80, so the first and second cells 61 and 62 of the basket 14 and the plate The displacement of the member 80 with respect to the first and second openings 81 and 82 is suppressed, and the first and second fuel assemblies 101 and 102 pass through the first and second openings 81 and 82, respectively. The two cells 61 and 62 are stored smoothly.

  In the present embodiment, either the first mark 71 or the second mark 72 may be omitted.

(Modification 1 of 4th Embodiment)
As shown in the plate member 80 </ b> D illustrated in FIG. 13, the first coloring portion 71 </ b> A may be provided around the first opening 81, and the second coloring portion 72 </ b> A may be provided around the second opening 82. As described in the second embodiment, the first colored portion 71A is provided to indicate the first cell 61 and the second colored portion 72A is provided to indicate the second cell 62, thereby preventing erroneous storage. Is done.

(Modification 2 of 4th Embodiment)
As shown in the plate member 80 </ b> E shown in FIG. 14, the first light emitter 71 </ b> B may be provided around the first opening 81, and the second light emitter 72 </ b> B may be provided around the second opening 82. As described in the third embodiment, the first light emitter 71B is provided to indicate the first cell 61 and the second light emitter 72B is provided to indicate the second cell 62, thereby suppressing erroneous storage. Is done.

<Fifth Embodiment>
A fifth embodiment will be described. FIG. 15 is a diagram illustrating an example of the plate member 90 according to the present embodiment. The plate member 90 is placed on the upper surface 65 of the basket 14 and can simultaneously close the plurality of second cells 62. The plate member 90 has an opening 91 at the center, and opens the plurality of first cells 61 in a state of being placed on the upper surface 65 of the basket 14. That is, the plate member 90 has a shape that simultaneously closes the plurality of second cells 62 and does not close the plurality of first cells 61.

  Next, a method for housing the first and second fuel assemblies 101 and 102 according to the present embodiment in the cask 11 will be described. FIG. 16 is a flowchart illustrating an example of a storage method according to the present embodiment.

  Zone loading design is performed, and the first and second cells 61 and 62 in which the first and second fuel assemblies 101 and 102 are stored are determined (step SC10).

  A plate member 90 is created based on the designed zone loading (step SC20). An opening 91 corresponding to the first cell 61 is formed in the plate member 90.

  Next, the plate member 90 is placed on the basket 14 (step SC30). By placing the plate member 90 on the basket 14, the second cell 62 is closed as shown in FIG.

  Next, the first fuel assembly 101 is stored in the first cell 61 through the opening 91 (step SC40).

  After the first fuel assemblies 101 are stored in all the first cells 61, the plate member 90 is withdrawn from the basket 14 (step SC50).

  When the plate member 90 is retracted from the basket 14, the second cell 62 is opened. After the second cell 62 is opened, the second fuel assembly 102 is stored in the second cell 62 (step SC60).

  After the first and second fuel assemblies 101 and 102 are accommodated in the first and second cells 61 and 62, the opening 22 is closed by the lid 13.

  As described above, according to the present embodiment, by placing the plate member 90 created based on the zone loading on the basket 14 and closing the second cell 62, the worker WM can make the first fuel assembly. The body 101 can be correctly stored in the unsealed first cell 61 without being erroneously stored in the second cell 62. After the first fuel assembly 101 is stored in the first cell 61, the worker WM correctly stores the second fuel assembly 102 in the second cell 62 by moving the plate member 90 away from the basket 14. Can do. When the second fuel assembly 102 is stored in the second cell 62, the first fuel assembly 101 is already stored in the first cell 61. Therefore, the worker WM places the second fuel assembly 102 in the first cell. It can be correctly stored in the second cell 62 without being erroneously stored in 61. Thereby, the occurrence of a human error is suppressed, and the occurrence of erroneous storage during zone loading is suppressed.

  In each of the above-described embodiments, the combustion assembly is divided into two-stage fuel assemblies (101, 102) according to the burnup. Of course, the fuel assemblies may be divided into a plurality of stages of three or more stages. For example, a plurality of fuel assemblies are divided into a first fuel assembly having a first burnup, a second fuel assembly having a second burnup different from the first burnup, a first burnup, and a second burnup. Is divided into third fuel assemblies having different third burnups, and first, second, and third cells in which the first, second, and third combustion assemblies are stored are determined. The first, second, and third combustion assemblies may be accommodated (zone loading) in the first, second, and third cells.

  In each of the above-described embodiments, zone loading is performed according to the burnup. Zone loading may be performed according to the cooling period or type of the combustion assembly.

11 Cask 12 Body 13 Cover 14 Basket 14A Basket 21 Body 22 Opening 23 Bottom 24 Cavity 25 Outer Tube 26 Heat Transfer Fin 27 Resin 28 Bottom Plate 29 Resin 30 Trunnion 31 Primary Cover 32 Secondary Cover 33 Secondary Cover 41 First Step portion 41a First seat portion 41b Screw hole 42 Second step portion 42a Second seat portion 42b Screw hole 43 Third step portion 43a Third seat portion 43b Screw hole 51 Bolt 52 Bolt 53 Bolt 61 First cell 61K Opening 62 Second cell 62K Opening 65 Upper surface 71 First mark 71A First mark (first colored part)
71B First mark (first light emitter)
72 2nd mark 72A 2nd mark (2nd coloring part)
72B Second mark (second light emitter)
73 First region 73B First region 74 Second region 74B Second region 80 Plate member 80D Plate member 80E Plate member 81 First opening 82 Second opening 83 Positioning member 90 Plate member 91 Opening 101 First fuel assembly 102 Second Fuel assembly 801 Disc 802 Flange

Claims (16)

Determining a first cell in which a first fuel assembly is stored and a second cell in which a second fuel assembly is stored among a plurality of cells provided in a basket of a cask;
Attaching a first mark indicating the first cell to at least a part of the periphery of the first cell;
Storing the first fuel assembly in the first cell and storing the second fuel assembly in the second cell based on the first mark;
For storing a fuel assembly including   2. The fuel assembly storage method according to claim 1, wherein the first mark is provided on an upper surface of the basket around the first cell. 3. Placing a plate member having an opening corresponding to the cell on the basket;
The fuel assembly storage method according to claim 1, wherein the first mark is provided on the plate member.   The method for storing a fuel assembly according to claim 3, further comprising a step of positioning the basket and the plate member with a positioning member provided on the plate member.   The fuel assembly storage method according to any one of claims 1 to 4, wherein the first mark includes a number associated with the first fuel assembly.   The fuel assembly storage method according to any one of claims 1 to 5, wherein the first mark includes a colored portion provided around the first cell.   The fuel assembly storage method according to claim 6, wherein the colored portion is colored with a retroreflective coating.   The method for storing a fuel assembly according to any one of claims 1 to 7, wherein the first mark includes a light emitter. Attaching a second mark indicating the second cell to at least a part of the periphery of the second cell;
The fuel assembly according to any one of claims 1 to 8, wherein the first and second fuel assemblies are stored in the first and second cells based on the first and second marks. Storage method. Determining a first cell in which a first fuel assembly is stored and a second cell in which a second fuel assembly is stored among a plurality of cells provided in a basket of a cask;
Placing a plate member on the basket and closing the second cell;
Storing the first fuel assembly in the first cell;
Withdrawing the plate member from the basket;
Storing the second fuel assembly in the second cell;
For storing a fuel assembly including A basket provided with a first cell in which storage of the first fuel assembly is determined and a second cell in which storage of the second fuel assembly is determined;
A first mark provided on at least a part of the periphery of the first cell and indicating the first cell;
Cask with   The cask according to claim 11, wherein the first mark includes a number associated with the first fuel assembly.   The cask according to claim 11 or 12, wherein the first mark includes a colored portion provided around the first cell.   The cask according to claim 13, wherein the colored portion is colored with a retroreflective coating.   The cask according to any one of claims 11 to 14, wherein the first mark includes a light emitter.   The cask according to any one of claims 11 to 15, further comprising a second mark provided on at least a part of the periphery of the second cell and indicating the second cell.

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