JP2012047526A - Fuel assembly and fuel number confirmation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speedily and securely confirm a fuel number given to a fuel assembly.SOLUTION: A fuel assembly 1 includes a fuel body 10 having a plurality of fuel rods 12, an upper tie plate 14 supporting upper end parts of the plurality of fuel rods 12 in a square lattice shape, and a handle 20 provided to the upper tie plate 14; and a channel box 30 having a rectangular tube member surrounding the fuel body 10, and a clip part 32 which engages with the fuel body 10 when the fuel body is inserted into the channel box. The handle 20 is stamped with a fuel number given to each fuel assembly 1, and the clip part 32 is stamped with a box number given to each channel box 30. The fuel number includes characteristic information different by a plurality of fuel assemblies 1 loaded in a nuclear reactor; and the box number is a number in which the fuel number is associated with information on the manufacturer of the channel box 30; the fuel number and box number are arranged to be confirmed from above.

Description

  The present invention relates to a fuel assembly and a fuel number confirmation method used in a nuclear power plant.

  Conventionally, in a nuclear power plant, a nuclear fission material such as uranium 235 is used as a fuel, water is boiled by heat generated by the fission of the fissile material, and steam is generated. A turbine that is rotated by steam, a generator that is connected to the turbine and generates power by rotating the turbine, and a condenser that converts the steam supplied to the turbine into water and then returns it to the reactor.

  In a nuclear reactor, in particular, a boiling water reactor (BWR), a fuel assembly is arranged as fuel. In this fuel assembly, a fuel body formed by bundling a plurality of fuel rods filled with a plurality of fuel pellets containing a fissile material in a square lattice pattern is called a channel box and has a square cross section. It is configured by surrounding with a rectangular tube.

  Here, the channel box is used by being attached to a fuel body. However, since the channel box and the fuel body are purchased separately, the information about the fuel body and the information about the channel box are not associated with each other. Therefore, the fuel body is managed by the fuel management system, and the channel box is managed by the channel box management system. As for the management of the channel box, as described in Patent Document 1, it has been proposed to manage the channel box in cooperation with the management of nuclear fuel in the fuel management system.

JP 2009-293945 A

  Conventionally, the manufacturer's serial number is marked on the side of the channel box, and the fuel number is marked on the fuel body. Here, when the fuel assembly is loaded in the nuclear reactor or the spent fuel storage pool, the fuel number is marked on the upper part of the fuel assembly, so it can be confirmed from above the fuel assembly, Since the serial number is attached to the side surface of the channel box, it is difficult to confirm from above the fuel assembly.

  For this reason, when trouble occurs in the channel box, in order to grasp the manufacturer of the channel box, find the box number from the channel box installation work results each time and use the channel box management system to identify the manufacturer from the fuel number. It was necessary to search, and there was a possibility that the response to the trouble might be delayed. Further, when a trouble occurs in the fuel assembly, the fuel assembly in which the trouble has occurred is specified by confirming the fuel number of the fuel assembly. However, there are cases where it is difficult to confirm the vicinity of the fuel number due to rust. In such a case, it takes time to confirm the fuel number, and there is a possibility that the response to the trouble may be delayed.

  Further, when the channel box is attached to the fuel body, it has not been possible to easily confirm whether or not the channel box originally planned for the fuel body has been attached.

  It is an object of the present invention to provide a fuel assembly and a fuel number confirmation method that solve such problems.

  In order to achieve the above object, the present invention has the following configuration.

  (1) It has a plurality of fuel rods formed by filling a cladding tube with a fissile material, a tie plate that supports upper end portions of the plurality of fuel rods in a square lattice shape, and a handle portion provided on the tie plate. A fuel body, a rectangular tube member that inserts the fuel body from a lower end side opening and surrounds the fuel body, and a part of a corner of the upper end side opening of the rectangular tube member, In the fuel assembly provided with a channel box having a clip portion that engages with the fuel body when inserted into the channel box, the handle portion displays a fuel number assigned to each fuel assembly. A fuel number display unit, and the clip unit includes a box number display unit that displays a box number assigned to each channel box, and the fuel number is a plurality of fuel cells loaded in a nuclear reactor. The box number is a number that associates the fuel number with the information of the manufacturer of the channel box, and the fuel number display part and the box number display part are from above. A fuel assembly, characterized in that it is arranged so as to be confirmed.

  According to (1), both the fuel number and the box number can be confirmed from above the fuel assembly. Here, since the fuel number and the box number are related to each other, when the channel box is attached to the fuel body, the fuel number and the box number are initially confirmed for the fuel body by checking the fuel number and the box number. It is possible to easily check whether or not the channel box is attached. In addition, when trouble occurs in the channel box, it is possible to easily grasp the manufacturer by visually checking the upper part of the fuel assembly and checking the box number, and promptly contact the manufacturer. It becomes possible to take. Further, when a trouble occurs in the fuel body, it is possible to identify the fuel body in which the trouble has occurred by confirming either the fuel number or the box number. In this way, it becomes possible to obtain the fuel number in addition to the manufacturer of the channel box from the box number assigned to the channel box.

  (2) In (1), when the channel box is attached to the fuel body, a fuel number character string displayed on the fuel number display portion and a box number character displayed on the box number display portion A fuel assembly is characterized in that the rows are parallel.

  According to (2), it becomes easy to confirm the fuel number and the box number.

  (3) The fuel assembly according to (1) or (2), wherein in the fuel number, the manufacturer information of the channel box is positioned next to the unique information in the fuel number. .

According to (3), since the specific information of the fuel number and the information of the manufacturer of the channel box are adjacent to each other in the box number, the information of the manufacturer of the channel box is recognized when identifying the fuel number from the box number. By doing so, it becomes possible to easily identify the fuel number.
(4) In (1) to (3), the fuel number display portion is a fuel number stamped on the handle portion, and the box number display portion is a box number stamped on the clip portion. A fuel assembly characterized by being.

  According to (4), the fuel number and the box number will not disappear.

  (5) The fuel number display section of the fuel assembly is photographed by photographing means for photographing the fuel assembly of (1) to (4) from above, and the fuel number photographed image is displayed on the monitor to confirm the fuel number. When it is difficult to confirm the fuel number, the photographing means is moved to photograph the box number display portion of the fuel assembly, and the photographed image of the box number is displayed on the monitor to confirm the fuel number. The fuel number confirmation method characterized by this.

  According to (5), when it is difficult to confirm the fuel number, it is possible to more reliably grasp the fuel number of the fuel assembly by confirming the box number.

  According to the present invention, since the fuel number and the box number are related to each other, when the channel box is attached to the fuel body, by confirming the fuel number and the box number, the fuel number and the box number are initially scheduled for the fuel body. It is possible to easily confirm whether or not the channel box that has been attached is attached. In addition, when trouble occurs in the channel box, it is possible to easily grasp the manufacturer by visually checking the upper part of the fuel assembly and checking the box number, and promptly contact the manufacturer. It becomes possible to take. Further, when a trouble occurs in the fuel body, it is possible to identify the fuel body in which the trouble has occurred by confirming either the fuel number or the box number.

It is a perspective view which shows the external appearance of the fuel assembly in one Embodiment of this invention. It is a perspective view which shows the external appearance of a fuel body. It is a perspective view which shows the external appearance of a channel box. It is a figure which shows the upper surface of a fuel body, and the upper surface of a channel box. It is a block diagram which shows the structure of the system which confirms a fuel number.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an external appearance of a fuel assembly in one embodiment of the present invention. The fuel assembly 1 includes a fuel body 10 and a channel box 30. As shown in FIG. 1, the fuel body 10 is a bundle of a plurality of fuel rods 12, and the channel box 30 is a rectangular tube-shaped member. The fuel assembly 1 is obtained by covering a fuel body 10 with a channel box 30 and combining them.

  FIG. 2 is a perspective view showing the appearance of the fuel body. The fuel body 10 includes a plurality of fuel rods 12, an upper tie plate 14, a spacer 16, a lower tie plate 18, and a handle 20.

  The fuel rod 12 is formed by filling a fuel pellet containing a fissile material into a rod-shaped cladding tube.

  The upper tie plate 14 has a square shape when viewed from above, and has a plurality of holes (not shown) for inserting and supporting the upper end of the fuel rod 12 on the surface, and is U-shaped along the diagonal line. A handle 20 is arranged. The upper tie plate 14 and the handle 20 are integrally formed. The handle 20 is used as a grip when the fuel assembly 1 is inserted and removed from a nuclear reactor (not shown). The lower tie plate 18 has a plurality of holes (not shown) for inserting and supporting the lower end of the fuel rod 12 on the surface, and the spacer 16 has a through hole (through which the fuel rod 12 is inserted). (Not shown).

  Then, the lower ends of the plurality of fuel rods 12 are inserted and fixed in the holes of the lower tie plate 18, the plurality of fuel rods 12 are inserted into the through holes of the spacer 16, and seven or more spacers 16 are provided. The fuel rods 12 are divided into eight equal positions, and the upper ends of the fuel rods 12 are inserted into the holes of the upper tie plate 14 and fixed. By the upper tie plate 14, the spacer 16, and the lower tie plate 18, the interval between the adjacent fuel rods 12 in the plurality of fuel rods 12 is maintained at a specified interval. As a result, the plurality of fuel rods 12 are bundled in a square lattice shape by the upper tie plate 14, the spacer 16, and the lower tie plate 18, thereby forming the fuel body 10.

  A fuel number assigned to the fuel body 10 is stamped on the upper surface of the handle 20. Thus, the upper surface of the handle 20 on which the fuel number is engraved corresponds to the fuel number display portion.

  FIG. 3 is a perspective view showing the appearance of the channel box. The channel box 30 is a substantially square rectangular tube member whose top view is slightly larger than the upper tie plate 14. In addition, clip portions 32 and 32 are formed at corner portions of the upper end side opening of the channel box 30 that are opposite to each other so as to cover a part of the upper end side opening.

  Further, the box number assigned to the channel box 30 is engraved on the upper surface of one clip portion 32. A screw hole 33 is formed on the upper surface of the other clip portion 32, and a channel fastener 34 (see FIG. 1) that is a metal fitting for connecting the fuel body 10 and the channel box 30 is fixed to the screw hole 33. The Thus, the upper surface of the clip part 32 on which the box number is engraved corresponds to the box number display part. In the following description, one clip portion 32 on which a box number is engraved is referred to as a clip portion 32a, and the other clip portion 32 in which a screw hole 33 is formed is referred to as a clip portion 32b.

  Then, the channel box 30 is inserted into the fuel body 10 from the opening on the lower end side, and the fuel body 10 is surrounded by the channel box 30 as shown in FIG. 1, and clip portions 32 and 32 are provided at the corners on the upper end side of the fuel body 10. And the handle 20 is projected from the upper end side opening of the channel box 30. Further, the fuel assembly 1 is configured by connecting the channel fastener 34 to the screw hole 33 with a screw.

  4A is a diagram showing the upper surface of the fuel body, FIG. 4B is a diagram showing the upper surface of the channel box, and FIG. 4C is a diagram showing the upper surface of the fuel assembly. As shown in FIG. 4A, the fuel number “S1A123” is engraved on the upper surface of the handle 20, and as shown in FIG. 4B, “S1AK123” is displayed on the upper surface of the clip portion 32a. Is engraved with the box number. As shown in FIG. 4C, the fuel number and the box number can be confirmed by viewing the fuel assembly 1 from above.

  As shown in FIG. 4A, the fuel numbers are stamped so as to be aligned along the longitudinal direction of the handle 20, that is, along the diagonal line of the upper tie plate 14. Further, as shown in FIG. 4B, the box numbers are engraved on the upper surface portion of the channel box 30 so as to be arranged in parallel to the diagonal line connecting the corner portions where the clip portions 32a and 32b are not formed. Yes. Therefore, when the channel box 30 is inserted into the fuel body 10 as shown in FIG. 4C, the character string of the fuel number and the character string of the box number become parallel.

  Next, the contents of the fuel number and box number will be described. The fuel number includes a number indicating the power plant number, a serial number indicating the number of regular inspections to be loaded, and a serial number assigned to each fuel assembly 1. According to the example shown in FIG. 4A, “S1” is a number indicating a power plant number, “A” is a serial number indicating the number of periodic inspections loaded, and “123” is a serial number. The fuel number “S1A123” is stamped on the handle 20. For example, a number indicating a power plant number is given as common information to a plurality of fuel assemblies 1 loaded in the same nuclear reactor. The serial number is assigned with a different value in each of the plurality of fuel assemblies 1 loaded in the same nuclear reactor, and becomes unique information of each fuel assembly 1. Information about each fuel assembly 1 can be browsed by inputting a fuel number into a fuel management system (not shown).

  The box number is configured by a combination of a fuel number and a character or a character string (for example, an initial letter of the manufacturer) that identifies the manufacturer of the channel box 30. According to the present embodiment, the box number is obtained by inserting a character or a character string specifying the manufacturer of the channel box 30 between the serial number indicating the number of regular inspections in the fuel number and the serial number. That is, the character or character string specifying the manufacturer of the channel box 30 is positioned next to the serial number in the fuel number. According to the example shown in FIG. 4B, the box number is “S1AK123”, and by visually recognizing this number, the fuel number of the fuel body 10 surrounded by the channel box 30 is “S1A123”. It can be seen that the character for identifying “K” is “K”. Information about each channel box 30 can be browsed by inputting a box number into a channel box management system (not shown).

  Incidentally, the use record of the fuel assembly 1 in the nuclear reactor is managed by a fuel management system (not shown). The replacement of the fuel assembly 1 is performed at the regular inspection except in an emergency. For this reason, the power plant in which the fuel assembly 1 is loaded, the number of periodic inspections scheduled for replacement, and the number of replacements of the fuel assembly 1 are planned in advance based on actual use. For example, if the power plant is “S1”, the number of periodic inspections is “Ath periodic inspection”, and the serial number determined based on the number of replacements is “123”, the fuel number is determined to be “S1A123”. Is done. Then, by ordering the manufacturer of the fuel body 10 to mark “S1A123”, the fuel body 10 having the fuel number “S1A123” stamped on the handle 20 is manufactured.

  On the other hand, if the initial of the manufacturer of the channel box 30 is “K”, the box number of the channel box 30 corresponding to the fuel body 10 with the fuel number “S1A123” is “S1AK123”. Then, by ordering the manufacturer of the channel box 30 to mark “S1AK123”, the channel box 30 having the box number “S1AK123” stamped on the clip portion 32a is manufactured.

  When the fuel assembly 1 is manufactured, the fuel assembly with the fuel number “S1A123” and the channel box 30 with the box number “S1AK123” are combined with the fuel assembly with the fuel number “S1A123”. Body 1 is completed.

  FIG. 5 is a block diagram showing a configuration of a system for confirming the fuel number. The system for confirming the fuel number includes an underwater camera 100, a lighting device 102, a moving device 104, a control device 200, and a monitor 202.

  A fuel assembly group 300 composed of a plurality of fuel assemblies 1 is arranged in the nuclear reactor 500, and an underwater camera 100 and an illumination device 102 corresponding to an imaging unit are arranged above the fuel assembly group 300. Yes.

  The underwater camera 100 captures the fuel assembly group 300, and image data captured by the underwater camera 100 is transmitted to the monitor 202. The illumination device 102 illuminates the shooting location of the underwater camera 100.

  The moving device 104 moves the underwater camera 100 and the illumination device 102 to change the shooting position.

  The control device 200 and the monitor 202 are provided on the moving device 104. The control device 200 controls the focus of the underwater camera 100 and the illuminance of the lighting device 102 by the operation of the worker. The monitor 202 processes image data from the underwater camera 100 and displays an image.

  For example, when loading the fuel assembly 1 that constitutes the fuel assembly group 300 into the nuclear reactor 500 and confirming whether or not the fuel assembly 1 is accommodated at a specified location, an operator uses the moving device 104. The underwater camera 100 and the monitor 202 are moved manually. Then, the worker confirms the state of the fuel assembly 1 by viewing the captured image of the underwater camera 100 displayed on the monitor 202. When the fuel assembly 1 does not fit in the specified location, the handle 20 is photographed from above the fuel assembly 1 that does not fit in the specified location, and the fuel number is displayed on the monitor 202. Thereby, it becomes possible to identify the fuel assembly 1 that does not fit in the specified location by the fuel number.

  At this time, for example, when the fuel number displayed on the monitor 202 cannot be confirmed due to adhesion of rust, or when it is difficult to confirm by adjusting light, the underwater camera 100 is moved to shoot the clip portion 32a. The box number is displayed on the monitor 202. And by grasping | ascertaining the fuel number contained in a box number, it becomes possible to specify the fuel assembly 1 which is not settled in a regulation location.

  According to the present embodiment configured as described above, both the fuel number and the box number can be confirmed from the upper part of the fuel assembly 1. Here, since the fuel number and the box number are related to each other, when the channel box 30 is attached to the fuel body 10, the fuel number and the box number are confirmed to be initially scheduled for the fuel body 10. It is possible to easily confirm whether or not the channel box 30 that has been attached is attached. In addition, when trouble occurs in the channel box 30, it is possible to easily grasp the manufacturer by visually checking the upper portion of the fuel assembly 1 and confirming the box number, and contact the manufacturer quickly. It becomes possible. Further, when a trouble occurs in the fuel body 10, it is possible to identify the fuel body 10 in which the trouble has occurred by confirming either the fuel number or the box number. As described above, it is possible to obtain information on the fuel body 10 in addition to the manufacturer of the channel box 30 from the box number assigned to the channel box 30.

  Further, according to the present embodiment, when the channel box 30 is attached to the fuel body 10, the character string of the fuel number displayed on the upper surface of the handle 20 and the character of the box number displayed on the upper surface of the clip portion 32a. The columns are parallel to each other. For this reason, after confirming the fuel number, the box number arranged in the same direction as the fuel number is displayed by changing the shooting position without changing the shooting direction of the underwater camera. As a result, the box number can be easily confirmed.

  Further, according to the present embodiment, in the box number, the serial number in the fuel number necessary for specifying the fuel assembly 1 and the character or character string of the manufacturer of the channel box 30 are adjacent to each other. When identifying the number, the serial number can be easily identified by recognizing the character or character string of the manufacturer of the channel box 30.

  Further, according to the present embodiment, the fuel number and the box number are displayed by engraving, so that the fuel number and the box number will not disappear.

  Further, according to the present embodiment, the fuel number of the fuel assembly 1 is photographed by the underwater camera 100 that photographs the fuel assembly 1 from above, and the photographed image of the fuel number is displayed on the monitor 202 to confirm the fuel number. When it is difficult to confirm the fuel number, the underwater camera 100 is moved to photograph the box number of the fuel assembly 1 and the photographed image of the box number is displayed on the monitor 202 to confirm the fuel number. As a result, when it is difficult to confirm the fuel number, it is possible to more reliably grasp the fuel number of the fuel assembly by confirming the box number.

  As mentioned above, although embodiment of this invention was described, embodiment of this invention is not restricted to what was mentioned above. For example, a surface treatment may be performed on the handle 20 so that the surface is a non-glossy surface and the surface of the fuel number stamped on the handle 20 is a glossy surface. Similarly, a surface treatment may be performed on the clip portion 32a so that the surface is a non-glossy surface and the box number surface marked on the clip portion 32a is a glossy surface. This makes it easier to check the fuel number and box number.

  Further, according to the above-described embodiment, the fuel number of the fuel assembly 1 in the nuclear reactor 500 is confirmed, but the fuel number of the used fuel assembly 1 loaded in the used fuel pool is determined. It is also possible to apply to confirmation.

DESCRIPTION OF SYMBOLS 1 Fuel assembly 10 Fuel assembly 12 Fuel rod 14 Upper tie plate 16 Spacer 18 Lower tie plate 20 Handle 30 Channel box 32, 32a, 32b Clip part 33 Screw hole 34 Channel fastener 100 Underwater camera 102 Illuminating device 104 Moving device 200 Control device 202 Monitor 300 Fuel assembly group 500 Reactor

Claims (5)

A plurality of fuel rods filled with a fissile material in a cladding tube, a tie plate supporting upper end portions of the plurality of fuel rods in a square lattice shape, and a fuel body having a handle portion provided on the tie plate ,
When the fuel body is inserted from the lower end opening, the square cylinder member surrounding the fuel body and a part of the corner of the upper end side opening of the square cylinder member are covered, and the fuel body is inserted. In addition, a fuel assembly comprising a channel box having a clip portion engaged with the fuel body,
The handle portion has a fuel number display portion for displaying a fuel number assigned to each fuel assembly,
The clip part has a box number display part for displaying a box number assigned to each channel box,
The fuel number includes unique information that is different for each of a plurality of fuel assemblies loaded in a nuclear reactor,
The box number is a number that associates the fuel number with the manufacturer information of the channel box,
The fuel assembly, wherein the fuel number display section and the box number display section are arranged so as to be confirmed from above.   When the channel box is attached to the fuel body, the fuel number character string displayed on the fuel number display portion and the box number character string displayed on the box number display portion are parallel to each other. The fuel assembly according to claim 1.   3. The fuel assembly according to claim 1, wherein the box number is obtained by positioning information of a manufacturer of the channel box next to the unique information in the fuel number. 4. The fuel number display portion is a fuel number stamped on the handle portion,
The fuel assembly according to any one of claims 1 to 3, wherein the box number display portion is a box number stamped on the clip portion.   5. A fuel number display section of the fuel assembly is photographed by a photographing means for photographing the fuel assembly according to any one of claims 1 to 4, and a photographed image of the fuel number is displayed on a monitor to display the fuel number. When it is difficult to confirm the fuel number, the photographing means is moved, the box number display part of the fuel assembly is photographed, and the photographed image of the box number is displayed on the monitor to confirm the fuel number. The fuel number confirmation method characterized by the above-mentioned.

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