JP6615696B2 - Control rod for boiling water reactor - Google Patents

Description

  The present invention relates to a boiling water nuclear reactor control rod, and more particularly to a boiling water nuclear reactor control rod having solid identification information on an upper portion of an axially upper tip structure material.

  The boiling water reactor control rod is properly used for reactor power adjustment or reactor shutdown. There are a plurality of types of boiling water reactor control rods, and it is determined at the operation planning stage whether to use them separately for reactor power adjustment or reactor shutdown. And the operator has arranged the control rod for boiling water reactors, confirming with a check sheet according to the procedure which showed the serial number and core coordinates.

  Regarding the structure of a boiling water reactor control rod, the technique described in Patent Document 1 is known. In Patent Document 1, mechanical properties of the sheath covering the reactivity control material with respect to the region located at the upper end in the longitudinal direction of the upper reactivity member and the region located at the lower end in the longitudinal direction of the lower reactivity member are described. In consideration of manufacturing errors in a range that is not harmful to the structure, an opening window is provided, and the end of the reactivity control material indicating the effective length of the reactivity control material is provided to the outside of the control rod through this opening window. It is described that the structure is exposed.

Japanese Patent Laid-Open No. 8-105989

  Various types of boiling water reactor control rods having multiple purposes can be identified by identification numbers (engraved identification numbers) provided on the side surfaces of the boiling water reactor control rods. However, after attaching the boiling water reactor control rod to the reactor, the gap between the fuel assemblies is narrow, so the appearance from the side of the boiling water reactor control rod cannot be confirmed. It is difficult to distinguish between reactor control rods, and strict management is required before installation.

  To identify the type of boiling water reactor control rod after the boiling water reactor control rod has been installed in the reactor, remove the boiling water reactor control rod and perform the work. The person will check the appearance from the side. However, such a series of operations is time-consuming and complicated for the operator.

  An object of the present invention is to provide a boiling water reactor control rod that can be identified by its type when attached to the reactor.

The gist of the present invention is that the tie rod has a cruciform shape and the tie rod extending outward from the respective end portions of members extending in four directions constituting the cross of the tie rod. A sheath that is welded and has a reactivity control material inside, and a tip structure that fixes both the tie rod and the sheath on the upper side and has a magnetic body as an identification portion for identifying the control rod on the upper surface; The tie rod and the sheath are fixed at the lower side, and the terminal structure is connected to a control rod drive mechanism for taking the control rod into and out of the boiling water reactor. The present invention relates to a boiling water reactor control rod.

  ADVANTAGE OF THE INVENTION According to this invention, the control rod for boiling water reactors which can identify the kind in the state attached to the reactor can be provided.

It is a side view of the control rod for boiling water reactors of a first embodiment. It is an enlarged view of the front-end | tip structure vicinity provided in the control rod for boiling water reactors of 1st embodiment. It is a top view of the front-end | tip structure vicinity with which the control rod for boiling water reactors of 1st embodiment is equipped. FIG. 3 is a side view of the fuel assembly and the boiling water reactor control rod when the boiling water reactor control rod of the first embodiment is inserted between the fuel assemblies. It is a top view of a fuel assembly and a control rod for boiling water reactor when the control rod for boiling water reactor of the first embodiment is inserted between fuel assemblies. It is an enlarged view of the front-end | tip structure vicinity with which the control rod for boiling water reactors of 2nd embodiment is equipped. It is a top view of the front-end | tip structure vicinity with which the control rod for boiling water reactors of 2nd embodiment is equipped. It is an enlarged view of the front-end | tip structure vicinity with which the control rod for boiling water reactors of 3rd embodiment is equipped. It is a top view of the front-end | tip structure vicinity with which the control rod for boiling water reactors of 3rd embodiment is equipped. It is an enlarged view of the front-end | tip structure vicinity provided in the control rod for boiling water reactors of 4th embodiment. It is a top view of the front-end | tip structure vicinity with which the control rod for boiling water reactors of 4th embodiment is equipped.

  Hereinafter, a form for carrying out the present invention (this embodiment) will be described with reference to the drawings as appropriate. In each of the drawings, the same members are denoted by the same reference numerals, and the detailed description after the second time is omitted.

  FIG. 1 is a side view of a boiling water nuclear reactor control rod 100 of the first embodiment. Hereinafter, in order to simplify the description, the “control rod for boiling water reactor” may be abbreviated as “control rod”. The control rod 100 (boiling water reactor control rod 100) has a cross-shaped cross-sectional structure in a top view (see also FIG. 3 related to the top view).

  The tie rod 103 includes four members that extend in four directions of 90 degrees. Therefore, the tie rod 103 has a cross shape. And the sheath 104 is welded with respect to the said protrusion from the edge part of each member formed in each of four directions as the starting point toward the outer side from the starting point. Therefore, in the control rod 100, the tie rod 103 and the sheath 104 are connected and fixed by the tip structure 101 on the upper side. On the other hand, on the lower side, the tie rod 103 and the sheath 104 are connected and fixed by a terminal structure 102 described later. The indentation 109 formed in the tip structure 101 will be described later with reference to FIGS.

  Further, in FIG. 1, what is indicated by a dotted line is a reactivity control material 105 included in the height direction of the sheath 104 having a U-shaped cross section. Depending on the type of the control rod, the reactivity control material 105 is shown. The material and shape of 105 change. The control rod 100 is stamped with a unique identification number 107 on the side surface. Therefore, before the reactor is inserted, the type of the control rod 100 can be identified by confirming the identification number 107 provided on the side surface from the side.

  Below the control rod 100, a cross-shaped end structure 102 is attached as viewed from below. A socket 108 is provided at the lower end of the end structure 102. The control rod 100 is connected to a control rod drive mechanism (not shown) provided at the bottom of the reactor pressure vessel by the socket 108. The control rod drive mechanism performs an operation of inserting the control rod 100 into the core and an operation of extracting the control rod 100 from the core.

  FIG. 2 is an enlarged view of the vicinity of the tip structure 101 provided in the boiling water reactor control rod 100 of the first embodiment. A recess 109 for identifying the control rod 100 is provided on the upper surface of the tip structure 101 attached to the upper end of the control rod 100. Although details will be described later, by providing the recess 109, the attached control rod 100 can be identified even when the control rod 100 is attached to the nuclear reactor.

  FIG. 3 is a top view of the vicinity of the tip structure 101 provided in the boiling water reactor control rod 100 of the first embodiment. The tip structure 101 has a cross shape as described above. In the first embodiment, the dent 109 is formed only on the upper surface of the portion extending in the left direction among the four sides of the left direction, the right direction, the near side direction, and the back direction as viewed from the center of the tip structure 101. Has been. Although details will be described later with reference to FIG. 4 and FIG. 5, a fuel assembly 106 having a rectangular cross section is disposed between adjacent sides among these four sides.

  FIG. 4 is a side view of the fuel assembly 106 and the boiling water reactor control rod 100 when the boiling water reactor control rod 100 of the first embodiment is inserted between the fuel assemblies 106. . More specifically, FIG. 4 shows that the control rod driving mechanism inserts the control rod 100 between the plurality of fuel assemblies 106 attached to the core in order to adjust the reactor power or stop the reactor. It shows the state when it was done.

  The control rod 100 is inserted into the gap of the fuel assembly 106 from below the fuel assembly 106 fixed in the reactor core, so that the state shown in FIG. 4 is obtained. In the state of FIG. 4 in which the control rod 100 is completely inserted, the upper end of the control rod 100 reaches a position immediately below the upper end of the fuel assembly 106.

  FIG. 5 is a top view of the fuel assembly 106 and the boiling water reactor control rod 100 when the boiling water reactor control rod 100 of the first embodiment is inserted between the fuel assemblies 106. . As shown in FIG. 5, when viewed from above, the upper surface of the tip structure 101 constituting the control rod 100 is confirmed through the gap between the four fuel assemblies 106. Since the dent 109 is provided on the upper surface of the tip structure 101 as described above, the dent 109 can be confirmed from above the fuel assembly 106. In particular, even if the number of fuel assemblies 106 is several tens to several hundreds as shown in FIG. 5, from the upper end of the tip structure 101 as shown in FIG. The distance to the upper end of the fuel assembly 106 does not change. Therefore, the dent 109 of the tip structure 101 can be confirmed from above the fuel assembly 106.

  Confirmation of the dent 109 is performed by using an illumination and a camera (both not shown) attached to a fuel changer (not shown) provided above the fuel assembly 106 and transporting the fuel assembly 106. Can do. Specifically, the dent 109 can be confirmed by illuminating the upper surface of the tip structure 101 with illumination and photographing the upper surface with a camera.

  In the first embodiment, the dent 109 is formed only in the control rod 100 used for adjusting the reactor power. On the other hand, the dent 109 is not formed in the control rod 100 used for stopping the reactor. Therefore, if the dent 109 is formed as a result of confirming the upper surface of the tip structure 101 with the camera, the control rod 100 is for adjusting the reactor power, and if the dent 109 is not formed, The control rod 100 can be identified as being for reactor shutdown.

  FIG. 6 is an enlarged view of the vicinity of the tip structure 101B provided in the boiling water reactor control rod 100B of the second embodiment. Since the control rod 100B has the same configuration as that of the control rod 100 below the sheath 104, the explanation will focus on the configuration above the sheath 104, that is, the configuration of the tip structure 101B. A bar code 109B is attached to the upper surface of the tip structure 101B constituting the control rod 100B shown in FIG. In FIG. 6, the form of the barcode itself is not shown for the sake of illustration. The bar code 109B is attached instead of the dent 109 in the tip structure 101.

  FIG. 7 is a top view of the vicinity of the tip structure 101B provided in the boiling water reactor control rod 100B of the second embodiment. As with the tip structure 101, the bar code 109B is attached only to the upper surface of the four sides extending in the left direction. The bar code 109B is detected by reading with a laser transmitter and a receiver (both not shown) attached to the fuel changer, unlike the above-described confirmation of the dent 109.

  Information (identification information) given by the bar code 109B is associated with information unique to the control rod 100B (one-to-one correspondence). Therefore, when the barcode 109B is read by a laser transmitter or the like, information unique to the control rod 100B to which the barcode 109B is attached is grasped. The “unique information” referred to here includes the control number of the control rod 100B, the manufacturing time, the use history, etc., in addition to the control power adjustment of the control rod 100B or the shutdown of the reactor.

  FIG. 8 is an enlarged view of the vicinity of the tip structure 101C provided in the boiling water reactor control rod 100C of the third embodiment. Since the control rod 100C has the same configuration as that of the control rod 100 below the sheath 104C, the explanation will focus on the configuration of the tip structure 101C above the sheath 104. A magnetic body 109C is provided on the upper surface of the tip structure 101C constituting the control rod 100C shown in FIG. This magnetic body 109 </ b> C is provided in place of the dent 109 in the tip structure 101.

  FIG. 9 is a top view of the vicinity of the tip structure 101C provided in the boiling water reactor control rod 100C of the third embodiment. Like the tip structure 101, the magnetic body 109C is provided only on the upper surface of the four sides extending in the left direction. The detection of the magnetic body 109C is performed by reading the magnetism with a magnetic sensor (not shown) attached to the fuel changer, unlike the confirmation of the dent 109. Therefore, even if clad or the like adheres to the upper surface of the tip structure 109C and the surface cannot be confirmed, the magnetic force is read by the magnetic sensor to adjust the reactor power of the control rod 101C or to stop the reactor. Another can be identified.

  In the third embodiment, similarly to the first embodiment, the magnetic body 109C is provided only in the control rod 100C used for adjusting the reactor power. On the other hand, the magnetic rod 109C is not provided in the control rod 100C used for stopping the reactor. Therefore, if the magnetism of the magnetic body 109C is detected by the magnetic sensor, the control rod 100C is for adjusting the reactor power, and if the magnetism of the magnetic body 109C is not detected, the control rod 100C is an atom. It can be determined that it is for the furnace shutdown. In order to more reliably detect the magnetism of the magnetic body 109C, a magnetic shield for suppressing the influence of magnetism from the surroundings can be provided around the magnetic body 109C.

  FIG. 10 is an enlarged view near the tip structure 101D provided in the boiling water nuclear reactor control rod 100D of the fourth embodiment. Since the control rod 100D has the same configuration as that of the control rod 100 below the sheath 104, the explanation will focus on the configuration above the sheath 104, that is, the configuration of the tip structure 101D. Concavities and convexities 109D are formed on the top surface of the tip structure 101D constituting the control rod 100D shown in FIG. The unevenness 109 </ b> D is formed in place of the dent 109 in the tip structure 101.

  FIG. 11 is a top view of the vicinity of the tip structure 101D provided in the boiling water reactor control rod 100D of the fourth embodiment. Similar to the tip structure 101, the unevenness 109D is formed only on the upper surface of the four sides extending in the left direction. Then, the confirmation of the unevenness 109D is performed by reading the shape of the unevenness with an uneven shape scanner (not shown) attached to the fuel changer, unlike the confirmation of the dent 109 described above. Therefore, even when a clad or the like adheres to the surface of the unevenness 109D on the tip structure 101D, the shape of the unevenness can be confirmed from above the cladding. Therefore, even if a clad adheres, the kind of control rod 100D can be identified.

  Further, the information given by the unevenness 109D is associated with information unique to the control rod 100D, like the barcode 109B. Therefore, the type of the control rod 100D can be identified by confirming the shape of the unevenness 109D with the uneven shape scanner. As a result, similar to the case of attaching the bar code 109B, it is possible to grasp unique information such as for adjusting the reactor power of the control rod 100D or for stopping the reactor.

  As mentioned above, although the four embodiment was mentioned and the control rod for boiling water reactors of this invention was demonstrated, this invention is not limited to the said embodiment at all. For example, the embodiments described above can be implemented in any combination. Specifically, for example, the bar code 109B in the second embodiment is information unique to the control rod 102B (in addition to adjusting the reactor power of the control rod 100B or stopping the reactor, the serial number of the control rod 100B, Manufacturing time, usage history, etc.), but only the reactor power adjustment or reactor shutdown may be identified as in the case of the dent 109 in the first embodiment. That is, the bar code 109B may identify only whether the control rod 100B is for reactor power adjustment or reactor shutdown.

  Further, for example, the dent 109 and the magnetic body 109C are formed or provided only in the control rods 100 and 100C for adjusting the reactor power. However, instead of this, the dent 109 and the magnetic body 109C may be formed or provided only in the control rods 100 and 100C for stopping the reactor. Further, in this case, since it is only necessary to distinguish between the reactor power adjustment and the reactor shutdown, for example, when the dent 109 is taken as an example, the reactor power regulation control rod 100 and the reactor shutdown The control rod 100 may form a dent 109 having a different shape so as to identify them. The same applies to the control rod 100C provided with the magnetic body 109C.

  Further, for example, in the fourth embodiment described above, the shape of the unevenness 109D (the order in which the concave portions and the convex portions are arranged) is recorded in advance in a database or the like, whereby information unique to the shape of the unevenness 109D and the control rod 100D. Can be linked. However, even if the shape of the unevenness 109D is not recorded in advance in the database or the like, if the unevenness 109D is formed according to the regularity of the order of arrangement of the concave and convex portions, the control is performed based on the regularity. The bar 100D can be identified. As a result, it is not necessary to construct a database or the like in which the shape of the unevenness 109D and the information unique to the control rod 100D are linked in advance, which is simple.

  In the first embodiment, the dent 109 is formed, and in the fourth embodiment, the unevenness 109D (that is, a combination of the dent and the protrusion) is formed. However, for example, only the protrusion may be formed. When only the protrusion is formed, for example, the cross section may be rectangular or the cross section may be triangular.

  Further, the identification unit such as the dent 109 may be provided in combination of a plurality of types. For example, the dent 109 and the barcode 109B may be used in combination.

100 Control rod, boiling water reactor control rod 100B Control rod, boiling water reactor control rod 100C Control rod, boiling water reactor control rod 100D Control rod, boiling water reactor control rod 101 Tip Structure 101B Tip structure 101C Tip structure 101D Tip structure 102 End structure 103 Tie rod 104 Sheath 105 Reactivity control material 106 Fuel assembly 107 Identification number 108 Socket 109 Recess (identification part)
109B barcode (identification part)
109C Magnetic body (identification part)
109D Concavity and convexity (identification part)
111 Fixing member

Claims (4)

A tie rod having a cross-shaped shape;
A sheath which is welded to the tie rod so as to extend outward from the respective end portions of the members extending in the four directions constituting the cross of the tie rod and has a reactivity control material inside;
A tip structure that fixes both the tie rod and the sheath on the upper side and has a magnetic body as an identification portion for identifying a control rod on the upper surface;
And a terminal structure connected to a control rod drive mechanism for moving the control rod into and out of a boiling water reactor while fixing both the tie rod and the sheath on the lower side. Control rod for water reactor. The identification unit is characterized in that the one in which boiling water nuclear reactor control rods are used to identify which of the reactor power adjustment or for nuclear reactors stopped, claim 1 A control rod for a boiling water reactor according to 1. 3. The boiling water atom according to claim 2 , wherein the identification unit is provided in one of the control rod for adjusting the reactor power and the control rod for stopping the reactor. 4. Control rod for furnace. The identification unit is configured such that the identification information given by the identification unit and the information unique to the control rod provided with the identification unit have a one-to-one correspondence. Item 3. A boiling water reactor control rod according to Item 1 .

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