JP2017009364A - Control rod storage unit and method for modifying the control rod storage unit - Google Patents

Abstract

A control rod storage device and a method for remodeling the control rod storage device that are simple in structure, easy to store and store control rods, and that can suitably prevent the suspended control rods from dropping off. I will provide a. A control rod storage device (1) includes a base (10) installed on a bottom surface (P1) of a storage pool (P), a support column (20) erected on the base unit (10), an upper part of the support column (20), and extending left and right. A hanger member 30 that supports the control rod 50, and the hanger member 30 extends at an inclination angle θ1 that inclines upward from the central portion in the left-right direction toward both ends in the left-right direction. It was. [Selection] Figure 1

Description

  The present invention relates to a control rod storage device installed in a storage pool and a method for remodeling the control rod storage device.

In boiling water nuclear power plants, all or a relatively large number of control rods may be removed from the core for inspection or other purposes. In this case, since it is necessary to return the control rod to the core again and reuse it, it is necessary to store and store the control rod while maintaining a healthy state temporarily in the storage pool.
Similarly, when the control rod is periodically replaced in the periodic inspection, it is stored and stored in the storage pool.

Conventionally, what was disclosed by patent document 1 as a technique which stores a control rod within a storage pool is known.
Patent Document 1 stores control rods in a storage pool in which a relatively deep water can be ensured from the viewpoint of handling restrictions in exchange work or the like and radiation shielding. In Patent Document 1, a storage rack is arranged in a portion that becomes a deep water area, a control rod is inserted into the rack from above, the control rod is seated in the rack, and the control rod is stored and stored.

  Here, in the deep water area, a space for storing the fuel body is mainly used. In Patent Document 1, racks are stacked one above the other in order to widen the storage space for the fuel body. That is, there is a restriction that the storage space for the control rods should be kept as narrow as possible in the deep water area. For this reason, it is necessary to minimize the storage capacity of control rods in deep water areas. If many control rods are taken out at the same time, such as inspection in the furnace, they can be stored and stored. There was a problem that it was difficult to secure a sufficient storage capacity.

  Therefore, it is conceivable to effectively use a shallow area with a relatively large space in the storage pool as a storage and storage space for control rods. However, the shallow water area has the restriction that the control rod cannot be handled in the same manner as the deep water area from the viewpoint of handling the control rod and shielding radiation during storage.

For this reason, in an area where the water depth is shallow, as disclosed in Patent Document 2, the storage hanger is used to move the control rod in a horizontal direction while maintaining a predetermined water depth from the viewpoint of radiation shielding, and the hanger is controlled. The method of hanging a stick is taken.
Moreover, as disclosed in Patent Document 3, a storage rack having a structure in which a gate-like component opens and closes is used, and a method of inserting control rods into the rack from the horizontal direction is employed.

JP-A-60-21491 Japanese Utility Model Publication No.59-98399 Japanese Examined Patent Publication No. 61-48877

  As shown in FIG. 8, the control rod storage device of Patent Document 2 hangs the upper handle portion 51 of the control rod 50 on a horizontal bar member 101 as a hanger provided at the upper end of the device 100 for storage and storage. It is a structure to perform. However, among the seismic conditions applied to the equipment, particularly when the vertical acceleration is large, as shown in FIG. 9, the horizontal bar member 101 vibrates up and down, and the suspended control rod 50 is located outside the apparatus. There was a risk of jumping and dropping off. In this case, when the control rod 50 falls into the storage pool P, there is a risk of damaging other important equipment in the storage pool P.

  Moreover, since the control rod storage equipment of patent document 3 receives the load of the control rod stored in the equipment by the lower structure (bottom part) of the rack, it is possible to maintain earthquake resistance and strength. However, when inserting the control rod into the rack, it is necessary to open the gate-shaped component in advance, close the component after inserting the control rod, and secure the rack strength even after storing the control rod. There was a complication associated with preparation and restoration work before and after. In addition, there is a problem that the structure of the storage rack becomes complicated.

  Therefore, the present invention provides a control rod storage device and a control rod storage device that are simple in structure, easy to store and store control rods, and that can suitably prevent the suspended control rods from dropping off. It is to provide a remodeling method.

  A control rod storage apparatus according to the present invention includes a base installed on the bottom surface of a storage pool, a support erected on the base, and a hanger attached to an upper portion of the support and extending left and right to support the control rod. And the hanger member extends at an inclination angle so as to incline upward from the central portion in the left-right direction toward both ends in the left-right direction.

  Further, the control rod storage device remodeling method of the present invention includes a base installed on the bottom surface of the storage pool, a column extending upward from the base, and attached to an upper part of the column and extending left and right. A hanger member for supporting the control rod, and a method for remodeling the control rod storage device, wherein the left and right ends of the hanger member are lifted with a jig with respect to the central portion in the left-right direction of the hanger member, It is characterized in that the hanger member is inclined so as to incline upward as it goes from the center portion in the left-right direction of the hanger member toward both ends in the left-right direction of the hanger member.

  According to the present invention, a control rod storage device and a control rod storage device that have a simple structure, can easily store and store the control rods, and can suitably prevent the suspended control rods from dropping off. The remodeling method is obtained.

It is a front view which shows the control-rod storage apparatus of one Embodiment of this invention. It is an enlarged front view which shows the hanger member of the control-rod storage apparatus of one Embodiment. (A) is an enlarged front view showing a notch portion of a hanger member, (b) is an enlarged front view showing a notch portion of a hanger member of a modification, and (c) is a state of the notch portion of the hanger member at a lower limit position of vibration. It is an enlarged front view shown. It is a front view which shows the mode at the time of the storage / storage operation | work of a control rod. It is a front view which shows the mode of the vertical vibration of a hanger member. It is a model perspective view which shows the state which installed multiple control-rod storage apparatuses in the storage pool. It is an enlarged front view of the hanger member which shows the remodeling procedure of a control-rod storage apparatus. It is explanatory drawing of a prior art. It is explanatory drawing of a prior art.

  Hereinafter, an embodiment of a control rod storage device according to the present invention will be described with reference to the drawings. Here, in the following description, when referring to “up and down” and “left and right”, the directions shown in FIGS. 1 and 2 are used as a reference.

  As shown in FIG. 1, the control rod storage device 1 is installed on the bottom surface P <b> 1 using the bottom surface P <b> 1 of the storage pool P. The control rod storage device 1 includes a base 10, a support 20, and a hanger member 30.

  The base 10 includes an inclined bar 11. The inclined beam 11 supports the column 20. The lower end of the inclined bar 11 is fixed to the bottom surface P1 of the storage pool P by fixing means (not shown).

  The support column 20 is erected and supported by the base 10 and has strength and rigidity that can withstand the load of the control rod 50 (see FIG. 4). A hanger member 30 is attached to the upper end 21 of the column 20. The hanger member 30 is fixed to the support column 20 by fixing means using welding or bolts.

  The hanger member 30 is a member that supports the control rod 50 (see FIG. 4). As shown in FIG. 2, the hanger member 30 is composed of a plate-like member extending to the left and right, and has a substantially V-shape when viewed from the front. The hanger member 30 extends so as to incline upward from the central portion 32 in the left-right direction toward both end portions 33a, 33b in the left-right direction.

  The hanger member 30 is configured to vibrate in the vertical direction while supporting the control rod 50 when receiving an external force such as an earthquake. At this time, as shown in FIG. 5, the hanger member 30 is configured to take a substantially horizontal posture (a posture in which the hanger member 30 extends in the horizontal direction) at the lower limit position of vibration. That is, the hanger member 30 has a configuration in which the left and right end portions 33a and 33b are unlikely to hang down below the horizontal reference plane S when receiving an external force such as an earthquake.

  In the present embodiment, the inclination angle θ1 (see FIG. 2) with respect to the horizontal reference plane S is set to 10 degrees or more and 15 degrees or less. The inclination angle θ1 is set in consideration of the amount of vibration in the vertical direction caused by external forces such as earthquakes and the like when storing the control rod 50 and the like. That is, the inclination angle θ1 is set so that the height dimension of the hanger member 30 fits within the frame of the upper handle portion 51 of the control rod 50 (see FIG. 4). Further, as described above, the hanger member 30 is set to take a substantially horizontal posture at the lower limit position of vibration when receiving an external force such as an earthquake.

  A notch 31 is formed on the upper edge of the hanger member 30 at a predetermined interval. As shown in FIG. 3A, the notch 31 is substantially U-shaped and includes a bottom 31a, one side 31b, and the other side 31c. The bottom 31a is flat and formed substantially horizontally. The one side portion 31b rises substantially vertically from one end portion of the bottom portion 31a (the left end portion of the bottom portion 31a in FIG. 3A). The other side portion 31 c rises in an inclined manner from the other end portion of the bottom portion 31 a (the right end portion of the bottom portion 31 a in FIG. 3A) toward the central portion 32 side of the hanger member 30.

  When the control rod 50 is supported by such a control rod storage device 1, as shown in FIG. 4, the control rod 50 is horizontally moved by a crane (not shown) or the like from the left and right sides of the hanger member 30, The control rod 50 is brought close to the hanger member 30. In this case, the control rod 50 is moved while ensuring the water depth (water thickness) of the control rod 50.

  Thereafter, the horizontal movement is continued, and the end 33a (33b) of the hanger member 30 is inserted into the upper handle portion 51 of the control rod 50. When the control rod 50 comes to the position of the notch 31, the control rod 50 is moved by a crane. Lower. As a result, the upper handle portion 51 is locked to the notch portion 31, and the control rod 50 is supported by the hanger member 30.

  In the present embodiment, the inclination angle θ1 (see FIG. 2) of the hanger member 30 is set to 10 degrees or more and 15 degrees or less, and the height of the hanger member 30 is set within the frame of the upper handle portion 51. The hanger member 30 can be inserted through the upper handle 51 only by performing horizontal movement. That is, the control rod 50 can be moved along the hanger member 30 without adding a vertical movement to the control rod 50. Therefore, the operation of the crane at the time of storage or the like is simple, and the storage and storage work is easy to perform.

  Moreover, since the inclination angle θ1 of the hanger member 30 is set to 10 degrees or more and 15 degrees or less, the hanger member 30 takes a substantially horizontal posture at the lower limit position of vibration when receiving an external force such as an earthquake. The left and right end portions 33a and 33b of the hanger member 30 are less likely to hang down below the horizontal plane. Therefore, it is possible to suitably prevent the suspended control rod 50 from jumping to the outside of the apparatus and dropping off.

  Next, a method for modifying the control rod storage device will be described with reference to FIG. In this remodeling method, in the existing control rod storage device, when the hanger member 30A extends horizontally, the hanger member 30A is remodeled using the jig 40, and the hanger member 30A is given an inclination angle θ1. It is intended to give it.

  The jig 40 includes a first bottom portion 41 that contacts the central portion 32A of the hanger member 30A, and a second bottom portion 42 that has an inclination angle of θ1 with respect to the first bottom portion 41.

  When remodeling, the first bottom portion 41 of the jig 40 is brought into contact with the central portion 32A of the hanger member 30A. Thereafter, the end 33b (33a) on the side where the first bottom 41 is brought into contact is lifted with a jig to plastically deform the hanger member 30A. By performing the same operation on the opposite side of the hanger member 30A, the hanger member 30A can be modified into a substantially V shape.

As described above, the hanger member 30A having a configuration extending in the horizontal direction can be remodeled into the hanger member 30A having the inclination angle θ1, and high earthquake resistance can be achieved.
Note that by preparing a plurality of types of jigs, the hanger member 30A having a desired inclination angle can be modified. Even when the hanger member is provided with an inclination angle in advance, it can be changed using a jig so as to have a different inclination angle.

  According to the present embodiment described above, the control rod storage device 1 is configured to include the base 10, the support column 20, and the hanger member 30. Therefore, the structure of the control rod 50 is simple and the cost is reduced. Storage is possible.

Moreover, since the hanger member 30 is substantially V-shaped, the control rod 50 is not easily dropped from the hanger member 30 even when subjected to an external force such as an earthquake, and stable storage and storage of the control rod 50 is possible. is there. Moreover, since the hanger member 30 takes a substantially horizontal position at the lower limit position of the vibration of the hanger member 30 when an external force such as an earthquake is applied, it is preferable that the suspended control rod 50 jumps outside the apparatus and falls off. Can be prevented. As a result, it is possible to minimize the ripple effect of damaging other highly important devices in the storage pool P.
Further, since the hanger member 30 has a substantially V-shape, when the control rod 50 is detached from the notch 31, the control rod 50 only moves to the central portion 32 of the hanger member 30. Even in this case, there is no spillover effect of damaging other important equipment in the storage pool P.

  Here, as shown in FIG. 3B, an angle θ <b> 2 may be given to the bottom 31 a of the notch 31 </ b> A of the hanger member 30. The bottom 31a is inclined from the horizontal reference plane S (see FIG. 2) by the angle θ2. On the other hand, as shown in FIG. 3C, the bottom 31a is in a substantially horizontal state at the lower limit position of vibration of the hanger member 30 when subjected to an external force such as an earthquake, depending on the angle θ2. Thus, since the bottom 31a is substantially horizontal at the lower limit position of the vibration of the hanger member 30, the control rod 50 suspended from the notch 31A is stabilized, and the control rod 50 jumps out of the apparatus and falls off. Can be more suitably prevented.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the meaning, it can change suitably.
For example, the inclination angle θ1 with respect to the horizontal reference plane S may be set to less than 10 degrees. By setting the angle less than 10 degrees in this way, the inclination angle θ1 is reduced, so that the insertability of the control rod 50 into the control rod storage device 1 is improved and the working time is shortened. Shortening work time contributes to cost reduction.

  On the contrary, the inclination angle θ1 with respect to the horizontal reference plane S may be set larger than 15 degrees. By setting the angle larger than 15 degrees as described above, the holding ability of the control rod 50 in the storage pool P at the time of an earthquake can be further improved.

  Further, as shown in FIG. 6, a plurality of control rod storage devices 1 can be installed in the storage pool P by connecting the upper ends of the columns 20 with a connecting member 35. In this case, the end 35a of the connecting member 35 is preferably extended to the side wall P2 of the storage pool P and fixed to the side wall P2. Further, in FIG. 6, the hanger member 30 is installed on the portion other than the upper end portion of the support column 20 using the connecting member 35. Thereby, the number of installation of the hanger member 30 can be increased, and more control rods 50 (see FIG. 4) can be efficiently stored. Further, by connecting with the connecting member 35, the strength of the control rod storage devices 1 can be improved.

  Further, the angle θ2 of the bottom 31a of the notch 31 with respect to the horizontal reference plane S can be set as appropriate. In this case, by increasing the angle θ2, at the lower limit position of the vibration, the bottom portion 31a is arranged in an inclined shape toward the central portion 32 of the hanger member 30, and the control rod 50 is prevented from dropping out of the apparatus. It can prevent more suitably.

DESCRIPTION OF SYMBOLS 1 Control rod storage apparatus 10 Base 20 Support | pillar 21 Upper part 30 Hanger member 30A Hanger member 31 Notch part 31a Bottom part 31b One side part (side part)
31c Other side (side)
32 Central part 33a, 33b End part 40 Jig 50 Control rod P Storage pool P1 Bottom face θ1 Inclination angle

Claims (7)

A base installed on the bottom surface of the storage pool, a support erected on the base, a hanger member attached to the upper part of the support and extending left and right to support the control rod,
The control rod storage device according to claim 1, wherein the hanger member extends at an inclination angle so as to incline upward from the central portion in the left-right direction toward both ends in the left-right direction. The hanger member is
When receiving external force, it will vibrate up and down,
2. The control rod storage device according to claim 1, wherein the control rod storage device maintains a substantially horizontal posture or a posture tilted upward from the substantially horizontal posture at a lower limit position of vibration. The hanger member has a notch for locking the control rod,
The notch includes a flat bottom and a side that rises from the bottom,
3. The control according to claim 1, wherein the bottom portion is disposed substantially horizontally or in an inclined shape descending toward a central portion of the hanger member at a lower limit position of vibration of the hanger member. Bar storage device.   The control rod storage device according to any one of claims 1 to 3, wherein the inclination angle is 10 degrees or more and 15 degrees or less with respect to a horizontal reference plane.   The control rod storage device according to any one of claims 1 to 3, wherein the inclination angle is less than 10 degrees with respect to a horizontal reference plane.   The control rod storage device according to any one of claims 1 to 3, wherein the inclination angle is larger than 15 degrees with respect to a horizontal reference plane. A control rod comprising: a base installed on the bottom surface of the storage pool; a support column extending upward from the base; and a hanger member attached to the upper portion of the support column and extending left and right to support the control rod. A remodeling method of the storage device,
The left and right end portions of the hanger member are lifted with a jig with respect to the center portion in the left-right direction of the hanger member, and as it goes from the center portion in the left-right direction of the hanger member toward both ends in the left-right direction of the hanger member, A method of remodeling a control rod storage device, characterized in that the hanger member is inclined at an upward angle.

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