JP2005082313A - Storage method for plate-shaped heavy structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to easily contain a disc-shaped structure in a storage part. <P>SOLUTION: For storing a water chamber drum lid 34 in a lid storage part 48 provided in a water chamber drum 12 of a heat exchanger, a support 70 is installed at a lower part of the water chamber drum 12 on the front side of the lid storage part 48. The water chamber drum lid 34 is suspended by a hoist 64, and disposed on the support 70. The support 70 comprises a support surface 74 for supporting a lower side circumferential surface of the water chamber drum lid 34 to set the axial center of the water chamber drum lid 34 to roughly coincide with the axial center of the lid storage part 48. A pushing bolt 78 is driven into a reaction receiving part 76 of the support 70 to be engaged. By driving the pushing bolt 78 further, the water chamber drum lid 34 is pushed into the lid storage part 48 as illustrated with an arrow 80. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for storing a heavy plate-like structure, and more particularly to a method for storing a plate-like heavy structure suitable for fitting a plate-like heavy structure in a standing state.

  A light water reactor such as a boiling water reactor (PWR) or a pressurized water reactor (PWR) supplies water, which is a coolant, into the reactor pressure vessel, and a fuel rod and coolant that are hot due to nuclear fission, Heat exchange. In a boiling water reactor, a coolant (water) is supplied into the reactor pressure vessel and boiled, taken out as high-temperature steam, rotated in the turbine, condensated and returned to the reactor pressure vessel. I try to return it.

  In the boiling water reactor in which the coolant is circulated in this way, rust generated on the inner surface of the piping, radionuclide activated by passing through the core, and the like are included in the coolant. Therefore, a reactor coolant purification system (CUW) is provided in which a part of the coolant (reactor water) in the reactor pressure vessel is taken out, purified and returned to the reactor pressure vessel. Purification of the coolant is performed by passing the reactor water through a filter (purification device) such as an ion exchange membrane. For this reason, the reactor coolant purification system is provided with a heat exchanger for cooling the high-temperature reactor water and sending it to the purification device. In consideration of ease of inspection and maintenance, a horizontal type using a U-shaped heat transfer tube may be used as the heat exchanger. FIG. 2 is a partial cross-sectional view showing an example of a horizontal heat exchanger of the reactor coolant purification system.

  In FIG. 2, the heat exchanger 10 has a water chamber body 12 and a body 14. The interior of the water chamber body 12 and the body 14 is partitioned by a tube plate 16. A water chamber 18 is provided inside the water chamber body 12. The water chamber 18 is provided with partition plates 20 and 22 inside, and by these partition plates 20 and 22, an inflow side chamber 26 into which low-temperature cooling water flows as shown by an arrow 24, and an arrow 28. It is partitioned into an outflow side chamber 30 through which cooling water flows out.

  The water chamber body 12 has an opening 32 on the left side in FIG. 2, and a lid storage portion 48 is provided between the opening 32 and the water chamber 18. The lid storage portion 48 accommodates a water chamber trunk lid (plate-like heavy structure) 34 formed in a disc shape. Although the size of the water chamber lid 34 varies depending on the type of the heat exchanger 10, it has a diameter of about 80 cm, a thickness of about 12 cm, and a weight of about 2 tons. The water chamber trunk lid 34 is fixed inside the water chamber trunk 12 by a fixing plate 50 disposed on the front side (left side in FIG. 2) while being housed in the lid storage portion 48. The fixing plate 50 has a donut shape divided into a plurality of parts, and an outer peripheral edge portion is inserted into a circumferential groove 52 formed in the water chamber body 12. Further, the fixing plate 50 has a bolt hole on the inner peripheral side, and is screwed to the water chamber trunk lid 34 by a bolt 54 inserted into the bolt hole. That is, a plurality of screw holes 56 into which the bolts 54 are screwed are formed in the front surface of the water chamber trunk lid 34. These screw holes 56 are arranged in a plurality of rows (for example, two rows) concentrically with the water chamber trunk lid 34.

  By the way, since nuclear power generation facilities are required to have a high degree of safety, they are regularly maintained and inspected. The heat exchanger 10 of the reactor coolant purification system is no exception, and the water chamber trunk lid 34 is removed to clean the inside of the water chamber 18 and the barrel 14, and to clean and inspect the heat transfer tubes described later. In the case where the water chamber trunk lid 34 is stored in the lid storage portion 48, the conventional method is shown in FIG.

  First, the guide pulley 60 is attached to the upper part of the opening 32 of the water chamber body 12. Then, an eyebolt 62 is screwed into an appropriate screw hole 56 provided in the water chamber trunk lid 34. Thereafter, the hook 66 of the hoist 64 is engaged with the eyebolt 62, and the water chamber trunk lid 34 is suspended by the hoist 64 as shown by a two-dot chain line in FIG. 3. Then, while adjusting the position of the suspended water chamber trunk lid 34 so that the axis of the water chamber trunk lid 34 coincides with the axis of the lid storage portion 48, the operator The water chamber trunk lid 34 is pushed into the lid storage 48. Thereafter, a fixing plate 50 is screwed onto the front surface of the water chamber trunk lid 34 with bolts 54 to fix the water chamber trunk lid 34.

  Moreover, the method described in patent document 1 is proposed as a method of storing a plate-shaped heavy structure. The storage method described in Patent Document 1 is performed as follows. First, the chain of the chain block is coupled to the upper part of the plate-like heavy structure, the plate-like heavy structure is inclined and suspended by the chain block, and the upper end of the plate-like heavy structure is inserted into the storage unit. In addition, a plurality of pulleys are attached to the lower part of the plate-like weight structure, a chain of a manual chain block whose tip is coupled to the lower part of the storage portion is passed over the plurality of pulleys, and the manual chain block is operated to operate the plate-like weight structure. Advance the lower part of the object toward the storage.

JP 2001-89080 A

  As described above, the operation of storing the conventional water chamber trunk lid 34 in the lid storage portion 48 of the water chamber trunk 12 is performed in a state where the water chamber trunk lid 34 is suspended by the hoist 64. However, as described above, the water chamber lid 34 has a large diameter of about 80 cm and a weight of about 2 tons. Moreover, since the water chamber trunk lid 34 is suspended by the hoist 64, it is easily shaken and unstable. For this reason, the storing operation for fitting the water chamber trunk lid 34 to the lid storage portion 48 is not easy to align the axis of the large and heavy water chamber trunk lid 34 with the axis center of the lid storage portion 48. Not only is it dangerous, but it takes a lot of time. As a result, the radiation exposure dose of workers increases.

In addition, the storage method described in Patent Document 1 is such that the plate-like heavy structure is suspended while being inclined by the chain block, and the upper end portion is inserted into the storage portion. As in the case of the case lid 34, it is not easy to position the plate-like heavy structure in the vertical direction. In addition, since the lower end portion is advanced toward the storage portion in a state where the plate-like weight structure is inclined, the lower end portion of the plate-like weight structure hits the edge of the storage portion and cannot be stored as it is. Therefore, in the method described in Patent Document 1, a construction for expanding the lower peripheral edge of the storage portion is performed, and cannot be applied to storage of the water chamber lid of the heat exchanger.
The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art, and an object of the present invention is to allow a disk-like structure to be easily stored in a storage unit.
Another object of the present invention is to reduce the work time.

  In order to achieve the above object, the plate-like weight structure storage method according to the present invention is configured such that a support is installed on the front side of a storage unit in which the plate-like weight structure is stored, and the plate-like weight structure is provided by the support. The plate-like weight structure is arranged substantially concentrically with the storage portion while supporting the lower side surface of the object, and the plate-like weight structure is pushed into the storage portion by a pushing mechanism provided on the support. . The plate-like weight structure may be formed in a disk shape or may be formed in a polygon such as an ellipse or a rectangle.

  In the present invention thus configured, a support is installed on the front side of the storage unit for storing the plate-like heavy structure, and the lower side surface of the plate-like heavy structure is supported by this support. Therefore, by adjusting the installation height of the support, it is possible to easily support the plate-like weight structure by substantially matching the axis of the plate-like weight structure with the axis of the storage portion. For this reason, the plate-like weight structure is formed by pushing the plate-like weight structure supported by the support by a pushing mechanism provided on the support, for example, a pushing bolt screwed to the support, and moving it forward toward the storage unit. Objects can be pushed into the storage part easily and quickly. Therefore, the working time can be greatly shortened, and the radiation exposure dose can be reduced.

  A preferred embodiment of a plate-like heavy structure storage method according to the present invention will be described in detail with reference to the accompanying drawings. In addition, about the part corresponding to the part demonstrated in the said prior art, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  FIG. 2 is a partial cross-sectional view of a heat exchanger of a reactor coolant purification system to which the plate-like heavy structure storage method according to the present invention is applied. In FIG. 2, the heat exchanger 10 has a water chamber body 12 and a body 14. The interior of the water chamber body 12 and the body 14 is partitioned by a tube plate 16. A water chamber 18 is provided inside the water chamber body 12. The water chamber 18 is provided with partition plates 20 and 22 inside, and by these partition plates 20 and 22, an inflow side chamber 26 into which low-temperature cooling water flows as shown by an arrow 24, and an arrow 28. It is partitioned into an outflow side chamber 30 through which cooling water flows out.

  On the other hand, a large number of heat transfer tubes 36 are accommodated in the body 14. These heat transfer tubes 36 are formed in a U shape, both ends are fixed to the tube plate 16, and cooling water flows through the inside. That is, the U-shaped heat transfer tube 36 has one end opened to the inflow side chamber 26 of the water chamber 18 and the other end opened to the outflow side chamber 30, and the cooling water flowing into the inflow side chamber 26 is inside the heat transfer tube 36. And flows into the outflow side chamber 30. Further, the body 14 is provided with a reactor water inlet 38 and a reactor water outlet 40. High-temperature reactor water taken out from a reactor pressure vessel (not shown) flows into the trunk 14 from the reactor water inlet 38 as indicated by an arrow 42, and is cooled by exchanging heat with cooling water flowing through the heat transfer tubes 36. It flows out from the reactor water outlet 40 as shown by an arrow 44 and is sent to a filter (purification device) (not shown) to remove the clad and radionuclide and return to the reactor pressure vessel.

  When the water chamber trunk lid 34 is removed from the lid storage portion 48 of the water chamber trunk 12 during maintenance or inspection of the heat exchanger 10, or when the water chamber trunk lid 34 is stored in the lid storage portion 48, the front side of the lid storage portion 48 A support 70 is attached to the opening 32 of the water chamber body 12. The support 70 is fixed to the lower portion of the water chamber body 12 by a plurality of bolts 72 so that the lower peripheral surface, which is the lower side surface of the water chamber body lid 34, can be supported. The support 70 is formed so that the support surface 74 that supports the water chamber trunk lid 34 has substantially the same curvature as the peripheral surface of the water chamber trunk lid 34, and the width of the support surface 74 (the left and right sides in FIG. 2). The length in the direction) is larger than the thickness of the water chamber trunk lid 34. When the support 70 is attached to the water chamber body 12, the axial center of the water chamber trunk lid 34 supported by the support surface 74 substantially coincides with the axis of the lid storage portion 48. Furthermore, the support 70 is provided with a reaction force receiving portion 76 at the tip. The reaction force receiving portion 76 is provided so as to be substantially orthogonal to the support surface 74 and has a plurality of screw holes (not shown). In addition, a push bolt 78 that forms a push mechanism together with the screw hole is screwed into these screw holes.

  Storage of the water chamber trunk lid 34 in the lid storage portion 48 using the support 70 thus configured is performed as follows. First, the support 70 is fixed to the lower part of the water chamber body 12 via the bolts 72. Further, as shown in FIG. 1, a guide pulley 60 is attached to the upper portion of the opening 32 of the water chamber body 12, and an eye bolt 62 is inserted into an appropriate screw hole 56 of the screw hole 56 provided on the front surface of the water chamber body lid 34. Screw on. A plurality of eyebolts 62 are desirably attached in consideration of stability when the water chamber trunk lid 34 is suspended by the hoist 64.

  Next, the hook 66 of the hoist 64 is engaged with the eyebolt 62, the water chamber trunk lid 34 is lifted by the hoist 64, and is carried on the support 70 and arranged as shown by the two-dot chain line in FIG. At this time, the water chamber trunk lid 34 is disposed on the support 70 in a state where the axis line is substantially horizontal, and the lower peripheral surface is supported by the support surface 74 of the support 70. Further, when the water chamber trunk lid 34 is arranged such that the lower peripheral surface thereof is supported by the support 70, the axis is substantially coincident with the axis of the lid storage portion 48 provided in the water chamber trunk 12.

  After that, as shown in FIG. 2, the push bolt 78 is screwed into the screw hole of the reaction force receiving portion 76 of the support 70, and the push bolt 78 is screwed to cover the water chamber lid 34 as indicated by the arrow 80. Push into storage 48. Further, a fixing plate 50 is screwed on the front surface of the water chamber trunk lid 34 to fix the water chamber trunk lid 34. The pushing of the water chamber lid 34 with the pushing bolt 78 is performed in a state where the hook 66 of the hoist 64 is engaged with the eyebolt 62 to prevent the water chamber lid 34 from falling over or falling. Further, when the water chamber lid 34 is moved forward toward the lid storage portion 48 and the end portion on the forward side is fitted into the opening portion 32 and there is no risk of the water chamber trunk lid 34 falling down, the hook 66 is moved. It is removed from the eyebolt 62 and a wire 82 is interposed between the eyebolt 62 and the hook 66. Then, by appropriately adjusting the tension of the wire 82, the water chamber trunk lid 34 can be smoothly pushed by the push bolt 78. That is, when the water chamber trunk lid 34 is caught in the pushing operation by the push bolt 78, the wire 82 is pulled or loosened to release the water chamber trunk lid 34 from being caught.

  As described above, in the embodiment, the support 70 is installed on the front side of the lid storage portion 48 to support the lower peripheral surface of the water chamber trunk lid 34, thereby allowing the water chamber trunk lid 34 and the lid storage portion 48 to The axial center can be easily aligned, and the water chamber trunk lid 34 can be easily and quickly stored in the lid storage portion 48. For this reason, it becomes possible to reduce the work man-hour to ¼ or less of the conventional one, the work time can be greatly shortened, and the radiation exposure dose can be reduced.

  In addition, when removing the water chamber trunk lid 34 from the water chamber trunk 12, the support 70 and the guide pulley 60 are attached to the water chamber trunk 12, as shown in FIG. Then, after removing the fixing plate 50 from the water chamber trunk lid 34, an eye bolt 62 is attached to the water chamber trunk lid 34 stored in the lid storage portion 48, as shown by the solid line in FIG. The hook 66 of the hoist 64 is connected through the wire 82. Further, an extraction bolt (not shown) is screwed into an appropriate screw hole 56 of the water chamber trunk lid 34, and the water chamber trunk lid 34 is moved to the opening 32 side by a pulling device such as a winch through the extraction bolt. Pull. When the water chamber trunk lid 34 is pulled out to an appropriate position, the hook 66 of the hoist 64 is engaged with the eyebolt 62, and the water chamber trunk lid 34 is further pulled, as shown by a two-dot chain line in FIG. The water chamber trunk lid 34 is placed on the support 70. Thereafter, the water chamber trunk lid 34 is lifted by the hoist 64 and conveyed to a predetermined position.

  In the above-described embodiment, the method for storing the heat exchanger provided in the reactor coolant purification system of the boiling water reactor into the lid storage portion 48 of the water chamber trunk lid 34 has been described. The present invention can also be applied to the water chamber trunk of the heat exchanger. Moreover, in the said embodiment, although the plate-shaped heavy structure demonstrated the case where it was the water chamber trunk lid 34 of the heat exchanger 10, it is not limited to this. That is, the present invention is not limited to a disk-shaped heavy structure, but a plate-shaped heavy structure formed in a polygonal shape such as an ellipse or a rectangle is moved in an upright state and stored in a storage unit. Can also be applied. Of course, the pushing mechanism may be a cylinder or the like. Furthermore, in the above-described embodiment, the case where the hook storage portion 48 is pushed and pulled out is explained by releasing the tension by adjusting the tension of the wire 82, but it may be performed by the hoist 64 chain.

It is a figure explaining the storing method to the lid storage part of the water chamber trunk lid which concerns on embodiment of this invention. It is a partial cross section figure of the heat exchanger installed in a nuclear reactor coolant purification system. It is a figure explaining the storing method to the lid storage part of the conventional water chamber trunk lid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ......... Heat exchanger, 12 ......... Water chamber trunk, 14 ......... Cylinder, 16 ......... Tube plate, 32 ...... Opening, 34 ......... Disk-like structure (water chamber trunk) 36 ......... Heat transfer tube, 48 ......... Storage section (lid storage section), 70 ......... Support, 74 ......... Support surface, 78 ......... Push-in bolt.

Claims (2)

  A support is installed on the front side of the storage unit in which the plate-like heavy structure is stored, and the lower side surface of the plate-like heavy structure is supported by the support, and the plate-like heavy structure is arranged substantially concentrically with the storage unit. A method for storing a plate-like heavy structure, wherein the plate-like heavy structure is pushed into the storage portion by a pushing mechanism provided on the support. In the storage method of the plate-shaped heavy structure of Claim 1,
The plate-like gravity structure is stored in a disk shape, and the plate-like weight structure is stored.

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