JPS6345556B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an underwater storage means for spent fuel of a nuclear reactor.

Underwater storage means for the spent fuel of this type of reactor generally maintains the fuel storage pit to prevent recriticality, is rigid against earthquakes, is light in weight from an economical point of view, and is easy to install. A good structure is desired.

By the way, spent fuel storage racks for light water reactors are known as this type of nuclear reactor spent fuel storage means, but since this is a cartridge type rack, the length of the fuel storage tube is the same as the length of the fuel. Because the required weight is heavy, and the spacing between the cartridges is set narrow to increase the efficiency of the spent fuel storage area, the bolts that are fastened to the bottom of the spent fuel storage pool are tightened using long tongs from above. It needs to be tightened, and the workability is poor. If the fixing bolts were to be tightened without using tongs, it would be necessary to increase the distance between the cartridges or to provide a stand between the bottom of the rack and the bottom of the storage pool for workers to access. Furthermore, in order to improve the earthquake resistance of the rack, the cartridge is fixed to the bottom of the pool with bolts, and a long beam is bridged between the pool walls in the middle of the rack. Consideration must be given to thermal stress.

Therefore, as a result of repeated research aimed at eliminating many of the above-mentioned difficulties and providing a nuclear reactor spent fuel storage rack that is lighter in weight, easier to install, and has an earthquake-resistant structure, we have developed a spent fuel storage rack. A frame structure is created by connecting steel materials, and the guide tube unit is installed separately on this frame to reduce the amount of guide tubes used. It was discovered that by fixing the fuel to the pool, excellent earthquake resistance can be obtained and thermal displacement caused by changes in water temperature in the spent fuel storage pool can be absorbed.

SUMMARY OF THE INVENTION It is, therefore, a general object of the present invention to provide a spent fuel storage rack that is lightweight, easy to install, earthquake resistant, and tolerant of thermal displacement.

In order to achieve the above object, the spent fuel storage rack of the present invention has steel members connected by connecting plates to form a rack frame, and three stages of guide plates consisting of an upper stage, an interrupted stage, and a lower stage are installed horizontally on this rack frame. A storage rack unit is constructed by attaching to these guide plates divided guide tubes consisting of an upper tier, an interrupted tier, and a lower tier, which correspond to each other vertically at a predetermined pitch. The installation liner plates are arranged and placed on the rack installation plates fixed to the bottom of the spent fuel storage pool, and the installation liner plates located in some of the columns and rows of the installation liner plates are described above. It is characterized by being fixedly arranged in a fixed direction on a rack installation plate via a guide key.

Next, embodiments of the spent fuel storage rack according to the present invention will be described in detail below with reference to the accompanying drawings.

The attached FIG. 1 is a plan view of the spent fuel storage pool building, FIG. 2 is a vertical sectional view of the spent fuel storage pool building shown in FIG. 1, and FIG. 3 is a spent fuel storage according to the present invention. Fig. 4 is a plan view of the storage rack shown in Fig. 3, Fig. 5 is a cross-sectional view of the main part of the storage rack showing the state in which one spent fuel is stored, Fig. 6 is a side view of the rack, and Fig. 6 is a plan view of the storage rack shown in Fig. 3. FIG. 7 is an enlarged sectional view of the installed portion of the spent fuel storage rack, and FIG. 7 is a plan view showing the position of the installed portion of the storage rack shown in FIG. 4.

1 and 2, the spent fuel storage pool building in which the spent fuel storage rack according to the present invention is installed includes a spent fuel storage pool 10 and a delivery pool 12 for delivering reactor fuel from the reactor building. , a spent fuel discharge pool 14 for storing spent fuel in a spent fuel transfer cask, and a cask cleaning chamber 16 for cleaning the spent fuel transfer cask.
and water gates 18, 18 for partitioning and communicating between the respective pools, and a rail 20 is laid on top of the water gates to move a fuel transfer machine 22 for transferring spent fuel in the pool water. Installed within the spent fuel storage pool 10 is a spent fuel storage rack 24 according to the present invention and described in detail below.

3 and 4, a nuclear reactor spent fuel storage rack (hereinafter simply referred to as rack) 24 according to the present invention is constructed as follows. That is, the structural steel 26 (including column members, upper, middle, and lower beam members, and bracing members) that is a component of the rack 24;
Each stage guide plate 32, 34, 36, guide tube 40, rack installation plate 56 and guide key 5
For the 8th grade, at the factory according to the prescribed plan,
Manufactured to the required dimensions and shape in advance,
It will be delivered to the spent fuel storage pool construction site. Then, at the site, the rack 24 is assembled and joined in the spent fuel pool (hereinafter simply referred to as the pool) 10 in the following order.

First, based on a predetermined plan, bolts are placed on a fixed frame 60 that is firmly fixed to the foundation 61 of the pool 10 by anchor bolts 62 that have been previously installed at the bottom of the pool 10. An easy installation plate 56 is welded to the pool lining and fixed in a watertight manner to form an installation seat. Next, the installation seat plate 44 located at the leg of the column member of the shaped steel 26 is placed on the rack installation plate 56, which is the installation seat, via the installation liner plate 63, and then the upper, middle, and lower parts of the shaped steel 26 are A rack frame 30 is formed by welding together each beam member and brace member using the connecting plate 28. Guide plates 32, 34, and 36 are horizontally suspended and joined to each of the formed upper, middle, and lower frames. Each of the guide plates 32, 34, and 36 has holes 38 for attaching guide tubes formed at a predetermined pitch.
The storage rack unit 42 is constructed by attaching the 0 by welding. Note that the installation seat plate 44
and the installation liner plate 63 are fixed by bolts (not shown), and in particular when the rack units 42 are adjacent to each other, as shown in FIG.
An installation seat plate 44 adjacent to the two installation liner plates is fixed. Therefore, the rack 24 is installed in the pool 10 with the rack 24 resting on the rack installation plate 56 with the installation liner plate 63 interposed therebetween.

The attached Figure 7 shows the storage rack 2 shown in Figure 4.
4 is a plan layout view of the rack installation plate 56 on which the No. 4 installation seat plate 44 is placed, and clearly shows the position and direction in which the slide key 58 is attached. In FIG. 7, the slide key 58 is welded and fixed on the rack installation plate at part A so as to sandwich the installation liner plate 63 from the front, back, left and right sides (see FIG. 6).
Guide keys 58 are arranged so that the legs of the rack 24 in the column A are held only from the left and right, and the legs in the row A are only held from the front and back. It is shown that the guide key 58 is not arranged in the section.

This means that the rack 24 is installed in the pool 10 with a load placed on the rack installation plate 56 provided at the bottom of the pool 10 via the installation liner plate 63, and many of its legs are Among them, A
Only the legs in the vertical and horizontal rows of the A section and the A section are clamped and fixed by guide keys 58, and the legs other than the A section are installed so as to be able to slide slightly left and right or front and back. By configuring the installation portion in this manner, thermal displacement of the rack 24 due to changes in the water temperature of the pool 10 can be absorbed.

As explained above, in the spent fuel storage rack according to the present invention, the storage rack unit is manufactured in advance on the spot, and it is possible to assemble this in the spent fuel storage pool building, thereby improving the area usage efficiency of the storage pool. This makes it possible to improve the quality and downsize, and to easily control the quality of each component. Furthermore, by arranging the guide tubes in three stages, the weight is significantly reduced, and by providing a guide key in the installation part of the storage rack, earthquake resistance and thermal expansion tolerance can be measured, and it is also economical. Enables spent fuel storage.

[Brief explanation of drawings]

Figure 1 is a plan view of the spent fuel storage pool building.
2 is a longitudinal sectional view of the storage pool building shown in FIG. 1, FIG. 3 is a side view of the spent fuel storage rack according to the present invention, and FIG. 4 is a plan view of the storage rack shown in FIG. 3. Figure 5 is a cross-sectional view of a single storage rack showing the state in which spent fuel is stored, Figure 6 is an enlarged cross-sectional view of the installation part of the spent fuel storage rack, and Figure 7 is a storage rack shown in Figure 4. FIG. 3 is a layout diagram of the installation parts of the rack. 10...Storage pool, 12...Delivery pool,
14...Discharge pool, 16...Cask cleaning room,
18...Sluice gate, 20...Rail, 22...Transfer machine, 24...Storage rack, 26...Shaped steel, 28...
... Connecting plate, 30 ... Rack frame, 32 ... Upper guide plate, 34 ... Middle guide plate, 36 ... Lower guide plate, 38 ... Hole, 40 ... Guide tube, 42 ... Storage rack unit, 44 ... Installation seat plate, 46 ... Spent fuel, 48 ... Upper guide tube, 50 ... Middle guide tube, 52 ... Lower guide tube, 54 ... Bottom, 56 ... Rack installation plate, 58
...Guide key, 60...Fixed frame, 62...
...Anchor bolt, 63...Installation liner plate.

Claims (1)

[Claims] 1. A rack frame is formed by connecting steel materials by connecting plates, and three stages of guide plates consisting of an upper stage, an interrupted stage, and a lower stage are horizontally suspended on this rack frame,
A storage rack unit is constructed by attaching divided guide tubes consisting of an upper stage, an interrupted stage, and a lower stage, which correspond to each other vertically at a predetermined pitch, to these guide plates, and a liner plate is installed opposite the lower end of each of the lower guide tubes. The installation liner plates are placed on the rack installation plates fixed to the bottom of the spent fuel storage pool, and the rack installation plates for the liner plates located in some of the columns and rows of these installation liner plates are placed on the rack installation plates fixed to the bottom of the spent fuel storage pool. A nuclear reactor spent fuel storage rack characterized by being fixedly arranged in a fixed direction via a guide key.