JPS6341514B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nuclear reactor fuel storage rack in a nuclear power generation facility, and particularly to an earthquake-resistant support structure thereof.

The fuel storage rack for a nuclear reactor must hold a fuel storage pit to prevent criticality or re-criticality, be strong against earthquakes, and have a structure that is light in weight and easy to install from an economic standpoint. is desired. By the way, this type of fuel storage rack is constructed by constructing a box-shaped beam 10 as shown in FIG. 1 and attaching the legs 12 to fixing fittings 16 buried in the floor 14 of the building to form a frame 17. , fuel 1 is placed on this frame 17.
A structure has been proposed in which 8 storage pipes 19 are left in place and the storage pipes 19 are held at the upper part 20 of the building, but this type has the following problems. That is, since the storage pipe 19 that accommodates the new fuel 18 needs to have a strong structure, the lower part of the storage pipe 18 is supported by a frame 17 having a steel frame structure. In addition, since the pedestal 17 has a large cross-sectional constant for each member in order to increase its rigidity, the structure inevitably becomes larger.
Weight also increases. Furthermore, since a horizontal load applied during an earthquake causes an overturning moment to be applied to the pedestal 17, the structure of the installation legs 12 and fixing fittings 16 becomes larger to prevent overturning. In addition, consideration must be given to thermal stress generated in the beams that make up the frame 17.
Installation work is also inconvenient.

Therefore, we have made repeated improvements with the aim of overcoming the above-mentioned difficulties and providing a nuclear reactor fuel storage rack that is lighter in weight, easier to install, and has an earthquake-resistant structure. It was discovered that by configuring the structure so that both of these effects are absorbed by a bracket installed on the wall of the building and a means of suspending it from the ceiling of the building, it is possible to obtain excellent earthquake resistance while also absorbing thermal displacement due to temperature changes. Ta.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fuel storage rack that is lightweight, easy to install, and has earthquake resistance and thermal displacement tolerance.

In order to achieve the above object, the seismic support structure for a fuel storage rack according to the present invention comprises fixing a plurality of brackets at a predetermined level on the inner wall of a building at predetermined intervals, and installing fuel storage pipes on these brackets. A perforated frame having a plurality of holes for insertion is hung thereon, and each perforated frame is suspended and supported from the ceiling of the building by a plurality of suspension means, and each fuel storage pipe is connected from the top of the building. and inserting the lower end into the hole of the perforated frame, and locking the upper end flange of each fuel storage pipe to the top of the building;
It is characterized by being constructed so that the horizontal load applied to the fuel storage pipe and the frame is transmitted to and absorbed by the bracket.

Next, a typical configuration example of the fuel storage rack according to the present invention will be described in detail with reference to the drawings.

In FIG. 2, brackets 24 are fixed to the side wall 22 of the building at predetermined intervals, a pedestal 26 is hung on the brackets, and the pedestal 26 is further suspended and fixed from the ceiling 28 of the building with a rope 30. do.

A hole 32 is opened at a predetermined pitch in the frame 26, the lower part of the fuel storage pipe 34 is inserted into the hole 32, and the upper part of the fuel storage pipe 34 is inserted into the top 36 of the building.
the upper end flange portion 38 of the fuel storage pipe 34.
Retained by

Fuel 40 is stored in the fuel storage pipe 34 and sealed with a plug 42.

In the seismic support structure for a fuel storage rack according to the present invention, since the fuel storage pipe 34 is supported at two points by the pedestal 26 and the top 36 of the building, horizontal loads are applied to the fuel storage pipe 34 and the pedestal 26 during an earthquake. is attached to the bracket 24 via the frame 26.
transmitted and absorbed. Therefore, the natural frequency increases to the extent that no bending deformation occurs in the vertical beam members of the box-shaped frame in the conventional fuel storage rack, which is advantageous in terms of earthquake-resistant structure. Further, the own weight under normal conditions and the vertical load during an earthquake are absorbed by the rope 30 suspending the bracket 24 and the pedestal 26. Furthermore, rope 3
By adjusting the number of zeros used, it is possible to prevent the center of the pedestal 26 from deforming downward due to its own weight, and even in the event of an earthquake, the pedestal 26 will not be lifted up because the gravitational acceleration is greater than the vertical seismic acceleration. do not have.

According to the seismic support structure for a fuel storage rack according to the present invention, as explained above, the legs of the pedestal are unnecessary, and the dead weight of the pedestal and the horizontal and vertical loads during an earthquake are carried by the brackets fixed to the side walls of the building. In addition, the following effects are expected: That is, since the lower part of the fuel storage pipe is directly supported by the side of the building, the natural frequency increases, which is advantageous in terms of earthquake-resistant structure. Furthermore, since there is no need for beam members to constitute the legs of the pedestal,
The overall weight is reduced, reducing material and manufacturing costs. Furthermore, in the event of a horizontal earthquake, there is no risk of an overturning moment being applied to the pedestal, so there is no need to take precautions to prevent overturning, and the design of the installation part is simplified.

The seismic support structure for a fuel storage rack according to the present invention described above is particularly advantageously used for a new fuel storage rack, but it can of course also be suitably applied to a spent fuel storage rack.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional earthquake-resistant support structure for a fuel storage rack, and FIG. 2 is a longitudinal sectional view of an earthquake-resistant support structure according to the present invention. 22...Side wall portion, 24...Bracket, 26...
... Frame, 28... Ceiling, 30... Rope, 32...
...hole, 34...fuel storage pipe, 36...top, 3
8... Upper end flange portion, 40... Fuel, 42...
plug.

Claims (1)

[Claims] 1. A plurality of brackets are fixed at a predetermined level on the inner wall of the building at predetermined intervals, and a perforated frame having a plurality of holes through which fuel storage pipes are inserted is hung on these brackets, and the perforated frame is Each frame is suspended and supported from the ceiling of the building by a plurality of suspension means, and each fuel storage pipe is inserted through the top of the building, and the lower end thereof is inserted into the hole of the perforated frame. An earthquake-resistant support structure for a fuel storage rack, characterized in that the upper end flange of the storage pipe is locked to the top of the building, and the horizontal load applied to the fuel storage pipe and the frame is transmitted to and absorbed by the bracket.