JPS58189589A - Spent fuel storage rack - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a storage rack installed in a nuclear power generation facility, and more particularly to a storage rank structure that is safe from an earthquake resistance perspective and suitable for design.

As shown in the plan view of the spent fuel pool in FIG. 1, the conventional storage racks 2, which divide and store spent fuel into a certain number of units from a functional standpoint, are each installed independently in the fuel pool 1. As shown in Figure 2, the storage rack 2 is fixed only to the foundation bolts 5 that connect the fuel pool foundation 3 and the fixed base 4 in Figure 3, and the hook mounting bolts 6 that connect the fixed base 4 and the storage rack 2. It is a self-supporting structure. Additionally, because the spent fuel pool is installed at a high level in the reactor building, the design of the foundation bolts and rack mounting bolts for the seismic structure is critical.

The purpose of the present invention is to provide a TiT seismic structure tube on the outer wall of the storage hook, which reduces the response acceleration of the upper part of the storage rack at the time of subsidence, and limits the relative displacement of the upper part of the storage rack, without causing thermal deformation of the storage rank or hindering loading/unloading of the storage rack. This provides a storage rack structure that is safe and easy to design by reducing earthquake loads generated on the foundation bolts and rack mounting bolts.

Originally, with regard to foundation bolts and hook attachment bolts, it is effective for seismic design to mount the storage hook rigidly to the pool wall, but it is impossible to escape thermal deformation of the storage rack due to pool water temperature. , loading and unloading storage racks requires work in highly radioactive areas.

Therefore, as in the present invention, it is effective to provide in advance an earthquake-resistant structure based on the principle described below on the outer wall of the storage rank. The seismic structure provided on the outer wall of the storage rack according to the present invention confines the water in the pool in the narrow space of this structure, thereby providing a damper function in the event of an earthquake, thereby reducing the amount of water in the ground. lol
By providing a small gap in this structure to allow the thermal deformation of the racks to escape, the relative displacement of the storage racks during an earthquake can be limited.

The earthquake-resistant structure of the present invention will be explained below with reference to FIG. It is installed in a relatively rigid structure, and its structure consists of storage racks facing each other and an earthquake-resistant structure installed on the structure with storage racks facing each other to create a space that confines a pool or a small gap. It is something that forms.

Therefore, the function of the seismic structure is to reduce the response during an earthquake by acting as a damper for the trapped pool water, and also to reduce the displacement of the storage rank by a small gap? By limiting 1lIIJ.

The purpose is to avoid excessive seismic loads on the fixing bolts and rank attachment bolts at the base of the storage hook.

The above will be explained with reference to FIG. 4 and FIG. 5, which shows an enlarged portion of the earthquake-resistant structure.
A concave structure 8 is provided in the storage rank 2' on the other side of the warehouse, and the concave structure 8 has a structure that restricts mutual movement in the horizontal direction so as not to obstruct loading and unloading of the storage rack 2' while hanging from above. In addition, the upper part 1119 is an opening, and the uneven structure is slid during loading and unloading.Also, the lower part 10 of the concave structure may be an opening, but from the point of view of confining the pool water in the earthquake-resistant structure, the method shown in Fig. 4 is used. As shown on the right side, the concave structure 8 and the convex structure 11 that form a one-piece structure that is better closed can be combined as shown in FIG. 5 to create a space 11 that confines a pool party. The pool water trapped in the space becomes fluid resistance when the storage rack 2 vibrates during an earthquake, and that resistance is equal to the resistance that the storage rack 2 receives when it is simply installed underwater (and the resistance that water receives due to this structure). This is due to the added resistance due to the fact that it is difficult to flow because it is confined, and it can be expected to have an effect as a damper, so the response reduction in earthquake 1#fK is remarkable. The gap should be set to a width that can sufficiently escape the deformation of the storage rack 2 due to the temperature, but in order to expect the above-mentioned damper effect, the gap should be 1 to 2 inches wider than the gap that takes into account the thermal deformation of the storage R2 rack 2.

Furthermore, because the gap 12 is narrow, in the event of an earthquake, this seismic structure will not allow the storage rack 2 to move in any horizontal direction.
Even if they vibrate, they collide with each other, and the relative displacement between the base of the two storage racks and the top of the storage rack is limited. For this reason, is it possible that earthquake loads such as excessive moment are applied to the bolts that fix the storage rank? It is possible to prevent it.

Other embodiments of the invention are shown below.

FIG. 6 shows a w-proof structure simply combining a concave structure 8 and a convex structure 7, which does not form a gap 9 for trapping pool water, but limits displacement in the horizontal direction.

It is an earthquake-resistant structure that combines the seventh factor ViL type 13, and is designed to increase fluid resistance underwater.

According to the present invention, even though the spent fuel pool is installed at a high level of the building where the building floor/Jl velocity is high during an earthquake, the response of the storage rack can be reduced and the relative velocity of the storage rack can be reduced. By limiting displacement, excessive seismic force is prevented from being generated on the fixing bolts and rank fastening bolts that fix the storage racks.

Since a highly safe spent fuel pool can be provided, it is effective in improving safety and simplifying design.

[Brief explanation of the drawings] Figure 1 is a plan view of the spent fuel pool, Figure 2 is an explanatory diagram of a conventional fuel storage rack, Figure 3 is a detailed diagram of parts A and B of Figure 2, and Mud 4. Figures (a) and (b) show one embodiment of the present invention; the top view and normal (3) view of the storage rank, Figure #g5 is an enlarged view of the earthquake-resistant structure, and Figures 6 and 7 are the embodiments of the present invention. It is another Example explanatory diagram. l... Spent fuel pool, 2... Storage R? 3.
... Fuel pool foundation, 4... Fixed base, 5... Foundation bolt, 6... Rack mounting bolt, 7... Convex structure, 8... Concave structure. 9... Upper side of concave structure, 10... Lower lit of concave structure,
11...9 space, 12...gear lug, 13...L type. Broom Z Exit' Dormitory 51E1 Chia 6's ¥q Exit

Claims (1)

[Claims] 1. In nuclear power generation facilities, in order to store spent fuel, a spent fuel storage rank (hereinafter referred to as storage rack) is installed in a spent fuel pool filled with cooling water. A spent fuel storage rack characterized by having a structure that provides earthquake resistance.