Dry storage structure for spent fuel of heavy water reactor

Abstract

The present disclosure belongs to the field of nuclear power technology, and particularly relates to a dry storage structure for spent fuel of a heavy water reactor. In the present disclosure, the storage module for storing spent fuel has a chamber inside, and a plurality of through holes are axially provided on the top plate of the chamber; each storage container is a cylindrical structure with an open top, each storage container is inserted into one of the through holes, and the bottom end of each storage container is fixedly connected to the bottom plate of the chamber; a plurality of fuel baskets are arranged in each storage container, and each fuel basket is used for placing spent fuel; each shielding plug is adapted to plug the opening at the top end of one storage container, thereby closing the storage container. By fixedly connecting the bottom end of each storage container to the bottom plate of the storage module, the supporting manner of the storage container is changed from being supported by the top plate of the storage module to being supported by the bottom plate of the storage module. It not only meets the requirement of dense storage of spent fuel but also meets the seismic requirement.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear power, and particularly relates to a dry storage structure for spent fuel of a heavy water reactor. Background Art

[0002] Qinshan Nuclear Power Plant Phase III is a CANDU-6 type heavy water reactor. The spent fuel is centrally stored in the dry storage modules within the plant area. Currently, 6 QM-400 type storage modules have been built and put into operation in three batches. In order to increase the storage capacity of the modules, the M1 type dense storage module has been developed. The storage containers of each M1 type storage module are increased from the 4×10 arrangement of the QM-400 type to a 5×28 arrangement, and the spacing of each storage container in the length and width directions of the module is reduced. However, the top plate of the storage module cannot support the weight of the storage containers and fuel baskets after densification. Therefore, how to adaptively store the storage containers and fuel baskets after densification has become an urgent problem to be solved. Summary of the Invention

[0003] To overcome the problems existing in the related art, a dry storage structure for spent fuel of a heavy water reactor is provided.

[0004] According to an aspect of the embodiments of the present disclosure, a dry storage structure for spent fuel of a heavy water reactor is provided. The dry storage structure for spent fuel of a heavy water reactor includes: a plurality of storage containers, a plurality of fuel baskets, and a plurality of shielding plugs. Each storage container and each shielding plug can shield radiation;

[0005] The interior of the storage module for storing spent fuel has a chamber, and a plurality of through holes are axially formed in the top plate of the chamber;

[0006] Each storage container is a cylindrical structure with an open top end. Each storage container is inserted into one of the through holes, and the bottom end of each storage container is fixedly connected to the bottom plate of the chamber;

[0007] A plurality of fuel baskets are arranged in each storage container, and each fuel basket is used for placing spent fuel;

[0008] Each shielding plug is adaptively plugged into the opening at the top end of one storage container to close the storage container.

[0009] In a possible implementation manner, a stepped portion extending radially inward is provided at a position on the inner wall of each storage container near the upper opening of the storage container, and the bottom end of the shielding plug inserted into the storage container presses against the stepped portion.

[0010] In a possible implementation manner, the edge of the top opening of each storage container has a first convex portion extending radially outward, and the edge of the top end of each shielding plug has a second convex portion extending radially outward;

[0011] The second protrusion of each shielding plug presses against the first protrusion of the inserted storage container.

[0012] In a possible implementation, the dry storage structure for spent fuel of the heavy water reactor further includes a plurality of anchor bolts;

[0013] Each storage container is fixedly connected to the bottom plate of the storage module through a plurality of anchor bolts.

[0014] In a possible implementation, there is a gap with a preset distance between the outer wall of the upper end of each storage container and the inner wall of the inserted through hole.

[0015] In a possible implementation, the plurality of fuel baskets in each storage container are arranged from bottom to top.

[0016] In a possible implementation, the plurality of storage containers are arranged in an array.

[0017] In a possible implementation, the number of the plurality of storage containers is between 40 and 140.

[0018] The beneficial effect of the present disclosure is that: in the present disclosure, by fixedly connecting the bottom end of each storage container to the bottom plate of the chamber, the support method of the storage container is changed from being supported by the top plate of the storage module to being supported by the bottom plate of the storage module. It not only meets the requirement of dense storage of spent fuel but also meets the seismic requirement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a dry storage structure for spent fuel of a heavy water reactor shown according to an exemplary embodiment.

[0020] In the figure:

[0021] 1, shielding plug; 2, gap; 3, top plate; 4, fuel basket; 5, storage container; 6, anchor bolt;

[0022] 7, bottom plate. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0024] Figure 1 is a schematic diagram of a dry storage structure for spent fuel of a heavy water reactor shown according to an exemplary embodiment. As Figure 1 shown, the dry storage structure for spent fuel of the heavy water reactor may include: a plurality of storage containers 5, a plurality of fuel baskets 4, and a plurality of shielding plugs 1. The materials of each storage container 5 and each shielding plug 1 can shield radiation. For example, the materials of each storage container 5 and each shielding plug 1 are carbon steel. The present disclosure does not limit the materials of each storage container 5 and each shielding plug 1.

[0025] In the present disclosure, the storage module can be formed by pouring concrete, for example. The storage module has a chamber inside, and the chamber has a top plate 3 and a bottom plate 7. A plurality of through holes are axially formed in the top plate 3 of the chamber.

[0026] Each storage container 5 is a cylindrical structure with an open top. Each storage container 5 can be axially inserted into a through hole, and the bottom end of each storage container 5 is fixedly connected to the bottom plate 7 of the chamber.

[0027] A plurality of fuel baskets 4 are arranged in each storage container 5, and each fuel basket 4 is used for placing spent fuel. For example, the plurality of fuel baskets 4 in each storage container 5 are arranged from bottom to top.

[0028] Each shielding plug 1 is adapted to plug the opening at the top of a storage container 5, thereby closing the storage container 5.

[0029] In the present disclosure, by fixedly connecting the bottom end of each storage container to the bottom plate of the chamber, the supporting manner of the storage container is changed from being supported by the top plate of the storage module to being supported by the bottom plate of the storage module, so that the top plate does not have to bear the weight brought by the storage container. This not only meets the requirement of dense storage of spent fuel but also meets the seismic requirement.

[0030] In a possible implementation, as Figure 1 shown, a stepped portion extending radially inward is provided at a position on the inner wall of each storage container 5 near the upper opening of the storage container 5, and the bottom end of the shielding plug 1 inserted into the storage container 5 presses against the stepped portion. A first convex portion extending radially outward is provided at the edge of the top opening of each storage container 5, and a second convex portion extending radially outward is provided at the edge of the top end of each shielding plug 1. The second convex portion of each shielding plug 1 presses against the first convex portion of the inserted storage container 5. In this way, through the cooperation of the shielding plug 1 and the stepped portion, and the cooperation of the first convex portion and the second convex portion, the storage container 5 can be better sealed.

[0031] In a possible implementation, the dry storage structure for spent fuel of the heavy water reactor further includes a plurality of anchor bolts 6; each storage container 5 is fixedly connected to the bottom plate 7 of the storage module through a plurality of anchor bolts 6. For example, a plurality of anchor bolt holes can be axially formed at the bottom end of each storage container 5, and each anchor bolt 6 can be threadedly connected to an anchor bolt hole and the bottom plate 7, thereby fixedly connecting the bottom end of the storage container 5 to the bottom plate 7.

[0032] In a possible implementation, a gap 2 with a preset distance is provided between the outer wall of the upper end of each storage container 5 and the inner wall of the inserted through hole. This can effectively prevent damage to the storage container 5 and the top plate 3 caused by the thermal expansion of the storage container 5.

[0033] In a possible implementation, the multiple storage containers are arranged in an array. The number of the multiple storage containers is between 40 and 140.

[0034] In an application example, the following operations can be performed to install the dry storage structure for spent fuel of the heavy water reactor of the present disclosure.

[0035] Divide the multiple anchor bolts 6 into multiple groups with the same number of anchor bolts 6 in each group, and the anchor bolts 6 can be pre-embedded on the bottom plate 7 of the storage module. When installing the storage container 5, insert each storage container 5 facing a group of anchor bolts 6 into the anchor bolt holes at the bottom of the storage container 5 and fix them. After the storage container 5 is installed, construct the side wall of the storage module and the top plate 3 of the storage module. After the storage container 5 and the storage module are completed, the fuel basket 4 can be loaded. When loading, first open the shielding plug 1 from the outer surface of the module top plate 3, and sequentially place the multiple fuel baskets 4 into the storage container 5. After the storage container 5 is filled with the fuel baskets 4, put in the shielding plug 1 and seal the storage container 5 by welding. The storage container 5 enters the operating state, that is, the long-term storage state.

[0036] The embodiments of the present disclosure have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application or the technical improvement of the technology in the market, or to enable other ordinary technical personnel in the technical field to understand the embodiments disclosed herein.

Claims

1. A dry storage structure for spent fuel of a heavy water reactor, characterized in that, The dry storage structure for spent fuel of the heavy water reactor comprises: a plurality of storage containers, a plurality of fuel baskets, and a plurality of shielding plugs, and each storage container and each shielding plug can shield radiation; The storage module for storing spent fuel has a chamber inside, and a plurality of through holes are axially formed in the top plate of the chamber; Each storage container is a cylindrical structure with an open top, each storage container is inserted into a through hole, and the bottom end of each storage container is fixedly connected to the bottom plate of the chamber; by fixedly connecting the bottom end of each storage container to the bottom plate of the chamber, the supporting mode of the storage container is changed from being supported by the top plate of the storage module to being supported by the bottom plate of the storage module, so that the top plate does not have to bear the weight brought by the storage container; A plurality of fuel baskets are arranged in each storage container, and each fuel basket is used for placing spent fuel; Each shielding plug is fitted and plugged at the opening at the top end of a storage container, so as to seal the storage container.

2. The dry storage structure for spent fuel of a heavy water reactor according to claim 1, characterized in that A step portion extending radially inward is provided at a position on the inner wall of each storage container near the upper opening of the storage container, and the bottom end of the shielding plug inserted into the storage container presses against the step portion.

3. The dry storage structure for spent fuel of a heavy water reactor according to claim 1, characterized in that A first convex portion extending radially outward is provided at the edge of the top opening of each storage container, and a second convex portion extending radially outward is provided at the edge of the top end of each shielding plug; The second convex portion of each shielding plug presses against the first convex portion of the inserted storage container.

4. The dry storage structure for spent fuel of a heavy water reactor according to claim 1, characterized in that, The dry storage structure for spent fuel of the heavy water reactor further comprises a plurality of anchor bolts; Each storage container is fixedly connected to the bottom plate of the storage module through a plurality of anchor bolts.

5. The dry storage structure for spent fuel of a heavy water reactor according to claim 1, characterized in that, A gap with a preset distance is provided between the outer wall of the upper end of each storage container and the inner wall of the inserted through hole.

6. The dry storage structure for spent fuel of a heavy water reactor according to claim 1, characterized in that, The plurality of fuel baskets in each storage container are arranged from bottom to top.

7. The dry storage structure for spent fuel of a heavy water reactor according to claim 1, characterized in that, The plurality of storage containers are arranged in an array.

8. The dry storage structure for spent fuel of a heavy water reactor according to claim 1, characterized in that, The number of the plurality of storage containers is between 40 and 140.

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