CN112951459A

CN112951459A - Spent fuel storage grillwork for nuclear power plant

Info

Publication number: CN112951459A
Application number: CN201911268722.4A
Authority: CN
Inventors: 陈胜利
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-12-11
Filing date: 2019-12-11
Publication date: 2021-06-11

Abstract

The invention discloses a spent fuel storage grillwork for a nuclear power plant, which comprises a peripheral plate, a wide plate, a narrow plate, a bottom plate and a support leg assembly. The periphery plate, the wide plate and the narrow plate are spliced into a grid structure in an embedding mode, the bottoms of the three plates are fixed on the base plate, the leg assembly is fixed on the base plate and supports the base plate, and neutron absorbers are fixed on the wide plate and the narrow plate respectively. Compared with the prior art, the main body of the nuclear power plant spent fuel storage grillwork is of an embedded splicing structure, so that the size of the grillwork can be relatively dense and stable, the storage density and the safety of fuel assemblies are improved, and the processing difficulty can be greatly reduced and the quality of the nuclear power plant spent fuel storage grillwork is improved due to the adoption of modular assembly.

Description

Spent fuel storage grillwork for nuclear power plant

Technical Field

The invention relates to a spent fuel storage technology in a nuclear power plant, in particular to a high-density spent fuel storage framework for the nuclear power plant.

Background

The nuclear power plant spent fuel storage grillwork is arranged in a spent fuel pool of a fuel factory building, is important equipment of a fuel operation and storage system in the nuclear power plant, has the main function of safely storing fuel assemblies, and particularly comprises irradiated temporary storage material pouring assemblies discharged from a reactor, spent fuel assemblies which are not piled, damaged fuel assemblies and new fuel assemblies (non-irradiated), wherein the enrichment degree of the stored fuel assemblies is different from the operating condition in the reactor, and different requirements are provided for the structural form, the grid distance and the content of neutron absorber materials of the storage grillwork.

The existing spent fuel storage grillwork of the nuclear power plant has various structural forms, and the widely applied spent fuel storage grillwork of the nuclear power plant comprises a bottom plate, an upper supporting plate, a coaming, a storage sleeve and other parts. However, the bottom plate and the upper support plate of the grid are difficult to process, and the grid pitch of the grid cannot be too small due to the structural form of the grid, so that the storage capacity of the spent fuel pool is affected if the structure is applied to a two-zone grid.

The grid designed by the company HOLTEC in America has a simpler structural form and processing, the neutron absorber material adopted by the grid is Al-based B4C, but the structural strength of the grid is not easy to guarantee. In addition, because the top of the grillwork is not provided with the guide section and the wall of the storage small chamber is provided with the boss, the drawing and inserting operation of the fuel assembly by operators is very unfavorable, and the risk of blocking the operation of the fuel assembly exists.

The storage grillwork of the first-stage nuclear power plant in Qinshan is in a splicing form, and the neutron absorber material is suspended, but the processing of the type of grillwork is more complicated, and the fuel consumption credit value of the components is not considered, so that the storage capacity is lower. The grids in the second region of the nuclear power plant of Australia Ling are also in a splicing form, boron stainless steel is adopted as a structural material, and the grids are formed by splicing boron stainless steel plates, but the grid structure is not beneficial to loading and unloading of fuel assemblies because no top guide section exists.

Along with large-scale construction and investment and operation of domestic nuclear power units, the problem that the spent fuel storage grillwork of the nuclear power plant, which is high in density and convenient for loading and unloading fuel assemblies, is needed to be solved urgently in fuel assembly storage is solved.

Disclosure of Invention

The invention aims to: the spent fuel storage grillwork of the high-density nuclear power plant is convenient for loading and unloading the fuel assemblies.

In order to achieve the purpose, the invention provides a spent fuel storage grillwork for a nuclear power plant, which comprises a peripheral plate, a wide plate, a narrow plate, a bottom plate and a leg assembly, wherein the peripheral plate, the wide plate and the narrow plate are spliced into a grid structure in an embedding mode, the bottoms of the three plates are fixed on the bottom plate, the leg assembly is fixed on the bottom plate and provides support for the bottom plate, and neutron absorbers are respectively fixed on the wide plate and the narrow plate.

As an improvement of the nuclear power plant spent fuel storage grillwork, the tops of the peripheral plate, the wide plate and the narrow plate are provided with inclined guide surfaces, so that the top of the four sides of each grid can guide the drawing and inserting of fuel assemblies in the grids.

As an improvement of the spent fuel storage grillwork of the nuclear power plant, the wall of the wide plate is provided with a plurality of rows of vertical racks

The long edge of the narrow plate is provided with a convex edge matched with the through groove of the wide plate, the convex edge of the narrow plate is inserted into the through groove of the wide plate, and the two form a grid structure for storing the fuel assembly.

As an improvement of the spent fuel storage framework in the nuclear power plant, the wall of the peripheral plate is provided with a plurality of rows of vertical through grooves, the edge of the long side of the wide plate is provided with a convex edge matched with the through grooves of the peripheral plate, the convex edge of the wide plate is inserted into the through grooves of the peripheral plate, and the peripheral plate firmly fixes the wide plate and the narrow plate.

As an improvement of the spent fuel storage framework of the nuclear power plant, the bottom plate is provided with a 'well' -shaped positioning groove, and the peripheral plate, the wide plate and the narrow plate are fixed in the 'well' -shaped positioning groove of the bottom plate in a welding mode.

As an improvement of the spent fuel storage framework of the nuclear power plant, the peripheral plate, the wide plate, the narrow plate and the bottom plate are respectively provided with a plurality of water flowing holes.

As an improvement of the spent fuel storage framework in the nuclear power plant, the neutron absorber is fixed on the corresponding plate body through L-shaped positioning blocks welded on the wide plate and the narrow plate.

As an improvement of the spent fuel storage framework of the nuclear power plant, the neutron absorber adopts Al-based B4C.

As an improvement of the spent fuel storage grillwork of the nuclear power plant, the support leg assembly is of an adjustable structure and comprises a base plate, a screw rod, a threaded sleeve and a gasket, the adjustable screw rod is supported on the base plate, the threaded sleeve is sleeved on the screw rod, the gasket is arranged between the base plate and the threaded sleeve, the outer surface of the threaded sleeve is of a stepped structure, and a positioning hole matched with the diameter of the top of the threaded sleeve is formed in a bottom plate.

Compared with the prior art, the main body of the nuclear power plant spent fuel storage grillwork is of an embedded splicing structure, so that the size of the grillwork can be relatively dense and stable, the storage density and the safety of fuel assemblies are improved, and the processing difficulty can be greatly reduced and the quality of the nuclear power plant spent fuel storage grillwork is improved due to the adoption of modular assembly.

Drawings

The spent fuel storage framework and the beneficial technical effects thereof in the nuclear power plant are described in detail below with reference to the accompanying drawings and the specific embodiments.

Fig. 1 is a schematic structural diagram of a spent fuel storage framework of a nuclear power plant.

Fig. 2 is a schematic structural diagram of a nuclear power plant spent fuel storage grid according to the invention, when a neutron absorber is not welded on a wide plate.

Fig. 3 is a schematic structural diagram of a nuclear power plant spent fuel storage grid after a neutron absorber is welded on a wide plate.

Fig. 4 is a schematic structural diagram of the nuclear power plant spent fuel storage grid without welding neutron absorbers on narrow plates.

Fig. 5 is a schematic structural diagram of a nuclear power plant spent fuel storage grid after neutron absorbers are welded to narrow plates.

Fig. 6 is a partial cross-sectional view of the spent fuel storage grid of the nuclear power plant of the present invention.

Fig. 7 is a schematic structural diagram of a leg assembly of the spent fuel storage grid of the nuclear power plant.

Fig. 8 is a schematic top structure view of the spent fuel storage grid of the nuclear power plant after combination of wide plates and narrow plates.

Fig. 9 is a schematic top view of the spent fuel storage grid of the nuclear power plant of the present invention.

Detailed Description

Referring to fig. 1, the spent fuel storage grid for a nuclear power plant of the present invention includes a peripheral plate 10, a wide plate 12, a narrow plate 14, a bottom plate 16 and a leg assembly 18. Wherein the peripheral panels 10, wide panels 12 and narrow panels 14 are connected in a grid-like fashion, the bottom of each panel being secured to a bottom panel 16, and leg assemblies 18 supported beneath the bottom panel 16 to support the entire grid in a sink.

The width of the peripheral plate 10 is slightly smaller than the corresponding side length of the bottom plate 12, and the top of each peripheral plate 10 is provided with an inclined guide surface 100, and the bottom is provided with a water flowing hole 102. The wall of the peripheral plate 10 is provided with a plurality of rows of vertical through grooves 104, and the distance between every two rows of through grooves 104 is the same as the designed side length of the grid.

Referring to fig. 2 and 3, the width of the wide plate 12 is approximately the same as that of the peripheral plate 10, and the top of each wide plate 12 is wedge-shaped, i.e., both sides have inclined guide surfaces 120, and the bottom is provided with water flow holes 122. The wall of the wide plate 12 is provided with a plurality of rows of vertical through grooves 124, and the distance between every two rows of through grooves 124 is the same as the designed side length of the grid. The long edges of the wide plate 12 are provided with rims 126 that fit into the through-slots 104 of the peripheral plate 10. A plurality of L-shaped positioning blocks 128 are welded to one surface of the wide plate 12, and the elongated neutron absorber 20 having a width substantially equal to the grid side length is fixed to the wide plate 12 by the positioning blocks 128.

Referring to fig. 4 and 5, the width of the narrow plates 14 is approximately the same as the designed side length of the grid, and the top of each narrow plate 14 is wedge-shaped, that is, both sides have inclined guide surfaces 140, and the bottom is provided with water flowing holes 142. The long edge of the narrow plate 14 is provided with a convex edge 146 matched with the through groove 124 of the wide plate 12. A plurality of L-shaped positioning blocks 148 are welded to one surface of the narrow plate 14, and the elongated neutron absorber 20 having a width substantially equal to the length of the grid side is fixed to the narrow plate 14 by the positioning blocks 148.

Referring to fig. 6 and 7, the bottom plate 16 is provided with a positioning slot 160 shaped like a Chinese character 'jing', a positioning hole and a water flowing hole 162.

Leg assembly 18 is an adjustable structure that includes a backing plate 180, a threaded rod 182, a threaded sleeve 184, and a spacer 186. The adjustable screw 182 is supported on the backing plate 180, the threaded sleeve 184 is sleeved on the screw 182, and the gasket 186 is arranged between the backing plate 180 and the threaded sleeve 184. Wherein, the outer surface of the screw sleeve 184 is a step-shaped structure, and the diameter of the top of the screw sleeve is matched with the positioning hole of the bottom plate 16. When assembling, the convex edge 146 of the narrow plate 14 is inserted into the through groove 124 of the wide plate 12, and the two together form a grid structure for storing fuel assemblies; the flange 126 of the wide plate 12 is inserted into the through-groove 104 of the peripheral plate 10, and the peripheral plate 10 firmly fixes the wide plate 12 and the narrow plate 14. The peripheral plate 10, the wide plate 12 and the narrow plate 14 are all fixed in the positioning groove 160 of the bottom plate 16 in a welding manner. The base plate of the leg assembly 18 is supported on the ground, and the top end of the threaded sleeve 184 is inserted into the positioning hole of the bottom plate 16 and threaded

The step of the sleeve 184 forms an effective support against the bottom plate 16. The 12 leg assemblies are uniformly supported on the floor 16 at various locations to support the entire grid on the pool.

The neutron absorber 20 used in the present invention is Al-based B4C, but neutron absorbers of other materials are also applicable.

In conclusion, the main body of the spent fuel storage framework of the nuclear power plant is of an embedded splicing structure, so that the size of the grid can be relatively dense; the 'well' -shaped positioning groove 160 on the bottom plate 16 ensures that the welding of the wide plate 12 and the narrow plate 14 has high positioning precision, ensures the size of the grid and enhances the stability of the grid structure; the top parts of the peripheral plate 10, the wide plate 12 and the narrow plate 14 are provided with

inclined guide surfaces

100, 120 and 140 to facilitate the plugging operation of the fuel assemblies in the grids; the peripheral plate 10, the wide plate 12, the narrow plate 14, the

water flowing holes

102, 122, 142, 162 formed on the bottom plate 16 and the through

grooves

104, 124 can be used as water passages, so that the grid has a larger water flowing area. Therefore, the nuclear power plant spent fuel storage grillwork can safely store fuel assemblies in a spent fuel pool in a fuel plant, the pool where the nuclear power plant spent fuel storage grillwork is located is kept subcritical and safe, meanwhile, the fuel assemblies are not blocked during operation and storage of spent fuel, and the safe storage of the fuel assemblies in the whole service life of the nuclear power plant is maintained.

It should be noted that, in actual use, in view of the overall arrangement of the spent fuel pool, the peripheral plates of the partial cell frames may be eliminated because the neutron absorber may not need to be reused for the adjacent spent fuel storage grids. In other embodiments, the leg assemblies may vary in structure, number, or arrangement; the structural form, the number or the arrangement mode of the positioning blocks can also be different, the arrangement modes of the through grooves and the convex edges among the wide plates, the narrow plates and the peripheral plates can be interchanged with each other, and the number can also be adjusted; the grid pitch and size of the grids can be changed according to the storage requirements of the actual fuel assemblies, and the number and layout of the grids of each storage grid can be different, such as 6 × 6, 9 × 9, 12 × 10 or 12 × 11.

Appropriate changes and modifications to the embodiments described above will become apparent to those skilled in the art from the disclosure and teachings of the foregoing description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. The utility model provides a spent fuel storage framework of nuclear power plant which characterized in that: including peripheral board, wide board, narrow board, bottom plate and landing leg subassembly, peripheral board, wide board and narrow board are the grid structure with the concatenation of inlaying the mode, and on the bottom of three kinds of boards all was fixed in the bottom plate, the landing leg subassembly was fixed in the bottom plate and provides the support to it, was fixed with neutron absorber on wide board and the narrow board respectively.

2. The nuclear power plant spent fuel storage grid according to claim 1, wherein: the top of the peripheral plate, the top of the wide plate and the top of the narrow plate are all provided with inclined guide surfaces, so that the four-surface top end of each grid can guide the drawing and inserting of the fuel assemblies in the grid.

3. The nuclear power plant spent fuel storage grid according to claim 1, wherein: the plate wall of the wide plate is provided with a plurality of rows of vertical through grooves, the edge of the long edge of the narrow plate is provided with a convex edge matched with the through grooves of the wide plate, the convex edge of the narrow plate is inserted into the through grooves of the wide plate, and the convex edge and the wide plate form a grid structure for storing fuel assemblies.

4. The nuclear power plant spent fuel storage grid according to claim 3, wherein: the plate wall of the peripheral plate is provided with a plurality of rows of vertical through grooves, the long edge of the wide plate is provided with a convex edge matched with the through grooves of the peripheral plate, the convex edge of the wide plate is inserted into the through grooves of the peripheral plate, and the peripheral plate firmly fixes the wide plate and the narrow plate.

5. The nuclear power plant spent fuel storage grid according to claim 1, wherein: the bottom plate is provided with a 'well' -shaped positioning groove, and the peripheral plate, the wide plate and the narrow plate are fixed in the 'well' -shaped positioning groove of the bottom plate in a welding mode.

6. The nuclear power plant spent fuel storage grid according to any one of claims 1 to 4, wherein: the periphery plate, the wide plate, the narrow plate and the bottom plate are respectively provided with a plurality of water flowing holes.

7. The nuclear power plant spent fuel storage grid according to any one of claims 1 to 4, wherein: the neutron absorber is fixed on the corresponding plate body through L-shaped positioning blocks welded on the wide plate and the narrow plate.

8. The nuclear power plant spent fuel storage grid according to any one of claims 1 to 4, wherein: the neutron absorber adopts Al-based B4C.

9. The nuclear power plant spent fuel storage grid according to any one of claims 1 to 4, wherein: the landing leg assembly is of an adjustable structure and comprises a base plate, a screw rod, a threaded sleeve and a gasket, the adjustable screw rod is supported on the base plate, the threaded sleeve is sleeved on the screw rod, the gasket is arranged between the base plate and the threaded sleeve, the outer surface of the threaded sleeve is of a step-shaped structure, and a positioning hole matched with the diameter of the top of the threaded sleeve is formed in the bottom plate.