A nuclear power plant containment structure

Abstract

The present invention belongs to the field of nuclear power technology, and specifically relates to a containment structure of a nuclear power plant. The containment structure comprises an inner containment consisting of an inner shell top (1) and an inner cylinder (2), and an outer containment (3) arranged outside the inner containment, wherein the inner shell top (1) is made of steel, the inner cylinder (2) is made of prestressed reinforced concrete, and the outer containment (3) is made of reinforced concrete. The present invention can effectively improve the pressure bearing capacity of traditional containment structures, reduce the difficulty of design and construction, and ultimately reduce the cost of containment, thereby improving the economic efficiency of nuclear power plants.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power, and in particular relates to a containment structure of a nuclear power plant. Background Art

[0002] The containment shell is an important item that contains the nuclear steam supply system. It is the last barrier to prevent the leakage of radioactive materials. It is also an important guarantee to protect the reactor from external natural and man-made events. It is the most important structure in a nuclear power plant and a very important part of ensuring the safety of a nuclear power plant. Analyzing the three major nuclear accidents that occurred in history, Three Mile Island, Chernobyl, and Fukushima, although the core melted at Three Mile Island, the containment shell prevented the large-scale leakage of radioactive materials. It can be seen that the containment shell plays an important role and contributes to the safety of nuclear power plants. At the same time, the containment shell system is expensive, which affects the economic efficiency of nuclear power plants and is a key factor in the balance between the pursuit of advancement and economy of nuclear power plants.

[0003] At present, various types of containment at home and abroad have certain research and engineering practice experience, from oblate spherical to hemispherical dome containment, from three buttresses to double buttresses, from prestressed concrete containment to steel containment, from single-layer containment to double-layer containment. For example, the US AP1000 model adopts a full steel inner containment + shielding shell, the Russian VVER model adopts a prestressed reinforced concrete structure + shielding shell, and the Chinese "ACP1000" model adopts a prestressed reinforced concrete structure + an outer layer of reinforced concrete structure that resists large aircraft impact. In engineering practice, these containment structure combinations have great differences in the pressure bearing capacity, cost, construction speed, design to resist large aircraft impact, and the lifting plan for the main equipment in the shell. However, they all generally have the problems of high cost and difficulty in design and construction, which affects the economic efficiency of nuclear power plants. Summary of the invention

[0004] The purpose of the present invention is to construct a nuclear power plant containment structure, which utilizes the characteristics of steel containment, prestressed reinforced concrete and ordinary reinforced concrete structures, combines the design of containment structure, shell gate, prestressed stretching, containment construction, etc., to achieve a new containment structure with strong pressure bearing capacity, low construction difficulty, fast speed and low cost.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is a nuclear power plant containment structure, which includes an inner containment shell composed of an inner shell top and an inner cylinder, and an outer containment shell arranged outside the inner containment shell, the inner shell top is made of steel, the inner cylinder is made of prestressed reinforced concrete, and the outer containment shell is made of reinforced concrete.

[0006] Furthermore, the bottom of the inner cylinder and the bottom of the outer containment shell are both arranged on a foundation bottom plate, and the material of the foundation bottom plate is reinforced concrete.

[0007] Furthermore, the shape of the inner shell top is arc-shaped or hemispherical, and the inner shell top is arranged on the top opening of the inner cylinder, and the two are connected by embedded bolts or anchor bolts; the position of the arc starting point where the inner shell top connects with the inner cylinder is determined by the lifting height requirement of the internal items of the inner containment.

[0008] Furthermore, the inner cylinder wall of the inner cylinder is provided with a steel lining in an annular shape, and the upper surface of the base bottom plate is covered with the steel lining; the connecting portion between the steel lining on the inner cylinder wall of the inner cylinder and the inner shell top is connected by welding.

[0009] further,

[0010] A first gate is arranged at the top center of the inner shell top, and a second gate is arranged at the top center of the outer containment shell, the first gate and the second gate are coaxial, and are used for transporting main equipment inside the inner containment shell;

[0011] A third gate is provided on one side of the inner cylinder, which is used for personnel entry and exit and installation and transportation of small-sized equipment in the shell, and also serves as an emergency gate; the third gate passes through the inner cylinder and the outer containment shell, and the connection position between the third gate and the inner cylinder and the outer containment shell is a sealed connection.

[0012] Furthermore, the inner shell top adopts an overall modular design, and is segmented and welded to form an integral structure. The first gate is made of steel and is welded to the inner shell top and the first gate to form a whole.

[0013] further,

[0014] A first steel bundle and a second steel bundle are arranged inside the cylinder wall of the inner cylinder, wherein the first steel bundle is a vertical prestressed steel bundle parallel to the axis of the inner cylinder, and the second steel bundle is a circumferential prestressed steel bundle arranged horizontally and surroundingly;

[0015] A tensioning corridor is provided inside the foundation slab, and the lower end of the first steel bundle vertically enters the tensioning corridor; the upper end of the first steel bundle extends to the junction of the top of the inner cylinder and the top of the inner shell, and the first steel bundle adopts bidirectional tensioning;

[0016] A buttress for annular prestressed tensioning anchoring is arranged outside the outer wall of the inner cylinder to anchor the second steel bundle.

[0017] Furthermore, a closed space is formed between the inner containment shell and the outer containment shell, which can retain radioactive substances; the outer containment shell is configured as a thin-walled shielding shell or a thick wall resistant to aircraft impact according to the site requirements.

[0018] The beneficial effects of the present invention are:

[0019] 1. The inner containment structure of the present invention adopts a steel inner shell top 1 matched with an inner cylinder 2 of prestressed reinforced concrete. The steel inner shell top 1 is spliced ​​and installed by modular construction, which can greatly reduce the traditional shell top reinforced concrete pouring work, the reactor building can be capped in advance, and the critical path construction period is greatly shortened.

[0020] 2. The prestressed reinforced concrete covers the inner cylinder 2. The prestressed vertical steel bundle (the first steel bundle 8) is significantly shorter than that of the traditional containment. The prestressed steel bundle reduces the prestress friction loss, and the prestress transmission is smoother. At the same time, the difficulty of the prestressing tensioning project is greatly reduced. Combined with the thermal conductivity of the steel inner shell top 1 under accident conditions, the pressure bearing capacity of the containment is effectively enhanced.

[0021] 3. The main equipment gate (first gate 5) is set at the top center of the inner shell top 1, which makes it convenient to hoist and transport the main equipment in the shell (steam generator, pressurizer, stack container, etc.) within the factory site, avoiding the protection problem of hoisting items in the shell by the open-top method; at the same time, the main equipment gate is set on the inner shell top 1 from a structural point of view. It avoids opening large-sized holes in the prestressed reinforced concrete structure of the inner cylinder 2, thereby improving the overall structural performance and sealing effect of the containment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a nuclear power plant containment structure described in a specific embodiment of the present invention;

[0023] In the figure: 1-inner shell top, 2-inner cylinder, 3-outer containment shell, 4-foundation bottom plate, 5-first gate, 6-second gate, 7-steel lining, 8-first steel bundle, 9-second steel bundle, 10-tensioning corridor, 11-top tensioning position, 12-enclosed space, 13-third gate. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, the present invention provides a nuclear power plant containment structure, which includes an inner containment consisting of an inner shell top 1 and an inner cylinder 2, and an outer containment 3 arranged outside the inner containment, the inner shell top 1 is made of steel, the inner cylinder 2 is made of prestressed reinforced concrete, and the outer containment 3 is made of reinforced concrete.

[0026] The bottom of the inner cylinder 2 and the bottom of the outer containment shell 3 are both arranged on a foundation slab 4, and the material of the foundation slab 4 is reinforced concrete cast on site.

[0027] The shape of the inner shell top 1 is arc-shaped or hemispherical. The inner shell top 1 is arranged on the top opening of the inner cylinder 2, and the two are connected by embedded bolts or anchor bolts; the position of the arc starting point where the inner shell top 1 and the inner cylinder 2 meet is determined by the lifting height requirement of the internal items of the inner containment.

[0028] The inner wall of the inner cylinder 2 is provided with a steel lining 7 in an annular manner, and the upper surface of the base bottom plate 4 is covered with the steel lining 7; the connection portion between the steel lining 7 on the inner wall of the inner cylinder 2 and the inner shell top 1 is connected by welding.

[0029] A first gate 5 is provided at the top center of the inner shell top 1, and a second gate 6 is provided at the top center of the outer containment shell 3. The first gate 5 and the second gate 6 are coaxial and are used for transportation of main equipment inside the inner containment shell (i.e., as a hoisting and transportation channel for main equipment such as steam generators and stack containers inside the shell);

[0030] A third gate 13 is provided on one side of the inner cylinder 2, which is used for the entry and exit of personnel and the installation and transportation of small-sized equipment in the shell, and also serves as an emergency gate; the third gate 13 passes through the inner cylinder 2 and the outer containment shell 3, and the connection position between the third gate 13 and the inner cylinder 2 and the outer containment shell 3 is a sealed connection.

[0031] The inner shell top 1 adopts an overall modular design. During construction and installation, the pieces are spliced ​​and welded in the factory to form an integral structure. The first gate 5 is made of steel, which is welded to the inner shell top 1 and the first gate 5 to be hoisted as a whole and put into place at the installation position.

[0032] A first steel bundle 8 and a second steel bundle 9 are arranged inside the wall of the inner cylinder 2. The first steel bundle 8 is a vertical prestressed steel bundle parallel to the axis of the inner cylinder 2, and the second steel bundle 9 is a circumferential prestressed steel bundle arranged horizontally and surroundingly.

[0033] A tensioning corridor 10 is provided inside the foundation slab 4, and the lower end of the first steel bundle 8 vertically enters the tensioning corridor 10; the upper end of the first steel bundle 8 extends to the top of the inner cylinder 2 and the junction of the inner shell top 1, and the first steel bundle 8 adopts bidirectional tensioning;

[0034] Buttresses for annular prestressed tension anchoring are arranged outside the outer wall of the inner cylinder 2 to anchor the second steel strand 9.

[0035] A closed space 12 is formed between the inner containment shell and the outer containment shell 3, which can retain radioactive substances; the outer containment shell 3 is configured as a thin-walled shielding shell or a thick wall resistant to aircraft impact according to the site requirements.

[0036] The device described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the technical innovation scope of the present invention.

Claims

1. A nuclear power plant containment structure, characterized by: The invention comprises an inner containment shell composed of an inner shell top (1) and an inner cylinder (2), and an outer containment shell (3) arranged outside the inner containment shell, wherein the inner shell top (1) is made of steel, the inner cylinder (2) is made of prestressed reinforced concrete, and the outer containment shell (3) is made of reinforced concrete; the shape of the inner shell top (1) is an arc or a hemisphere; the inner shell top (1) is arranged on the top opening of the inner cylinder (2), and the two are connected by embedded bolts or anchor bolts; the inner shell top (1) adopts an overall modular design, and the pieces are spliced ​​and welded to form an integral structure; a first gate (5) is arranged at the top center of the inner shell top (1), and a gate (6) is arranged at the top center of the inner shell top (1). A second gate (6) is arranged at the center of the top of the outer containment shell (3); the first gate (5) and the second gate (6) are coaxial and are used for transporting main equipment inside the inner containment shell; a third gate (13) is arranged on one side of the inner cylinder (2) and is used for the entry and exit of personnel and the installation and transportation of small-sized equipment inside the shell, and also serves as an emergency gate; the third gate (13) passes through the inner cylinder (2) and the outer containment shell (3); the third gate (13) is sealed at the connection position with the inner cylinder (2) and the outer containment shell (3); the first gate (5) is made of steel and is welded to the inner shell top (1) and the first gate (5) to form a whole.

2. A nuclear power plant containment structure according to claim 1, characterized in that: The bottom of the inner cylinder (2) and the bottom of the outer containment shell (3) are both arranged on a foundation slab (4), and the material of the foundation slab (4) is reinforced concrete.

3. A nuclear power plant containment structure as claimed in claim 2, characterized in that: The position of the arc starting point where the inner shell top (1) and the inner cylinder (2) meet is determined by the lifting height requirement of the internal items of the inner containment.

4. A nuclear power plant containment structure as claimed in claim 3, characterized in that: The inner cylinder wall of the inner cylinder (2) is provided with a steel lining (7) in an annular shape, and the upper surface of the base bottom plate (4) is covered with the steel lining (7); the connection portion between the steel lining (7) on the inner cylinder wall of the inner cylinder (2) and the inner shell top (1) is connected by welding.

5. A nuclear power plant containment structure as claimed in claim 4, characterized in that: A first steel bundle (8) and a second steel bundle (9) are provided inside the wall of the inner cylinder (2); the first steel bundle (8) is a vertical prestressed steel bundle parallel to the axis of the inner cylinder (2); and the second steel bundle (9) is a circumferential prestressed steel bundle horizontally arranged around the inner cylinder (2); A tensioning corridor (10) is provided inside the foundation slab (4), and the lower end of the first steel bundle (8) vertically enters the tensioning corridor (10); the upper end of the first steel bundle (8) extends to the top of the inner cylinder (2) and the junction of the inner shell top (1), and the first steel bundle (8) adopts bidirectional tensioning; Buttresses for annular prestressed tension anchoring are arranged outside the outer wall of the inner cylinder (2) to anchor the second steel bundle (9).

6. A nuclear power plant containment structure as claimed in claim 1, characterized in that: A closed space (12) is formed between the inner containment shell and the outer containment shell (3), which can retain radioactive substances; the outer containment shell (3) is configured as a thin-walled shielding shell or a thick wall resistant to aircraft impact according to the requirements of the plant site.

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