Steel-UHPC composite containment structure

Abstract

The present invention relates to the technical field of nuclear power plant containments, and discloses a steel-UHPC composite containment structure. The top end of a steel plate-UHPC concrete cylinder extends upward and forms an outer dome at the top; the steel plate-UHPC concrete cylinder and the outer dome each comprise an inner steel plate, an outer steel plate, and UHPC concrete filled between the two steel plates; a variable cross-section structure is formed at the connection between the outer dome and the top end of the steel plate-UHPC concrete cylinder; and a steel dome is arranged on the inner side of the outer dome, and the bottom of the steel dome is fixedly connected to the variable cross-section structure by means of a steel dome base. According to the present invention, a containment cylinder employs a steel plate + UHPC high-performance concrete configuration, and a dome adopts a double dome design of steel plate-UHPC high-performance reinforced concrete dome + steel containment top head, enabling the containment structure to withstand various accident loads internally and to resist the impact of large commercial aircrafts externally. Compared with a double containment of generation III reactors, the design and construction are simplified while the safety is ensured.

Description

A steel-UHPC hybrid containment structure

[0001] Cross-references to related applications

[0002] This invention claims priority to Chinese Patent Application No. 202510342801.4, filed with the China National Intellectual Property Administration on March 21, 2025, entitled “A Steel-UHPC Hybrid Containment Structure”, the entire contents of which are incorporated herein by reference and constitute a part of this invention for all purposes. Technical Field

[0003] This invention relates to the field of nuclear power plant containment technology, and in particular to a steel-UHPC hybrid containment structure. Background Technology

[0004] The containment system is the outer shell that encloses the reactor's primary loop system and emergency safety facilities. It is the fourth safety barrier of a nuclear power plant, and its function is to ensure that radioactive gases and materials are completely sealed within the containment system in the event of a severe accident such as a strong earthquake or loss of water, preventing them from escaping and polluting the atmosphere and environment. By installing a containment system, even in the most severe accident, radioactive materials can still be completely contained within the containment system without affecting the surrounding environment.

[0005] Existing nuclear power plant containment structures are mainly divided into Generation II reactors, which use a single-layer prestressed concrete containment structure, and Generation III reactors, which use a double-layer containment structure. The single-layer containment structure of Generation II reactors cannot withstand the impact of a large commercial aircraft, while the double-layer containment structure of Generation III reactors decouples internal and external events. The outer containment structure can withstand the impact of a large commercial aircraft, while the inner containment structure bears the various accident loads and effects of the internal nuclear power plant. However, the construction of a double-layer containment structure is complex, costly, and time-consuming. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a steel-UHPC hybrid containment structure. The containment shell is constructed using steel plates and UHPC high-performance concrete, while the dome employs a double-dome design consisting of a steel plate UHPC high-performance reinforced concrete dome and a steel containment top end cap. Internally, this structure can withstand various accident loads, and externally, it can withstand the impact of large commercial aircraft. Compared to the double-layer containment structure of third-generation reactors, this design and construction are simplified while ensuring safety.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] A steel-UHPC hybrid containment structure includes:

[0009] The steel plate-UHPC concrete cylinder extends upward at its top and forms an outer dome at the top. Both the steel plate-UHPC concrete cylinder and the outer dome include an inner steel plate, an outer steel plate, and UHPC concrete filled between the two steel plates. The connection between the outer dome and the top of the steel plate-UHPC concrete cylinder forms a variable cross-section structure.

[0010] The steel dome is located inside the outer dome, and its bottom is fixedly connected to the variable cross-section structure via a steel dome base.

[0011] As a further implementation, the inner diameter of the bottom end of the inner steel plate of the outer dome is larger than the inner diameter of the top end of the inner steel plate of the steel plate-uhpc concrete cylinder to form an annular variable cross-section structure.

[0012] As a further implementation, the steel dome base includes a circular steel plate structure connected to the bottom of the steel dome. The outer diameter of the bottom end of the steel dome is smaller than the outer diameter of the circular steel plate structure. The outer diameter of the circular steel plate structure is adapted to the inner diameter of the bottom end of the inner steel plate of the outer dome. A ring of stiffening ribs is provided at the bottom of the circular steel plate structure. The stiffening ribs are located at the variable cross-section structure and extend downward into the UHPC concrete of the steel plate-UHPC concrete cylinder. The circular steel plate structure is connected to the UHPC concrete of the steel plate-UHPC concrete cylinder by anchor bolts.

[0013] As a further implementation, an annular passive cooling water tank is provided at the top center of the outer dome. The passive cooling water tank is formed by the inner steel plate and the outer steel plate extending outward. The bottom of the passive cooling water tank extends to the space between the outer dome and the steel dome through a spray pipe, and sprays water onto the top of the steel dome through the spray pipe.

[0014] As a further implementation, a drain pipe is provided at the steel plate near the bottom of the outer dome for discharging spray water; a ventilation hole is formed at the center of the top of the outer dome, which extends upward through the passive cooling water tank and connects to the outside, and the ventilation hole is coaxial with the containment structure.

[0015] As a further implementation, a concrete protective layer is provided on the outer side of the bottom of the steel dome near the variable cross-section position, and the drainage pipe is higher than the concrete protective layer.

[0016] As a further implementation, the outer steel plate and the inner steel plate are connected by connectors to form a skeleton structure.

[0017] As a further implementation, shear studs are also arranged on the sides of the outer and inner steel plates that are close to each other.

[0018] As a further implementation, the cross-sectional shape of the steel dome is arc-shaped or semi-circular.

[0019] As a further implementation, the bottom end of the steel dome is located between the inner steel plate of the steel plate-uhpc concrete cylinder and the inner steel plate at the bottom end of the outer dome.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1. The steel-UHPC hybrid containment structure of this invention uses a steel plate + UHPC high-performance concrete for the containment shell, and a double-dome design consisting of a steel plate UHPC high-performance reinforced concrete dome and a steel containment shell top end cap. Internally, it can withstand various accident loads, and externally, it can withstand the impact of a large commercial aircraft. Compared to the double-layer containment structure of third-generation reactors, it simplifies design and construction while ensuring safety.

[0022] 2. This invention utilizes the passive spray system of the water tank mounted on the containment dome, and fully leverages the passive heat dissipation characteristics of the steel containment to remove heat from the interior of the containment during an accident, ensuring structural safety. The ventilation holes allow for the supply of water vapor and external air circulation, further enhancing heat dissipation. The passive cooling water tank at the top can also act as a damper during earthquakes, reducing containment vibration and improving the overall performance of the containment.

[0023] 3. The steel-UHPC hybrid containment structure of the present invention adopts a steel plate + UHPC concrete design. The inner and outer double-layer steel plates and internal connectors can form a skeleton, which facilitates modular and layered hoisting, greatly improves construction efficiency and shortens the construction period. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0025] Figure 1 shows a schematic diagram of the overall structure of the steel-UHPC hybrid containment vessel in an embodiment of the present invention;

[0026] Figure 2 is a top view of the steel-UHPC hybrid containment structure in an embodiment of the present invention;

[0027] Figure 3 is an enlarged view of a partial structure of the steel-UHPC hybrid containment vessel in an embodiment of the present invention;

[0028] Figure 4 is a schematic cross-sectional view of a standard section of the steel-UHPC hybrid containment vessel in an embodiment of the present invention.

[0029] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0030] The components are: 1. Steel dome, 2. Outer dome, 3. Passive cooling water tank, 4. Spray pipe, 5. Anchor bolt, 6. Variable cross-section structure, 7. Steel plate-UHPC concrete cylinder, 8. Containment foundation, 9. Steel dome base, 10. Drainage pipe, 11. Ventilation hole, 12. Water flow direction, 13. Concrete protective layer, 14. Cylinder steel plate, 15. UHPC concrete, 16. Connecting parts; 91. Annular steel plate, 92. Stiffening rib, 93. Circular steel plate structure. Detailed Implementation

[0031] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] Example 1

[0033] In a typical embodiment of the present invention, referring to Figure 1, a steel-UHPC hybrid containment structure includes a steel plate-UHPC concrete cylinder 7, an outer dome 2, a steel dome 1, a passive cooling water tank 3, and a containment foundation 8. The bottom end of the steel plate-UHPC concrete cylinder 7 is set on the containment foundation 8. The outer dome 2 is a dome structure extending upward from the steel plate-UHPC concrete cylinder 7. The steel dome 1 is located inside the outer dome 2, forming a double-dome structure with the outer dome 2.

[0034] As shown in Figure 1, the steel plate-UHPC concrete cylinder is cylindrical in shape, with its top extending upward to form an outer dome 2. The lower end of the outer dome 2 is also cylindrical, while the upper end is shaped like a frustum, with a ventilation hole 11 formed at the center of the top. The axis of the ventilation hole 11 is the same as the axis of the containment structure.

[0035] As shown in Figures 1 and 3, both the steel plate-UHPC concrete cylinder 7 and the outer dome 2 include an inner steel plate, an outer steel plate, and UHPC concrete 15 filled between the two steel plates. A variable cross-section structure 6 is formed at the connection between the outer dome 2 and the top of the steel plate-UHPC concrete cylinder 7. The bottom of the steel dome 1 is fixedly connected to the variable cross-section structure 6 through a steel dome base 9.

[0036] As shown in Figures 1 and 3, the inner diameter of the bottom end of the inner steel plate of the outer dome 2 is larger than the inner diameter of the top end of the inner steel plate of the steel plate-uhpc concrete cylinder 7, so as to form an annular variable cross-section structure. Through this variable cross-section structure, it can communicate downward with the space between the two layers of steel plates of the steel plate-uhpc concrete cylinder 7.

[0037] As shown in Figure 3, the steel dome base 9 includes an annular steel plate 91 connected to the bottom of the steel dome. The bottom end of the steel dome 1 is fixedly connected to the top surface of the annular steel plate 91, and the outer diameter of the bottom end of the steel dome 1 is adapted to the outer diameter of the top surface of the annular steel plate 91 for welding purposes. The bottom of the annular steel plate 91 also has an integral circular steel plate structure 93. The outer diameter of the circular steel plate structure 93 is larger than the outer diameter of the annular steel plate 91, and the inner diameter of the circular steel plate structure 93 is adapted to the inner diameter of the inner steel plate of the steel plate-uhpc concrete cylinder 7 for welding purposes. The thickness of the circular steel plate structure 93 is smaller than the thickness of the annular steel plate 91. Therefore, the outer diameter of the bottom end of the steel dome 1 is smaller than the outer diameter of the circular steel plate structure 93.

[0038] As shown in Figure 3, the outer diameter of the annular steel plate structure 93 located at the bottom of the annular steel plate 91 is adapted to the inner diameter of the bottom end of the inner steel plate of the outer dome 2, so that the edge of the annular steel plate structure 93 is welded to the inner side of the bottom end of the inner steel plate of the outer dome 2 for sealing. This allows the edge of the annular steel plate structure 93 to seal the variable cross-section structure 6. The axis of the annular steel plate 91 is set perpendicular to the plane where the annular steel plate structure 93 is located.

[0039] Of course, in other examples, the annular steel plate 91 can be omitted, and the bottom of the steel dome 1 can be directly welded to the annular steel plate structure 93.

[0040] The welding position between the bottom end of the steel dome 1 and the annular steel plate 91 is between the inner steel plate of the steel plate-uhpc concrete cylinder 7 and the inner steel plate at the bottom end of the outer dome, so that an annular channel is formed between the outer side of the annular steel plate 91 and the inner side of the bottom end of the inner steel plate of the outer dome 2.

[0041] To improve the structural connection strength at the variable cross-section structure 6, a ring of vertical stiffening ribs 92 is provided at the bottom of the circular steel plate structure 93. The stiffening ribs 92 are plate-shaped structures, and the length of the stiffening ribs 92 is less than the distance between the inner steel plate of the steel plate-uhpc concrete cylinder 7 and the inner steel plate of the outer dome 2. This allows the stiffening ribs 92 to extend into the lower part of the variable cross-section structure 6 after the outer dome 2 and the steel dome base 9 are hoisted into their corresponding positions. At the same time, the stiffening ribs 92 are also located on the outer side of the top of the inner steel plate of the steel plate-uhpc concrete cylinder 7.

[0042] Through holes are provided on the annular steel plate structure. These through holes are located on both the inner and outer sides of the annular steel plate 91 body and near the stiffening ribs. The through holes are used to install anchor bolts 5. The bottom end of the anchor bolt 5 passes through the through hole and extends to the bottom of the variable cross-section structure 6 to be fixed to the UHPC concrete inside the steel plate-UHPC concrete cylinder 7. Nuts are installed on the top. This achieves the connection between the annular steel plate structure 93 and the UHPC concrete of the steel plate-UHPC concrete cylinder 7 via the anchor bolts 5.

[0043] A concrete protective layer 13 is provided at the annular channel near the variable cross-section structure 6 on the outer side of the bottom of the steel dome 1 to isolate water and anchor bolts 5.

[0044] As shown in Figure 1, a ring-shaped passive cooling water tank 3 is located at the center of the top of the outer dome 2. The passive cooling water tank 3 is formed by the inner and outer steel plates of the outer dome 2 extending outwards. The passive cooling water tank 3 is filled with water and is used to spray water onto the top surface of the steel dome 1 for cooling. A ventilation hole 11 extends upward through the passive cooling water tank 3 and connects to the outside. The ventilation hole 11 is coaxial with the passive cooling water tank 3 and the containment structure; therefore, the bottom surface of the passive cooling water tank is an inverted conical surface.

[0045] The water capacity of the passive cooling water tank 3 is determined according to the design cooling function requirements, and is equipped with corresponding inlet pipes and valve structures. The water volume in the tank should be able to guarantee a water flow rate of 72 hours. The inner wall of the tank is lined with stainless steel to ensure sealing and durability.

[0046] The bottom of the passive cooling water tank 3 extends through the spray pipe 4 between the outer dome 2 and the steel dome 1. The nozzle is located near the center of the top of the steel dome. The spray pipe 4 sprays water onto the top of the steel dome. During spraying, the water flow direction 12 is as shown in Figure 1. This is used to inject water into the steel dome in case of an accident, so as to achieve comprehensive spraying and cooling of the top of the steel dome.

[0047] In this embodiment, the passive cooling water tank 3 is located at the center of the top of the containment vessel and can act as a damper in the event of an earthquake, reducing the vibration of the containment vessel. The ventilation hole 11 at the center of the passive cooling water tank 3 allows water vapor and external air to circulate, thus providing a cooling effect.

[0048] To drain the sprayed water, a drain pipe 10 is installed on the steel plate at the bottom of the outer dome 2 near the variable cross-section structure 6. The drain pipe 10 has a set slope for draining the sprayed water. One end of the drain pipe 10 extends to the outside, and the other end passes through the steel plate at the bottom of the outer dome 2 and is connected to the aforementioned annular channel. The drain pipe is higher than the concrete protective layer 13. Under the action of gravity, the water flowing along the water flow direction 12 to the annular channel can be discharged through the drain pipe 10, thereby carrying away heat.

[0049] By setting up a drain pipe 10, the water sprayed down from the upper passive cooling water tank 3 under accident conditions is directed to the outside of the containment. Cooling is mainly achieved through the action of the water film, which removes the heat under accident conditions. When the water in the tank is depleted, natural air can also flow between the ventilation hole 11 and the drain pipe 10 to remove the heat from the steel dome 1.

[0050] In other examples, the containment may not have a drain pipe 10, and water may accumulate between the outside of the steel dome 1 and the outer dome 2, carrying away heat through boiling and evaporation.

[0051] As shown in Figure 4, the outer and inner steel plates 14 of the cylindrical body are connected by connectors 16 to form a skeleton structure. UHPC concrete 15 is filled between the steel plates. To improve the connection strength, shear studs are also arranged on the sides of the outer and inner steel plates that are close to each other to enhance the connection with the UHPC concrete.

[0052] Connector 16 can be a steel structure, without specific limitations. The outer steel plate, steel section, connector, and shear studs can be made of ordinary steel, while the inner steel plate should be made of steel with good toughness, such as special boiler steel.

[0053] It is understood that the aforementioned UHPC concrete is ultra-high performance concrete. Given the characteristics of nuclear power plant containment structures, organic materials cannot be used as reinforcing fibers in ultra-high performance concrete.

[0054] In one optional example, the upper part of the outer dome 2 is hemispherical; or flattened shell or conical. The cross-section of the steel dome 1 can be semi-circular, semi-elliptical or composed of multiple arcs, and the steel dome 1 and its accessories are all made of special boiler steel.

[0055] This embodiment features a steel-UHPC hybrid containment structure. The containment shell is constructed from steel plates and UHPC high-performance concrete, while the dome employs a double-dome design consisting of a steel plate UHPC high-performance reinforced concrete dome and a steel containment top end. Internally, this design can withstand various accident loads, and externally, it can withstand the impact of a large commercial aircraft. Furthermore, the passive sprinkler system, which houses water tanks on the containment dome and fully utilizes the passive heat dissipation characteristics of the steel containment, effectively removes heat from the containment interior during an accident, ensuring structural safety. Compared to the double-layer containment structure of third-generation reactors, this design and construction are simplified while maintaining safety.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A steel-UHPC hybrid containment structure, characterized in that, include: The steel plate-UHPC concrete cylinder extends upward at its top and forms an outer dome at the top. Both the steel plate-UHPC concrete cylinder and the outer dome include an inner steel plate, an outer steel plate, and UHPC concrete filled between the two steel plates. The connection between the outer dome and the top of the steel plate-UHPC concrete cylinder forms a variable cross-section structure. The steel dome is located inside the outer dome, and its bottom is fixedly connected to the variable cross-section structure via a steel dome base.

2. The steel-UHPC hybrid containment structure according to claim 1, characterized in that, The inner diameter of the bottom end of the inner steel plate of the outer dome is larger than the inner diameter of the top end of the inner steel plate of the steel plate-uhpc concrete cylinder to form an annular variable cross-section structure.

3. The steel-UHPC hybrid containment structure according to claim 2, characterized in that, The steel dome base includes a circular steel plate structure connected to the bottom of the steel dome. The outer diameter of the bottom end of the steel dome is smaller than the outer diameter of the circular steel plate structure. The outer diameter of the circular steel plate structure is adapted to the inner diameter of the bottom end of the inner steel plate of the outer dome. A ring of stiffening ribs is provided at the bottom of the circular steel plate structure. The stiffening ribs are located at the variable cross-section structure and extend downward into the UHPC concrete of the steel plate-UHPC concrete cylinder. The circular steel plate structure is connected to the UHPC concrete of the steel plate-UHPC concrete cylinder by anchor bolts.

4. The steel-UHPC hybrid containment structure according to claim 1, characterized in that, The outer dome is equipped with a ring-shaped passive cooling water tank at the top center. The passive cooling water tank is formed by the inner steel plate and the outer steel plate extending outward. The bottom of the passive cooling water tank extends to the space between the outer dome and the steel dome through a spray pipe, which sprays water onto the top of the steel dome.

5. A steel-UHPC hybrid containment structure according to claim 4, characterized in that, A drain pipe is provided near the bottom of the steel plate of the outer dome for discharging spray water; a ventilation hole is formed at the center of the top of the outer dome, which extends upward through the passive cooling water tank and connects to the outside, and the ventilation hole is coaxial with the containment structure.

6. The steel-UHPC hybrid containment structure according to claim 5, characterized in that, A concrete protective layer is provided on the outer side of the bottom of the steel dome near the variable cross-section position, and the drainage pipe is higher than the concrete protective layer.

7. A steel-UHPC hybrid containment structure according to claim 1, characterized in that, The outer steel plate and the inner steel plate are connected by connectors to form a skeleton structure.

8. A steel-UHPC hybrid containment structure according to claim 7, characterized in that, Shear studs are also arranged on the sides of the outer and inner steel plates that are close to each other.

9. A steel-UHPC hybrid containment structure according to claim 1, characterized in that, The cross-sectional shape of the steel dome is arc-shaped or semi-circular.

10. A steel-UHPC hybrid containment structure according to claim 1, characterized in that, The bottom of the steel dome is located between the inner steel plate of the steel plate-uhpc concrete cylinder and the inner steel plate at the bottom of the outer dome.

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