Anti-leakage device for integrated small pressurized water reactor pressure vessel

Abstract

The invention relates to the technical field of nuclear reactors, and discloses a leakproof device for a pressure vessel of an integrated small pressurized water reactor, a reactor core is arranged in the pressure vessel, the leakproof device comprises a base plate, and the pressure vessel is arranged on the base plate; a plurality of apron boards are arranged on the outer wall of the pressure container at intervals in the height direction of the pressure container, and the apron boards are annularly arranged outside the pressure container in a sleeving mode; the first sealing sleeve is arranged at the bottom of the pressure container in a sleeving mode, and the upper end and the lower end of the first sealing sleeve are connected with the bottommost apron board and the base plate in a sealed mode; the second sealing sleeves arranged outside the pressure container in a sleeving mode are arranged between every two adjacent apron boards, and the upper ends and the lower ends of the second sealing sleeves are connected with the two corresponding apron boards in a sealed mode respectively; the sealing cover is connected to the uppermost apron board in a sealed mode and covers the top of the pressure container. By arranging the full-wrapping sealing structure capable of intercepting the coolant, the occurrence of leakage accidents can be restrained from the source.

Description

Technical Field

[0001] This invention relates to the field of nuclear reactor technology, and in particular to an integrated leak-proof device for a small pressurized water reactor pressure vessel. Background Technology

[0002] The integrated small pressurized water reactor is a small nuclear reactor developed based on the mature technology of traditional pressurized water reactors. Its core adopts an integrated design concept, which is to concentrate the primary loop core equipment of the large pressurized water reactor in the same reactor pressure vessel. From the structural design, this significantly reduces the risk of coolant loss accidents.

[0003] Currently, some integrated small pressurized water reactors have multiple main pumps (to provide forced circulation power for the coolant) arranged outside the pressure vessel, and control rods extending from the top of the pressure vessel (used to precisely adjust the core reactivity, realize reactor start-up / shutdown and power stabilization control). This type of design increases the number of penetrations and sealing interfaces of the pressure vessel. If the sealing structure ages, fails, or is affected by fluctuations in operating conditions, it may cause coolant leakage risks. In extreme cases, coolant loss may lead to core exposure, which may then trigger a meltdown accident.

[0004] Another type of integrated small pressurized water reactor eliminates the main pump and uses a tightly sealed container to cover the pressure vessel. When coolant leaks, it is trapped in the interlayer space between the pressure vessel and the sealed container, which can mitigate the direct impact of coolant loss to some extent. However, the problem with this design is that after eliminating the main pump, the core heat must rely entirely on natural circulation to be discharged, which means that the height of the pressure vessel needs to be increased to nearly 20 meters (to form a sufficient natural circulation head). Even if the sealed container is as close to the pressure vessel as possible, the operating space required for inspection and construction still needs to be reserved, which means that the actual volume of the interlayer cannot be further reduced. In extreme cases, if the pressure vessel leaks, the interlayer space cannot completely block the coolant loss, and the core may still be exposed, which may lead to a core meltdown accident. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an integrated leak-proof device for small pressurized water reactor pressure vessels.

[0006] This invention provides an integrated leak-proof device for a small pressurized water reactor pressure vessel. The pressure vessel contains a reactor core and includes: a base plate on which the pressure vessel is mounted; multiple skirts spaced along the height of the outer wall of the pressure vessel, the skirts being annularly fitted around the pressure vessel; a first sealing sleeve fitted at the bottom of the pressure vessel, the upper and lower ends of the first sealing sleeve being sealed to the lowermost skirt and the base plate, respectively; a second sealing sleeve fitted between adjacent skirts, the upper and lower ends of the second sealing sleeve being sealed to the two corresponding skirts, respectively; and a sealing cover, sealed to the uppermost skirt, covering the top of the pressure vessel.

[0007] Optionally, the pressure vessel includes a lower shell that is open at the top and an upper shell that is open at the bottom, with flanges connected to the top of the lower shell and the bottom of the upper shell, and the two flanges are sealed together by fasteners.

[0008] Optionally, one of the multiple skirts may be positioned between two flanges.

[0009] Optionally, a through-hole is installed on the pressure vessel, the through-hole having a through-hole pipe, one end of the through-hole pipe being inside the pressure vessel, and the other end extending out of the pressure vessel and passing through the sealing sleeve or sealing cover, the through-hole pipe being sealed to the sealing sleeve or sealing cover.

[0010] Optionally, the sealing sleeve or sealing cover has an opening, the through pipe is inserted into the opening, and a connector is fitted onto the through pipe. The connector is inserted into the opening and is sealed to the sealing sleeve or sealing cover.

[0011] Optionally, the diameter of the opening gradually decreases on the side away from the pressure vessel, and the connector is located on the side of the opening closer to the pressure vessel; a flexible connector made of flexible material is provided on the side of the opening away from the pressure vessel, and the flexible connector and the connector are connected.

[0012] Optionally, the through-pipe is equipped with a shut-off valve and a pressure relief valve.

[0013] Optionally, the gate valve includes a valve body and a valve stem extending from the valve body, with a turbine having blades mounted on the valve stem.

[0014] Optionally, a pressure relief valve is located upstream of the shut-off valve. The pressure relief valve includes a housing located on and connected to the inside of the through-pipe. A piston and a spring are provided in the housing. The upper surface of the piston is connected to the lower end of the spring, and the upper end of the spring is connected to the housing. An outlet pipe is connected to the housing, and the outlet end of the outlet pipe is connected to a nozzle facing the turbine. When the liquid in the through-pipe pushes the piston, causing the piston to be positioned above the inlet of the outlet pipe, the liquid in the through-pipe is ejected from the nozzle and sprayed onto the turbine, causing the shut-off valve to close.

[0015] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art: This device constructs a sealing structure using a base plate, multiple sets of annular skirts, sealing sleeve one, sealing sleeve two, and a sealing cover, forming a fully enclosed protection system of bottom sealing, segmented sealing, and top sealing. Compared to existing technologies that rely solely on a single sealed container or through-hole sealing, this effectively reduces the probability of sealing interface failure. Even if the local sealing structure of the pressure vessel ages or is affected by operating condition fluctuations, the fully enclosed sealing structure can still intercept coolant, preventing leakage accidents from the source. Adjacent skirts and sealing sleeve two form independent segmented sealing chambers. Bottom sealing sleeve one, the base plate, and the bottom skirt form the bottom sealing chamber, while the top sealing cover and the top skirt form the top sealing chamber. When a pressure vessel leaks, the coolant is confined to the corresponding chamber, avoiding the problem of rapid coolant diffusion and loss caused by excessive interlayer volume in existing tightly sealed containers. At the same time, the segmented chamber design facilitates rapid location of the leak, buying time for subsequent handling and reducing the risk of core exposure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an integrated small pressurized water reactor pressure vessel leak prevention device provided in Embodiment 1 of the present invention.

[0017] Figure 2 This is a schematic diagram of the structure of a sealing sleeve provided in Embodiment 1 of the present invention, which is disposed between the skirt plate and the base plate.

[0018] Figure 3 This is a schematic diagram of the upper and lower housings connected by a flange, as provided in Embodiment 1 of the present invention.

[0019] Figure 4 This is a schematic diagram of the structure of the sealing sleeve 2 provided in Embodiment 1 of the present invention, which is provided with a flexible connector and a connector.

[0020] Figure 5 This is a schematic diagram of a through-pipe with a shut-off valve and a pressure relief valve provided in Embodiment 1 of the present invention.

[0021] Explanation of reference numerals in the attached drawings: 1. Base plate; 2. Pressure vessel; 3. Core; 4. Skirt; 5. Sealing sleeve one; 6. Penetrating component; 7. Sealing sleeve two; 8. Sealing cover; 9. Flange; 10. Flexible connector; 11. Connector; 12. Penetrating component pipe; 13. Gate valve; 14. Outlet pipe; 15. Spring; 16. Outer shell; 17. Lower shell; 18. Upper shell. Detailed Implementation

[0022] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] Example 1: like Figure 1 and Figure 2 As shown, this embodiment provides an integrated small pressurized water reactor pressure vessel leak-proof device. The pressure vessel 2 is equipped with a reactor core 3 and includes: a base plate 1, on which the pressure vessel 2 is disposed; skirts 4, on which multiple skirts 4 are spaced along the height direction on the outer wall of the pressure vessel 2, and the skirts 4 are annularly fitted around the pressure vessel 2; a first sealing sleeve 5, fitted around the bottom of the pressure vessel 2, with the upper and lower ends of the first sealing sleeve 5 respectively sealingly connected to the lowermost skirt 4 and the base plate 1; a second sealing sleeve 7, which is provided between two adjacent skirts 4 and fitted around the pressure vessel 2, with the upper and lower ends of the second sealing sleeve 7 respectively sealingly connected to the two corresponding skirts 4; and a sealing cover 8, which is sealed and connected to the uppermost skirt 4 and covers the top of the pressure vessel 2.

[0025] In this embodiment, two adjacent skirts and sealing sleeve 2 7 form independent segmented sealing chambers, sealing sleeve 1 5, base plate 1, and lowermost skirt 4 form a bottom sealing chamber, and sealing cover 8 and uppermost skirt 4 form a top sealing chamber.

[0026] like Figure 3 As shown, the pressure vessel 2 includes a lower shell 17 with an open top and an upper shell 18 with an open bottom. The top of the lower shell 17 and the bottom of the upper shell 18 are both connected to flanges 9, and the two flanges 9 are sealed together by fasteners.

[0027] In this embodiment, the fasteners are bolts and nuts, and a sealing gasket is also provided between the two flanges 9.

[0028] like Figure 3 As shown, one of the multiple skirts 4 is positioned between two flanges 9.

[0029] In this embodiment, the skirt 4 is internally held between two flanges 9, and the two flanges 9 extend externally from the skirt 4.

[0030] like Figure 1and Figure 4 As shown, a through-hole 6 is installed on the pressure vessel 2, and the through-hole 6 has a through-hole pipe 12. One end of the through-hole pipe 12 is located inside the pressure vessel 2, and the other end extends out of the pressure vessel 2 and passes through the sealing sleeve 7 or the sealing cover 8. The through-hole pipe 12 is sealed and connected to the sealing sleeve 7 or the sealing cover 8.

[0031] In this embodiment, the penetrating component is a part installed on the pressure vessel, not a specific part, but a general term for the parts that penetrate the pressure vessel, such as heat pipes and control rods. The penetrating component pipe 12 is the pipe of the penetrating component itself, such as steam pipes, control rod pipes, and some monitoring lines.

[0032] like Figure 1 and Figure 4 As shown, the sealing sleeve 7 or the sealing cover 8 has an opening, the through pipe 12 is inserted into the opening, and the through pipe 12 is fitted with a connector 11, which is inserted into the opening and sealed to the sealing sleeve 7 or the sealing cover 8.

[0033] The diameter of the opening gradually decreases on the side away from the pressure vessel 2, and the connector 11 is located on the side of the opening close to the pressure vessel 2; a flexible connector 10 made of flexible material is provided on the side of the opening away from the pressure vessel 2, and the flexible connector 10 and the connector 11 are connected.

[0034] In this embodiment, by providing a flexible connector 10, when liquid diffuses out of the sealed cavity through the opening, the flexible connector 10 will generate a clamping force under the action of the internal and external pressure difference and the curved surface of the opening, thereby forming an effective seal.

[0035] like Figure 5 As shown, the through pipe 12 is equipped with a shut-off valve 13 and a pressure relief valve.

[0036] like Figure 5 As shown, the shut-off valve 13 includes a valve body and a valve stem extending from the valve body, on which a turbine with blades is mounted.

[0037] like Figure 5 As shown, the pressure relief valve is located upstream of the shut-off valve 13. The pressure relief valve includes a housing 16 located on the through pipe 12 and communicating with the inside of the through pipe 12. A piston and a spring 15 are provided in the housing 16. The upper surface of the piston is connected to the lower end of the spring 15, and the upper end of the spring 15 is connected to the housing 16. An outlet pipe 14 is connected to the housing 16, and the outlet end of the outlet pipe 14 is connected to a nozzle facing the turbine. When the liquid in the through pipe 12 pushes the piston, causing the piston to be located above the inlet of the outlet pipe 14, the liquid in the through pipe 12 is ejected from the nozzle and sprayed onto the turbine, causing the shut-off valve 13 to close.

[0038] By setting flexible connectors 10 and 11, when an opening is provided on the sealing sleeve 7 or the sealing cover 8, when leakage occurs at the opening, the flexible connector 10 will form a clamping force under the action of the internal and external pressure difference and the cooperation of the conical curved surface of the opening, so that the opening is effectively sealed. When leakage occurs inside the penetrating part 6 and is discharged from the pressure vessel through the penetrating part pipe 12, by setting a shut-off valve 13 and a pressure limiting valve, the pressure limiting valve leads the liquid out and drives the shut-off valve 13 to close, thereby achieving a sealing effect. Therefore, by preventing leakage at the opening and leakage inside the penetrating part through passive protection design, leakage accidents can be curbed from the source.

[0039] The above inventions are merely a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. An integrated leak-proof device for a small pressurized water reactor pressure vessel, wherein the pressure vessel contains a reactor core, characterized in that... The utility model relates to a pressure container, comprising: a substrate, on which the pressure container is arranged; a plurality of skirt plates are arranged on the outer wall of the pressure container along the height direction of the pressure container, and the skirt plates are annularly arranged on the pressure container; a first sealing sleeve is arranged on the bottom of the pressure container, and the upper and lower ends of the first sealing sleeve are sealingly connected with the lowermost skirt plate and the substrate, respectively; a second sealing sleeve is arranged between two adjacent skirt plates, and the upper and lower ends of the second sealing sleeve are sealingly connected with the two corresponding skirt plates, respectively; a sealing cover is sealingly connected with the uppermost skirt plate and covers the top of the pressure container.

2. The integrated small-sized pressurized water reactor pressure vessel leak protection device of claim 1, wherein The pressure container comprises a lower shell with an open top and an upper shell with an open bottom, and the top end of the lower shell and the bottom end of the upper shell are connected with flanges, and the two flanges are sealingly connected by fasteners.

3. The integrated small-sized pressurized water reactor pressure vessel leak protection device of claim 2, wherein One of the plurality of skirt plates is arranged between the two flanges.

4. The integrated small-sized pressurized water reactor pressure vessel leak protection device of claim 1, wherein A through piece is arranged on the pressure container and penetrates the pressure container, and the through piece is provided with a through piece pipeline, one end of which is located in the pressure container and the other end of which extends out of the pressure container and penetrates the second sealing sleeve or the sealing cover, and the through piece pipeline is sealingly connected with the second sealing sleeve or the sealing cover.

5. The integrated small-sized pressurized water reactor pressure vessel leak protection device of claim 4, wherein An opening is formed in the second sealing sleeve or the sealing cover, and the through piece pipeline is inserted into the opening, and a connecting piece is arranged on the through piece pipeline and is inserted into the opening and sealingly connected with the second sealing sleeve or the sealing cover.

6. The integrated small-sized pressurized water reactor pressure vessel leak protection device of claim 5, wherein The diameter of the side of the opening away from the pressure container gradually decreases, and the connecting piece is arranged on the side of the opening close to the pressure container; a flexible connecting piece made of flexible material is arranged on the side of the opening away from the pressure container, and the flexible connecting piece is connected with the connecting piece.

7. The integrated small-sized pressurized water reactor pressure vessel leak protection device of claim 4, wherein The through piece pipeline is provided with a stop valve and a pressure limiting valve.

8. The integrated small-sized pressurized water reactor pressure vessel leak protection device according to claim 7, wherein The stop valve comprises a valve body and a valve rod extending from the valve body, and a turbine with blades is arranged on the valve rod.

9. The integrated small-sized pressurized water reactor pressure vessel leak protection device of claim 8, wherein The pressure limiting valve is arranged upstream of the stop valve, and the pressure limiting valve comprises an outer shell arranged on the through piece pipeline and in communication with the through piece pipeline, a piston and a spring arranged in the outer shell, the upper surface of the piston is connected with the lower end of the spring, the upper end of the spring is connected with the outer shell, an outlet pipe is connected with the outer shell, and a nozzle directed towards the turbine is connected with the outlet end of the outlet pipe; When the liquid in the through piece pipeline pushes the piston, the piston is located above the inlet of the outlet pipe, the liquid in the through piece pipeline is sprayed from the nozzle and sprayed to the turbine, and the stop valve is closed.

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