A containment rapid pressure relief discharge device with shielding function

Abstract

The present invention discloses a containment rapid pressure relief and discharge device with a shielding function, comprising an isolation structure and a radiation shielding structure. The isolation structure is disposed within the containment, the isolation structure being fixedly connected to the inner sidewall of the containment, the isolation structure being provided with a blasting panel, and the isolation structure, the blasting panel, and the inner sidewall of the containment together forming an isolation chamber; the blasting panel is made of a pressure-sensitive material; the inner sidewall of the containment is provided with a through-hole, and the through-hole is provided with a connecting pipe connected to a pressure relief box. The beneficial effects of the present invention are as follows: the blasting panel is made of a pressure-sensitive material, and when the pressure in the containment (or reactor compartment) reaches a set value, it can be opened in a relatively short time and achieve a flow area that meets the requirements, thereby being safe, flexible, and reliable.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power safety technology, and in particular to a containment rapid pressure relief discharge device with a shielding function. Background Art

[0002] When a main coolant pipe ruptures in the containment vessel (or reactor compartment) of a nuclear power plant, coolant will be released into the containment vessel (or reactor compartment) through the rupture, generating a large amount of steam through flash evaporation and releasing a large amount of heat into the containment vessel (or reactor compartment), causing the pressure and temperature of the gas inside the containment vessel (or reactor compartment) to rise rapidly. For some small or compact floating nuclear power plants and marine nuclear power plants, the design pressure of their containment vessels (or reactor compartments) is low and the internal free volume is small. To ensure the structural integrity of the containment vessel (or reactor compartment) after the design basis accident conditions, a containment vessel (or reactor compartment) suppression system is required. This system rapidly decompresses the steam inside the containment vessel (or reactor compartment) after the accident and discharges it into a suppression water tank for condensation. By absorbing the heat inside the containment vessel (or reactor compartment), the pressure of the containment vessel (or reactor compartment) does not exceed its design pressure.

[0003] During normal operation of the nuclear power system, for the through-holes of the containment (or reactor compartment) and the pipes connecting the containment (or reactor compartment) and the pressure relief box, isolation devices should be installed to ensure effective isolation between the containment (or reactor compartment) and the pressure relief box and local airtightness of the containment (or reactor compartment), so as to prevent the radioactive materials in the containment (or reactor compartment) from diffusing out of the containment (or reactor compartment); on the other hand, local shielding should be provided to reduce the leakage of neutrons and gamma rays in the containment (or reactor compartment) through the through-holes and connecting pipes to the outside of the containment (or reactor compartment), so as to ensure that the radiation field outside the containment (or reactor compartment) meets the prescribed safety limit requirements. After the main coolant pipeline ruptures, the coolant is released from the rupture into the containment (or reactor compartment) and the steam flow generated by flash evaporation is large, and the heat transferred to the containment (or reactor compartment) is large. Therefore, the through-holes of the containment (or reactor compartment) and the pipelines connecting the containment (or reactor compartment) and the pressure relief tank need to have a considerable pressure relief discharge area to ensure that sufficient steam can enter the pressure relief tank for condensation and pressure reduction; and the process of coolant being released from the rupture into the containment (or reactor compartment) and flashing to form steam is fast, and the pressure of the containment (or reactor compartment) rises quickly. In order to ensure that the pressure in the containment (or reactor compartment) does not exceed its design pressure, the isolation device between the containment (or reactor compartment) and the pressure relief tank is required to be able to be opened within a short time after the accident and to achieve a flow area that meets the requirements.

[0004] Therefore, an isolation device should be installed between the containment (or reactor compartment) and the pressure relief tank. The isolation device should have the following functions and capabilities:

[0005] 1) Under normal operating conditions of the nuclear power plant, good sealing should be ensured to prevent the radioactive materials in the containment (or reactor compartment) from spreading outside the containment (or reactor compartment); local shielding should be provided to reduce the leakage of neutrons and gamma rays in the containment (or reactor compartment) through the through-holes and connecting pipes to the outside of the containment (or reactor compartment);

[0006] 2) After a main coolant pipeline rupture accident occurs in the containment (or reactor compartment) of a nuclear power plant, the isolation device can be opened quickly and reach a flow area that meets the requirements, ensuring that sufficient steam enters the pressure relief tank for condensation within the required time, preventing the pressure in the containment (or reactor compartment) from exceeding its designed pressure. Summary of the Invention

[0007] The object of the present invention is to provide a containment rapid pressure relief discharge device with a shielding function in order to address the deficiencies of the prior art.

[0008] The technical solution adopted by the present invention is: a quick pressure relief and discharge device for a containment shell with a shielding function, comprising an isolation structure and a radiation shielding structure, wherein the isolation structure is arranged in the containment shell, the isolation structure is connected and fixed to the inner wall of the containment shell, the isolation structure is provided with a blasting panel, and the isolation structure, the blasting panel and the inner wall of the containment shell are enclosed to form an isolation cavity; the inner wall of the containment shell is provided with a through hole, and the through hole is provided with a connecting pipe connected to the pressure relief box.

[0009] According to the above scheme, the blasting panel is provided with notches and / or gaps as a weakening structure.

[0010] According to the above solution, the blasting panel is an arc-shaped plate that is recessed toward the isolation cavity.

[0011] According to the above solution, a radiation shielding structure is provided in the isolation cavity, which faces the through-hole. Gaps are respectively left between the radiation shielding structure and the inner wall of the isolation structure, and between the radiation shielding structure and the inner wall of the containment shell.

[0012] According to the above scheme, the isolation structure includes a panel and a front cover plate. The rear end of the panel is connected to the inner wall of the containment shell through a first flange structure. The cover plate is arranged on the front side of the panel and connected to the front end of the panel.

[0013] According to the above solution, a blasting pipe communicating with the isolation cavity is provided on the enclosure; and the blasting panel is provided at the port of the blasting pipe.

[0014] According to the above scheme, the radiation shielding structure includes a radiation shielding block and a mounting frame, and the radiation shielding block is made of radiation shielding material; the radiation shielding block is arranged opposite to the through-channel, and the radiation shielding block is installed on the mounting frame through a second flange structure. A toggle plate is provided at the rear of the mounting frame, the rear end of the toggle plate is fixed to the inner wall of the containment shell, and the front end of the toggle plate is connected to the bottom of the mounting frame.

[0015] According to the above scheme, the isolation structure is a square structure, which includes four side panels and a cover plate, and the cover plate is welded and fixed to the panel; the rear end of the panel is welded with an upper flange plate of the first flange structure, and the inner wall of the containment shell is welded with a lower flange plate of the first flange structure, and the upper and lower flange plates of the first flange structure are connected by a number of bolts.

[0016] According to the above scheme, the radiation shielding block is a cylindrical structure coaxial with the hole. The upper flange plate of the second flange structure is welded to the rear of the radiation shielding block, and the lower flange plate of the second flange structure is welded to the mounting frame. The upper and lower flange plates of the second flange structure are connected by a plurality of bolts. The ends of the bracket are respectively welded to the inner side wall of the containment vessel and the mounting frame.

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention has good sealing and shielding properties in the closed state. The designed ray shielding block is made of ray shielding material to reduce the leakage of neutrons and gamma rays in the containment vessel (or reactor compartment) to the outside of the containment vessel (or reactor compartment) through the through-holes and connecting pipes; the blasting panel is made of pressure-sensitive material. When the pressure in the containment vessel (or reactor compartment) reaches the set value, it can be opened in a relatively short time and reach the required flow area. It is safe, flexible and reliable.

[0019] 2. The blasting panel is a passive component. Its opening function at the required pressure does not rely on external inputs such as drive or power source. It has high reliability and fast opening speed.

[0020] 3. The blasting panel is installed at the penetration hole of the containment, in an area that is accessible to personnel and easy to reach, so as to facilitate inspection and replacement.

[0021] 4. The integrated design of the radiation shielding structure and the isolation structure at the through-hole of the containment (or reactor compartment) has advantages in weight, size, etc. compared with the separate setting of local shielding and large-diameter isolation valves.

[0022] 5. The device of the present invention has strong environmental adaptability and can adapt to earthquake or impact environments. The opening process is simple and reliable, and the difficulty of maintenance and replacement of parts is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of a specific embodiment of the present invention.

[0024] Figure 2 is a cross-sectional view of this embodiment.

[0025] Among them, 1 is the through-hole, 2 is the radiation shielding block, 3 is the second flange structure, 4 is the elbow plate, 5 is the blasting panel, 6 is the enclosure plate, 7 is the cover plate, 8 is the inner wall of the containment, 9 is the mounting frame, and 10 is the blasting pipe. DETAILED DESCRIPTION

[0026] In order to better understand the present invention, the present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0027] like Figure 1 and Figure 2 The quick pressure relief and discharge device for a containment shell with a shielding function shown in the figure includes an isolation structure and a radiation shielding structure. The isolation structure is arranged in the containment shell, and the isolation structure is connected and fixed to the inner wall 8 of the containment shell. The isolation structure is provided with a blasting panel 5. The isolation structure, the blasting panel 5 and the inner wall 8 of the containment shell are enclosed to form an isolation cavity; the blasting panel 5 is made of pressure-sensitive material; the inner wall 8 of the containment shell is provided with a through channel 1, and the through channel 1 is provided with a connecting pipe connected to the pressure relief box.

[0028] In this embodiment, the blasting panel 5 is designed with multiple layers and is an arc-shaped plate that is recessed toward the isolation chamber. Notches and / or slits are provided on the blasting panel 5 as weakening structures. The blasting panel 5 is made of materials such as stainless steel, titanium, and nickel-based alloys. In the present invention, the thickness, size, and number of notches and slits of the blasting panel 5 are designed based on actual production. The blasting pressure of the blasting panel 5 is controlled by the surface weakening structures of the notches or slits. When the pressure outside the isolation chamber reaches the designed blasting pressure, the blasting panel 5 is stretched and ruptured along the weakening structures, connecting the containment shell, the isolation chamber, and the through-hole 1. The steam within the containment shell is decompressed and discharged into the pressure relief box through the isolation chamber, through-hole 1, and the connecting pipe, where it condenses. The blasting panel 5 requires regular inspection or replacement to ensure its stable and reliable structural performance.

[0029] Preferably, a radiation shielding structure is provided in the isolation cavity, the radiation shielding structure faces the through-hole 1, and gaps are respectively left between the radiation shielding structure and the inner wall of the isolation structure, and between the radiation shielding structure and the inner wall 8 of the containment shell.

[0030] Preferably, the isolation structure includes a panel 6 and a front cover plate 7, the rear end of the panel 6 is connected to the inner wall 8 of the containment shell through a first flange structure; the cover plate 7 is arranged on the front side of the panel 6 and connected to the front end of the panel 6.

[0031] In this embodiment, the isolation structure is a square structure, comprising four side panels 6 and a cover plate 7, which are welded to the panel 6. The rear end of the panel 6 is welded to an upper flange plate of the first flange structure, and the inner side wall 8 of the containment vessel is welded to a lower flange plate of the first flange structure. The upper and lower flange plates of the first flange structure are connected by a plurality of bolts.

[0032] Preferably, a blasting pipe 10 communicating with the isolation cavity is provided on the enclosure 6 ; and the blasting panel 5 is provided at the port of the blasting pipe 10 .

[0033] In this embodiment, the number of blasting pipes 10 is designed based on the required flow area. Blasting pipes 10 are integrated with enclosure 6. The end of each blasting pipe 10 is connected to a blasting panel 5 via a third flange structure. The blasting panels 5 are redundant, so only one blasting panel 5 needs to be opened to meet the required flow area and rapid pressure relief requirements.

[0034] Preferably, the radiation shielding structure includes a radiation shielding block 2 and a mounting frame 9. The radiation shielding block 2 is made of radiation shielding material, preferably a lightweight composite radiation shielding material such as lead boron polyethylene; the radiation shielding block 2 is arranged opposite the through-channel 1, and the radiation shielding block 2 is installed on the mounting frame 9 through a second flange structure 3. A toggle plate 4 is provided at the rear of the mounting frame 9, and the rear end of the toggle plate 4 is fixed to the inner wall 8 of the containment shell, and the front end of the toggle plate 4 is connected to the bottom of the mounting frame 9.

[0035] In this embodiment, the radiation shielding block 2 is a cylindrical structure coaxial with the through-hole 1. The distance between the radiation shielding block 2 and the through-hole 1 should meet the shielding requirements and the flow area requirements. The radiation shielding block 2 is made of lightweight composite shielding material, and its size and thickness are designed through shielding performance analysis. The rear of the radiation shielding block 2 is welded with the upper flange plate of the second flange structure 3, and the mounting frame 9 is welded with the lower flange plate of the second flange structure 3. The upper and lower flange plates of the second flange structure 3 are connected by a plurality of bolts. The two ends of the toggle plate 4 are respectively welded to the inner side wall 8 of the containment vessel and the mounting frame 9.

[0036] In this embodiment, the design of the mounting frame 9, elbow plate 4 and second flange structure 3 should ensure effective support for the radiation shielding block 2, and its shear stress should be lower than the structural strength limit; the design of the first flange structure should ensure effective support for the enclosure 6 and cover plate 7, and its shear stress should be lower than the structural strength limit, to ensure that under earthquake or impact conditions, the strength of the device should meet the requirements of earthquake or impact resistance.

[0037] The working principle of the present invention is:

[0038] 1. When the nuclear power system is operating normally, a slightly negative pressure state is maintained in the containment vessel (or reactor compartment), and the blasting panel 5 is closed (the blasting panel 5 is intact). At this time, the enclosure 6, the cover plate 7, the blasting panel 5 and the inner wall 8 of the containment vessel (or reactor compartment) form a closed isolation chamber, which encloses the through-hole 1 and the radiation shielding structure of the containment vessel (or reactor compartment). The containment vessel (or reactor compartment) and the pressure relief box are effectively isolated by this device; the radiation shielding structure reduces the leakage of neutrons and gamma rays in the containment vessel (or reactor compartment) through the through-hole 1 and the connecting pipe to the outside of the containment vessel (or reactor compartment), thereby ensuring that the radiation field outside the containment vessel (or reactor compartment) meets the specified safety limit requirements.

[0039] 2. After a main coolant pipeline rupture accident occurs in the containment (or reactor compartment) of a nuclear power plant, coolant is released from the rupture into the containment (or reactor compartment), and steam is generated by flash evaporation; the pressure in the containment (or reactor compartment) increases, and under the action of the pressure difference between the containment (or reactor compartment) and the suppression water tank, the pressure on the blasting panel 5 reaches the designed blasting pressure and then ruptures, and the steam enters the isolation cavity through the blasting panel 5, and is then quickly decompressed and discharged into the pressure relief box through the through-hole 1 and connecting pipe of the containment (or reactor compartment) to condense, absorb heat in the containment (or reactor compartment), and ensure that the pressure in the containment (or reactor compartment) is lower than its designed pressure.

[0040] The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the contents disclosed in the embodiment and the accompanying drawings. Therefore, any equivalent or modified implementation that does not depart from the spirit disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A containment rapid pressure relief and discharge device with shielding function, characterized in that: The containment chamber comprises an isolation structure and a radiation shielding structure. The isolation structure is arranged in the containment shell and is fixedly connected to the inner wall of the containment shell. The isolation structure is provided with a blasting panel. The isolation structure, the blasting panel and the inner wall of the containment shell together form an isolation chamber. The inner wall of the containment shell is provided with a through-hole, and the through-hole is provided with a connecting pipe connected to the pressure relief box. A radiation shielding structure is provided in the isolation cavity, the radiation shielding structure is directly opposite to the through-hole, and gaps are respectively left between the radiation shielding structure and the inner wall of the isolation structure, and between the radiation shielding structure and the inner wall of the containment vessel; The isolation structure includes a coaming and a front cover plate, the rear end of the coaming is connected to the inner wall of the containment shell via a first flange structure; the cover plate is provided on the front side of the coaming and connected to the front end of the coaming; The enclosure is provided with a blasting pipe communicating with the isolation cavity; the blasting panel is provided at the port of the blasting pipe; The radiation shielding structure includes a radiation shielding block and a mounting frame. The radiation shielding block is made of radiation shielding material. The radiation shielding block is arranged opposite to the through-channel and is mounted on the mounting frame through a second flange structure. A toggle plate is provided at the rear of the mounting frame. The rear end of the toggle plate is fixed to the inner wall of the containment shell, and the front end of the toggle plate is connected to the bottom of the mounting frame.

2. The containment rapid pressure relief discharge device according to claim 1, characterized in that: The blasting panel is provided with notches and / or gaps as weakening structures.

3. The containment rapid pressure relief discharge device according to claim 1, characterized in that: The blasting panel is an arc-shaped plate that is concave toward the isolation cavity.

4. The containment rapid pressure relief discharge device according to claim 1, characterized in that: The isolation structure is a square structure, which includes four side panels and a cover plate, and the cover plate is welded and fixed to the panel; the rear end of the panel is welded with an upper flange plate of the first flange structure, and the inner wall of the containment shell is welded with a lower flange plate of the first flange structure, and the upper and lower flange plates of the first flange structure are connected by a number of bolts.

5. The containment rapid pressure relief discharge device according to claim 1, characterized in that: The radiation shielding block is a cylindrical structure coaxial with the through-channel; the rear part of the radiation shielding block is welded with an upper flange plate of the second flange structure, and the mounting frame is welded with a lower flange plate of the second flange structure. The upper and lower flange plates of the second flange structure are connected by a number of bolts, and the two ends of the elbow plate are respectively welded to the inner wall of the containment shell and the mounting frame.

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