A reactor building, layout design method and nuclear power plant

Abstract

The application discloses a reactor building, a layout design method and a nuclear power plant, and relates to the technical field of nuclear power. The reactor building comprises an internal refueling water tank, a first flooded area and a second flooded area. The first flooded area comprises at least a reactor pit and a main equipment compartment communicating with the reactor pit. The reactor pit has a flooded liquid level. The first flooded area is located below the flooded liquid level. The first flooded area communicates with the internal refueling water tank. The second flooded area comprises at least one functional compartment. The second flooded area is provided with a first channel communicating with the first flooded area. In an accident condition, the cooling water in the internal refueling water tank enters the first flooded area. When the water level in the first flooded area rises to a set height above the flooded liquid level, the cooling water overflows to the second flooded area through the first channel. The reactor building can realize a sequential and phased flooding mechanism, improve the utilization efficiency of the cooling water, and reduce the requirement on the volume of the internal refueling water tank.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and in particular to a reactor building, layout design method, and nuclear power plant. Background Technology

[0002] If an accident occurs, such as a breach in the reactor pit, main equipment compartment, or functional compartment, coolant in the reactor loop will leak through the breach, resulting in insufficient total coolant supply to continuously cool the reactor core. After the nuclear reaction, the reactor core continuously releases decay heat. If the coolant is lost, the core temperature will rise rapidly, potentially leading to radioactive material leakage and threatening nuclear safety. Therefore, to avoid safety risks caused by breach accidents, the reactor core must be completely submerged in cooling water after a breach accident. The cooling water efficiently removes the continuously released decay heat from the core, maintaining the core temperature within a safe range while preventing radioactive material leakage and ensuring the safety of the reactor building and surrounding environment.

[0003] Passive safety systems, which rely on natural forces such as gravity-driven automatic water filling of high-level tanks to achieve cooling functions under accident conditions, have gradually become one of the core technologies in nuclear power plant design. Currently, the In-Containment Refill Tank (IRWST) is usually located inside the containment. Under accident conditions, water from the IRWST is injected into the flood zone by gravity to immerse the reactor core in cooling water, thereby achieving core cooling.

[0004] However, due to the limited space inside the containment, adopting the traditional full-area flooding strategy would lead to a significant increase in the capacity requirement of the internal refueling tank, which would not only increase the difficulty of tank structure design and construction, but also potentially conflict with the layout of other equipment inside the containment. Secondly, under accident conditions, the utilization efficiency of the safety-grade water source directly determines the flooding effect. The existing flow channel design is difficult to achieve orderly distribution of the water source, cannot ensure that the core area is flooded first, and cannot guarantee the liquid level required for the core to be heated. Summary of the Invention

[0005] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention proposes a reactor building capable of implementing a sequential, phased flooding mechanism, improving the utilization efficiency of cooling water, and reducing the volume requirement of the internal refueling tank.

[0006] The present invention also proposes a layout design method applicable to the above-mentioned reactor building.

[0007] The present invention also proposes a nuclear power plant having the above-mentioned reactor building.

[0008] A reactor building according to a first aspect of the present invention includes: Internal refill water tank; A first flooded area, the first flooded area includes at least a pile pit and a main equipment compartment connected to the pile pit, the pile pit has a flooding level, the first flooded area is located below the flooding level, and the first flooded area is connected to the internal refueling tank. The second flooded area includes at least one functional compartment, and the second flooded area is connected to the first flooded area by a first passage. The reactor building is configured such that, under accident conditions, cooling water in the internal refueling tank enters the first flooding zone, and when the water level in the first flooding zone rises to a set height above the flooding level, the cooling water overflows into the second flooding zone through the first channel.

[0009] The reactor building according to embodiments of the present invention has at least the following beneficial effects: Under accident conditions, the reactor building flooding process of this application is divided into two stages. In the initial stage of an accident, cooling water from the internal refueling tank is preferentially injected into the first flooding area, including the reactor pit and main equipment compartments, via gravity drive, rapidly raising the liquid level to the flooding level to ensure continuous and effective cooling of the reactor core, thereby effectively containing the accident risk. After the liquid level in the first flooding area rises to a set height above the flooding level, the cooling water overflows naturally through the first channel to the second flooding area, thus achieving the second stage of orderly flooding and ultimately reaching the equilibrium liquid level. This sequential, staged flooding mechanism can accelerate the reactor core cooling response speed in the initial stage of an accident, avoiding the dispersion of water sources and the sluggish liquid level rise caused by simultaneous flooding of the entire area, and quickly responding to the reactor core cooling needs. Compared with the full-area flooding method, this application improves the utilization efficiency of cooling water through priority flooding of the core area and staged overflow control, thereby reducing the design requirements for the internal refueling tank volume and high-level arrangement, ensuring both safety margin and optimizing the building space layout.

[0010] According to some embodiments of the present invention, the second flooded area includes a distribution area and a plurality of said functional compartments. The distribution area is connected to the first flooded area through the first channel. The distribution area is located above each of said functional compartments. The distribution area is configured to sequentially introduce cooling water into each of said functional compartments in a set order.

[0011] According to some embodiments of the present invention, the reactor building further includes a ground layer separating the distribution area and the functional compartments, the ground layer being provided with a communication port connecting the distribution area and the functional compartments, and the reactor building further includes a cofferdam, the cofferdam protruding from the ground layer and surrounding the outer periphery of the communication port, the cofferdam being configured such that at least two of the cofferdams have different elevations, and when the level of cooling water in the distribution area is higher than the elevation of the cofferdam, the cooling water enters the corresponding functional compartment.

[0012] According to some embodiments of the present invention, at least one of the functional compartments is designated as a first functional compartment, which is used to accommodate the injection equipment and its connected pipes and valves; wherein the elevation of the cofferdam corresponding to the first functional compartment is greater than the elevation of the cofferdam corresponding to the other functional compartments.

[0013] According to some embodiments of the present invention, the reactor building includes two first functional rooms, and the cofferdams corresponding to the two first functional rooms have different elevations.

[0014] According to some embodiments of the present invention, the first flooded area further includes a pit compartment communicating with the pile pit, the pit compartment being disposed below the main equipment compartment, and each of the main equipment compartments communicating with the pit compartment.

[0015] According to some embodiments of the present invention, the ground height of the functional compartment is greater than the top height of the pit compartment, and the reactor building further includes a second channel connecting the pit compartment and the functional compartment, the second channel being configured to: transport cooling water from the functional compartment to the pit compartment.

[0016] According to some embodiments of the present invention, the second channel is provided with at least one check valve, the check valve causing the second channel to unidirectionally deliver cooling water in the direction from the functional compartment to the pit compartment.

[0017] According to some embodiments of the present invention, the reactor building has a connecting passage connecting the sump compartment and the reactor pit, and the reactor building further includes a protective component disposed in the connecting passage. The protective component includes a first protective door and a second protective door arranged sequentially from bottom to top. The first protective door is normally closed, and the second protective door can be opened unidirectionally from the sump compartment to the reactor pit.

[0018] According to some embodiments of the present invention, the protective assembly further includes a mounting wall for mounting the first protective door and the second protective door, wherein the first protective door is disposed on the side of the mounting wall facing the pit compartment, and the second protective door is disposed on the side of the mounting wall facing the pit.

[0019] According to some embodiments of the present invention, the reactor building further includes a reactor pool, the reactor pool comprising a first region located above the reactor pit and a second region located above a portion of the main equipment compartment, the second region being deeper than the first region.

[0020] According to some embodiments of the present invention, the second region is connected to the main equipment compartment below via a third channel, the third channel being provided with at least one-way valve, the one-way valve being capable of controlling the opening and closing of the third channel.

[0021] According to some embodiments of the present invention, the reactor building includes walls, and the reactor building also includes a protective sleeve penetrating the walls and process pipelines passing through the protective sleeve. The protective sleeve includes a first sleeve located below the submerged liquid level and a second sleeve located above the submerged liquid level. The first sleeve is provided with a sealing element connected to the process pipeline to seal the gap between the process pipeline and the first sleeve.

[0022] A method for designing the layout of a reactor building according to a second aspect of the present invention includes the following steps: Determine the location of the crater and the flooding level; The pile pit and the main equipment compartment are set as the first flooding zone, and the first flooding zone is set below the flooding liquid level; The functional compartment is set as a second flooded area. A first channel is set between the second flooded area and the first flooded area so that when the water level in the first flooded area rises to a set height above the flooded level, the cooling water in the first flooded area overflows into the second flooded area through the first channel.

[0023] According to a third aspect of the present invention, a nuclear power plant includes the reactor building as described in any of the above embodiments.

[0024] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a top view of the reactor building at a first height position, according to an embodiment of the present invention. Figure 2 This is a top view of the reactor building at a second height position, according to an embodiment of the present invention. Figure 3This is a top view of the reactor building at the third height position according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the liquid level in the reactor building along the circumference (under normal conditions) according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the liquid level along the circumferential direction of the reactor building in an embodiment of the present invention (in the initial flooding state after a breach accident). Figure 6 This is a schematic diagram of the liquid level along the circumferential direction of the reactor building in an embodiment of the present invention (under long-term submersion). Figure 7 This is a schematic diagram of the structure of the wall below the submerged liquid level according to an embodiment of the present invention; Figure 8 This is a schematic diagram of another structure of the wall below the submerged liquid level according to an embodiment of the present invention.

[0026] Figure label: Internal refill water tank 100; First flooding zone 200; crater 210; reactor pressure vessel 211; reactor core 212; main equipment compartment 220; steam generator 221; reactor coolant pump 222; crater compartment 230; connecting passage 240; first protective door 241; second protective door 242; mounting wall 243; reactor pool 250; first zone 251; second zone 252; Second flooding zone 300; Functional compartment 310; RRA system valve room 311; A-row injection equipment room 312; B-row injection equipment room 313; RCV system valve room 314; Pit ventilation functional room 315; Distribution area 320; First channel 400; Overflow channel 410; Second channel 420; Third channel 430; Check valve 440; Ground layer 500; cofferdam 550; Wall 600; Protective sleeve 610; Process pipeline 620; Sealing component 630; Containment 700. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing 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 limiting this invention.

[0029] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0030] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0031] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] If an accident occurs, such as a breach in the reactor pit, main equipment compartment, or functional compartment, coolant in the reactor loop will leak through the breach, resulting in insufficient total coolant supply to continuously cool the reactor core. After the nuclear reaction, the reactor core continuously releases decay heat. If the coolant is lost, the core temperature will rise rapidly, potentially leading to radioactive material leakage and threatening nuclear safety. Therefore, to avoid safety risks caused by breach accidents, the reactor core must be completely submerged in cooling water after a breach accident. The cooling water efficiently removes the continuously released decay heat from the core, maintaining the core temperature within a safe range while preventing radioactive material leakage and ensuring the safety of the reactor building and surrounding environment.

[0033] Passive safety systems, which rely on natural forces such as gravity-driven automatic water filling of the high-level water tank to achieve cooling under accident conditions, have gradually become one of the core technologies in nuclear power plant design. Currently, refueling tanks are usually located inside the containment. Under accident conditions, water from the IRWST (Intake Water Storage Tank) inside the containment is injected into the flood zone by gravity flow to immerse the reactor core in cooling water and achieve core cooling.

[0034] However, due to the limited space within the containment, adopting the traditional full-area flooding strategy would significantly increase the capacity requirement of the Intake Replacement Water Tank (IRWST), which would not only increase the difficulty of tank structure design and construction, but also potentially conflict with the layout of other equipment within the containment. Secondly, under accident conditions, the utilization efficiency of the safety-grade water source directly determines the flooding effect. The existing flow channel design is difficult to achieve orderly distribution of the water source, cannot ensure that the core area is flooded first, and cannot guarantee the liquid level required for the core to be heated.

[0035] To address the aforementioned problems, this application proposes a reactor building, such as... Figures 1 to 7 As shown, the reactor building includes an internal refueling tank 100, a first flooding zone 200, and a second flooding zone 300. It should be noted that... Figures 1 to 3 These are top views of the reactor building at different elevation positions. For ease of description, they are... Figure 1 The section height is set as the first section height. Figure 2 The section height is set to the second section height. Figure 3 The profile height is set as the third profile height, where the first profile height is greater than the third profile height, which is greater than the second profile height.

[0036] refer to Figure 5 As shown, the first flooding zone 200 includes at least a crater 210 and a main equipment compartment 220. The crater 210 is used to house the reactor pressure vessel 211, and the reactor core 212 is located within the reactor pressure vessel 211, forming the core reaction zone of the reactor. Figures 1 to 3 As shown, the main equipment compartment 220 is used to house major equipment such as the steam generator 221 and the reactor coolant pump 222. The second flooding zone 300 includes at least one functional compartment, such as... Figures 4 to 6 As shown, this functional compartment includes the RRA system valve room 311 (residual heat removal system), the A-row safety injection equipment room 312, the B-row safety injection equipment room 313, the RCV system valve room 314 (chemical and volume control system), and the sump ventilation function room 315. The internal refueling water tank 100 is usually located in a high area within the containment 700. In the event of a breach, the water in the internal refueling water tank 100 is discharged into the first flooding zone 200 under gravity along a pre-designed flow channel.

[0037] After the reactor pressure vessel 211 is installed in the crater 210, the liquid level required to completely submerge the reactor core 212 is determined based on the dimensions and cooling requirements of the reactor core 212 located within the reactor pressure vessel 211. This liquid level must meet the cooling requirements of the reactor core 212 after an accident and be able to continuously and reliably remove the heat generated by the reactor core 212. For ease of subsequent description, this liquid level is named the submersion level.

[0038] It should be noted that the flooding priority of the first flooding zone 200 is higher than that of the second flooding zone 300; that is, the flooding sequence of the second flooding zone 300 lags behind that of the first flooding zone 200. Therefore, in the layout design of the reactor building, the first flooding zone 200 is positioned below the flooding level. The first flooding zone 200 is connected to the internal refueling tank 100, so that when an accident occurs, water in the internal refueling tank 100 is injected into the first flooding zone 200 under gravity, rapidly forming an effective cooling coverage of the core area of ​​the reactor building.

[0039] The second flooding zone 300 is not directly connected to the internal refueling tank 100, but is connected to the first flooding zone 200 through the first channel 400. The second flooding zone 300 is also located below the flooding level. When an initial accident occurs in a specific compartment of the second flooding zone 300 (such as the RRA system valve compartment 311, the A-row safety injection equipment compartment 312, or the B-row safety injection equipment compartment 313), the cooling water, after flooding that specific compartment, flows through the top channel of that specific compartment to the distribution area 320, and then quickly enters the main equipment compartment 220 of the first flooding zone 200 through the first channel 400, thereby achieving rapid core flooding. For example, in... Figure 3 In the embodiment shown, the first channel 400 is located in the top area of ​​the main equipment compartment 220 and is connected to the distribution area 320.

[0040] Based on the above, it can be seen that under accident conditions, the flooding process of the reactor building in this application is divided into two stages. In the early stage of the accident, the cooling water of the internal refueling tank 100 is preferentially injected into the first flooding area 200, such as the reactor pit 210 and the main equipment compartment 220, by gravity drive, and the liquid level is quickly raised to the flooding level to ensure that the reactor core 212 is continuously and effectively cooled so that the accident risk can be effectively contained. After the liquid level of the first flooding area 200 rises to a set height above the flooding level (specifically the top elevation of the first channel 400), the cooling water overflows naturally through the first channel 400 to the second flooding area 300, thereby realizing the orderly flooding of the second stage and achieving the final balanced liquid level.

[0041] This sequential, phased flooding mechanism can accelerate the cooling response of core 212 in the early stages of an accident, avoiding water source dispersion and delayed liquid level rise caused by simultaneous flooding of the entire area. Compared with the traditional full-area flooding method, this application improves the utilization efficiency of cooling water by prioritizing flooding of the core heat-generating area and controlling overflow in stages, thereby reducing the design requirements for the 100-volume internal refueling tank and its high-level arrangement, ensuring both safety margin and optimizing the plant space layout.

[0042] Each functional compartment 310 is interconnected with the storage pit 210 and the main equipment compartment 220 at the bottom via process pipelines. Under normal circumstances, surface condensate in each functional compartment 310 is discharged to the pit compartment 230 through these bottom process pipelines for surface condensate collection. In case of an accident, condensate in each functional compartment 310 is discharged to the pit compartment 230 through these bottom process pipelines to reduce the amount of cooling water lost during an accident and ensure the effective cooling water volume within the first flooded area 200.

[0043] In some embodiments, the second flooded area 300 includes a distribution area 320 and a plurality of functional compartments 310, the distribution area 320 being connected to the first flooded area 200 via a first channel 400. Figure 2 As shown, in order to make full use of the space within the containment 700, the various functional compartments 310 are located in the space surrounding the stack pit 210 and the main equipment compartment 220. For example... Figure 3 and Figure 5 As shown, the distribution area 320 is located above each functional compartment 310 and is connected to each functional compartment 310. When cooling water flows from the first flooded area 200 into the second flooded area 300 through the first channel 400, it first accumulates in the distribution area 320, and then is introduced into each functional compartment 310 in the distribution area 320 according to a set order.

[0044] It should be noted that, based on the differences in the safety levels of the equipment in the functional compartments 310, the functional compartments 310 need to be submerged in order of increasing safety level. That is, water should be injected first into the functional compartments 310 containing items with no safety level, then into the functional compartments 310 containing items with lower safety levels, and finally into the functional compartments 310 containing items with higher safety levels.

[0045] Specifically, in some embodiments (not shown in the figures), the connecting pipes between the distribution area 320 and each functional compartment 310 are equipped with one-way valves 440 that open in a set sequence. The opening sequence of the one-way valves 440 strictly matches the safety level of the corresponding functional compartment 310, ensuring that the compartment with no safety level is water-intake first, followed by the compartment with a low safety level, and the compartment with a high safety level is submerged last. Alternatively, in other embodiments (not shown in the figures), the functional compartments 310 are connected sequentially in a set order so that cooling water flows sequentially from the compartment with a low safety level to the compartment with a high safety level. For example, the functional compartment 310 with no safety level is directly connected to the distribution area 320, the functional compartment 310 with a low safety level is connected to the compartment with no safety level through an overflow port, and the functional compartment 310 with a high safety level is connected to the compartment with a low safety level through another overflow port, thereby naturally achieving a submersion sequence from low to high during the gradual rise of the liquid level.

[0046] In such Figures 3 to 6 In the illustrated embodiment, the reactor building includes a ground floor 500 separating a distribution area 320 and functional compartments 310. The ground floor 500 defines a connection port connecting the distribution area 320 and the functional compartments 310, allowing each functional compartment 310 to be directly connected to the distribution area 320. To achieve sequential flooding of the functional compartments 310, the reactor building also includes a cofferdam 550, which protrudes from the ground floor 500 and surrounds the outer periphery of the connection port. When the cooling water level in the distribution area 320 exceeds the elevation of the cofferdam 550, the cooling water begins to overflow the cofferdam 550 and enter the corresponding functional compartment 310. It is understood that, depending on the type and number of functional compartments 310, at least two cofferdams 550 will have different elevations.

[0047] For example, the cofferdams 550 of different functional compartments 310 are raised in stages from low to high according to safety level. The cofferdam 550 of compartments without safety level has the lowest elevation, and the cofferdam 550 of compartments with high safety level has the highest elevation. Thus, the liquid level is raised in stages and the compartments are submerged in sequence under gravity. No external energy is required throughout the process, and no active control is required.

[0048] Furthermore, at least one functional compartment 310 houses the safety injection equipment and its connected piping and valves, and this functional compartment 310 is designated as the first functional compartment. It should be noted that the safety injection equipment is the core equipment of the reactor safety injection system, belonging to the high-safety-level items, and mainly includes the safety injection tank, safety injection piping, and related drive devices. In the event of a breach accident within the reactor primary loop isolation boundary, the safety injection equipment will automatically activate, injecting cooling water from the internal refueling tank 100 into the reactor loop and core 212 area, and into the first flooding area 200, rapidly replenishing the coolant loss and rapidly flooding the crater 210 area where the reactor pressure vessel 211 is located, to ensure continuous core cooling.

[0049] The first functional compartment is classified as high safety, requiring it to be submerged in the later stages of an accident. Therefore, the elevation of the cofferdam 550 corresponding to the first functional compartment is higher than the elevation of the cofferdam 550 corresponding to the other functional compartments 310.

[0050] Furthermore, reactor buildings often contain multiple primary functional compartments (such as the A-row safety injection equipment compartment 312 and the B-row safety injection equipment compartment 313 in this application) to enhance system redundancy and reliability. Each primary functional compartment is arranged independently. It should be noted that the cofferdam 550 elevation of the primary functional compartment is higher than that of the cofferdam 550 elevation of other functional compartments 310. However, there must also be a difference in the cofferdam 550 elevation between two primary functional compartments to avoid simultaneous flooding. This ensures that during the accident evolution process, each safety injection device is put into operation in a staggered manner, extending the available time window for the safety injection devices. When the first primary functional compartment begins to flood, the safety injection devices in the other primary functional compartment continue to operate until the other primary functional compartment begins to flood, forming a tiered response mechanism.

[0051] Functional compartment 310 includes a sump air supply compartment 315, an RCV system valve compartment 314, a safety injection equipment compartment 312 (A-row), an RRA system valve compartment 311, and a safety injection equipment compartment 313 (B-row). Among these, the sump air supply compartment 315 and the RCV system valve compartment 314 have no safety-grade items and are therefore prioritized for flooding, with their corresponding cofferdam elevation 550 being H1. The cofferdam elevation 550 corresponding to the safety injection equipment compartment 312 (A-row) is H2, and the cofferdam elevation 550 corresponding to the RRA system valve compartment 311 and the safety injection equipment compartment 313 (B-row) is H3, where H3 > H2 > H1.

[0052] In addition, in such Figures 4 to 6In the illustrated embodiment, the first channel 400 is specifically a channel connecting the main equipment compartment 220 and the distribution area 320. An overflow channel 410 is also provided between the reactor pool 250 and the distribution area 320. When an accident occurs in a specific area of ​​the functional area 310 (such as the A-row safety injection equipment room 312, the RRA system valve room 311, or the B-row safety injection equipment room 313), the cooling water first floods the specific area of ​​the functional area 310, and then flows through the channel connecting the flooded specific area of ​​the functional area 310 to the distribution area 320 (i.e., the top of the compartment). The cofferdam (550) overflows to the ground level (500). At this time, the cooling water enters the main equipment compartment (220) of the first submerged area (200) through the first channel (400) of the second submerged area (300) and the first submerged area (200). On the other hand, it enters the reactor pool (250) through the overflow channel (410) of the distribution area (320) connected to the reactor pool (250). Then, it enters the main equipment compartment (220) of the first submerged area (200) through the third channel (430) at the bottom of the reactor pool (250), and then fills the entire first submerged area (200) so that the liquid level reaches the predetermined submerged liquid level.

[0053] Among them, the bottom elevation of the overflow channel 410 connecting the distribution area 320 and the reactor pool 250 is lower than the lowest elevation H1 of the cofferdam 550 of the functional compartment 310.

[0054] In some embodiments, the first flooded area 200 further includes a pit compartment 230 communicating with the manhole 210. It should be noted that... Figures 4 to 6 This is a schematic diagram of the reactor building. To clearly illustrate the flooding sequence of the various spaces within the building, the layout of some spaces has been simplified and does not represent the actual layout. (Reference) Figure 1 As shown, the outer periphery of the reactor pit 210 is surrounded by six main equipment compartments 220, which are used to house the three steam generators 221 and the three reactor coolant pumps 222 in the three-loop reactor, respectively. The sump compartment 230 is located below the main equipment compartments 220. Each main equipment compartment 220 is connected to the sump compartment 230 and is connected to the reactor pit 210 through the sump compartment 230.

[0055] Furthermore, the floor height of functional compartment 310 is greater than that of sump compartment 230, and the reactor building also includes a second passageway 420 connecting sump compartment 230 and functional compartment 310, such as... Figure 4As shown, the second channel 420 is connected to the ground of the functional compartment 310, thus forming a ground drainage structure. If the rupture occurs in a specific compartment of the functional compartment 310, the second channel 420 can transport the cooling water in the functional compartment 310 to the pit compartment 230, and then flow through the pit compartment 230 to the stack pit 210, achieving orderly collection of coolant. If the rupture occurs in the main equipment compartment 220, the cooling water flows directly from the main equipment compartment 220 into the pit compartment 230 and then into the stack pit 210.

[0056] To prevent backflow of cooling water during the accident, each second channel 420 is equipped with at least one check valve 440. The check valve 440 enables the second channel 420 to flow unidirectionally from the functional compartment 310 to the pit compartment 230, effectively blocking the backflow of water in the pit compartment 230 back to the functional compartment 310, so as to maintain the stability of the liquid level in the first flooded area 200.

[0057] In addition, the reactor building has a connecting passage 240 that connects the sump compartment 230 and the reactor pit 210. Protective components are installed in the protective passage, including a first protective door 241 and a second protective door 242 arranged sequentially from bottom to top. The first protective door 241 is used to shield radiation in the reactor pit 210 and is normally closed, only opening during equipment maintenance or emergency operations. The second protective door 242 is a passive one-way door that can be opened unidirectionally from the sump compartment 230 to the reactor pit 210, allowing only cooling water to flow unidirectionally from the sump compartment 230 into the reactor pit 210. It opens automatically based on pressure difference during accident conditions. It should be noted that the first protective door 241 and the second protective door 242 are arranged sequentially in the vertical direction; that is, the bottom of the first protective door 241 is connected to the bottom wall of the connecting passage 240, and its top is spaced apart from the top wall of the connecting passage 240. The bottom of the second protective door 242 is spaced apart from the bottom wall of the connecting channel 240, and its top is connected to the top wall of the connecting channel 240. Thus, the first protective door 241 and the second protective door 242 together form a sealing effect on the connecting channel 240.

[0058] It should be noted that the first protective door 241 is always closed. The second protective door 242 located above it serves as a flow channel for cooling water under accident conditions. When the liquid level in the pit compartment 230 exceeds the top of the first protective door 241, the second protective door 242 will naturally open under water pressure to form a flow channel, so that cooling water can flow into the sump 210, ensuring that cooling water continuously and controllably converges into the sump 210 under passive conditions.

[0059] Understandably, during reactor power operation, both the first protective door 241 and the second protective door 242 are closed to ensure the organization of airflow inside the reactor pit 210.

[0060] In addition, the protective assembly also includes a mounting wall 243 for installing a first protective door 241 and a second protective door 242. The first protective door 241 is located on the side of the mounting wall 243 facing the pit compartment 230, so that the first protective door 241 can be opened from the pit compartment 230 during maintenance. The second protective door 242 is located on the side of the mounting wall 243 facing the storage pit 210, so that the second protective door 242 can be opened on one side facing the storage pit 210.

[0061] In some embodiments, the reactor building also includes a reactor pool 250, which is an area within the reactor building providing environmental space for reactor loading and unloading operations and equipment maintenance. During loading and unloading, the pool maintains a high water level to ensure that the fuel assemblies are always submerged during loading and unloading, achieving radiation safety objectives during the loading and unloading operations. To provide sufficient water depth, the reactor pool 250 is designed with partial submersion. Figure 4 As shown, the reactor pool 250 includes a first region 251 located above the reactor pit 210 and a second region 252 located above a portion of the main equipment compartment 220. The depth of the second region 252 is greater than the depth of the first region 251.

[0062] Furthermore, such as Figure 5 As shown, a third channel 430 connecting the main equipment compartment 220 is provided at the bottom of the second area 252 of the reactor pool 250. At least one check valve 440 is provided in the third channel 430, which can prevent water in the flooded area from flowing back into the reactor pool 250.

[0063] The third channel 430 is normally open to allow cooling water in the reactor pool 250 to enter the main equipment compartment 220 via the third channel 430 during accident conditions. Before performing refueling operations during overhaul, the one-way valve 440 must be manually closed to seal the third channel 430 and prevent water leakage from the reactor pool during refueling.

[0064] It should be explained that the connectivity mentioned in this article refers to the connectivity of cooling water channels. The connectivity of equipment wiring, personnel passage, or ventilation systems between different spaces is not within the scope of connectivity defined in this invention. For example, in the reactor building, each main equipment compartment 220 and the reactor pit 210 must be provided with a through hole for the main pipeline to pass through, and the two ends of the main pipeline are respectively connected to the steam generator 221, the reactor coolant pump 222, and the reactor pressure vessel 211; or, the equipment in the functional compartment 310 is provided with cables for power supply and signal transmission, and the cables need to pass through the reactor building and be linked with the equipment in other spaces.

[0065] Therefore, it can be understood that the reactor building also includes process piping 620. For process piping 620 located in different areas, leak-proof measures also need to be implemented according to specific circumstances to maintain the stability of the liquid level in the flooded area. Specifically, such as... Figure 7 and Figure 8 As shown, the reactor building includes a wall 600 and process pipeline protection sleeves 610 passing through the wall 600. The process pipeline protection sleeves 610 include a first sleeve located below the submerged liquid level and a second sleeve located above the submerged liquid level. It should be noted that the wall 600 mentioned here is a partition that separates various spaces, including but not limited to floor slabs, solid walls between adjacent functional compartments 310, etc.

[0066] Specifically, for the first sleeve below the submerged liquid level, a sealing element 630 connected to the process pipeline 620 is installed at one end of the first sleeve to seal the gap between the process pipeline 620 and the first sleeve, thereby preventing cooling water from leaking outward through the gap between the first sleeve and the process pipeline 620. The second sleeve, being above the submerged liquid level, does not require additional sealing between itself and the process pipeline 620; it only needs to meet conventional fire protection, radiation protection, and airtightness requirements. It is understood that the sealing element 630 can be a C-type end cap (such as...). Figure 7 (as shown) or metal bellows structure (such as Figure 8 (as shown in the figure), these sealing structures are all mature solutions well known to those skilled in the art when sealing, and will not be described in detail here.

[0067] A second aspect of this application provides a layout design method for a reactor building, which is applied to the design of the reactor building described in the foregoing embodiments. Specifically, the layout design method includes the following steps: S100, Determine the location of the crater 210 and the flooding level; S200, The sump 210 and the main equipment compartment 220 are designated as the first flooding zone 200, and the first flooding zone 200 is set below the flooding level: S300, the functional compartment 310 is set as the second flooded area 300, and a first channel 400 is set to connect the second flooded area 300 and the second flooded area 300, so that the cooling water in the first flooded area 200 overflows to the second flooded area 300 through the first channel 400, or so that the cooling water in the second flooded area 300 flows to the first flooded area 200 through the first channel 400.

[0068] Furthermore, it may also include the following steps: S400. Classify each functional compartment 310 according to the safety level from low to high: functional compartment 310 containing items with no safety level, functional compartment 310 containing items with low safety level, and functional compartment 310 containing items with high safety level. Then flood them in the order of no safety level, low safety level, and high safety level.

[0069] The third aspect of this application proposes a nuclear power plant, which includes the reactor building mentioned in any of the above embodiments, and has the technical solutions and beneficial effects of the above embodiments, which will not be repeated here.

[0070] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A reactor building, characterized in that, include: Internal refill water tank; A first flooded area, the first flooded area includes at least a pile pit and a main equipment compartment connected to the pile pit, the pile pit has a flooding level, the first flooded area is located below the flooding level, and the first flooded area is connected to the internal refueling tank. The second flooded area includes at least one functional compartment, and the second flooded area is connected to the first flooded area by a first passage. The reactor building is configured such that, under accident conditions, cooling water in the internal refueling tank enters the first flooding zone, and when the water level in the first flooding zone rises to a set height above the flooding level, the cooling water overflows into the second flooding zone through the first channel.

2. The reactor building according to claim 1, characterized in that, The second flooded area includes a distribution area and multiple functional compartments. The distribution area is connected to the first flooded area through the first channel. The distribution area is located above each of the functional compartments. The distribution area is configured to sequentially introduce cooling water into each of the functional compartments in a set order.

3. The reactor building according to claim 2, characterized in that, The reactor building also includes a ground floor separating the distribution area and the functional compartments. The ground floor has a connecting opening between the distribution area and the functional compartments. The reactor building also includes a cofferdam, which protrudes from the ground floor and surrounds the outer perimeter of the connecting opening. The cofferdam is configured such that at least two cofferdams have different elevations. When the cooling water level in the distribution area is higher than the elevation of the cofferdam, the cooling water enters the corresponding functional compartment.

4. The reactor building according to claim 3, characterized in that, At least one of the functional compartments is designated as a first functional compartment, which is used to accommodate the injection equipment and the pipes and valves connected thereto; wherein the elevation of the cofferdam corresponding to the first functional compartment is greater than the elevation of the cofferdam corresponding to the other functional compartments.

5. The reactor building according to claim 4, characterized in that, The reactor building includes two first functional rooms, and the cofferdams corresponding to the two first functional rooms have different elevations.

6. The reactor building according to claim 1, characterized in that, The first flooded area also includes a pit compartment connected to the pile pit. The pit compartment is located below the main equipment compartment, and each of the main equipment compartments is connected to the pit compartment.

7. The reactor building according to claim 6, characterized in that, The floor height of the functional compartment is greater than the top height of the pit compartment. The reactor building also includes a second channel connecting the pit compartment and the functional compartment. The second channel is configured to transport cooling water from the functional compartment to the pit compartment.

8. The reactor building according to claim 7, characterized in that, The second channel is provided with at least one check valve, which enables the second channel to unidirectionally deliver cooling water in the direction from the functional compartment to the pit compartment.

9. The reactor building according to claim 6, characterized in that, The reactor building has a connecting passage connecting the sump compartment and the reactor pit. The reactor building also includes a protective component disposed in the connecting passage. The protective component includes a first protective door and a second protective door arranged sequentially from bottom to top. The first protective door is normally closed, and the second protective door can be opened unidirectionally from the sump compartment to the reactor pit.

10. The reactor building according to claim 9, characterized in that, The protective assembly also includes a mounting wall for installing the first protective door and the second protective door, wherein the first protective door is disposed on the side of the mounting wall facing the pit compartment, and the second protective door is disposed on the side of the mounting wall facing the pit.

11. The reactor building according to claim 9, characterized in that, The reactor building also includes a reactor pool, which comprises a first region located above the reactor pit and a second region located above a portion of the main equipment compartments, the second region being deeper than the first region.

12. The reactor building according to claim 11, characterized in that, The second area is connected to the main equipment compartment below through a third channel, which is equipped with at least one check valve that can control the opening and closing of the third channel.

13. The reactor building according to claim 1, characterized in that, The reactor building includes walls, and the reactor building also includes a protective sleeve penetrating the walls and process pipelines passing through the protective sleeve. The protective sleeve includes a first sleeve located below the submerged liquid level and a second sleeve located above the submerged liquid level. The first sleeve is provided with a sealing element connected to the process pipeline to seal the gap between the process pipeline and the first sleeve.

14. A layout design method for a reactor building, applied to the reactor building according to any one of claims 1 to 13, the layout design method comprising the following steps: Determine the location of the crater and the flooding level; The pile pit and the main equipment compartment are set as the first flooding zone, and the first flooding zone is set below the flooding liquid level; The functional compartment is set as a second flooded area. A first channel is set between the second flooded area and the first flooded area so that when the water level in the first flooded area rises to a set height above the flooded level, the cooling water in the first flooded area overflows into the second flooded area through the first channel.

15. A nuclear power plant, characterized in that, Includes the reactor building as described in any one of claims 1 to 13.

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