REACTOR BODY STRUCTURE AND REACTOR SYSTEM

Abstract

A reactor shell structure (100) and a reactor system (300) are provided. The reactor shell structure (100) comprises: a reactor pressure vessel (1) containing a bottom cover (3) with an inner wall (32) in the shape of a bow; reactor internal fittings (2) containing a core support bottom plate (22); and a core (21) placed on the core support bottom plate (22); where the core support bottom plate (22) is positioned below the center of the sphere (31) of the inner wall (32) in the shape of a bow, and a flow guiding corner (221) is provided on the outer edge of the core support bottom plate (22); the core support bottom plate (22) is fitted with a series of through holes (222) which is a stepped hole and contains a top hole (222a) on the top and a bottom hole (222b) on the bottom, the diameter of which is smaller than the diameter of the top hole (222a).

Description

1 TARIFF REACTOR BODY STRUCTURE AND REACTOR SYSTEM REFERENCE TO RELEVANT APPLICATIONS This application was submitted on June 14, 2023, and concerns 'High security and low flow resistance'. Chinese document number 202310709542.5, titled "Reactor body structure and reactor system". It claims priority of the patent application, and the application in question, in its entirety, is referenced. It is included here via this method. TECHNICAL FIELD This invention relates to the field of nuclear reactor technology and, in particular, to a reactor casing structure. It is directed towards a reactor system. 10 STATE OF THE ART A nuclear reactor essentially consists of a core, a reactor pressure vessel, and a reactor inner tube. It includes its components. The reactor pressure vessel consists of a cylindrical shell, a top cover, and a bottom cover. It consists of a cover. The core is the reactor internal equipment inside the reactor pressure vessel. It is located inside. In the event of a serious accident in the core, 15 kilometers outside the reactor. a safety injection system is activated and the core is submerged. The aim is to inject boron-containing water into the reactor. Existing nuclear... In reactor shell structures, the core reactor pressure vessel is relatively high compared to the bottom cover. It is located in a position where, in other words, the volume below the core is relatively small. It is large. Therefore, in order for the core to be left underwater, a large amount of boron is needed, which is 20 Water is needed, and this takes a long time. This is a serious situation. In the event of an accident, it negatively affects the removal of heat from the core and therefore It reduces the safety of the reactor. A BRIEF DESCRIPTION OF THE INVENTION Considering the shortcomings in the current state of the art, this invention, with its 25 cores... due to the long time required to leave it underwater and from the core In order to overcome the safety problems that make heat transfer unfavorable, both high This provides a reactor shell structure that offers both safety and low flow resistance. The first aspect of this invention provides for a reactor shell structure which includes the following: a bow. A reactor pressure vessel containing a bottom cover with a shaped inner wall; reactor pressure vessel 30 reactor internal equipment arranged within it and including a core support substrate; 2 and a core arranged on a core support substrate; here, the core support substrate The plate is positioned below the center of the sphere on the arc-shaped inner wall, and the core The outer edge of the support base plate is equipped with a flow guiding corner; additionally, the core The support base plate includes a top hole on the top and a bottom hole on the bottom, and the diameter of the bottom hole... with a through hole that is a stepped hole smaller than the diameter of the top hole 5 It is equipped. Preferably, the flow guiding corner and the curved inner wall of the bottom cover should be evenly spaced or It creates an approximately equally spaced flow channel, and approximately equally spaced flow The range of variation in channel width does not exceed 100 mm. Ideally, the flow guiding corner is a conical corner or an arc corner, with the lower 10 of the conical corner Its diameter is smaller than its top diameter, and the angle between the outer wall of the conical corner and the vertical direction is 5°. It is between 10°. Preferably, the upper surface of the core support sub-plate should be 0 degrees Celsius above the center of the sphere of the arc-shaped inner wall. It is located below 300 mm. Ideally, the top surface of the core support subplate and the center of the sphere of the arc-shaped inner wall should be 15. The distance between them is 250 mm. Ideally, the diameter of the bottom hole of the through-hole is between 38 mm and 64 mm. Ideally, the reactor shell structure should consist of, from the outside to the inside, a reactor pressure vessel cylinder, a The reactor pressure vessel is equipped with a hanger basket cylinder and a core housing. No neutron shielding plate is arranged between the cylinder and the suspension basket cylinder. 20 Preferably, the thickness of the hanging basket cylinder should be between 60 mm and 90 mm, with the core housing intact. thickness between 30 mm and 100 mm and core housing with hanging basket cylinder. The gap between them is between 30 mm and 60 mm. Preferably, the thickness of the hanging basket cylinder should be 60 mm, and the thickness of the core housing should be 30 mm. The gap between the hanger basket cylinder and the core housing is 40 mm. 25 Ideally, the reactor pressure vessel also includes a top cover, which should be a single, integral part. It has a monolithic structure, and the bottom cover also has a monolithic structure. Ideally, an outlet tube is arranged on the reactor pressure vessel; the inside of the outlet tube It has a conical opening on one side, and the inner diameter of this conical opening is the same as the outer diameter of the outlet pipe. It is larger than its diameter. 30 Ideally, the conical mouth in question should be a conical flow with a conical surface between 5° and 15°. It is a channel. 3 The second aspect of this invention involves a pump, a steam generator, and a reactor shell structure. It provides a reactor system; the reactor shell structure in question includes the following: A reactor pressure vessel containing a bottom cover with a curved inner wall; reactor pressure vessel reactor internal equipment arranged within it and including a core support substrate; and 5 a core arranged on a core support base plate; here, the core support base The plate is positioned below the center of the sphere on the arc-shaped inner wall, and the core The outer edge of the support base plate is fitted with a flow guiding corner; core support The bottom plate includes a top hole on the top and a bottom hole on the bottom, and the diameter of the bottom hole is the same as the top hole. a through hole which is a stepped hole smaller than the diameter of the hole 10 It is equipped; The reactor pressure vessel has an inlet pipe and an outlet pipe, and the pump outlet The fluid is connected to the inlet pipe of the reactor pressure vessel, and the outlet pipe of the reactor pressure vessel. The pipe is connected to the steam generator via a fluid connection, and the steam generator is connected to the pump inlet. It is fluid-related. 15 One or more technical solutions provided in the sample applications of this invention shall be at least It has the following technical effects or advantages: According to this invention, the position of the core support substrate is such that the arc-shaped inner wall forms a sphere. By adjusting it to the bottom of the center, the core will be underwater in case the core melts. The time required for release is reduced by external water injection, thus ensuring safety. is being increased. In addition, a flow is created at the outer edge of the core support substrate. The arrangement of the guiding corners not only reduces fluid resistance, but also... The flow of fluid rapidly downwards over time is directed rapidly under the influence of the flow channel. By allowing it to be modified, it improves the smoothness of the flow distribution at the core input. The stepped hole on the core support base plate is narrow at the bottom and wide at the top, directing the flow. 25 under the coordination of its corner, equal to the transition zone in the bottom cover of the reactor pressure vessel. or by creating a flow channel of approximately equal cross-section, allowing the fluid to flow under the influence of the flow channel. This enables rapid changes in direction, thus allowing for a more fluid core. The flow is directed to the surrounding vents and the flow vents around the core The flow distribution effect is being improved. 30 According to this invention, the core support base plate is located below the center of the sphere of the arc-shaped inner wall. placement on the side, flow direction on the outer edge of the core support subplate. corner arrangement and core support base plate, narrow at the bottom and wide at the top. By providing stepped holes, the three components can work together, only 4 This not only reduces fluid resistance inside the reactor pressure vessel, but also... It enhances security by ensuring a smoother distribution of the core's input flow. According to this invention, increasing the thickness of the core casing and the hanging basket cylinder, Adjusting the width of the water gap between the core housing and the hanger basket cylinder, and Elimination of the neutron shielding plate on the outer wall of the suspension basket cylinder 5 In this way, the flow area of ​​the flow channel on the outer wall of the hanger basket cylinder is increased, and this Flow resistance in the region is reduced; thus, the power of the main pump for the circulating flow is increased. the need is being reduced; at the same time, the nucleus is being irradiated for a long period of time due to neutron irradiation. By avoiding the problem of stress corrosion cracking that may occur in the bolts in this region, The reliability of the reactor's internal equipment is being increased. 10 BRIEF DESCRIPTION OF THE FIGURES This application provides more detailed technical solutions to the sample applications. To illustrate this, the attached drawings will be used in the sample applications of this application. is briefly introduced below. Figure 1 shows a schematic view of a reactor shell structure in the known state of the art. 15 It shows; Figure 2 shows a schematic of a reactor shell structure according to a specific example application of this invention. It shows its appearance; Figure 3 shows the bottom cover of the reactor shell structure according to a specific example application of this invention. It shows a partially magnified view of its location; 20 Figure 4 shows a core support substrate according to a specific example application of this invention. It shows a partially magnified view; Figure 5 shows a partial design of an outlet pipe according to a specific example application of this invention. It shows an enlarged view; Figure 6 shows a schematic view of a top cover according to a specific example application of this invention. 25 It shows; Figure 7 shows a schematic view of a bottom cover according to a specific example application of this invention. It shows; and Figure 8 shows a schematic of a reactor system according to a specific example application of this invention. It shows its appearance. 30 REFERENCE NUMBERS: 100 – Reactor shell structure; 1 – Reactor pressure vessel; 2 – Reactor internal equipment; 21 – The kernel; 22 – Core support base plate; 5 221 – Flow guidance corner; 222 – Through holes; 222a – Top hole; 222b – Bottom hole; 23 – Core casing; 10 24 – Core top plate; 3 – Bottom cover; 31 – The spherical center of the arc-shaped inner wall; 32 – Arc-shaped inner wall; – Hanging basket cylinder; 15 6 – Outlet pipe; 61 – Conical mouth; 7 – Top cover; 8 – Inlet pipe; 9 – Cylinders; 20 300 – Reactor system; 301 – Pump; 302 – Steam generator DETAILED DESCRIPTION OF THE INVENTION In order to better understand the technical solutions to this application, this application's 25 Example applications are explained in detail below, along with the attached illustrations. Figure 1 shows a schematic view of a reactor shell structure (200) of the known state of the art. It shows. As shown in Figure 1, the reactor shell structure of the known state of the art (200) is the basic as a core (201), reactor internal equipment (202), a reactor pressure vessel (203), a 30 The control rod consists of the drive mechanism (204) and other equipment. Inside the reactor hardware (202) is used to house and support the kernel (201), reactor pressure vessel (203), reactor internal equipment (202), core (201) and internal coolant It contains the fluid and provides support for the control rod drive mechanism (204). 6 The reactor pressure vessel (203) mainly consists of a top cover (2031), a cylinder (2032) and a bottom cover. It includes (2033). Reactor shell structure (200), from outside to inside, respectively the cylinder of the reactor pressure vessel (2032), Equipped with a hanging basket cylinder (205) and a core housing (206), the hanging basket A neutron shielding plate (207) is arranged on the outer wall of the cylinder (205). 5 The safety of reactors in nuclear power plants has always been a primary concern. In the conventional reactor shell structure (200), the reactor core (201), the reactor pressure vessel (203) is located in a relatively high position relative to the lower cover (2033). The core (201), In general, the spherical center of the bottom cover (2033) of the reactor pressure vessel (203) is approximately 750 It is positioned on mm. This situation means that in the event of a serious accident, the core (201) will be short 10 mm. external water injection is carried out to submerge the reactor for a period of time and from This makes it difficult to remove the heat in a timely manner. The applicant encountered the following problem during the research and development process: If the position of the kernel (201) is directly lowered, on the one hand the kernel The fluid distribution at the inlet becomes irregular, while the fluid flow resistance is 15. is increasing; in particular the flow resistance in the area of ​​the lower cover (2033) of the reactor pressure vessel (203). is increasing significantly. In terms of fluid distribution, the lower volume decreases when the core (201) is lowered. This prevents the fluid inside the reactor from flowing sufficiently, and the reactor pressure vessel... (203) The bottom cover (2033) cannot be completely dispersed after a 180° change in direction; this 20 This situation leads to the flow distribution at the core (201) being extremely irregular. It opens. In the traditional kernel (201), the deviation in the input flow distribution is greater than 13%, This deviation increases even more when the kernel (201) is lowered. Kernel (201) The irregular flow distribution at the inlet also leads to the following two main problems: 1) Simultaneous and complete combustion of hundreds of fuel bundles within the core 25 not suitable; low-flow fuel assemblies, efficient of the whole core (201) limiting combustion or otherwise low-flow fuel bundles easily It can be damaged by burning; 2) The fluid flows from high-flow channels to low-flow channels, which is related to By increasing cross-flow between fuel bundles in the channels, larger fuel rods can be used. 30 This causes vibration and increases the risk of wear and damage to the fuel rods in the fuel bundles. It increases significantly. 7 From a fluid flow resistance perspective, as the unit power exceeds 1350 MWe, the reactor to accommodate more fuel assemblies and generate more heat The body structure needs to be continuously enlarged and the core (201) More refrigerant is needed to cool it down. However, large Due to current capacity limitations in the forging of scale vessels, the reactor structure is 5 The outer diameter of the container is limited. Therefore, the unit power is only measured within the reactor structure. This can be increased by increasing the fluid flow rate, which is why the reactor shell structure (200) This increases the fluid resistance inside. On this basis, the position of the core (201) is further If it is lowered, the outer edge of the core support subplate supporting the core (201) The fluid volume between the reactor pressure vessel (203) and the bottom cover (2033) is decreasing and this 10 The fluid resistance in the region increases significantly, negatively impacting the overall flow resistance of the reactor structure. It affects. As a result, the increasing flow resistance of the reactor coolant main pump (301) This necessitates a higher power requirement for the coolant main pump to overcome the challenge. Increased power requirements lead to the following problems: 1) significantly complicates the development of the main pump; 15 2) Circulating the coolant inside the reactor requires more energy, and This leads to increased electricity consumption. Based on the problems described above, this invention aims to provide high power, low flow resistance, and high performance. a passive reactor shell structure and a reactor system that offers reliability and safety It recommends. 20 Figure 2 shows a reactor shell structure (100) according to a specific example application of this invention. It shows a schematic view. As shown in Figure 2, the reactor shell structure (100) of this example application is a The core (21) includes a reactor pressure vessel (1) and reactor internal equipment (2). Reactor pressure vessel (1), reactor internal equipment (2), core (21) and internal coolant 25 It is used to house (not shown). Reactor pressure vessel (1), a top It includes a lid (7), a cylinder (9) and a bottom lid (3). The bottom lid (3) has a spring-shaped inner It has a wall (32). The reactor pressure vessel (1) has an inlet pipe (8) and an outlet pipe (6). It is equipped. The coolant enters the reactor pressure vessel (1) from the inlet pipe (8) and It flows out through the outlet pipe (6). The reactor internal equipment (2) is a core support sub-30 It includes the plate (22) and the core (21) on the core support subplate (22) It has been arranged. 8 Reactor shell structure (100), from outside to inside, respectively the cylinder of the reactor pressure vessel (9), one It is equipped with a hanger basket cylinder (5) and a core housing (23). Hanger basket cylinder (5) carries the core (21) and is like a fuel bundle inside the core casing (23). The core components (not shown) have been edited. The main flow path of the coolant in the reactor is shown by the thick arrow in Figure 2: main pump 5 The coolant driven by the reactor pressure vessel (1) through the inlet pipe (8) entering it; located between the cylinder (9) of the reactor pressure vessel and the hanger basket cylinder (5) The field flows downwards through the annular gap; reactor pressure vessel bottom cover (3) by changing direction 180° through the flow holes of the core support bottom plate (22) (i.e. (through the passage holes) flows upwards and then into the core (21) (fuel bundles) 10 It enters. The coolant passes through the fuel bundles and the core top plate (24). reaching the upper chamber area and then the outlet pipe (6) of the reactor pressure vessel (1) It flows out of the reactor shell structure (100) through the melting of the core (21). In this case, the direct safety valve located on the cylinder (9) of the reactor pressure vessel (1) Inject water into the core (21) via the injection inlet tube (not shown) 15 The core (21) is submerged in water and cooled by injecting water. Figure 3 shows the bottom of the reactor shell structure (100) according to a specific example application of this invention. It shows a partially enlarged view of the cover (3). As shown in Figure 3, the arc-shaped inner wall (32) of the lower cover (3) is connected to the center of a sphere (31) has; core support bottom plate (22), lower 20 of the sphere center (31) of the arc-shaped inner wall (32). It is located on the side and a flow at the outer edge of the core support subplate (22) The guiding corner (221) is arranged. The core support base plate (22) has a stepped hole. It is equipped with a passage hole (222) of the type In this invention, the position of the core support base plate (22) is determined by the sphere of the arc-shaped inner wall (32). By adjusting to the lower side of the center (31), the volume at the lower side of the core (21) is reduced and 25 If the core (21) melts, the core (21) can be kept underwater by external water injection. The time required for disabling the reactor is shortened, thus improving its resilience to serious accidents. Capabilities are being enhanced and security is being improved. In this respect, a flow guiding corner on the outer edge of the core support subplate (22) (221) By arranging the outer contour of the core support bottom plate (22) and the reactor pressure 30 between the spring-shaped inner wall (32) of the bottom cover (1) of the container (1) or approximately An evenly spaced flow channel is created. This structure allows the fluid to flow in the region in question. by widening the flow area to reduce fluid resistance inside the reactor pressure vessel (1) 9 not only does it not remain, but it also rapidly flows downwards due to the effect of the fluid flow channel. by causing the flow at the outer edge of the core support subplate (22) to change direction. This makes it possible to direct more fluid into the holes and thus the core (21) It improves the uniformity of the flow distribution at the inlet. The evenly spaced flow channel, the curvature of the flow guiding corner 221, the curve of the arc-shaped inner wall 5 (32) has the same curvature as the core support subplate (22) and the spring-shaped inner The distances in the width direction of the flow channel created between the wall (32) should be equal This refers to the approximately equally spaced flow channels of the core support substrate. (22) flow created between the flow guiding corner (221) and the curved inner wall (32) This means that the range of variation in the channel width should not exceed 100 mm. For example, 10 flow direction corner (221) at a specific location and the curved inner wall (32) of the bottom cover (3) If the vertical distance between them is 300 mm, the flow guiding corner (221) along the flow channel The width between the curved inner wall (32) should not exceed 200 mm to 400 mm. If the cross-section of the flow channel suddenly narrows or widens, due to the inertial effect... Significant eddies form between the main flow channel and the point of abrupt change; these 15 Vortices are formed when the pressure around this sudden change point drops sharply. This increases the flow resistance. In this invention, the flow resistance of the core support substrate plate (22) is increased. by arranging the holes as passage holes (222) which are narrow at the bottom and wide at the top The flow resistance in the main flow channel is reduced. As a result of flow field analyses, it is determined that the flow is in a stepped manner. 20 narrowing and widening passage holes (222) together with the flow guiding corner (221) by working to reduce the vortices formed in the flow holes around the core (21); thus More fluid is directed into the transition holes (222) around the core (21) and the flow distribution effect of the transition holes (222) around the core (21) is improved It is seen. According to this invention, the core support subplate (22) has a curved inner wall (32) with a sphere 25 Placement of the lower side of the center (31) on the outer edge of the core support bottom plate (22) Arrangement of the flow guiding corner (221) and on the core support subplate (22) By providing narrow passage holes at the bottom and wide passage holes at the top (222), the three components in question Coordination is only to reduce the fluid resistance inside the reactor pressure vessel (1) not only that, but also the flow distribution at the inlet of the core (21) is relatively uniform 30 This ensures and increases safety. The flow resistance of the reactor shell structure (100) and If the flow distribution performance at the core inlet meets the requirements, the reactor The height of the core (21) relative to the bottom cover (3) of the reactor pressure vessel (1) is possible It is set to the lowest possible level. As shown in Figure 3, the upper surface of the core support bottom plate (22) and the spring-shaped inner The distance between the center of the sphere (31) and the wall (32) is between 0 and 300 mm. Preferably, The sphere center (31) of the upper surface of the core support bottom plate (22) and the arc-shaped inner wall (32) The distance between them is approximately 250 mm. The bottom of the upper surface of the core support bottom plate (22) Positioning the lid (3) below the center of the sphere (31), melting the core (21) 5 In this case, external water injection is required to leave the core (21) underwater. This contributes to shortening the duration and thus improves the reactor's resilience to serious accidents. Its capabilities are being enhanced. In one example application, flow guiding corner 221 is either a conical corner or an arc corner; The lower diameter of the conical corner is smaller than its upper diameter, and the vertical distance between the outer wall of the conical corner and the outer wall is 10°. The angle between them is between 5° and 10°. The outer edge of the lower end of the core support subplate (22) The transition zone between the contour and the bottom cover (3) of the reactor pressure vessel (1) is evenly spaced or They are arranged to form a flow channel with approximately equal spacing between them. The slope at the tangent point does not exceed 30°; that is, the flow is as shown in Figure 3. the inclined surface of the orientation corner (221) and a 15 in the corresponding position on the arc The angle between the tangent lines does not exceed 30°. This ensures a smooth flow of the refrigerant. This allows the flow to continue in this way, and the variation in pressure drop is reduced. Three-dimensional flow field Analyses show that the flow distribution deviation at the core inlet for 193 fuel assemblies is less than 6%. This shows that the arrangement of the flow routing corner (221) is only this It not only reduces flow resistance in the region, but also the flow at the core inlet is 20 It also improves the uniformity of the distribution. The outer edge of the lower end of the reactor internal equipment. Implementation of the contour as a flow guiding corner (221) in the range of 5° to 10°, It is even more advantageous in terms of flow distribution at the core inlet. Furthermore, the flow in this invention Note the difference between the directional corner (221) and the commonly used chamfer. It should be noted that the function of the flow guiding corner (221) in this invention is to reduce flow resistance and 25 While the function of the bevel is to increase the uniformity of the flow distribution at the core inlet; the function of the bevel is to remove burrs. The goal is to eliminate the problem and ensure an aesthetically pleasing appearance. Figure 4 shows a core support substrate (22) according to a specific example application of this invention. This shows a partially magnified view. As shown in Figure 4, the through hole (222) has a top hole (222a) on the top and a 30 on the bottom. It includes a lower hole (222b), the diameter of which is greater than the diameter of the upper hole (222a). It is small. As shown in Figure 4, the diameter of the bottom hole (222b) of the through hole is between 38 mm and 64 mm. It is within the range and the diameter of the upper hole (222a) shown is equal to or greater than 70 mm. 11 The core support subplate (22) allows the flow channel to gradually narrow and widen. It is implemented in the form of a stepped coolant flow orifice to provide the bottom orifice (222b). It is important to choose a diameter between 38 mm and 64 mm; a diameter that is too small will compromise fuel safety. a very large diameter will negatively affect the heat exchange (heat transfer) effect of the core. will reduce. 5 As shown in Figure 1, in the known state of the technology, conventional reactors typically: neutron radiation dose to which the reactor pressure vessel (203) is exposed during its service life In order to limit it, a neutron shielding plate is placed on the outer wall of the suspension basket cylinder (205). (207) is going to be regulated. Neutron shielding plate (207), during reactor operation To limit the arrival of fast neutrons emitted from the core (201) to the reactor pressure vessel (203) 10 In order to reduce the adverse irradiation effects on the reactor pressure vessel (203), The outer part of the suspension basket cylinder (205) to cover the entire height region of the core (201). It is mounted on the wall. Neutron armor plate (207) is usually bolted to the outer wall of the hanger basket cylinder (205). It is assembled via. The bolts located in this area are 15 from the reactor core (201). due to prolonged exposure to emitted fast neutrons, neutron irradiation It is exposed to stress corrosion cracking. At the same time, the hanger basket cylinder (205) its outer wall being located in an area where reactor coolant flows at high speed Therefore, the placement of a neutron shielding plate (207) on this outer wall is only possible in this region. not only does it increase fluid resistance, but also the neutron shielding plate (207) and related 20 It also increases the risk of parts failing. Flow resistance of neutron shield plate (207) and parts associated with neutron shield plate (207) In order to address the problem of increasing the risk of failure, a specific example of this invention In the application, the reactor shell structure (100) is externally constructed with water gaps between them. Inwards, respectively, a reactor pressure vessel cylinder (9), a hanger basket cylinder (5) and a 25 It is equipped with a core housing (23) and neutron slowing and shielding of metal and water. by taking advantage of their effects, between the reactor pressure vessel cylinder (9) and the hanger basket cylinder (5) No neutron shielding plates have been installed. In a conventional reactor, the thickness of the core casing (206) is usually between 20 mm and 25 mm The minimum water level between the core housing (206) and the hanging basket cylinder (205) is 30 The gap is between 80 mm and 100 mm and the thickness of the hanger basket cylinder (205) is approximately 50 The dimensions are mm. The applicant requested thermal-hydraulic analysis, shielding analysis, and reactor physics analysis. and by performing structural-thermal-solid flow multi-physics domain coupled analyses, the core the thickness of the casing (23), between the core casing (23) and the hanger basket cylinder (5) 12 He adjusted the gap and the thickness of the hanger basket cylinder (5); thus, the neutron shield plate This made its removal possible. In one example application, the thickness of the hanging basket cylinder (5) is between 60 mm and 90 mm, The thickness of the core housing (23) is between 30 mm and 100 mm and the hanger basket cylinder (5) The gap between the core casing (23) and the core casing is between 30 mm and 60 mm. 5 The wall thickness of the core casing (23) is conventionally between 20 mm and 25 mm. By increasing the thickness of the thermal neutrons emitted from the core (21) to the range of mm to 100 mm, the thickness of the thermal neutrons emitted from the core (21) is increased. absorption by the core housing (23) and thermal absorption of more fast neutrons The neutrons are slowed down. Core housing (23) and hanger basket cylinder (5) By adjusting the minimum water gap width between them to a range of 30 mm to 60 mm, core 10 further slowing down of neutrons (thermal and fast) coming out of the containment (23) and the suspension basket It is more effectively absorbed by the cylinder (5). The hanging basket cylinder (5) By increasing the wall thickness between 10 mm and 40 mm, thermal neutrons can be more It is possible to effectively absorb the reactor pressure vessel (1) exposed to The radiation dose is reduced. 15 Preferably, the thickness of the hanging basket cylinder (5) is 60 mm, the thickness of the core housing (23) is 30 The gap between the hanger basket cylinder (5) and the core housing (23) is 40 mm. As a result of reactor physical shielding analyses, on the outer wall of the hanger basket cylinder (5) Even without any neutron shielding plate, the reactor pressure vessel (1) has a 60-year lifespan. It has been confirmed that it can have a design life. The core casing (23) thickness is 30 20 40 mm, the minimum water gap between the core housing (23) and the hanger basket cylinder (5) In the case where the thickness of the hanger basket cylinder (5) is 60 mm, the reactor pressure vessel (1) The neutron flux at the end of its life is 2.82 × 10¹⁹ n / cm², which is a value for conventional reactor shells. This corresponds to approximately half of its structure. In this invention, increasing the thickness of the core housing (23) and the hanging basket cylinder (5), 25 Adjusting the width of the water gap between these two components and the hanger basket cylinder (5) Thanks to the removal of the neutron shielding plate on its outer wall, only the cross-section of the flow channel is visible. Increasing the area does not reduce the flow resistance in this region, but it also increases the circulation flow rate. The power requirement of the main pump is reduced and the length of the bolts in the core (21) region is reduced. The problem of stress corrosion cracking due to prolonged neutron irradiation is also eliminated. 30 By removing the reactors, the reliability of the reactor internal equipment (2) is increased. In addition, in the event of a serious accident in which the core (21) melts, nuclear power plants An important serious accident mitigation measure is containing the molten material within a pressure vessel (IVR). 13 The purpose is to cool the outer wall of the bottom cover (3) of the reactor pressure vessel (1); The approach was first applied in the conversion of the Loviisa power plant. Today, IVR Although studies are being carried out on measures, the bottom of the pressure vessel (1) is mostly Focus on the melt pool (3) in the lid and the external melt containment, reactor shell Studies on the involvement of metal mass in IVR (Integrated Voltage Resistance) have been limited. 5 When the core (21) melts and settles on the bottom cover (3), a stratified melt pool is formed, and this The metal plate on top of the pool is due to its small mass and thin thickness. exposed to high heat flux density and a thermal focusing effect This occurs when the thickness of the metal layer is relatively small. There is a serious threat to the integrity of the reactor pressure vessel (1). The core (21) 10 If it melts, the weight of the metal contributing to heat transfer involved in the accident is relatively low. The core (21) is not suitable for heat transfer in severe accidents. In this invention, the mass of the core housing (23) and the suspension basket cylinder (5) is increased. In this way, under severe accident conditions (melting of the core (21)), the bottom cover of the reactor pressure vessel (1) (3) Heat transfer of the core (21) can be effectively improved. 15 Figure 5 shows a partial discharge pipe (6) according to a specific example application of this invention. This shows an enlarged view. As shown in Figure 5, the reactor pressure vessel (1) is equipped with an outlet pipe (6), There is a conical opening (61) on the inside of the outlet pipe (6); the said conical opening (61) inside (close to the inside of the reactor pressure vessel (1), i.e. on the right side in Figure 5 20 The diameter of the outer (remaining on the left side in Figure 5) is larger than the diameter of the conical mouth (61), It forms a conical flow channel, and this conical flow channel has a taper between 5° and 15°. It was applied at a surface angle. In this invention, the outlet pipe (6) of the reactor pressure vessel (1) is a conical connection structure. applied and the inner flow channel of the outlet pipe (6) with a conical surface in the range of 5° to 15° 25 It was created; this structure, on the one hand, reduces the diameter of the outlet pipe (6) of the reactor internal equipment. by increasing the flow resistance, on the other hand, the outlet of the reactor pressure vessel (1) By providing a gradual transition in the pipe (6), it contributes to reducing the flow resistance. It provides. In existing reactor pressure vessels, the top and bottom covers are made from multiple forged parts. This is caused by the formation of stress corrosion cracks. This creates a risk of corrosion cracking in the weld seams of the reactor pressure vessel cover. This increases the inspection time during operation and causes stress in the weld seams. 14 This corrosion carries the risk of crack formation, compromising the reliability of the reactor and It negatively affects safety. In this context, according to this invention, the pressure vessel (1) has both a top cover (7) and a bottom cover (3) It is designed as an integrated structure. Figure 6 shows the schematic view of the top cover (7) according to a specific example application of this invention; 5 Figure 7 shows the schematic of the bottom cover (3) according to a specific example application of this invention. It shows its appearance. As shown in Figure 6 and Figure 7, the top cover (7) and bottom cover of the reactor pressure vessel (1) (3) designed in an integrated manner, and the relevant structures are manufactured by forging as a single piece. Thus, a weld seam of 10 was formed at the pressure-exposed boundaries of the components in question. This ensures that stress corrosion does not occur in the weld seams that form the pressure limit. The risk of cracking is eliminated and thus the reliability of the pressure vessel (1) is ensured. It is increased. At the same time, the reactor pressure vessel (1) is checked during operation. By reducing the number of required weld seams, the radiation dose to which personnel are exposed is also decreased. In the sample applications of this invention described above, 15 different sample applications By combining and improving these elements, multiple beneficial effects can be achieved. Firstly, 1) a core casing with suitable thicknesses for the reactor internal equipment (2) (23) and hanging basket cylinder (5) are provided; core housing (23) and hanging basket cylinder the water gap between (5) and the hanger basket cylinder (5) and the reactor pressure vessel (1) The widths of the water gap are adjusted and the neutron shield 20 from the outer surface of the hanger basket cylinder (5) By removing the plate, the flow resistance in the ring gap region is reduced. 2) the outer edge of the core support subplate (22) carrying the core and the reactor pressure vessel (1) the transition zone between the lower cover (3) as a flow channel with equal or nearly equal cross-section is arranged so that the reactor internal equipment (2) at the lower end and the lower cover (3) passage Flow resistance is reduced in the region; 25 3) core support bottom plate (22), with stepped (stepped) coolant flow holes By being equipped, gradual narrowing and widening of the flow channel is achieved, thus the core The flow resistance of the support subplate (22) is reduced; and 4) The outlet pipe (6) of the pressure vessel is fitted with a conical connection interface. The flow resistance in the region is reduced. 30 Thanks to the improvements mentioned above (1), 2), 3), and 4), calculations As shown, the total flow resistance of the reactor shell structure (100) is approximately 30%. This can be reduced. This situation not only facilitates the development of the main pump, but also... not only that, it reduces the power of the main pump by approximately 2300 kW. A nuclear power unit... Over its 60-year service life, this will generate approximately 483 million RMB in additional economic benefits. It is predicted to generate profit. Secondly, 1) the top cover (7) and bottom cover (3) of the reactor pressure vessel are an integrated design 5 It has and the core measuring tube housing of the pressure vessel and the top cover are in one piece. They were manufactured by forging. Thus, the relevant structures were forged as an integrated unit, as described above. The absence of weld seams at the pressure-exposed boundaries of the specified components. This is achieved only in weld seams located at pressure limits, where stress is reduced. This not only reduces the risk of corrosion cracking, but also protects the reactor pressure vessel from cracking. the number of weld seams that need to be inspected during operation and the exposure of personnel to them It also reduces radiation dose. 2) hundreds of bolts with neutron shielding plate from the outer surface of the suspension basket cylinder (5) This is being done by removing the flow resistance in the area, thereby reducing it, and at the same time... Long-term exposure of bolts in the core (21) region to neutron radiation resulted in 15 This prevents the potential problem of stress corrosion cracking; and 3) a flow guiding corner (221) on the outer edge of the core support subplate (22) It is arranged and this flow guiding corner is the passage of the reactor pressure vessel bottom cover (3) By forming a flow channel with an equal or nearly equal cross-section along with the region, a flow distribution It functions as an element. Thanks to this, the flow distribution performance at the core input is 20. is brought to an international advanced level and thus on the core (21) (fuel assemblies) Wear and damage resulting from irregular flow distribution at the core inlet are largely due to is being reduced. Thanks to the improvements mentioned above (1), 2), and 3), the reactor shell structure (100) reliability is significantly increased. 25 Finally, 1) the reactor core (21) is possible with respect to the bottom cover (3) of the reactor pressure vessel. It is located in the lowest position, and this situation is external in case of melting of the core (21). shortening the time required to leave the core (21) underwater by water injection This contributes to increasing the reactor's resilience to severe accidents; and 30 2) core housing (23), hanger basket cylinder (5) and core support bottom plate (22) by appropriately increasing their weights under severe accident (nuclear disintegration) conditions 16 The heat transfer of the core (21) through the reactor pressure vessel (1) is efficient. It is being improved. Thanks to the improvements mentioned in points 1) and 2) above, under severe accident conditions The safety of the reactor shell structure (100) is greatly increased, thus all nuclear The power plant's security is being improved. 5 Figure 8 shows a schematic of a reactor system (300) according to a specific example application of this invention. It shows the diagram. As shown in Figure 8, according to this example application, the reactor system (300) consists of a pump (301), a steam generator (302) and the reactor shell of the example application described above. It includes the structure (100). 10 The reactor shell structure (100) is a pressure reactor with inlet pipe (8) and outlet pipe (6). It includes the vessel (1); the outlet of the pump is connected to the inlet pipe (8) of the reactor pressure vessel (1). It has fluid communication and the outlet pipe (6) of the reactor pressure vessel (1) steam generator (302) is in fluid communication with the steam generator (302) and the fluid is in the pump inlet. It is connected through communication. 15 In the reactor system, water or boron-containing coolant is pumped through the reactor shell via a pump (301). The structure (100) is pressed into the reactor pressure vessel (1); flowing through the fuel bundles It absorbs heat energy and then enters the steam generator (302). Steam In the generator (302), heat energy is transferred to the cycle cooler on the opposite side; after The reactor coolant returns to the pump (301) via the pipeline, thus the primary 20 The cycle of the cycle system is being completed. The above are only preferred examples of how this application should be implemented, and this This is not intended to limit the scope of the application. For experts in the field, this Various changes and adaptations may be made within the scope of this application; Any changes, equivalent substitutions, made within the spirit and principles of the application, 25 Improvements and similar arrangements are within the scope of protection of this application. will be evaluated.

Claims

17 REQUESTS 1. A reactor shell structure (100) includes: - a reactor pressure vessel (1) containing a bottom cover (3) with a curved inner wall (32); - placed inside the reactor pressure vessel (1) and a core support bottom plate (22) including reactor internal equipment (2); and 5 - a core (1) placed on the core support base plate (22); Here, The core support bottom plate (22) is located below the sphere center (31) of the arc-shaped inner wall. is positioned and a flow on the outer edge of the core support subplate (22) There are directional corners (221); and 10 Core support bottom plate (22), with a top hole (222a) on the top and a bottom hole on the bottom. It is fitted with a through hole (222), which is a stepped hole containing (222b), and the bottom hole The diameter of the (222b) hole is smaller than the diameter of the top hole (222a).

2. According to claim 1, the reactor shell structure is (100), with flow guiding corner (221) and bottom The inner wall of the header, in the shape of a curve (32), has an evenly spaced or approximately evenly spaced flow channel 15 It creates and the deviation range in channel width of the approximately equally spaced flow channel is 100 It does not exceed mm.

3. According to claim 2, the reactor shell structure is (100) and the flow guiding corner (221) is a conical one. It is a corner or arc-shaped corner, where the lower diameter of the conical corner is smaller than the upper diameter, and the conical The angle between the outer surface of the corner and the vertical line is between 5° and 10°. 20 4. According to claim 1, the reactor shell structure is (100), and the core support bottom plate (22) is on top The surface is positioned 0 to 300 mm below the center of the sphere (31) of the arc-shaped inner wall.

5. According to claim 4, the reactor body structure is the core support bottom plate (22), and the core support distance between the upper surface of the bottom plate (22) and the sphere center of the arc-shaped inner wall (31) It is 250 mm. 25 6. According to claim 1, the reactor shell structure is (100) and the bottom hole of the transition hole (222) is (222b) Its diameter is between 38 mm and 64 mm.

7. According to claim 1, the reactor shell structure is (100), and from the outside to the inside, there is a reactor shell. The pressure vessel cylinder (9) includes a hanger basket cylinder (5) and a core housing (23). no neutron 30 between reactor pressure vessel cylinder (9) and hanger basket cylinder (5) There is no shield plate.

8. According to claim 7, the reactor body structure is (100) and the thickness of the hanger basket cylinder (5) is 60 The thickness of the core casing (23) is between 30 and 100 mm and is between 90 mm. 18 The gap between the hanger basket cylinder (5) and the core housing (23) is 30 to 60 mm It is among them.

9. According to claim 8, the reactor body structure is (100) and the thickness of the hanger basket cylinder (5) is 60 mm, core housing (23) thickness 30 mm and core with hanger basket cylinder (5) The gap between the housing (23) is 40 mm. 5 10. According to claim 1, the reactor shell structure is (100) and the reactor pressure vessel (1) is also an upper It includes a cover (7), the top cover (7) has an integrated structure and the bottom cover (3) It has an integrated structure.

11. According to claim 1, the reactor shell structure is (100) and there is an outlet on the reactor pressure vessel (1). There is a pipe (6), on the inside of the outlet pipe (6) there is a conical opening, 10 The inner diameter of the conical opening in question is larger than its outer diameter.

12. According to claim 11, the reactor shell structure is (100), with a conical opening between 5° and 15°. It is a conical flow channel with a conical surface.

13. A reactor system (300) consisting of a pump (302), a steam generator (302) and a reactor Body structure includes (100); 15 The reactor shell structure (100) includes: - a reactor pressure vessel containing a bottom cover (3) with a curved inner wall (32) (1); - placed inside the reactor pressure vessel (1) and a core support sub reactor internal equipment (2) including plate (22); and 20 - a core (21) placed on the core support base plate (22); Here, The core support bottom plate (22) is located below the sphere center (31) of the arc-shaped inner wall. is positioned and a flow on the outer edge of the core support subplate (22) There is a directional (221) corner; 25 Core support bottom plate (22), with a top hole (222a) on the top and a bottom hole on the bottom. It is fitted with a through hole (222), which is a stepped hole containing (222b), and the bottom hole (222b) diameter is smaller than the diameter of the top hole (222a); and The reactor pressure vessel (1) includes an inlet tube (8) and an outlet tube (6), the outlet of the pump (301) flows through the inlet pipe (8) of the reactor pressure vessel (1) and the fluid 30 is in communication with the reactor pressure vessel (1) outlet pipe (6) steam generator (302). is in fluid communication and the steam generator (302) is in the inlet of the pump (301) and the fluid It is in communication.

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