Fuel assembly and lead-based reactor system containing solid lead bismuth

Abstract

The utility model relates to nuclear fuel technical field and disclose a kind of fuel assembly and lead-based reactor system containing solid lead bismuth, fuel assembly includes first sleeve, second sleeve, positioning frame and lead bismuth module, second sleeve is located in first sleeve, and the outside of second sleeve and the inside of first sleeve are spaced apart, positioning frame is located in second sleeve, positioning frame has the positioning hole of honeycomb arrangement, the radial axial of positioning hole is parallel to the radial axial of first sleeve, lead bismuth module is filled in second sleeve, lead bismuth module has the reserved mounting hole corresponding with positioning hole, the radial axial of reserved mounting hole is parallel to the radial axial of first sleeve.The fuel assembly can overcome how to realize the technical problem of filling coolant and fuel simultaneously, by filling lead bismuth module into fuel assembly, so that filling coolant and fuel into lead-based reactor system simultaneously can be realized.

Description

Technical Field

[0001] This utility model relates to the field of nuclear fuel technology, specifically to fuel assemblies containing solid lead and bismuth and lead-based reactor systems. Background Technology

[0002] Miniaturized reactors are characterized by long lifespan and high safety. They typically use liquid metals, such as lead-based reactors. However, due to the problem that liquid lead-bismuth alloys are easily oxidized by oxygen in the air at high temperatures, conventional charging methods have limitations for charging lead-based reactors.

[0003] Existing reactor fuel loading methods typically employ dry and wet loading. Wet loading involves filling the reactor with liquid coolant first, but this method has drawbacks for lead-based reactors, including operational difficulties, sensitivity to coolant levels, and system complexity. Dry loading, on the other hand, involves loading the reactor without coolant first, followed by the injection of coolant. This method, for lead-based reactors, suffers from long operation cycles, susceptibility to mechanical impacts leading to fuel cladding damage, difficulty in controlling reactivity during coolant injection, and the tendency for lead and bismuth to solidify and block flow channels. CN104637554A, "A Zero-Power Reactor Fuel Assembly with Lead Alloy Coolant," uses a simultaneous loading method for coolant and fuel. However, this patent's zero-power reactor does not require the melting of lead alloys, while miniaturized reactors do require the melting of lead alloys as a coolant.

[0004] In the existing technology, how to realize the use of solid lead-bismuth fuel assemblies in miniaturized reactors is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] This invention aims to at least partially solve one of the technical problems in the related art. To this end, embodiments of this invention propose a fuel assembly containing solid lead-bismuth and a lead-based reactor system. The fuel assembly overcomes the technical problem of how to simultaneously load coolant and fuel. By filling the fuel assembly with lead-bismuth modules, simultaneous loading of coolant and fuel into the lead-based reactor system can be achieved.

[0006] The fuel assembly containing solid lead-bismuth of this invention includes:

[0007] First casing;

[0008] The second sleeve is disposed inside the first sleeve, and the outer side of the second sleeve is spaced apart from the inner side of the first sleeve.

[0009] A positioning frame is installed inside the second sleeve. The positioning frame has positioning holes arranged in a honeycomb pattern, and the axial direction of the positioning holes is parallel to the axial direction of the first sleeve.

[0010] A lead-bismuth module is filled inside the second sleeve. The lead-bismuth module has a reserved mounting hole corresponding to the positioning hole, and the axis of the reserved mounting hole is parallel to the axis of the first sleeve.

[0011] According to the fuel assembly in a specific embodiment of this utility model, by adding a lead-bismuth module to the fuel assembly, the volume of lead-bismuth alloy entering the lead-based reactor system can be controlled in advance, increasing the inherent safety of the lead-based reactor system. This prevents accidents caused by excessive lead-bismuth loading and avoids unplanned critical events. Simultaneously, the fuel assembly includes a lead-bismuth module, allowing lead-bismuth coolant to be added simultaneously during fuel loading into the lead-based reactor system, effectively replacing the lead-bismuth loading into the system.

[0012] Optionally, the second sleeve has a folding plate, the folding line of which is parallel to the axial direction of the first sleeve.

[0013] Optionally, multiple folding plates are provided, and the multiple folding plates are arranged circumferentially on the second sleeve.

[0014] Optionally, the cross-section of the second sleeve is a regular hexagon, and there are six folding plates, each located at a vertex of the regular hexagon.

[0015] Optionally, a positioning arch plate is provided on the inner surface of the positioning hole, and the two arch toes of the positioning arch plate are respectively connected to the inner surface of the positioning hole in the axial direction of the first sleeve and are arranged opposite to each other.

[0016] Optionally, multiple positioning arches are provided, and the multiple positioning arches are arranged circumferentially on the inner surface of the positioning hole.

[0017] Optionally, the cross-section of the positioning hole is a regular hexagon, and there are six positioning arch plates, with the positions of the six positioning arch plates respectively located at the center of the six inner sides of the positioning hole.

[0018] Optionally, the positioning frame is provided with guide wings on its edge, and the guide wings are provided with through holes.

[0019] Optionally, the guide wing is provided in multiples, and the multiple guide wing are arranged in an array on the edge of the positioning frame.

[0020] The lead-based reactor system of this invention includes the aforementioned fuel assembly containing solid lead and bismuth. Attached Figure Description

[0021] Figure 1 This is a front view schematic diagram of the fuel assembly in a specific embodiment of this utility model.

[0022] Figure 2 This is a cross-sectional schematic diagram of the fuel assembly in a specific embodiment of this utility model.

[0023] Figure 3 This is a schematic diagram showing the fit between the first sleeve and the second sleeve in a specific embodiment of this utility model.

[0024] Figure 4 This is a three-dimensional schematic diagram of the positioning frame in a specific embodiment of this utility model.

[0025] Reference numerals: 1000-fuel assembly, 100-first sleeve, 200-second sleeve, 210-folding plate, 300-positioning frame, 310-positioning hole, 311-positioning arch plate, 320-guide wing, 321-through hole, 400-lead-bismuth module. Detailed Implementation

[0026] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The following description, with reference to the accompanying drawings, describes an embodiment of the present invention including a fuel assembly 1000 containing solid lead-bismuth and a lead-based reactor system. Figures 1 to 4 As shown, the fuel assembly 1000 containing solid lead-bismuth in this embodiment of the present invention includes a first sleeve 100, a second sleeve 200, a positioning frame 300 and a lead-bismuth module 400.

[0028] The second sleeve 200 is disposed inside the first sleeve 100, with the outer surface of the second sleeve 200 spaced apart from the inner surface of the first sleeve 100. The positioning frame 300 is disposed inside the second sleeve 200 and has positioning holes 310 arranged in a honeycomb pattern. The axial direction of the positioning holes 310 is parallel to the axial direction of the first sleeve 100. The lead-bismuth module 400 is filled inside the second sleeve 200 and has a reserved mounting hole corresponding to the positioning hole 310. The axial direction of the reserved mounting hole is parallel to the axial direction of the first sleeve 100.

[0029] According to the fuel assembly 1000 in a specific embodiment of this utility model, by filling the fuel assembly 1000 with the lead-bismuth module 400, the volume of lead-bismuth alloy entering the lead-based reactor system can be controlled in advance, increasing the inherent safety of the lead-based reactor system. This prevents accidents caused by excessive lead-bismuth liquid alloy filling the lead-based reactor system and avoids unplanned critical events. Simultaneously, the fuel assembly 1000 includes the lead-bismuth module 400, allowing lead-bismuth coolant to be added simultaneously during the fuel addition process of the lead-based reactor system, thus replacing the lead-bismuth filling of the lead-based reactor system.

[0030] like Figures 1 to 4 As shown, in order to make the technical solution of this application easier to understand, the technical solution of this application will be described in more detail below with a specific embodiment of a lead-based reactor system.

[0031] In some specific embodiments, such as Figures 1 to 3 As shown, the first sleeve 100 is tubular in shape and mainly serves as the outer shell of the fuel assembly 1000.

[0032] In some specific embodiments, such as Figures 1 to 3 As shown, the second sleeve 200 is tubular in shape and is disposed inside the first sleeve 100. The outer surface of the second sleeve 200 is spaced apart from the inner surface of the first sleeve 100, that is, there is a certain gap between the second sleeve 200 and the first sleeve 100. When the lead-bismuth module 400 is heated and melts, the lead-bismuth module 400 will expand to a certain extent. By adopting the double-layer structure of the second sleeve 200 and the first sleeve 100, the second sleeve 200 can withstand a certain expansion pressure, and the gap between the second sleeve 200 and the first sleeve 100 can provide a certain space, which can effectively prevent the expanding lead-bismuth module 400 from damaging the first sleeve 100 and causing the fuel assembly 1000 to fail.

[0033] In some specific embodiments, the expansion of the lead-bismuth module 400 may not be caused by thermal melting, but by expansion caused by other operating conditions. In this embodiment, thermal melting expansion is taken as an example.

[0034] In some specific embodiments, such as Figures 1 to 3As shown, the second sleeve 200 has a folding plate 210, the folding line of which is parallel to the axial direction of the first sleeve 100. Specifically, the second sleeve 200 can expand its diameter through the folding plate 210. When the lead-bismuth module 400 is heated and melts, expanding, the second sleeve 200 will be subjected to the compressive force of the lead-bismuth module 400. The folding plate 210 can extend appropriately in the circumferential direction of the second sleeve 200, thereby expanding the diameter of the second sleeve 200 and alleviating the compressive force of the lead-bismuth module 400, preventing excessive compressive force from damaging or deforming the second sleeve 200. At the same time, fuel rods are pre-installed in the fuel assembly 1000. If the expansion force of the lead-bismuth module 400 cannot be relieved in time, the expansion force of the lead-bismuth module 400 will compress the fuel rods, which may cause the fuel rods to fail.

[0035] In some specific embodiments, such as Figures 1 to 3 As shown, multiple folding plates 210 are provided, and these multiple folding plates 210 are arranged circumferentially on the second sleeve 200, which can effectively relieve the expansion force of the lead-bismuth module 400. Specifically, the lead-bismuth module 400 is located inside the second sleeve 200. After being heated, the lead-bismuth module 400 expands uniformly, that is, the extrusion force of the lead-bismuth module 400 on the second sleeve 200 is uniform. By providing multiple circumferentially arranged folding plates 210 on the second sleeve 200, the expansion force of the lead-bismuth module 400 can be uniformly relieved, avoiding excessive local extrusion force that could damage the second sleeve 200 if some areas of the second sleeve 200 are not provided with folding plates 210.

[0036] In some specific embodiments, such as Figures 1 to 3 As shown, the cross-section of the second sleeve 200 is a regular hexagon, and there are six folding plates 210, which are located at the vertices of the regular hexagon.

[0037] In some specific embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the positioning frame 300 is located inside the second sleeve 200. The positioning frame 300 has positioning holes 310 arranged in a honeycomb pattern. The axial direction of the positioning holes 310 is parallel to the axial direction of the first sleeve 100. The fuel rod is installed in the positioning holes 310. The positioning frame 300 can fix and position the fuel rod.

[0038] In some specific embodiments, such as Figure 1 , Figure 2 and Figure 4As shown, a positioning arch plate 311 is provided on the inner surface of the positioning hole 310. The two arched toes of the positioning arch plate 311 are respectively connected to the inner surface of the positioning hole 310 in the axial direction of the first sleeve 100 and are arranged opposite to each other. Specifically, the positioning arch plate 311 on the inner surface of the positioning hole 310 can play a certain role in fastening the fuel rod and prevent the fuel rod from shaking. The positioning arch plate 311 is arched and has a certain degree of elasticity. While fastening the fuel rod, it can also prevent the positioning arch plate 311 from exerting excessive pressure on the fuel rod, which could lead to damage or failure of the fuel rod.

[0039] It should be noted that the two arched toes of the positioning arch plate 311 are respectively connected to the inner surface of the positioning hole 310 in the axial direction of the first sleeve 100. When the lead-bismuth module 400 is heated and melted, it will expand in the axial direction of the first sleeve 100. Compared with the traditional positioning arch plate 311, the positioning arch plate 311 has a larger axial force-bearing area and can better withstand the axial expansion force of the lead-bismuth module 400, thus avoiding damage or failure of the positioning arch plate 311. In contrast, the two arched toes of the traditional positioning arch plate 311 are connected laterally to the inner surface of the positioning hole 310, that is, the connection direction is perpendicular to the connection direction of the positioning arch plate 311 in this solution.

[0040] In some specific embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, multiple positioning arches 311 are provided, and these multiple positioning arches 311 are arranged circumferentially on the inner surface of the positioning hole 310. Specifically, the multiple positioning arches 311 on the inner surface of the positioning hole 310 can uniformly compress the outer side of the fuel rod, thereby further securing the fuel rod. In addition, since the positioning arches 311 have a certain degree of elasticity, they can better secure the fuel rod and avoid excessive compressive force on the fuel rod caused by the positioning arches 311, which could lead to damage or failure of the fuel rod.

[0041] In some specific embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the cross-section of the positioning hole 310 is a regular hexagon, and there are six positioning arch plates 311. The positions of the six positioning arch plates 311 are respectively located at the center of the six inner sides of the positioning hole 310.

[0042] In some specific embodiments, such as Figure 1 , Figure 2 and Figure 4As shown, the positioning frame 300 has a guide wing 320 on its edge, and the guide wing 320 has a through hole 321. Specifically, compared with a traditional guide wing, the guide wing 320 with the through hole 321 allows the liquid lead-bismuth in the expanded part to pass through the through hole 321 when the lead-bismuth module 400 melts and expands, which can reduce the damage of liquid lead-bismuth to the guide wing 320 and prevent damage to the guide wing 320 caused by the expansion force of the lead-bismuth module 400. In addition, the guide wing 320 with the through hole 321 can enhance the heat exchange of the coolant when the lead-based reactor system is operating normally.

[0043] In some specific embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, there are multiple guide wings 320, which are arranged in an array on the edge of the positioning frame 300.

[0044] In some specific embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the guide wing 320 is provided with at least two through holes 321.

[0045] In some specific embodiments, such as Figure 1 and Figure 2 As shown, the lead-bismuth module 400 is filled inside the second sleeve 200. The lead-bismuth module 400 has a reserved mounting hole corresponding to the positioning hole 310, and the axis of the reserved mounting hole is parallel to the axis of the first sleeve 100. Specifically, when the fuel rods are installed inside the fuel assembly 1000, the fuel rods are mainly installed in the reserved mounting holes on the lead-bismuth module 400 and the positioning holes 310 on the positioning frame 300. Specifically, the lead-bismuth module 400 is filled into the fuel assembly 1000. The lead-bismuth module 400 can be placed into the lead-based reactor system at the same time as the fuel assembly 1000 is placed. After the lead-bismuth module 400 is heated and melted, it can be used as a liquid metal coolant in the lead-based reactor system.

[0046] It should be noted that the lead-bismuth module 400 mainly consists of a lead-bismuth alloy, which serves as a liquid metal coolant for lead-based reactor systems.

[0047] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0049] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0050] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0051] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0052] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A fuel assembly containing solid lead-bismuth, characterized in that, include: First casing; The second sleeve is disposed inside the first sleeve, and the outer side of the second sleeve is spaced apart from the inner side of the first sleeve. A positioning frame is installed inside the second sleeve. The positioning frame has positioning holes arranged in a honeycomb pattern, and the axial direction of the positioning holes is parallel to the axial direction of the first sleeve. A lead-bismuth module is filled inside the second sleeve. The lead-bismuth module has a reserved mounting hole corresponding to the positioning hole, and the axis of the reserved mounting hole is parallel to the axis of the first sleeve.

2. The fuel assembly containing solid lead-bismuth according to claim 1, characterized in that, The second sleeve has a folding plate, the folding line of which is parallel to the axial direction of the first sleeve.

3. The fuel assembly containing solid lead-bismuth according to claim 2, characterized in that, The folding plate is provided in multiple ways, and the multiple folding plates are arranged circumferentially on the second sleeve.

4. The fuel assembly containing solid lead-bismuth according to claim 3, characterized in that, The second sleeve has a regular hexagonal cross-section, and there are six folding plates, each located at a vertex of the regular hexagon.

5. The fuel assembly containing solid lead-bismuth according to claim 1, characterized in that, The inner surface of the positioning hole is provided with a positioning arch plate, and the two arch toes of the positioning arch plate are respectively connected to the inner surface of the positioning hole in the axial direction of the first sleeve and are arranged opposite to each other.

6. The fuel assembly containing solid lead-bismuth according to claim 5, characterized in that, The positioning arch plate is provided in multiple ways, and the multiple positioning arch plates are arranged circumferentially on the inner surface of the positioning hole.

7. The fuel assembly containing solid lead-bismuth according to claim 6, characterized in that, The positioning hole has a regular hexagonal cross-section, and there are six positioning arch plates, each located at the center of one of the six inner sides of the positioning hole.

8. The fuel assembly containing solid lead-bismuth according to claim 1, characterized in that, The positioning frame has guide wings on its edge, and the guide wings have through holes.

9. The fuel assembly containing solid lead-bismuth according to claim 8, characterized in that, The guide wing is provided in multiple forms, and the multiple guide wing are arranged in an array on the edge of the positioning frame.

10. A lead-based reactor system, characterized in that, include: The fuel assembly containing solid lead bismuth according to any one of claims 1-9.

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