Annular fuel irradiation test assembly

Abstract

This application relates to the field of nuclear reactor testing technology, and particularly to a ring fuel irradiation test assembly. The ring fuel irradiation test assembly includes a support member, at least one connector, a base, and a positioning member. The connector is connected to the support member, and each connector forms multiple through holes for multiple ring fuel element rod assemblies to pass through. The base is connected to the lower end of the support member, and the base forms multiple first through holes for multiple ring fuel element rod assemblies to pass through. The positioning member is used to position each ring fuel element rod assembly to the base. The ring fuel irradiation test assembly provided in this application can simultaneously irradiate multiple ring fuel element rod assemblies during irradiation testing, and the coolant in the reactor core can flow radially inward through each ring fuel element rod assembly, so as to make the environment in which the ring fuel element rod assemblies are located within the reactor core as close as possible to the actual working environment during the irradiation test.

Description

Technical Field

[0001] This application relates to the field of nuclear reactor testing technology, and in particular to a toroidal fuel irradiation test assembly. Background Technology

[0002] This section provides background information relevant to this application only and does not necessarily constitute prior art. The design of in-reactor irradiation test components and subsequent irradiation tests are crucial steps in the development of new fuels. A series of checks after irradiation can provide important feedback for the design and provide technical verification for engineering applications. Summary of the Invention

[0003] An embodiment of this application provides a ring-shaped fuel irradiation test assembly, which includes a support member, at least one connector, a base, and a positioning member. The connector is connected to the support member, and each connector forms multiple through holes for multiple ring-shaped fuel element rod assemblies to pass through. The base is connected to the lower end of the support member, and the base forms multiple first through holes for multiple ring-shaped fuel element rod assemblies to pass through. The positioning member is used to position each ring-shaped fuel element rod assembly to the base.

[0004] The annular fuel irradiation test assembly provided in the embodiments of this application can irradiate multiple annular fuel element rod assemblies simultaneously during irradiation testing, and the coolant in the reactor core can flow through the radial inner side of each annular fuel element rod assembly, so as to make the environment in the reactor core of the annular fuel element rod as close as possible to the actual working environment during the irradiation test. Attached Figure Description

[0005] To further illustrate the above and other advantages and features of this application, the specific embodiments of this application will be described in more detail below with reference to the accompanying drawings. The drawings, together with the following detailed description, are included in and form a part of this specification. Elements having the same function and structure are indicated by the same reference numerals. It should be understood that these drawings only depict typical examples of this application and should not be considered as limiting the scope of this application.

[0006] Figure 1 This is a schematic diagram of the structure of a ring-shaped fuel irradiation test assembly according to an embodiment of this application;

[0007] Figure 2 This is a schematic diagram of the structure of a connector according to an embodiment of this application;

[0008] Figure 3 yes Figure 2 Top view of the connector shown;

[0009] Figure 4This is a schematic diagram of the bottom structure of an annular fuel irradiation test assembly according to an embodiment of this application;

[0010] Figure 5 This is a cross-sectional schematic diagram of an annular fuel element rod assembly according to an embodiment of this application;

[0011] Figure 6 This is a schematic diagram of the structure of a positioning element according to an embodiment of this application;

[0012] Figure 7 This is a cross-sectional schematic diagram of a support member according to an embodiment of this application;

[0013] Figure 8 This is a schematic diagram of a bottom positioning member according to an embodiment of this application;

[0014] Figure 9 This is a schematic diagram of the upper part of an annular fuel irradiation test assembly according to an embodiment of this application;

[0015] Figure 10 This is a schematic diagram of the structure of the third locating pin according to an embodiment of this application;

[0016] Figure 11 This is a cross-sectional schematic diagram of an annular fuel element rod assembly according to another embodiment of this application;

[0017] Figure 12 This is a cross-sectional schematic diagram of an annular fuel element rod assembly according to yet another embodiment of this application.

[0018] Figure 13 This is a schematic diagram of the bottom structure of a ring-shaped fuel irradiation test assembly according to another embodiment of this application.

[0019] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding.

[0020] Explanation of reference numerals in the attached figures:

[0021] 10. Support component; 11. First positioning hole; 12. Second positioning hole; 13. Third positioning hole; 14. Fourth positioning hole; 15. Connecting section; 16. Positioning part;

[0022] 20. Connector; 21. Elastic component; 22. Welded part; 23. Connecting through hole;

[0023] 30. Base; 301. Positioning channel; 31. First through hole; 32. Second through hole; 33. Third through hole; 34. Fourth through hole; 35. Curved surface; 36. Slide rail; 37. Positioning component;

[0024] 40. Positioning component; 41. Connecting rod; 411. Through hole; 42. First positioning pin; 43. Blocking plate;

[0025] 50. Annular fuel element rod assembly; 501. Positioning hole; 51. Annular fuel element rod; 5111. Outer casing tube; 5112. Inner casing tube; 5113. Upper plug; 5114. Lower plug; 512. Bulk cartridge; 513. Elastic element; 52. Bottom connecting fitting; 521. Notch; 53. Connecting ring;

[0026] 60. Bottom positioning component; 61. Second positioning hole; 62. First positioning hole; 63. Thread; 64. Positioning part;

[0027] 70. Blocking component; 71. Third positioning hole; 72. Third positioning pin; 73. Blocking piece; 74. Fifth through hole. Detailed Implementation

[0028] The embodiments of this application are described in detail below. Examples of the 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 this application, and should not be construed as limiting this application.

[0029] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0030] The following disclosure provides several different implementations or examples for carrying out this application. To simplify the disclosure of this application, specific examples of components and methods are described below. Of course, these are merely examples and are not intended to limit this application. In the description of the embodiments of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] The design and subsequent irradiation testing of in-reactor fuel reactor assemblies are crucial steps in the development of novel fuels. A series of post-irradiation checks provide vital feedback for the design and offer technical verification for engineering applications. Irradiation test assemblies typically consist of representative fuel element rods and supporting structures. Currently, existing irradiation test assemblies are not suitable for irradiating annular fuel element rods.

[0032] To address the aforementioned problems, embodiments of this application provide a ring-shaped fuel irradiation test assembly, such as... Figure 1 As shown, Figure 1A schematic diagram of a ring-shaped fuel irradiation test assembly according to an embodiment of this application is shown. The ring-shaped fuel irradiation test assembly includes a support member 10, at least one connector 20, a base 30, and a positioning member 40.

[0033] Connector 20 is connected to support 10. See also Figures 1 to 3 Each connector 20 forms multiple connecting through holes 23 for passage of multiple annular fuel element rod assemblies 50. See also Figure 1 and Figure 4 The base 30 is connected to the lower end of the support member 10. A plurality of first through holes 31 are formed on the base 30 for a plurality of annular fuel element rod assemblies 50 to pass through. The positioning member 40 is used to position each annular fuel element rod assembly 50 to the base 30.

[0034] This application provides an annular fuel irradiation test assembly suitable for irradiating annular fuel element rod assemblies 50. Because the base 30 of the test assembly forms multiple first through holes 31 for the annular fuel element rod assemblies 50 to pass through, multiple annular fuel element rod assemblies 50 can be irradiated simultaneously during the irradiation test. Furthermore, the coolant in the reactor core can flow radially inward through the annular fuel element rod assemblies 50, thereby making the environment of the annular fuel element rod assemblies 50 within the reactor core as close as possible to the actual working environment during the irradiation test. In addition, the annular fuel irradiation test assembly provided by this application is easy to assemble and remains detachable after irradiation, facilitating remote handling of the radioactive annular fuel element rod assemblies 50 after irradiation.

[0035] In this embodiment of the application, by connecting the connector 20 to the support 10 and connecting the base 30 to the lower end of the support 10, the support 10 forms a skeleton, thereby improving the overall connection strength of the annular fuel irradiation test assembly.

[0036] The connection between the connector 20 and the support 10 can be, for example, by welding.

[0037] like Figure 2 and Figure 3 As shown, in some embodiments, the connector 20 may further include a welding portion 22, and the support 10 may be welded to the welding portion 22 so that the connector 20 is fixed to the support 10.

[0038] Each annular fuel element rod assembly 50 passes sequentially through the connection through-hole 23 of each connector 20 and the first through-hole 31 of the base 30.

[0039] like Figure 2 and Figure 3As shown, in some embodiments, the connector 20 may include an elastic member 21 disposed at the wall of the connecting through hole 23 for providing radial preload to the annular fuel element rod assembly 50.

[0040] The elastic element 21 can elastically clamp the annular fuel element rod assembly 50 and, through an interference fit with the annular fuel element rod assembly 50, provide radial positioning for the annular fuel element rod assembly 50 to further prevent the annular fuel element rod assembly 50 from moving in the radial direction. The elastic element 21 can be, for example, a spring.

[0041] In some embodiments, the connector 20 has a central through hole through which the support 10 passes, and the wall of the central through hole extends to form a plurality of weld portions 22, to which the support 10 is welded. Welding the support 10 to the weld portions 22 extending from the hole wall facilitates both the welding operation and the cutting of the weld portions 22 after the test, thereby separating the support 10 from the connector 20.

[0042] like Figure 4 As shown, the base 30 can be, for example, a square thick sheet, and the number and position of the first through holes 31 can be determined according to the number of annular fuel element rod assemblies 50.

[0043] like Figure 5 As shown, Figure 5 A schematic diagram of an annular fuel element rod assembly 50 according to one embodiment of the present application is shown. In this embodiment, a radially penetrating positioning hole 501 may be formed at the lower end of the annular fuel element rod assembly 50; a plurality of positioning channels 301 are formed in the base 30 along the axial direction perpendicular to the first through hole 31, and one or more first through holes 31 are penetrated by a positioning channel 301; a positioning member 40 passes through the positioning channel 301 and the positioning hole 501 of the annular fuel element rod assembly 50 to position each annular fuel element rod assembly 50 to the base 30.

[0044] The positioning element 40 can be, for example, a positioning pin. After passing through the base 30 and the annular fuel element rod assembly 50, the positioning element 40 can position the annular fuel element rod assembly 50, restricting its translation along the axial or radial direction, and restricting its rotation along the circumferential direction.

[0045] In some embodiments, these first through holes 31 can be arranged in multiple rows, with each positioning channel 301 extending through the first through hole 31 in each row. For example... Figure 6 As shown, Figure 6 A schematic diagram of a positioning member 40 according to an embodiment of the present application is shown. The positioning member 40 includes a connecting rod 41 and a plurality of first positioning pins 42, each first positioning pin 42 being connected to the connecting rod 41 and passing through a positioning channel 301 and a positioning hole of a corresponding annular fuel element rod assembly 50.

[0046] Compared to using a locking nut to position an annular fuel element rod assembly 50, this embodiment uses a connecting rod 41 to connect a first positioning pin 42, and uses the first positioning pin 42 to position the annular fuel element rod assembly 50, facilitating the installation and removal of the annular fuel element rod assembly 50. Furthermore, see... Figure 4 Since the embodiments of this application use the first positioning pin 42 to be positioned radially through the positioning hole 501 and the first through hole 31 of the annular fuel element rod assembly 50, compared with the method of positioning an annular fuel element rod assembly 50 using a locking nut, there is a gap between the annular fuel element rod assembly 50 and the first through hole 31 in this application, which allows coolant to flow and is closer to the actual working environment of the fuel assembly in the reactor core.

[0047] See Figure 6 In some embodiments, the connecting rod 41 may form a plurality of through holes 411 along the axial direction perpendicular to the first through hole 31.

[0048] The connecting rod 41 can cause uneven flow of coolant along the circumference of the base 30. The through hole 411 allows coolant to pass through the connecting rod 41, thereby reducing the above-mentioned adverse effects.

[0049] In some embodiments, see Figure 7 The lower end of the support member 10 may have a first positioning hole 11 extending radially through it; see also Figure 4 The base 30 forms a second through hole 32 for the support member 10 to pass through. One of the multiple positioning channels 301 also passes through the second through hole 32, and one of the multiple first positioning pins 42 also passes through the first positioning hole 11.

[0050] In this embodiment, the annular fuel element rod assembly 50, the base 30, and the support 10 are positioned using the same positioning element 40, which facilitates the assembly and disassembly of the annular fuel element rod assembly 50, the base 30, and the support 10 before and after irradiation.

[0051] In some embodiments, a second through hole 32 is disposed in the middle of the base 30, and eight first through holes 31 can be formed around the second through hole 32. The eight first through holes 31 and the second through holes 32 can be arranged in three rows and three columns, and the eight annular fuel element rod assemblies 50 pass through these eight first through holes 31 respectively. The positioning member 40 may include a connecting rod 41 and three first positioning pins 42, wherein two first positioning pins 42 are disposed at both ends of the connecting rod 41, and the other first positioning pin 42 is disposed in the middle of the connecting rod 41. Each positioning channel 301 passes through one row of first through holes 31, and the three first positioning pins 42 pass through the three positioning channels 301 and the positioning holes 501 of the corresponding annular fuel element rod assemblies 50 and the first positioning holes 11 of the support member 10 respectively, so as to position the annular fuel element rod assemblies 50. A blocking plate 43 can be respectively set on the two first positioning pins 42 located at both ends of the connecting rod 41. The blocking plate 43 can be bent to lock the annular fuel element rod assembly 50. When disassembling the annular fuel element rod assembly 50, it is only necessary to straighten the blocking plate 43 and remove the first positioning pin 42 from the positioning channel 301 to disassemble the annular fuel element rod assembly 50 and the base 30, which is relatively convenient.

[0052] See Figure 7 In some embodiments, the portion of the support 10 located below the first positioning hole 11 forms a connecting segment 15, which extends downward from the second through hole 32 of the base 30. See also Figure 8 The annular fuel irradiation test assembly may also include a bottom positioning element 60 for positioning with the reactor core, the bottom positioning element 60 being detachably connected to the connection section 15 of the support element 10 below the base 30.

[0053] The bottom positioning member 60 is configured to be detachably connected to the base 30, which facilitates the assembly and disassembly of the bottom positioning member 60 before and after irradiation. In some embodiments, the bottom positioning member 60 may also form a first positioning hole 62 for positioning the annular fuel element rod assembly 50 with the reactor core.

[0054] In some embodiments, the connection segment 15 between the bottom positioning member 60 and the support member 10 can be threaded together.

[0055] See Figure 8 The bottom positioning member 60 includes a tube with a thread 63 formed on its radially inner side. Correspondingly, the outer surface of the connecting section 15 is threaded to engage with the bottom positioning member 60. The threaded connection increases the stability of the connection between the bottom positioning member 60 and the support member 10.

[0056] like Figure 7 and Figure 8As shown, in some embodiments, the bottom positioning member 60 may form a second positioning hole 61, and the connecting segment 15 of the support member 10 may also form a second positioning hole 12, so as to position the bottom positioning member 60 and the connecting segment 15 of the support member 10 by means of a second positioning pin passing through the second positioning hole 61 and the second positioning hole 12. In the embodiments of this application, the bottom positioning member 60 is threadedly connected to the support member 10, and the bottom positioning member 60 and the support member 10 are connected by a second positioning pin, which further ensures the reliability of the connection and facilitates disassembly.

[0057] In some embodiments, the bottom positioning member 60 may include a positioning portion 64 located at the bottom for positioning with the core. Similarly, a positioning portion 16 may also be provided on the support member 10 to facilitate positioning.

[0058] like Figure 4 As shown, in some embodiments, a plurality of third through holes 33 extending vertically through the base 30 may also be formed on the base 30 to provide flow channels for the coolant within the stack.

[0059] In actual use, the support member 10 is not required for the annular fuel element rod assembly 50, and coolant also passes through the radial outer side of the annular fuel element rod assembly 50. By providing a third through hole 33 on the base 30, coolant can pass through the third through hole 33 and flow in the gap between the annular fuel element rod assemblies 50, making the test environment of the annular fuel element rod assembly 50 closer to the actual working conditions, thus making the test results more accurate. The shape of the third through hole 33 can be, for example, a rounded rectangle.

[0060] In some embodiments, a plurality of first through holes 31 and a plurality of third through holes 33 may be distributed around a second through hole 32, with the plurality of third through holes 33 being closer to the second through hole 32 than the plurality of first through holes 31.

[0061] The bottom positioning component 60 increases the flow resistance of the coolant. In this embodiment, the positions of the first through hole 31 and the third through hole 33 have a better effect on reducing the flow resistance of the coolant.

[0062] For example, when there are 8 first through holes 31, and the 8 first through holes 31 form a square, the number of third through holes 33 can be 4, which are set on the diagonal of the square and located between the first through holes 31 and the second through holes 32. This arrangement can make the coolant flow more evenly into the gap between the annular fuel element rod assembly 50, and make the test environment of the annular fuel element rod assembly 50 closer to the actual working conditions, so as to make the test results more accurate.

[0063] In some embodiments, the cross-sectional area of ​​the third through hole 33 may be smaller than the cross-sectional area of ​​the first through hole 31, but larger than half the cross-sectional area of ​​the first through hole 31.

[0064] The larger the cross-sectional area of ​​the third through hole 33, the smaller the flow resistance of the coolant; however, at the same time, the area of ​​the base 30 is constant. The inventors of this application have discovered that when the cross-sectional area of ​​the third through hole 33 is smaller than the cross-sectional area of ​​the first through hole 31, but larger than half the cross-sectional area of ​​the first through hole 31, it is beneficial to minimize the flow resistance of the coolant within a limited space.

[0065] like Figure 4 As shown, in some embodiments, a plurality of fourth through holes 34 extending vertically through the base 30 may also be formed on the base 30, each fourth through hole 34 being disposed between two adjacent first through holes 31 for providing a flow channel for the coolant in the stack.

[0066] The positioning channel 301 is also connected to one or more fourth through holes 34, allowing coolant to flow into the positioning channel 301, accelerating coolant circulation within the positioning channel 301 and preventing high temperatures within the positioning channel 301. In this embodiment, coolant can pass through the fourth through holes 34 into the gap between two adjacent annular fuel element rod assemblies 50 to cool the annular fuel element rod assembly 50, or it can enter the positioning channel 301 to accelerate coolant circulation within the positioning channel 301, making the test environment of the annular fuel element rod assembly 50 closer to actual operating conditions, thus making the test results more accurate. The shape of the fourth through hole 34 can be, for example, circular.

[0067] In some embodiments, see Figure 13 The base 30 may also be provided with multiple slides 36, each slide 36 having a positioning element 37 that can move along the slide 36. After the annular fuel element rod assembly 50 is inserted into the first through hole 31, its notch 521 faces the positioning element. The positioning element 37 can slide to the position of entering the notch 521 and to the position of being completely disengaged from the notch 521. When the positioning element 37 slides to the position of entering the notch 521, it can prevent the annular fuel element rod assembly 50 from rotating. In such an embodiment, the extending direction of the slide 36 can be perpendicular to the positioning channel 301 to avoid affecting the arrangement of the fourth through hole 34 communicating with the positioning channel 301 due to the setting of the slide 36.

[0068] like Figure 4 As shown, in some embodiments, the sidewall of the base 30 at the position corresponding to the first through hole 31 can form an arc surface 35 that matches the shape of the first through hole 31, for guiding the coolant in the stack.

[0069] It is easy to understand that the shape of the arc surface 35 allows the coolant on the outside of the base 30 to be closer to the annular fuel element rod assembly 50, making the test environment of the annular fuel element rod assembly 50 closer to the actual working conditions, so as to make the test results more accurate.

[0070] like Figure 9 As shown, Figure 9 A schematic diagram of the upper part of an annular fuel irradiation test assembly according to an embodiment of this application is shown. In this embodiment, the annular fuel irradiation test assembly may further include a blocking member 70 detachably disposed at the upper end of the support member 10 for blocking the annular fuel element rod assembly 50 when the annular fuel element rod assembly 50 moves upward.

[0071] During irradiation, if the connections between connector 20, base 30, and annular fuel element rod assembly 50 all fail, the annular fuel element rod assembly 50 may move upwards with the coolant flowing from bottom to top. In this case, the blocking member 70 can prevent the annular fuel element rod assembly 50 from moving upwards. The blocking member 70 is detachably connected to the upper end of support 10, facilitating its removal after irradiation.

[0072] In some embodiments, the blocking member 70 may form a plurality of vertically extending fifth through holes 74 for providing flow channels for coolant within the reactor. The fifth through holes 74 can reduce the flow resistance of the coolant, making the test environment of the annular fuel element rod assembly 50 closer to actual operating conditions, thereby making the test results more accurate.

[0073] The size of the fifth through hole 74 is smaller than the size of the annular fuel element rod assembly 50, so as to prevent the annular fuel element rod assembly 50 from moving upward through the fifth through hole 74.

[0074] like Figure 9 As shown, in some embodiments, the blocking member 70 may form a third positioning hole 71, and the upper end of the support member 10 may form a third positioning hole 13, so as to position the blocking member 70 and the upper end of the support member 10 by means of a third positioning pin 72.

[0075] The upper ends of the blocking member 70 and the support member 10 are positioned by the third locating pin 72, which facilitates the assembly and disassembly of the blocking member 70 before and after irradiation. Figure 10 As shown, Figure 10 A schematic diagram of a third locating pin 72 according to one embodiment of this application is shown. Similar to the first locating pin 42, the third locating pin 72 may also include a stop tab 73.

[0076] In some embodiments, the upper end of the support member 10 above the blocking member 70 may also form a fourth positioning hole 14 for positioning the annular fuel element rod assembly 50 with the mounting mechanism.

[0077] join Figure 5The annular fuel element rod assembly 50 may include one or more annular fuel element rods 51 spliced ​​along the axial direction and bottom connecting pipes 52 connected to the bottom ends of these annular fuel element rods 51. The positioning member 40 is used to position the bottom connecting pipe 52 of each annular fuel element rod assembly 50 to the base 30.

[0078] The annular fuel element rod assembly 50 includes only one bottom connecting pipe 52. Each annular fuel element rod assembly 50 has a substantially identical shape and dimensions (diameter, length, etc.). Since the annular fuel element rod assembly 50 may include one or more annular fuel element rods 51 joined axially, the irradiation test assembly of this embodiment can simultaneously irradiate multiple annular fuel element rods 51 of different lengths, and the coolant within the reactor core can flow radially inward from each annular fuel element rod 51, so that the environment in which the annular fuel element rods 51 are located within the reactor core is as close as possible to the actual working environment during the irradiation test.

[0079] It is easy to understand that the annular fuel element rod 51 needs to remain intact to prevent leakage of radioactive materials. By providing a bottom connecting pipe 52 that connects to the bottommost annular fuel element rod 51 of each annular fuel element rod assembly 50, and positioning the bottom connecting pipe 52 to the base 30 with the positioning member 40, damage to the integrity of the annular fuel element rod 51 can be avoided.

[0080] Positioning hole 501 can be formed on bottom connecting pipe 52.

[0081] like Figure 5 As shown, in some embodiments, a notch 521 may be formed at the end of the bottom connecting tube 52 away from the annular fuel element rod 51. When the bottom connecting tube 52 is assembled with the base 30, the notch 521 protrudes at least partially outward from the side surface of the base 30 away from the connector 20.

[0082] In actual use, the end opening of the bottom connecting pipe 52 may become blocked. By setting the notch 521, it can be ensured that the coolant can enter the annular fuel element rod assembly 50 and flow inside.

[0083] In some embodiments, each annular fuel element rod 51 includes a sealed annular casing structure 511 and an annular core 512 located inside the annular casing structure 511.

[0084] The annular casing structure 511 may include an outer casing tube 5111 and an inner casing tube 5112 disposed radially inside the outer casing tube 5111. The outer casing tube 5111 and the inner casing tube 5112 form an annular structure with openings at both ends. The annular casing structure 511 also includes an upper end plug 5113 for sealing the upper opening of the annular structure and a lower end plug 5114 for sealing the lower opening of the annular structure. The annular fuel element rod 51 also includes an elastic element 513 disposed inside the annular casing structure 511 for providing axial preload to the annular pellet 512.

[0085] exist Figure 5 In the embodiment shown, the annular fuel element rod assembly 50 includes only one annular fuel element rod 51.

[0086] exist Figure 11 and Figure 12 In the illustrated embodiment, the annular fuel element rod assembly 50 includes two or more annular fuel element rods 51. Adjacent annular fuel element rods 51 are connected by a connecting ring 53.

[0087] In actual use, the lengths of the annular fuel element rods 51 may not be the same. By splicing multiple shorter annular fuel element rods 51 along the axial direction to form a relatively longer annular fuel element rod assembly 50, the requirement to conduct irradiation tests on annular fuel element rods 51 of different lengths can be met.

[0088] The connecting ring 53 can be welded to the lower end plug 5114 and upper end plug 5113 of two adjacent annular fuel element rods 51. The connecting ring 53 can be, for example, a metal cylinder with an I-shaped cross-section along the axial direction.

[0089] like Figure 11 As shown, in some embodiments, the annular fuel element rod assembly 50 may include two annular fuel element rods 51, the two annular fuel element rods 51 may be of the same length or different lengths. Figure 12 As shown, in some embodiments, the annular fuel element rod assembly 50 may include three annular fuel element rods 51, each annular fuel element rod 51 may have the same or different lengths.

[0090] For ease of description, Figure 5The annular fuel element rod assembly 50 shown, which includes only one annular fuel element rod 51, is referred to as the first annular fuel element rod assembly; the annular fuel element rod assembly 50, which includes two annular fuel element rods 51, and the length of the upper annular fuel element rod 51 is greater than the length of the lower annular fuel element rod 51, is referred to as the second annular fuel element rod assembly; the annular fuel element rod assembly 50, which includes two annular fuel element rods 51, and the length of the upper annular fuel element rod 51 is less than the length of the lower annular fuel element rod 51, is referred to as the third annular fuel element rod assembly; and the annular fuel element rod assembly 50, which includes three annular fuel element rods 51, is referred to as the fourth annular fuel element rod assembly.

[0091] In some embodiments, the first annular fuel element rod assembly, the second annular fuel element rod assembly, the third annular fuel element rod assembly, and the fourth annular fuel element rod assembly may have the same length.

[0092] In some embodiments, the annular fuel irradiation test assembly includes eight annular fuel element rod assemblies 50 and three connectors 20. The eight annular fuel element rod assemblies 50 can be combined in the form of four first annular fuel element rod assemblies, two second annular fuel element rod assemblies, and two third annular fuel element rod assemblies. The eight annular fuel element rod assemblies 50 are arranged such that two second annular fuel element rod assemblies pass through a first through hole 31 corresponding to one diagonal of a square, two third annular fuel element rod assemblies pass through a first through hole 31 corresponding to the other diagonal of a square, and four first annular fuel element rod assemblies pass through the remaining four first through holes 31.

[0093] In other embodiments, the annular fuel irradiation test assembly includes eight annular fuel element rod assemblies 50 and three connectors 20. The eight annular fuel element rod assemblies 50 can be arranged in the following configuration: four first annular fuel element rod assemblies, two third annular fuel element rod assemblies, and two fourth annular fuel element rod assemblies. The eight annular fuel element rod assemblies 50 are arranged such that two third annular fuel element rod assemblies pass through a first through-hole 31 corresponding to one diagonal of a square, two fourth annular fuel element rod assemblies pass through a first through-hole 31 corresponding to the other diagonal of a square, and four first annular fuel element rod assemblies pass through the remaining four first through-holes 31.

[0094] In the two embodiments described above, arranging annular fuel element rod assemblies 50 with different structural forms and sizes at various locations of the annular fuel irradiation test assembly enables a uniform power distribution within the annular fuel element rod assemblies 50, minimizing the impact on the target reactor used for irradiation. Those skilled in the art can also select other arrangements and combinations of the annular fuel element rod assemblies 50 according to actual needs.

[0095] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0096] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A ring-shaped fuel irradiation test assembly, comprising: Support components; At least one connector is connected to the support member, and each connector forms a plurality of connection through holes for multiple annular fuel element rod assemblies to pass through. A base, connected to the lower end of the support member, having multiple first through holes formed on the base for the passage of multiple annular fuel element rod assemblies; and Positioning elements are used to position each of the annular fuel element rod assemblies relative to the base; Each of the annular fuel element rod assemblies has a radially penetrating positioning hole at its lower end. The base forms multiple positioning channels along the axial direction perpendicular to the first through hole, and one or more of the first through holes are penetrated by one of the positioning channels; The positioning element passes through the positioning channel and the positioning hole of the annular fuel element rod assembly to position each of the annular fuel element rod assemblies to the base.

2. The irradiation test assembly according to claim 1, wherein, The plurality of first through holes are arranged in multiple rows, and each positioning channel passes through the first through hole in each row; The positioning element includes: Connecting rod; and A plurality of first locating pins, each first locating pin being connected to the connecting rod, wherein each first locating pin passes through a locating channel and a corresponding locating hole of the annular fuel element rod assembly.

3. The irradiation test assembly according to claim 2, wherein, The connecting rod forms multiple through holes along the axial direction perpendicular to the first through hole.

4. The irradiation test assembly according to claim 2, wherein, The lower end of the support member has a first positioning hole that extends radially through it; The base forms a second through hole for the support member to pass through. One of the plurality of positioning channels also extends through the second through hole, and one of the plurality of first positioning pins also passes through the first positioning hole.

5. The irradiation test assembly according to claim 4, wherein, The portion of the support member located below the first positioning hole forms a connecting segment, which extends downward from the second through hole; The irradiation test assembly further includes a bottom positioning element for positioning with the reactor core, wherein the bottom positioning element is detachably connected to the connecting section of the support element below the base.

6. The irradiation test assembly according to claim 5, wherein, The bottom positioning component is threadedly connected to the connecting section of the support component.

7. The irradiation test assembly according to claim 5 or 6, wherein, The connecting section of the bottom positioning member and the support member also forms a second positioning hole, so as to position the connecting section of the bottom positioning member and the support member by means of a second positioning pin.

8. The irradiation test assembly according to claim 4, wherein, The base also has multiple third through holes that extend vertically through it, providing channels for the coolant within the stack.

9. The irradiation test assembly according to claim 8, wherein, The plurality of first through holes and the plurality of third through holes are respectively distributed around the second through hole. The plurality of third through holes are closer to the second through hole than the plurality of first through holes.

10. The irradiation test assembly according to claim 9, wherein, The cross-sectional area of ​​the third through hole is smaller than that of the first through hole, but larger than half the cross-sectional area of ​​the first through hole.

11. The irradiation test assembly according to claim 8, wherein, The base also has a plurality of fourth through holes formed vertically through the base, each of the fourth through holes being disposed between two adjacent first through holes, for providing a flow channel for the coolant in the stack; The positioning channel is also connected to one or more of the fourth through holes.

12. The irradiation test assembly according to claim 1, wherein, The sidewall of the base forms an arc surface that matches the shape of the first through hole at the position of the first through hole, which is used to guide the coolant in the stack.

13. The irradiation test assembly according to claim 1, wherein, The connector includes an elastic element disposed on the wall of the connecting through hole, for providing radial preload to the annular fuel element rod assembly.

14. The irradiation test assembly according to claim 1, further comprising: A blocking element, detachably disposed at the upper end of the support member, is used to block the annular fuel element rod assembly when the annular fuel element rod assembly moves upward.

15. The irradiation test assembly according to claim 14, wherein, The blocking element forms a fifth through hole extending vertically to provide a flow channel for the coolant within the stack.

16. The irradiation test assembly according to claim 14, wherein, The upper ends of the blocking member and the supporting member are respectively formed with third positioning holes, so as to position the upper ends of the blocking member and the supporting member by means of third positioning pins.

17. The irradiation test assembly according to claim 1, further comprising: Multiple annular fuel element rod assemblies, each of the annular fuel element rod assemblies being sequentially connected through a connecting through hole of each of the connectors and a first through hole of the base; The annular fuel element rod assembly includes: one or more annular fuel element rods spliced ​​along the axial direction and a bottom connecting pipe connected to the bottom end of the one or more annular fuel element rods, wherein the positioning member is used to position the bottom connecting pipe of each annular fuel element rod assembly to the base.

18. The irradiation test assembly according to claim 17, wherein, The bottom connecting pipe has a notch formed at the end away from the one or more annular fuel element rods.

19. The irradiation test assembly according to claim 17, wherein, The annular fuel element rod includes: a sealed annular cladding structure and an annular core located inside the annular cladding structure.

20. The irradiation test assembly according to claim 19, wherein, When the annular fuel element rod assembly comprises multiple annular fuel element rods joined together axially, the annular cladding structures of two adjacent annular fuel element rods are connected by a connecting ring.

21. The irradiation test assembly according to claim 1, wherein, The connector has a through hole through which the support passes, and the wall of the through hole extends to form a plurality of welded portions, to which the support is welded.

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