Fuel rod device

Abstract

This utility model discloses a fuel rod device for measuring the leakage of fission products. The fuel rod device includes a shell, a core, a sealing section, and a clamping section. The shell defines a cavity and a rupture and a feed port communicating with the cavity. The core is housed in the cavity. The sealing section is connected to the shell and has a first state and a second state. In the first state, the sealing section closes the rupture; in the second state, the sealing section opens at least partially of the rupture. The clamping section connects the sealing section and the shell. The clamping section is configured to clamp the sealing section and the shell, keeping the sealing section in the first state, and the clamping section can release the sealing section to switch the sealing section from the first state to the second state. This solution can effectively improve the reliability of simulation testing of fission product leakage, improve the accuracy of nuclear reactor mechanism source term analysis, and provide effective support for model development.

Description

Technical Field

[0001] This utility model relates to the field of nuclear reactor technology, and in particular to a fuel rod device. Background Technology

[0002] During nuclear reactor operation, the fuel rod assemblies in the reactor core generate a large number of radioactive fission products during fission. Under the influence of fretting erosion, foreign object erosion, chemical corrosion, irradiation creep, swelling, and the high pressure exerted by fission products within the fuel cladding, the fuel cladding may rupture, creating a breach. This breach releases fission products into the coolant. In addition to common fission gases, the fission products released through the breach include non-gaseous fission products such as solid and liquid fission products.

[0003] In related technologies, liquid and solid fission products are generally simulated using aerosol particles in program calculations. Currently, in the process of conducting source term analysis of nuclear reactor mechanisms, the proportion of aerosols released from the breach is assumed, which introduces uncertainty into the source term calculation results. In other words, the reliability of existing simulation tests of fission product leakage is low. Utility Model Content

[0004] The main objective of this invention is to propose a fuel rod device that addresses the technical problem of low reliability in the simulation test of fission product leakage.

[0005] To achieve the above objectives, this utility model provides a fuel rod device for measuring the leakage of fission products. The fuel rod device includes:

[0006] The shell defines a cavity and an opening and a feed inlet communicating with the cavity;

[0007] The core rod is housed in the cavity;

[0008] A sealing portion is connected to the housing. The sealing portion has a first state and a second state. In the first state, the sealing portion closes the opening. In the second state, the sealing portion opens at least part of the opening.

[0009] A clamping part connects the closure part and the housing. The clamping part is configured to clamp the closure part and the housing so that the closure part is held in the first state, and the clamping part is capable of releasing the closure part so that the closure part switches from the first state to the second state.

[0010] In some embodiments, the clamping portion includes a first fixed end and a second fixed end arranged opposite to each other, the first fixed end and the second fixed end being located on opposite sides of the housing along its circumference;

[0011] The first fixed end and the second fixed end can be relatively far apart so that the clamping part releases the closing part, and the first fixed end and the second fixed end can be relatively close together so that the clamping part clamps the closing part and the housing.

[0012] In some embodiments, the clamping portion includes an adjusting member and a base, the adjusting member including a first fixed end, the base including a second fixed end, and the adjusting member being rotatable relative to the base to bring the first fixed end and the second fixed end closer or farther apart.

[0013] In some embodiments, the fuel rod assembly includes a first gasket and a truncated pyramid, both of which are connected to the housing and are located on opposite sides of the housing along its circumference.

[0014] The first gasket has an opening communicating with the tear, the first fixing end is adapted to abut against the first gasket, and the second fixing end is adapted to abut against the frustum, so that the closing portion closes the opening.

[0015] In some embodiments, the first gasket is detachably connected to the housing;

[0016] And / or,

[0017] The closure portion is movably connected to the housing. The closure portion has a first position and a second position relative to the first gasket. In the first position, the closure portion closes a portion of the opening, and the exposed area of ​​the opening is S1. In the second position, the closure portion closes a portion of the opening, and the exposed area of ​​the opening is S2. Wherein, S1 > S2.

[0018] In some embodiments, the closure includes a pressure cap and a second gasket, the second gasket being located on the side of the pressure cap facing the first gasket, the second gasket being used to close the opening, and the second fixed end being adapted to abut against the pressure cap so that the pressure cap presses the second gasket against the first gasket.

[0019] In some embodiments, the gland has a first through hole, and in the second state, the first through hole communicates with at least a portion of the opening. The fuel rod assembly includes a pressure tube, which has a second through hole that communicates with the first through hole.

[0020] In some embodiments, the core includes a core block, a first reflective layer, and a second reflective layer, the core block connecting the first reflective layer and the second reflective layer, and the first reflective layer and the second reflective layer being located on opposite sides of the core block along the extension direction of the housing.

[0021] In some embodiments, the housing has an upper top wall along its extending direction, and the rod core is elastically connected to the top wall; the housing also has a lower bottom wall along its extending direction, the bottom wall being spaced from the rod core to form a gas space.

[0022] In some embodiments, the housing includes a first sampling port, which is spaced apart from the rupture and the feed port; and / or, the housing includes a second sampling port, which is spaced apart from the rupture and the feed port.

[0023] Compared with the prior art, the beneficial effects of this utility model include:

[0024] In this invention, a fuel rod device is used to measure the leakage of fission products. The fuel rod device includes a shell, a core, a sealing section, and a clamping section. The shell defines a cavity and a rupture and a feed inlet communicating with the cavity. The core is housed in the cavity, the sealing section is connected to the shell, and the clamping section connects the sealing section and the shell. In the prior art, the proportion of aerosol released from the rupture is assumed, which introduces uncertainty into the source term calculation results, meaning that the reliability of existing simulation tests of fission product leakage is low. The sealing section of this invention has a first state and a second state. In the first state, the sealing section can close the rupture; in the second state, the sealing section can open at least part of the rupture. That is, the sealing section can ensure the airtightness of the fuel rod device, allowing the aerosol input from the feed inlet to be fully deposited, improving the reliability of the detection. Furthermore, the sealing section can switch states to close or open the rupture, facilitating sampling and measurement operations. Furthermore, the clamping part can clamp the sealing part and the shell, keeping the sealing part in a first state, and the clamping part can release the sealing part, allowing the sealing part to switch from the first state to a second state. In other words, the clamping part can effectively improve the stability of the sealing part in sealing breaches and facilitates the switching of the sealing part between the first and second states. In summary, this solution can effectively improve the reliability of simulation tests of fission product leakage, enhance the accuracy of nuclear reactor mechanism source term analysis, and provide effective support for model development. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a cross-sectional view of a fuel rod device according to an embodiment of the present invention along one direction; wherein, the housing, rod core, enclosure, and gas space are shown;

[0027] Figure 2 This is a cross-sectional view of a fuel rod device according to one embodiment of the present invention along another direction; wherein, the clamping part and the closing part are shown.

[0028] Explanation of icon numbers:

[0029] Fuel rod assembly 10;

[0030] Shell 100; cavity 110; opening 120; feed inlet 130; top wall 140; bottom wall 150; gas space 151; first sampling port 160; second sampling port 170; extension direction Z;

[0031] Rod core 200; core block 210; first reflective layer 220; second reflective layer 230;

[0032] Sealing part 300; Pressure cap 310; First through hole 311; Second gasket 320;

[0033] Clamping part 400; First fixed end 410; Second fixed end 420;

[0034] First gasket 500; Opening 510;

[0035] 600 truncated pyramid;

[0036] Pressure tube 700; Second through hole 710;

[0037] Elastic component 800.

[0038] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] This utility model embodiment provides a fuel rod device 10, which is used to measure the leakage of fission products, thereby effectively improving the reliability of simulation tests for the leakage of fission products. The following refers to... Figure 1 and Figure 2 The present application will now describe a fuel rod device 10 according to an embodiment of the present application. Specifically, the fuel rod device 10 includes a housing 100, a rod core 200, a sealing portion 300, and a clamping portion 400.

[0041] Reference Figure 1 and Figure 2 The shell 100 is used to house the fuel rod 200. The outer contour of the shell 100 can be cylindrical, and the specific shape of the shell 100 can refer to the spatial structure of the fuel rods in a pre-designed real nuclear reactor. The shell 100 can define a cavity 110, which can house the fuel rod 200. The shell 100 has a vent 120 and a feed port 130 communicating with the cavity 110. The feed port 130 is used to input aerosols and gases, etc. The vent 120 is used to allow the reaction gases to escape. It should be noted that in some embodiments, the vent 120 needs to be able to remain closed under high pressure (maximum 10 MPa) and be able to open at the start of the experiment. The specific shape and size of the vent 120 and the feed port 130 can be determined according to the actual situation.

[0042] Reference Figure 1 and Figure 2 The sealing portion 300 is used to close the breach 120. The sealing portion 300 is connected to the housing 100. Specifically, the sealing portion 300 has a first state and a second state. In the first state, the sealing portion 300 can close the breach 120, thereby sealing the fuel rod assembly 10 and allowing the aerosol inside the injection cavity 110 to deposit sufficiently. In the second state, the sealing portion 300 leaves at least a partial opening of the breach 120, allowing gas release. It should be noted that in some embodiments, the sealing portion 300 can completely open the entire breach 120. In other embodiments, the sealing portion 300 can only open a partial opening of the breach 120. The specific size of the closure of the breach 120 by the sealing portion 300 can be determined according to the actual situation.

[0043] The clamping part 400 is used to fix the sealing part 300 to the housing 100, and connects the sealing part 300 and the housing 100. When it is necessary to keep the sealing part 300 in the first state, that is, when the sealing part 300 needs to close the opening 120, the clamping part 400 can clamp the sealing part 300 and the housing 100 to ensure the stability of the connection between the sealing part 300 and the housing 100. When it is necessary to switch the sealing part 300 from the first state to the second state, that is, when the sealing part 300 needs to open the opening 120, the clamping part 400 can release the sealing part 300, so that the gas can be released normally from the opening 120.

[0044] In the technical solution of this utility model, the fuel rod device 10 is used to measure the leakage of fission products. The fuel rod device 10 includes a housing 100, a rod core 200, a sealing portion 300, and a clamping portion 400. The housing 100 defines a cavity 110 and a rupture 120 and a feed port 130 communicating with the cavity 110. The rod core 200 is housed in the cavity 110, the sealing portion 300 is connected to the housing 100, and the clamping portion 400 connects the sealing portion 300 and the housing 100. In the prior art, the proportion of aerosols released from the rupture is assumed, which introduces uncertainty into the source term calculation results, i.e., the reliability of existing simulation tests of fission product leakage is low. The sealing part 300 of this solution has a first state and a second state. In the first state, the sealing part 300 can close the opening 120; in the second state, the sealing part 300 can open at least part of the opening 120. That is, the sealing part 300 can ensure the sealing of the fuel rod device 10, allowing the aerosol input from the feed port 130 to be fully deposited, improving the reliability of detection. Furthermore, the sealing part 300 can switch states to close or open the opening 120, facilitating sampling and measurement operations. Further, the clamping part 400 can clamp the sealing part 300 and the housing 100, keeping the sealing part 300 in the first state. The clamping part 400 can also release the sealing part 300, switching it from the first state to the second state. In other words, the clamping part 400 can effectively improve the stability of the sealing part 300 in closing the opening 120 and facilitates switching between the first and second states. In summary, this approach can effectively improve the reliability of simulation tests of fission product leakage, enhance the accuracy of nuclear reactor mechanism source term analysis, and provide effective support for model development.

[0045] Reference Figure 1 and Figure 2 The following describes the specific clamping arrangement of the clamping part 400 on the housing 100. In some embodiments, the clamping part 400 includes a first fixed end 410 and a second fixed end 420 arranged opposite to each other. The first fixed end 410 and the second fixed end 420 are respectively located on opposite sides of the housing 100 along its circumference, as shown in the figure. Figure 2 In terms of orientation, the first fixing end 410 can be the fixing end on the left side of the clamping part 400, and the second fixing end 420 can be the fixing end on the right side of the clamping part 400. In some embodiments, the structure of the first fixing end 410 can be the same as that of the second fixing end 420. In other embodiments, the structure of the first fixing end 410 can be different from that of the second fixing end 420. This application embodiment is described using the example of the first fixing end 410 and the second fixing end 420 having the same structure.

[0046] Specifically, when it is necessary for the clamping part 400 to release the closing part 300, that is, when it is necessary for the closing part 300 to open the opening 120, the first fixing end 410 and the second fixing end 420 can move away from each other. In some embodiments, the position of the first fixing end 410 is fixed, and the second fixing end 420 can move away from the first fixing end 410. In other embodiments, the position of the second fixing end 420 is fixed, and the first fixing end 410 can move away from the second fixing end 420. In other embodiments, the first fixing end 410 and the second fixing end 420 can also move away from each other. It should be noted that when it is necessary for the closing part 300 to remain closed to the opening 120, the first fixing end 410 and the second fixing end 420 can be relatively close, so that the clamping part 400 can clamp the closing part 300 and the housing 100. The clamping part 400 of this solution clamps on opposite sides of the housing 100 along the circumferential direction, which can make the fuel rods bear force evenly and ensure the stability of the clamping part 400 in fixing the sealing part 300.

[0047] The specific structure of the clamping part 400 is described below. In some embodiments, the clamping part 400 includes an adjusting member and a base. The adjusting member includes a first fixed end 410, and the base includes a second fixed end 420. The adjusting member can rotate relative to the base to bring the first fixed end 410 and the second fixed end 420 closer or further apart. Specifically, the adjusting member can be a screw, the base can be provided with a threaded hole, and the screw can pass through the threaded hole and be threaded to the base. This solution can precisely control the distance between the first fixed end 410 and the second fixed end 420 by turning the adjusting member, thereby achieving reliable control of the closing state of the closing part 300, and the relative movement of the first fixed end 410 and the second fixed end 420 is convenient and quick.

[0048] It should be noted that in some embodiments, the fuel rod assembly 10 has a drive unit that can directly drive the first fixed end 410 and the second fixed end 420 to move closer or further apart. It is understood that the drive unit can be electrically driven, pneumatically driven, or hydraulically driven, etc.

[0049] Reference Figure 1 and Figure 2The specific structure of the fuel rod assembly 10 is described below. In some embodiments, the fuel rod assembly 10 includes a first gasket 500 and a truncated pyramid 600. The first gasket 500 has an opening 510, which communicates with the rupture 120 of the housing 100, meaning that gas can be released through the opening 510 of the first gasket 500. Both the truncated pyramid 600 and the first gasket 500 are connected to the housing 100 and are located on opposite sides of the housing 100 in the circumferential direction. When the sealing portion 300 needs to close the rupture 120, the first fixing end 410 can abut against the first gasket 500, and the second fixing end 420 can abut against the truncated pyramid 600. That is, the first gasket 500 and the truncated pyramid 600 in this solution can improve the stability and sealing performance of the sealing portion 300 in closing the rupture 120.

[0050] The specific mating arrangement between the enclosure 300 and the housing 100 is described below. In some embodiments, the first gasket 500 is detachably connected to the housing 100. Specifically, the first gasket 500 can be snap-fitted, threaded, or sleeved with the housing 100. The detachable connection between the first gasket and the housing 100 in this design allows for the replacement of gaskets with various opening sizes 510. Therefore, it is possible to obtain the gas release rate and aerosol release percentage of lead-bismuth reactor fuel rods under different pressures and different breach 120 parameters, adapting to different testing needs and providing experimental data support for the study of lead-bismuth reactor mechanism source terms.

[0051] In other embodiments, the sealing portion 300 is movably connected to the housing 100. The sealing portion 300 has a first position and a second position relative to the first gasket 500. In the first position, the sealing portion 300 closes a portion of the opening 510, at which time the exposed area of ​​the opening 510 is S1. In the second position, the sealing portion 300 closes a portion of the opening 510, at which time the exposed area of ​​the opening 510 is S2. Wherein, S1 > S2. Therefore, this solution can flexibly adjust the size (actual open size) of the opening 510 of the first gasket 500 according to actual needs, that is, it can obtain the gas release rate and aerosol release ratio of the lead-bismuth reactor fuel rod under different pressures and different rupture 120 parameters, adapting to different testing requirements.

[0052] The specific configuration of the closure 300 movably connecting to the housing 100 is described below. In some embodiments, the closure 300 can be slidably connected to the housing 100. In other embodiments, the closure 300 can be rotatably connected to the housing 100. The specific connection configuration between the closure 300 and the housing 100 may vary depending on the actual situation.

[0053] Reference Figure 2The specific structure of the closure 300 is described below. In some embodiments, the closure 300 includes a pressure cap 310 and a second gasket 320. The second gasket 320 is used to close the opening 510. Specifically, the second gasket 320 may be located on the side of the pressure cap 310 facing the first gasket 500. (Refer to...) Figure 2 That is, the second gasket 320 is located between the gland 310 and the first gasket 500. When the sealing part 300 closes the opening 120, the second fixed end 420 can abut against the gland 310 so that the gland 310 presses the second gasket 320 against the first gasket 500, thus ensuring the sealing effect of the fuel rod assembly 10.

[0054] The gas venting configuration of the fuel rod assembly 10 is described below. In some embodiments, the pressure cap 310 is provided with a first through hole 311. When the closure portion 300 is in the second state (open vent 120), the first through hole 311 connects to at least a portion of the opening 510. It is understood that the size and shape of the first through hole 311 may be the same as or different from the opening 510. The fuel rod assembly 10 includes a pressure tube 700, which is provided with a second through hole 710, which communicates with the first through hole 311. The size and shape of the second through hole 710 may be the same as or different from the opening 510. The specific configuration of the first through hole 311 and the second through hole 710 can be determined according to the actual situation. In this embodiment, the first through hole 311 and the second through hole 710 can form a gas channel, that is, the gas reacted inside the housing 100 can enter the first through hole 311 through the opening 510, and then enter the second through hole 710 connected to the first through hole 311, which facilitates gas sampling and measurement.

[0055] Reference Figure 1 The specific arrangement of the fuel rod core 200 of the fuel rod assembly 10 is described below. In some embodiments, the fuel rod core 200 includes a core block 210, a first reflective layer 220, and a second reflective layer 230. The core block 210 connects the first reflective layer 220 and the second reflective layer 230. The first reflective layer 220 and the second reflective layer 230 are respectively located on opposite sides of the core block 210 along the extending direction of the housing 100, as shown in the figure. Figure 1 Orientation: The shell 100 can extend vertically, the first reflective layer 220 can be located above the core block 210, and the second reflective layer 230 can be located below the core block 210. It should be noted that the first reflective layer 220, the second reflective layer 230, and the core block 210 can all be replaced by metal cylinders of the same size to ensure the safety of the experiment.

[0056] Reference Figure 1 The specific connection arrangement between the housing 100 and the core 200 is described below. In some embodiments, the housing 100 has a top wall 140 located on the upper side along its extending direction, as shown in the figure. Figure 1In terms of orientation, the upper wall of the housing 100 can be a top wall 140. The fuel rod core 200 is elastically connected to the top wall 140. Specifically, the fuel rod assembly 10 has an elastic element 800, one end of which can be connected to the top wall 140 and the other end can be connected to the first reflective layer 220. In this design, the fuel rod core 200 is elastically connected to the top wall 140, which can absorb and buffer the impact of gas, reducing the impact on the internal structure.

[0057] Reference Figure 1 In some embodiments, the housing 100 has a bottom wall 150 located on its lower side along its extending direction, see reference. Figure 1 Orientation: The lower wall of the casing 100 can be a bottom wall 150. The bottom wall 150 is spaced from the core 200 to form a gas space 151. The gas space 151 can provide support. It should be noted that the fuel rod assembly 10 can be designed to be hollow in the middle and open around the perimeter to facilitate the containment of gas.

[0058] In some embodiments, the housing 100 includes a first sampling port 160, which is spaced apart from the rupture 120 and the feed inlet 130. In some embodiments, the housing 100 includes a second sampling port 170, which is also spaced apart from the rupture 120 and the feed inlet 130. This application embodiment uses the simultaneous provision of the first sampling port 160 and the second sampling port 170 as an example. It can be understood that the first sampling port 160 can be located on the upper side of the housing 100, and the second sampling port 170 can be located on the lower side of the housing 100. The first sampling port 160 and the second sampling port 170 of this solution can be used by a particle size analyzer to sample, satisfying the measurement of aerosol concentration inside the fuel rod.

[0059] The following describes the testing process of a fuel rod device 10 according to a specific embodiment of this application, taking the measurement of aerosol release fraction as an example. First, the upstream gas or aerosol supply device is connected through the feed port 130 to ensure that all parts are working properly, all connections are well sealed, and there is no obvious damage or leakage. In addition, the gas supply is made to meet the experimental requirements, and the clamping part 400 clamps the sealing part 300 so that the sealing part 300 reliably seals the opening 120.

[0060] Next, inject gas or aerosol into the fuel rod assembly 10 until the specified operating pressure is reached, then stop the injection, allow it to stand for a sufficient time, and observe the internal pressure of the casing 100. If the pressure drops significantly, readjust the sealing part 300 or the clamping part 400; if the pressure is maintained at the predetermined operating condition, it indicates that the fuel rod assembly 10 has good airtightness and can meet the requirements of subsequent experiments.

[0061] Then, the upstream aerosol injection device is turned on. After the aerosol injection is completed, the entire experimental system is allowed to stand for a sufficient period of time to ensure that the aerosol in the fuel rod device 10 can be fully deposited. After a small amount of gas in the fuel rod device 10 is discharged through the sampling port, the sampling channel is closed, and the particle size analyzer is turned on to take a small sample through the measurement channel for measurement.

[0062] Finally, remove the second gasket 320, allowing the gas to flow along the rupture 120 to the opening 510 for release. Once the internal pressure of the housing 100 stabilizes at approximately atmospheric pressure, the gas release is complete. Then, turn on the particle size analyzer and measure a certain amount of sample gas from the collection device through the measurement channel.

[0063] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0064] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or," "and / or," or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where A and B are simultaneously satisfied. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0065] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A fuel rod device for measuring the leakage of fission products, characterized in that, The fuel rod assembly includes: The shell defines a cavity and an opening and a feed inlet communicating with the cavity; The core rod is housed in the cavity; A sealing portion is connected to the housing. The sealing portion has a first state and a second state. In the first state, the sealing portion closes the opening. In the second state, the sealing portion opens at least part of the opening. A clamping part connects the closure part and the housing. The clamping part is configured to clamp the closure part and the housing so that the closure part is held in the first state, and the clamping part is capable of releasing the closure part so that the closure part switches from the first state to the second state.

2. The fuel rod device as claimed in claim 1, characterized in that, The clamping part includes a first fixed end and a second fixed end arranged opposite to each other, the first fixed end and the second fixed end being located on opposite sides of the housing along its circumference; The first fixed end and the second fixed end can be relatively far apart so that the clamping part releases the closing part, and the first fixed end and the second fixed end can be relatively close together so that the clamping part clamps the closing part and the housing.

3. The fuel rod device as claimed in claim 2, characterized in that, The clamping part includes an adjusting member and a base. The adjusting member includes a first fixed end, and the base includes a second fixed end. The adjusting member is configured to rotate relative to the base so that the first fixed end and the second fixed end are relatively close to or relatively far apart.

4. The fuel rod device as claimed in claim 2, characterized in that, The fuel rod assembly includes a first gasket and a truncated pyramid, both of which are connected to the housing and are located on opposite sides of the housing along its circumference. The first gasket has an opening communicating with the tear, the first fixing end is adapted to abut against the first gasket, and the second fixing end is adapted to abut against the frustum, so that the closing portion closes the opening.

5. The fuel rod device as claimed in claim 4, characterized in that, The first gasket is detachably connected to the housing; And / or, The closure portion is movably connected to the housing. The closure portion has a first position and a second position relative to the first gasket. In the first position, the closure portion closes a portion of the opening, and the exposed area of ​​the opening is S1. In the second position, the closure portion closes a portion of the opening, and the exposed area of ​​the opening is S2. Wherein, S1 > S2.

6. The fuel rod device as claimed in claim 4, characterized in that, The closure includes a pressure cap and a second gasket. The second gasket is located on the side of the pressure cap facing the first gasket and is used to close the opening. The second fixed end is adapted to abut against the pressure cap so that the pressure cap presses the second gasket against the first gasket.

7. The fuel rod device as claimed in claim 6, characterized in that, The pressure cap has a first through hole, and in the second state, the first through hole communicates with at least a portion of the opening. The fuel rod assembly includes a pressure tube, which has a second through hole, and the second through hole communicates with the first through hole.

8. The fuel rod device as claimed in claim 1, characterized in that, The core includes a core block, a first reflective layer, and a second reflective layer. The core block connects the first reflective layer and the second reflective layer, and the first reflective layer and the second reflective layer are located on opposite sides of the core block along the extension direction of the shell.

9. The fuel rod device as claimed in claim 8, characterized in that, The housing has an upper top wall along its extending direction, and the rod core is elastically connected to the top wall; the housing has a lower bottom wall along its extending direction, and the bottom wall is spaced from the rod core to form a gas space.

10. The fuel rod device as claimed in claim 1, characterized in that, The housing includes a first sampling port, which is spaced apart from the rupture and the feed port; and / or, the housing includes a second sampling port, which is spaced apart from the rupture and the feed port.

Images