Fuel cladding damage release experimental device
By designing a fuel cladding failure and release experimental device suitable for high-temperature liquid metal environments, and employing a simulated failure test rod, a gas storage outer liner, and a remotely controllable transmission mechanism, the applicability and control issues of existing devices were solved, enabling failure and release experiments and radioactivity experiments in high-temperature environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHINA NATIONAL NUCLEAR CORP SOUTHERN TECHNOLOGY CO LTD
- Filing Date
- 2025-05-08
- Publication Date
- 2026-04-28
AI Technical Summary
Existing fuel cladding failure simulation experimental devices are not suitable for high-temperature liquid metal reactors and cannot be used for remotely controlled radioactive experiments.
An experimental device was designed, comprising a simulated break test rod, a gas storage outer liner, a heating and temperature control sealing rod, and a remotely controllable transmission control mechanism. It is suitable for high-temperature liquid metal environments and enables remote closing and opening of the break through the transmission control mechanism.
It enables damage release experiments in a high-temperature liquid metal environment, has remote control capabilities, is suitable for radioactive experiments, and improves the flexibility and safety of experiments.
Smart Images
Figure CN224177118U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of nuclear fuel cladding damage testing technology, and in particular to a fuel cladding damage release testing device. Background Technology
[0002] During nuclear power plant operation, fuel cladding may be damaged by various physicochemical factors such as abrasion and chemical corrosion. Fission products within the fuel rods can then enter the primary coolant through the breach, potentially increasing radiation dose levels for operation and maintenance personnel and even necessitating reactor shutdown for repairs. As the first line of defense against radioactive nuclides, the integrity monitoring of the fuel cladding is a crucial component of radiochemical technical specifications. In the event of damage, the extent of the damage and the severity of the accident must be assessed promptly based on monitoring data to determine whether a reactor shutdown is necessary. Accurate damage assessment requires extensive experimentation to determine the relationship between the degree of damage and the monitoring indicator nuclides in the coolant. Currently, most international experiments are conducted on experimental reactors, with relatively fixed experimental variables, resulting in a lack of scalability. This is particularly true for liquid metal reactors, where the primary coolant temperature can reach up to 800°C, depending on the medium. Fuel cladding damage release simulation experimental devices, as key components in these experiments, currently lack practical designs.
[0003] An existing reactor cladding failure simulation test bench includes a fuel rod simulator, end plugs, sealing sleeves, and a core single-channel simulator. The simulated failure closure is achieved by detachably installing the fuel rod simulator on the core single-channel simulator and manually controlling the end plugs on the heating rods by lifting the handle. The test rod shell is equipped with interfaces for measuring pressure, temperature, and humidity instruments and an exhaust port. It can be used to simulate cladding failure under various operating conditions and measure gas release and internal pressure changes under different hydraulic conditions, different types of cracks, and different internal temperature fields. However, this device has the following shortcomings: (1) This device is suitable for gas rupture release experiments in water media. The maximum applicable water medium temperature is generally no higher than 350℃, and it is not suitable for liquid metal reactors with a maximum medium temperature of 800℃; (2) The test hole closure is achieved manually by controlling the end plugs on the heating rods by lifting the handle. This method cannot be remotely controlled and is not suitable for radioactive experiments. Utility Model Content
[0004] The technical problem to be solved by this utility model is to provide an improved experimental device for fuel cladding failure and release.
[0005] The technical solution adopted by this utility model to solve its technical problem is: to provide a fuel cladding failure and release test device, including a simulated failure test rod, a gas storage outer liner, a heating and temperature control sealing rod, and a remotely controllable transmission control mechanism.
[0006] The gas storage outer liner has a gas storage cavity inside; the simulated rupture test rod is sealed to the first end of the gas storage outer liner at the first end, and the first end of the simulated rupture test rod is provided with a gas channel connecting the interior of the simulated rupture test rod and the gas storage cavity; the heating and temperature control sealing rod passes through the gas storage cavity from the opposite end of the gas storage outer liner and is opposite to the first end of the simulated rupture test rod.
[0007] The transmission control mechanism is located outside the gas storage outer bushing, and is connected to and drives the heating and temperature control sealing rod to move back and forth along the gas storage cavity in the direction of approaching and moving away from the first end of the simulated breakage test rod, thereby closing or opening the gas channel.
[0008] In one embodiment, the fuel cladding breakage and release experimental apparatus further includes a control system connected to the transmission control mechanism to control the start and stop of the transmission control mechanism.
[0009] In one embodiment, the simulated rupture test rod includes a high-temperature resistant and hollow test rod body and a high-temperature resistant first sealing ring. The side wall of the test rod body is provided with a simulated shell rupture. The test rod body has a first end and a second end opposite to each other. The first end of the test rod body is fitted to the first end of the gas storage outer liner, and the gas channel is opened at the first end of the test rod body.
[0010] The first end face of the experimental rod is provided with a first groove surrounding the gas channel, and the first sealing ring is fitted in the first groove to seal between the first end face of the experimental rod and the mating surface of the heating and temperature control sealing rod.
[0011] In one embodiment, the first end of the experimental rod is threadedly connected to one end of the gas storage outer liner; and / or, a high-temperature resistant second sealing ring is provided between the mating surfaces of the first end of the experimental rod and one end of the gas storage outer liner.
[0012] In one embodiment, the heating and temperature control sealing rod includes a hollow sealing rod body and a heating rod that passes through the sealing rod body axially inside the sealing rod body;
[0013] The first end of the sealing rod is located inside the gas storage cavity, and the end face of the first end forms a mating surface, which is directly opposite the first end of the simulated breakage test rod. The opposite second end of the sealing rod is located outside the second end of the gas storage outer bushing and is connected to the transmission control mechanism.
[0014] The outer peripheral surface of the sealing rod is provided with a raised sealing structure, which fits tightly with the inner wall of the gas storage cavity.
[0015] In one embodiment, a high-temperature resistant third sealing ring is further provided between the sealing structure and the inner wall surface of the gas storage cavity.
[0016] In one embodiment, the heating and temperature control sealing rod further includes a temperature instrument.
[0017] In one embodiment, the gas storage outer liner includes a hollow and sealed gas storage rod, the hollow inner cavity of which forms the gas storage chamber; an air inlet channel is provided on the side wall of the gas storage rod, the air inlet channel communicating with the gas storage chamber for introducing experimental gas.
[0018] In one embodiment, the gas storage outer bushing further includes a temperature monitoring unit and a pressure monitoring unit disposed on the gas storage rod body, respectively used to monitor the temperature and pressure inside the gas storage chamber.
[0019] In one embodiment, the transmission control mechanism includes a transmission rod and a drive unit that connects to and drives the transmission rod to move back and forth in the axial direction.
[0020] The beneficial effects of this utility model are as follows: Through the optimized setting between the simulated breach test rod, the gas storage outer liner, and the heating and temperature control sealing rod, it is suitable for the high-temperature metal medium environment of the primary loop of various existing high-temperature metal reactors; the heating and temperature control sealing rod is driven to move by a remotely controllable transmission control mechanism, so as to realize remote controllable breach closure, which is suitable for radioactive experiments. Attached Figure Description
[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:
[0022] Figure 1 This is a schematic diagram of the structure of a fuel cladding breakage and release experimental device according to an embodiment of the present invention. Detailed Implementation
[0023] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.
[0024] like Figure 1 As shown, an embodiment of the fuel cladding failure and release experimental device of this utility model includes a simulated failure test rod 10, a gas storage outer liner 20, a heating and temperature control sealing rod 30, and a remotely controllable transmission control mechanism 40; it may also include a control system 50 connected to the transmission control mechanism 40 to remotely control the start and stop of the transmission control mechanism 40.
[0025] The simulated breach test rod 10 serves as a simulation component, simulating a fuel cladding with a breach. It is a hollow and sealed structure with a first end and a second end. The gas storage outer liner 20 has a gas storage cavity inside. The simulated breach test rod 10 is sealed to the first end of the gas storage outer liner 20 at its first end. A heating and temperature-controlled sealing rod 30 enters the gas storage cavity 200 from the opposite end of the gas storage outer liner 20, opposite to the first end of the simulated breach test rod 10. The first end of the simulated breach test rod 10 has a gas channel 100 connecting the interior of the simulated breach test rod 10 and the gas storage cavity 200. A transmission control mechanism 40 is located outside the gas storage outer liner 20, connecting to and driving the heating and temperature-controlled sealing rod 30 to move back and forth along the gas storage cavity in a direction approaching and away from the first end of the simulated breach test rod 10, thus closing or opening the gas channel 100.
[0026] Specifically, the simulated rupture test rod 10 may include a high-temperature resistant and hollow test rod body 11 and a high-temperature resistant first sealing ring 12. The test rod body 11 is a hollow metal rod closed at both ends (the first end and the second end). For this structure, it can be further constructed by a rod body with one end closed and the other end open, and an end plug sealing the open end. The first end of the test rod body 11 is fitted to the first end of the gas storage outer bushing 20, and the gas channel 100 is opened at the first end of the test rod body 11. The first sealing ring 12 is disposed on the end face of the first end of the test rod body 11 and is located around the gas channel 100, for sealing the mating surface of the first end face of the test rod body 11 and the heating and temperature control sealing rod 30.
[0027] The side wall of the experimental rod 11 is provided with a simulated cladding break 110 to simulate a break in the fuel cladding.
[0028] Corresponding to the first sealing ring 12, the first end face of the experimental rod 11 is provided with a first groove (not shown) surrounding the gas channel 100. The first sealing ring 12 fits into the first groove, thereby positioning the first sealing ring 12 on the first end face of the experimental rod 11. The gas channel 100 may be, but is not limited to, a circular channel.
[0029] The experimental rod 11 is made of stainless steel, preferably austenitic stainless steel, which has good corrosion resistance and mechanical properties in high-temperature liquid lead-bismuth media. The first sealing ring 12 is made of special ceramic fiber composite material, which can withstand temperatures up to 3000℃ and has excellent high-temperature resistance, tensile strength, oxidation resistance, creep resistance, and abrasion resistance, fully ensuring the sealing and functional integrity of the entire device in high-temperature gas and high-temperature liquid metal media environments.
[0030] The first end of the experimental rod 11 and the first end of the gas storage outer liner 20 can be connected by threads. Further optionally, a high-temperature resistant second sealing ring 13 is provided between the mating surfaces of the first end of the experimental rod 11 and the first end of the gas storage outer liner 20 to achieve a sealed fit between the first end of the experimental rod 11 and the first end of the gas storage outer liner 20, ensuring the sealing performance at the connection point. The second sealing ring 13 is preferably a special ceramic fiber composite material, which can withstand temperatures up to 3000℃ and has excellent high-temperature resistance, tensile strength, oxidation resistance, creep resistance, and abrasion resistance.
[0031] The gas storage outer liner 20 may further include a hollow and sealed gas storage rod 21, the hollow inner cavity of which forms a gas storage chamber 200. The gas storage rod 21 has a first end and a second end. The first end of the gas storage rod 21 has a first interface that is adapted to the first end of the experimental rod 11, allowing the first end of the experimental rod 11 to be tightly connected at the first interface. The gas storage chamber 200 can communicate with the internal chamber of the simulated rupture experimental rod 10 through a gas channel 100. The second end of the gas storage rod 21 has a second interface for engaging with a heating and temperature control sealing rod 30. An air inlet channel 210 is provided on the side wall of the gas storage rod 21, which connects to the gas storage chamber 200 for receiving experimental gas; the experimental gas can be stored within the gas storage chamber 200.
[0032] The gas storage rod 21 can be further structurally composed of a gas storage rod body that is open at one end and an end plug that is sealed at the open end.
[0033] The gas inlet channel 210 can be realized by a gas interface protruding from the outer surface of the gas storage rod 21, which facilitates connection to an external gas supply device via a gas pipeline to access the experimental gas. Depending on the requirements, the experimental gas can be a radioactive monitoring indicator nuclide or its non-radioactive simulant nuclide, as well as an inert gas or other carrier gas. The temperature, pressure, flow rate, and other parameters of the experimental gas can be used to simulate the fission gas conditions of liquid metal reactor fuel cladding at different lifespans, depending on the experimental requirements.
[0034] Furthermore, the gas storage outer liner 20 also includes a temperature monitoring unit 22 and a pressure monitoring unit 23 mounted on the gas storage rod 21, for monitoring the temperature and pressure within the gas storage chamber 200, respectively. The temperature monitoring unit 22 can be implemented using a temperature instrument or a temperature sensor, and the pressure monitoring unit 23 can be implemented using a pressure instrument or a pressure sensor. The power lines and wiring of the temperature monitoring unit 22 and the pressure monitoring unit 23 are connected to an external power supply and control system 50 through a measurement interface.
[0035] The outer periphery of the gas storage rod 21 may also be provided with a mounting flange 24, which is used to cooperate with the mounting port of the simulated reactor device to realize the installation of the fuel cladding failure and release experimental device on the simulated reactor device.
[0036] The heating and temperature-controlled sealing rod 30 is used to heat the gas storage chamber 200, thereby enabling the experimental gas in the gas storage chamber 200 to reach a preset experimental temperature. The heating and temperature-controlled sealing rod 30 may further include a hollow sealing rod body 31 and a heating rod 32 that passes through the sealing rod body 31 axially.
[0037] The sealing rod 31 has a first end and a second end. The first end of the sealing rod 31 is inserted into the gas storage cavity 200 through the second interface of the gas storage rod 21. The first end face of the sealing rod 31 forms a mating surface, which is directly opposite the first end of the simulated rupture test rod 10. The second end of the sealing rod 31 is located outside the second end of the gas storage outer bushing 20 and is connected to the transmission control mechanism 40. The transmission control mechanism 40 can drive the sealing rod 31 to move back and forth axially, causing the mating surface to move closer to and fit the first end face of the simulated rupture test rod 10, thus closing the gas channel 100, or causing the mating surface to move away from the first end face of the simulated rupture test rod 10, thus opening the gas channel 100.
[0038] Inside the gas storage chamber 200, there is a gap between the outer peripheral surface of the sealing rod 31 and the inner wall surface of the gas storage chamber 200, forming an annular cavity.
[0039] The outer peripheral surface of the sealing rod 31 may also be provided with a raised sealing structure 311. The sealing structure 311 fits tightly with the inner wall of the gas storage chamber 200 to ensure the sealing between the heating and temperature control sealing rod 30 and the gas storage outer bushing 20. The sealing structure 311 is located on the sealing rod 31 near its second end, and the experimental gas is mainly stored in the chamber between the sealing structure 311 and the first end of the gas storage rod 21.
[0040] Furthermore, a high-temperature resistant third sealing ring 33 is provided between the sealing structure 311 and the inner wall of the gas storage chamber 200 to improve the sealing performance between the heating and temperature control sealing rod 30 and the gas storage outer bushing 20. The third sealing ring 33 is made of special ceramic fiber composite material, which can withstand temperatures up to 3000℃ and has excellent high-temperature resistance, tensile strength, oxidation resistance, creep resistance, and abrasion resistance.
[0041] The connecting end of the heating rod 32 is located at the second end of the sealing rod body 31, and its power cord is connected to the external power supply and control system 50.
[0042] The heating and temperature control sealing rod 30 also includes a temperature instrument 34 for monitoring the temperature of the heating rod 32.
[0043] The transmission control mechanism 40 is specifically connected to the sealing rod body 31 of the heating and temperature control sealing rod 30. By driving the sealing rod body 31 to move back and forth in the gas storage chamber 200, the entire heating and temperature control sealing rod 30 is moved.
[0044] In some embodiments, the transmission control mechanism 40 includes a transmission rod 41 and a drive unit 42 that connects to and drives the transmission rod 41 to move back and forth in the axial direction. The transmission rod 41 is connected to the second end of the sealing rod body 31, and the drive unit 42 connects to and drives the transmission rod 31 to move back and forth in the axial direction, thereby causing the heating and temperature control sealing rod 30 to move back and forth.
[0045] Alternatively, the drive unit 42 may include a motor, and the transmission rod 41 may be a ball screw, converting the rotational motion of the motor into linear motion. The control system 50 controls the connection of the drive unit 42 to achieve movement control of the transmission rod 41 and obtain the movement distance and position of the heating and temperature control sealing rod 30.
[0046] This invention relates to a fuel cladding failure and release experimental device suitable for environments where the high-temperature metallic medium is high-temperature liquid lead-bismuth. Throughout the device, all materials in contact with the liquid metallic medium (such as various rods) are made of austenitic stainless steel, a material with excellent corrosion resistance and mechanical properties in high-temperature liquid lead-bismuth media. The heating rod 32 of the heating and temperature control sealing rod 30 is made of silicon molybdenum, with a maximum operating temperature of 1800℃, ensuring a long service life even under high-temperature heating conditions.
[0047] During the experiment, experimental gas is introduced into the gas storage chamber 200 through the air inlet channel 210, ensuring that the mating surface of the sealing rod 31 is sealed and in close contact with the first end face of the experimental rod 11, thus closing the gas channel 100 and storing the experimental gas within the gas storage chamber 200. The heating and temperature control sealing rod 30 is energized to heat the experimental gas in the gas storage chamber 200 to the set experimental temperature. Simultaneously, the temperature and pressure of the experimental gas are acquired in real time through the temperature monitoring unit 22 and the pressure monitoring unit 23. During the release of the burst, the transmission control mechanism 40 drives the sealing rod 31 to move away from the experimental rod 11, opening the gas channel 100. The experimental gas in the gas storage chamber 200 enters the simulated burst experimental rod 10 through the gas channel 100 and is then released from the simulated burst 110.
[0048] The released gas can be sampled and analyzed using a sampling and measuring device to measure its composition, radioactivity, and other properties. The measuring instruments in the sampling and measuring device include at least one of gas chromatography, ICP-MS, and a high-purity germanium detector; the specific instrument configuration will be adjusted according to experimental requirements.
[0049] This invention enables the study of monitored nuclide release behavior under different simulated fuel cladding damage conditions, and has the advantages of being applicable to high-temperature metallic media environments and having remotely controllable closure of the breach.
[0050] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.
Claims
1. A fuel cladding break release experiment apparatus, characterized by, It includes a simulated break test rod, a gas storage outer liner, a heating and temperature control sealing rod, and a remotely controllable transmission control mechanism. The gas storage outer liner has a gas storage cavity inside; the simulated rupture test rod is sealed to the first end of the gas storage outer liner at the first end, and the first end of the simulated rupture test rod is provided with a gas channel connecting the interior of the simulated rupture test rod and the gas storage cavity; the heating and temperature control sealing rod passes through the gas storage cavity from the opposite end of the gas storage outer liner and is opposite to the first end of the simulated rupture test rod. The transmission control mechanism is located outside the gas storage outer bushing, and is connected to and drives the heating and temperature control sealing rod to move back and forth along the gas storage cavity in the direction of approaching and moving away from the first end of the simulated breakage test rod, thereby closing or opening the gas channel.
2. The fuel cladding break release experiment apparatus of claim 1, wherein, The fuel cladding breakage and release experimental device also includes a control system, which is connected to the transmission control mechanism and controls the start and stop of the transmission control mechanism.
3. The fuel cladding break release experiment apparatus according to claim 1 or 2, characterized by, The simulated rupture test rod includes a high-temperature resistant and hollow test rod body and a high-temperature resistant first sealing ring. The side wall of the test rod body is provided with a simulated shell rupture. The test rod body has a first end and a second end opposite to each other. The first end of the test rod body is fitted to the first end of the gas storage outer liner, and the gas channel is opened at the first end of the test rod body. The first end face of the experimental rod is provided with a first groove surrounding the gas channel, and the first sealing ring is fitted in the first groove to seal between the first end face of the experimental rod and the mating surface of the heating and temperature control sealing rod.
4. The fuel cladding breakage and release experimental apparatus according to claim 3, characterized in that, The first end of the experimental rod is connected to one end of the gas storage outer liner by a thread; and / or, a high-temperature resistant second sealing ring is provided between the mating surfaces of the first end of the experimental rod and one end of the gas storage outer liner.
5. The fuel cladding breakage and release experimental apparatus according to claim 1 or 2, characterized in that, The heating and temperature control sealing rod includes a hollow sealing rod body and a heating rod that passes through the sealing rod body axially inside the sealing rod body; The first end of the sealing rod is located inside the gas storage cavity, and the end face of the first end forms a mating surface, which is directly opposite the first end of the simulated breakage test rod. The opposite second end of the sealing rod is located outside the second end of the gas storage outer bushing and is connected to the transmission control mechanism. The outer peripheral surface of the sealing rod is provided with a raised sealing structure, which fits tightly with the inner wall of the gas storage cavity.
6. The fuel cladding breakage and release experimental apparatus according to claim 5, characterized in that, A high-temperature resistant third sealing ring is also provided between the sealing structure and the inner wall of the gas storage cavity.
7. The fuel cladding breakage and release experimental apparatus according to claim 5, characterized in that, The heating and temperature control sealing rod also includes a temperature instrument.
8. The fuel cladding breakage and release experimental apparatus according to claim 1 or 2, characterized in that, The gas storage outer liner includes a hollow and sealed gas storage rod, the hollow inner cavity of which forms the gas storage chamber; an air inlet channel is provided on the side wall of the gas storage rod, the air inlet channel is connected to the gas storage chamber, and is used to introduce experimental gas.
9. The fuel cladding breakage and release experimental apparatus according to claim 8, characterized in that, The gas storage outer liner also includes a temperature monitoring unit and a pressure monitoring unit disposed on the gas storage rod body, which are used to monitor the temperature and pressure inside the gas storage chamber, respectively.
10. The experimental apparatus for fuel cladding failure and release according to claim 1 or 2, characterized in that, The transmission control mechanism includes a transmission rod and a drive unit that connects to and drives the transmission rod to move back and forth in the axial direction.