Experimental Apparatus for Corrosion Product Deposition of Lead-Bismuth Fast Reactor Fuel Assemblies

Abstract

The present invention provides an experimental device for studying corrosion product deposition in lead-bismuth fast reactor fuel assemblies, relating to the technical field of core thermal-hydraulic property research. The experimental device comprises a storage tank, an experimental section, and a glove box. The experimental section and the glove box are connected end-to-end via a second pipe to form a closed loop. An electrically heated simulated fuel assembly, including a cladding tube, is disposed within the internal cavity of the experimental section. The storage tank is connected to the second pipe via a first pipe and is located at the liquid inlet end of the experimental section. The glove box is used to release particles into the liquid lead-bismuth in the experimental device. Compared with existing technologies, this experimental device has a simple structure and can reduce both the experimental cost and experimental time for studying corrosion product deposition in lead-bismuth fast reactor fuel assemblies.

Description

Technical Field

[0001] The invention relates to the technical field of core thermal hydraulic characteristics research, and in particular to an experimental device for corrosion product deposition of a lead-bismuth fast reactor fuel assembly. Background Art

[0002] When the core fuel assemblies of lead-bismuth fast reactors operate in a long-term high-temperature and strong radiation environment, a deposit layer will form on the cladding surface. The existence of the deposit layer will seriously affect the heat transfer characteristics of the fuel assemblies and the coolant, causing local heat transfer deterioration and local corrosion, and even leading to damage and other hazards, posing a huge safety hazard to the safe operation of the nuclear reactor.

[0003] Existing research on the impact of corrosion product deposits on the safety of lead-bismuth fast reactor (Pb-BFRU) operations has primarily focused on computational simulations and theoretical model predictions. These methods are unable to accurately simulate the relationship between corrosion product deposition thickness and particle concentration in the actual Pb-BFRU environment, and therefore fail to meet the requirements for assessing the safe operation of fuel assemblies in this reactor environment. Simulating the deposition layer based on the actual operating time of a Pb-BFRU would be time-consuming and costly, as the deposition of corrosion products on the fuel cladding surface is a lengthy solute migration process.

[0004] In addition, there are many technologies in the existing technology that simulate the corrosion product deposition phenomenon of pressurized water reactors. However, the coolant media used in lead-bismuth fast reactors and pressurized water reactors are different. The difference in the thermophysical properties of the coolant will lead to essential differences in the corrosion product deposition phenomenon. Therefore, the existing technology applicable to the corrosion product deposition phenomenon of pressurized water reactors is not suitable for the study of corrosion product deposition of lead-bismuth fast reactor fuel assemblies.

[0005] Based on this, the present application proposes an experimental device suitable for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, so as to at least solve one or more of the problems mentioned above. Summary of the Invention

[0006] (1) Technical problems solved

[0007] In view of the shortcomings of the existing technology, the present invention provides an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, which at least solves the problem that the existing experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies is time-consuming and costly.

[0008] (2) Technical solution

[0009] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0010] An experimental device for corrosion product deposition of lead-bismuth fast reactor fuel assemblies, comprising:

[0011] storage tanks, experimental sections, and glove boxes;

[0012] The experimental section and the glove box are connected end to end through a second pipeline to form a closed loop;

[0013] An electrically heated simulated fuel assembly including a cladding tube is disposed in the internal cavity of the experimental section; the storage tank is connected to a second pipe via a first pipe and is located at the liquid inlet end of the experimental section;

[0014] The glove box is used to release particles into the liquid lead bismuth in the experimental device.

[0015] In one embodiment, the material of the first pipe includes 304 stainless steel, and the material of the second pipe includes 316L stainless steel.

[0016] In one embodiment, the electrically heated simulated fuel assembly further includes: an electric heating rod and a thermocouple; the electric heating rod is covered by a cladding tube, and an insulating material is used to evenly fill the gap between the electric heating rod and the cladding tube; the thermocouple is arranged on the inner wall surface of the cladding tube.

[0017] Preferably, the cavity tube wall material of the experimental section is T91 stainless steel, the material of the cladding tube is T91 stainless steel, and the material of the electric heating rod is Cr20Ni80 nickel-chromium alloy.

[0018] More preferably, the insulating material comprises magnesium oxide.

[0019] In one embodiment, the experimental device further comprises: an electric heater, which is disposed on the second pipe between the storage tank and the experimental section.

[0020] In one embodiment, the experimental device further includes: an electromagnetic pump and a flow meter; the electromagnetic pump is arranged on the second pipe between the glove box and the experimental section; and the flow meter is arranged on the second pipe between the glove box and the electric heater.

[0021] In one embodiment, the experimental device further includes: a filter, which is disposed on the flow pipeline between the electromagnetic pump and the flow meter and is connected in parallel with the glove box.

[0022] In one embodiment, the experimental device further includes: an oxygen control box and a liquid level gauge; the oxygen control box is arranged on the second pipeline between the electromagnetic pump and the experimental section; the liquid level gauge is used to detect the liquid level height of liquid lead and bismuth in the oxygen control box.

[0023] In one embodiment, the experimental device further includes: a heat exchanger, which is disposed on the second pipeline between the electromagnetic pump and the oxygen control box.

[0024] Preferably, the heat exchanger is a shell-and-tube heat exchanger, the tube-side flow medium of which is liquid lead-bismuth, and the shell-side flow medium is high-temperature heat transfer oil.

[0025] In one embodiment, the structure of the cladding tube includes: a structure in which the cladding and spiral grooves are combined, or a structure in which the cladding and trapezoidal ribs are combined.

[0026] Preferably, the spiral groove includes but is not limited to a single spiral groove, a double spiral groove and a quadruple spiral groove; the trapezoidal ribs include but are not limited to a single trapezoidal rib, a double trapezoidal rib and a quadruple trapezoidal rib.

[0027] In one embodiment, the experimental device further includes: a melting tank, wherein the melting tank is connected to the storage tank through the first pipe.

[0028] In one embodiment, the experimental device further includes: a high-pressure argon gas cylinder; the high-pressure argon gas cylinder is connected to the storage tank, the oxygen control box and the glove box respectively through a third pipe.

[0029] In one embodiment, the experimental device further includes: a heating system, a temperature measuring thermocouple, and a temperature controlling thermocouple; wherein the electric heating wire of the heating system is arranged in all areas through which lead and bismuth flow in the experimental device, and the temperature measuring thermocouple and the temperature controlling thermocouple are both arranged in all areas through which lead and bismuth flow in the experimental device.

[0030] In one embodiment, the experimental device further comprises: a vacuum pump, wherein the vacuum pump is connected to the oxygen control box through a third pipe.

[0031] (3) Beneficial effects

[0032] The present invention provides an experimental device for corrosion product deposition of lead-bismuth fast reactor fuel assemblies. Compared with the existing technology, it has the following advantages:

[0033] This application proposes an experimental setup for corrosion product deposition on lead-bismuth fast reactor fuel assemblies. By adding a glove box to the experimental pipeline, this setup effectively shortens the experimental time required to simulate particle generation from lead-bismuth corrosion of structural materials and the deposition of dirt on the surface of lead-bismuth fast reactor fuel. Compared to existing technologies, this experimental setup boasts a simpler structure, reducing both experimental costs and experimental time. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is a schematic diagram of the structure of the experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies in the embodiment of the present application;

[0036] Figure 2 This is a schematic diagram of the structure of the electrically heated simulated fuel assembly in the embodiment of the present application, wherein: Figure 2 (a) is a schematic diagram of the structure of the electrically heated simulated fuel assembly from one perspective; Figure 2 (b) is the effect of the electrically heated simulated fuel assembly from another perspective;

[0037] Figure 3 Schematic diagram of the position of the thermocouple in the embodiment of the present application;

[0038] Figure 4 This is a structural diagram of the cladding structure 1 in an embodiment of the present application;

[0039] Figure 5 This is a rendering of the cladding structure 1 in the embodiment of the present application;

[0040] Figure 6 This is a structural diagram of the second cladding structure in the embodiment of the present application;

[0041] Figure 7 This is a rendering of the second cladding structure in the embodiment of this application;

[0042] In the picture:

[0043] 1-Melting tank; 2-Storage tank; 3-Electric heater; 4-Experimental section; 5-Electrically heated simulated fuel assembly; 6-Electric heating rod; 7-Cladding tube; 8-Thermocouple; 9-Oxygen control box; 10-Heat exchanger; 11-Electromagnetic pump; 12-Glove box; 13-Filter; 14-Flowmeter; 15-High-pressure argon cylinder; 16-Vacuum pump; 17-Heating system; 18-First high-temperature electric hydraulic valve; 19-Second high-temperature electric hydraulic valve; 20-Third high-temperature electric hydraulic valve; 21-Fourth high-temperature electric hydraulic valve; 22-Fifth high-temperature electric hydraulic valve; 23-Sixth high-temperature electric hydraulic valve; 24-First electric gas valve; 25-Second electric gas valve; 26-Third electric gas valve; 27-First pipeline; 28-Second pipeline; 29-Third pipeline; 30-Liquid level gauge; 31-Temperature-measuring thermocouple; 32-Temperature-control thermocouple. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] Long-term operation in high-temperature, high-radiation environments in lead-bismuth fast reactor core fuel assemblies leads to the formation of deposits on the cladding surface. This deposit can severely affect the heat transfer characteristics between the fuel assembly and the coolant, leading to localized deterioration of heat transfer and increased corrosion, and even damage, posing a significant safety hazard to the safe operation of the nuclear reactor.

[0046] In the particle corrosion deposition phenomenon at the core of the lead-bismuth fast reactor, the sources of the particles are diverse. For example, the metal dissolves in the high-temperature section (core), and the particles crystallize and precipitate in the low-temperature section (heat exchanger), or the liquid lead-bismuth impacts the oxide film, causing the oxide film to peel off. At the same time, the particle formation time in the particle corrosion deposition process in the reactor is relatively long. For example, the particles formed by the impact of liquid lead-bismuth on the oxide film must first form an oxide film on the surface of the material through oxidative corrosion, and then the liquid lead-bismuth impacts the oxide film to form particles, or they are formed through crystallization experiments. Specifically, the particles formed by the impact of the oxide film are Fe3O4. The oxide film has a three-layer structure. The outermost layer of Fe3O4 is easy to peel off, and the Fe3O4 formed by the dissolution of the metal Fe of the high-temperature section structural material 2+ or Fe 3+ , in the low temperature range Fe 2+ or Fe 3+ Combined with oxygen, it forms Fe3O4, which is precipitated in the form of crystals. In the low-temperature section, the lead in liquid lead bismuth combines with oxygen to form PbO, which is precipitated in the form of crystals.

[0047] These particles exhibit different deposition behaviors in different areas. For example, after exiting the low-temperature section (heat exchanger) and entering the high-temperature section (core), the particles formed in the low-temperature section are less likely to dissolve due to the higher oxygen concentration in the core (oxidative corrosion only occurs in the high-temperature region, so the oxygen concentration in the core must be maintained at a high level to form an oxide film that protects the cladding from corrosion and reduces the dissolution of structural materials). Furthermore, due to the force of the fluid acting on the particles, a deposit layer forms on the surface of the core cladding.

[0048] In existing technologies, research on the impact of deposits on the safety of lead-bismuth fast reactors (PBFRs) has primarily focused on computational simulations and theoretical model predictions. These studies are unable to accurately simulate the relationship between corrosion product deposition thickness and particle concentration and other parameters in the actual PBFR environment, and therefore fail to meet the safety assessment requirements for fuel assembly operation in the reactor environment. Simulating deposits based on the actual operating time of PBFRs is time-consuming and costly. This is because the deposition of corrosion products on the fuel cladding surface is a lengthy solute migration process that requires precise control of solute conditions and prolonged heat, mass transfer, and deposition. Assessing the impact of core oxidation corrosion product deposition on core safety requires significant time and material costs.

[0049] In addition, there are different strategies in the existing technology to simulate the deposition phenomenon of corrosion products in pressurized water reactors. For example, some technologies construct a WALT experimental system, control the water chemical conditions of the WALT experimental system, and run it continuously for thousands of hours to obtain the deposition of oxidation corrosion products on the cladding of pressurized water reactor fuel rods; there are also technologies that disclose experimental devices that simulate dirt deposition and boron precipitation on the surface of pressurized water reactor fuel. By controlling the electric heating rods of the condenser and the reactor, the experimental device can be quickly cooled down, shortening the simulation experiment time; there are also technologies that disclose methods for reproducing the oxidation corrosion product deposition layer of the pressurized water reactor core, by forming a wet gel with nickel salt and iron salt and coating it on the alloy surface, and obtaining a dense intermediate layer after heating, and mixing nickel ferrite powder, adhesive, and pore-forming agent and grinding them into a paste; applying the paste on the intermediate layer, and obtaining an oxidation corrosion product deposition layer after heating, and so on.

[0050] However, the coolant media used in lead-bismuth fast reactors (PWRs) differ from those used in pressurized water reactors (PWRs). These differences in coolant thermophysical properties lead to fundamentally different corrosion product deposition phenomena. For example, liquid lead-bismuth corrodes structural materials more severely, producing a more diverse range of corrosion deposits, including both soluble and particulate corrosion deposits. Liquid lead-bismuth has a higher density, and compared to water, particles in liquid lead-bismuth tend to move against gravity due to buoyancy.

[0051] Based on this, this application proposes an experimental device suitable for the corrosion product deposition of lead-bismuth fast reactor fuel assemblies to realize the analysis of corrosion product deposition and the analysis of the impact of corrosion product deposition on flow heat transfer, core neutron physics and reactor safety.

[0052] The embodiment of the present application provides an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, which at least solves the problem that the existing experimental devices for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies are time-consuming and costly, thereby achieving the goal of low-cost and efficient experiments.

[0053] The technical solution in the embodiments of the present application is to solve the above technical problems, and the overall idea is as follows:

[0054] In order to solve one or more technical problems existing in the above-mentioned prior art, the experimental device proposed in this application is designed with two pipelines. On the one hand, the pipeline where the glove box is located can realize the uniform distribution of particles in the liquid lead bismuth through circulating flow, and the concentration of particles in the liquid lead bismuth can be increased online in real time through the glove box, which effectively shortens the experimental time of particles generated by lead bismuth corrosion structural materials; on the other hand, the pipeline where the filter is located can filter impurities in lead bismuth after the experiment, which is convenient for experiments with other concentrations. In addition, considering that one experimental device cannot complete the multiple tasks described above, the existing experiment can be verified by simulation calculation to predict the approximate particle diameter. Then, the device can directly use the particle size predicted by simulation calculation to adjust different particle types and particle sizes, which can be used to quickly conduct particle corrosion deposition experiments and save experimental time. At the same time, by designing different cladding tube wall structures, the deposition phenomenon of different fuel assembly structures in lead-bismuth fast reactors can be studied, and the experimental cost is low.

[0055] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with the description of the drawings, the structure and function of the specific components in the drawings, and the specific implementation methods.

[0056] The following describes in detail an embodiment of the present invention and the implementation process of its preferred embodiment in conjunction with the accompanying drawings and explanations of the specific structure.

[0057] See also Figure 1 , an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, comprising: a storage tank 2, an experimental section 4, and a glove box 12. The experimental section 4 and the glove box 12 are connected end to end via a second pipe 28 to form a closed loop. The storage tank 2 is used to store liquid lead-bismuth, and the storage tank 2 is connected to the second pipe 28 via a first pipe 27 and is located at the liquid inlet end of the experimental section 4. The experimental section 4 contains a cavity, and the interior of the cavity is configured to accommodate an electrically heated simulated fuel assembly 5, which includes a cladding tube 7. After the particles are evenly mixed, the electrically heated simulated fuel assembly 5 is started to heat the liquid lead-bismuth in the cavity of the experimental section 4 at a certain power. Under the action of thermophoretic force, Saffman force, drag force and buoyancy, the particles in the liquid lead-bismuth will be deposited on the outer wall of the cladding tube 7 and the wall of the cavity of the experimental section 4. The glove box 12 is used to store particles and to release and deliver particles in a timely and multiple times according to experimental needs, so as to adjust the particle concentration in the liquid lead-bismuth, effectively shortening the experimental time for generating particles caused by lead-bismuth corrosion of structural materials and simulating dirt deposition on the surface of lead-bismuth fast reactor fuel.

[0058] Both first and second pipes 27 and 28 are liquid pipes through which liquid lead and bismuth flow. However, considering the temperature difference between the liquid lead and bismuth flowing through the pipes, in a preferred embodiment, 316L stainless steel is used for second pipe 28 and 304 stainless steel is used for first pipe 27. This is because the temperature of the liquid lead and bismuth flowing through experimental section 4 is no higher than 450°C, within which the degree of dissolution and corrosion of 316L stainless steel is low. Therefore, 316L stainless steel is used for second pipe 28. Meanwhile, the temperature of the liquid lead and bismuth at the liquid inlet end of experimental section 4 is no higher than 350°C, within which the degree of dissolution and corrosion of 304 stainless steel is low. Therefore, 304 stainless steel is used for first pipe 27.

[0059] In one embodiment, the electrically heated simulated fuel assembly 5 includes, in addition to the cladding tube 7, an electric heating rod 6 and a thermocouple 8. Figure 2-3 As shown. The electric heating rod 6 is covered by the cladding tube 7, and the gap between the electric heating rod 6 and the cladding tube 7 is evenly filled with the insulating material magnesium oxide; the insulating material adjacent to the inner wall of the cladding tube 7 is grooved, and multiple thermocouples 8 are set in multiple grooves adjacent to the inner wall of the cladding tube 7 for measuring the cladding temperature. Figure 3 shown.

[0060] In a preferred embodiment, the cavity wall material of the experimental section 4 is T91 stainless steel, the cladding tube 7 is T91 stainless steel, and the electric heating rod 6 is made of Cr20Ni80 nickel-chromium alloy.

[0061] It should be noted that the particles are affected by the force of the fluid and form a deposition layer on the surface of the core cladding. The structural form of the cladding will affect the flow channel structure, thereby affecting the force acting on the particles. Therefore, it is considered to design different cladding structures to study the particle corrosion deposition phenomenon under different cladding structures.

[0062] The experimental section of existing test benches typically utilizes a combination of cladding and spiral wire winding. The wire winding is secured to the cladding surface via spot welding. While the wire winding enhances fluid mixing and heat transfer, it can also cause problems such as wire shedding and localized overheating at weld points. The accumulation of corrosion particles can further exacerbate this localized overheating.

[0063] In order to solve the above problems existing in the prior art, the cladding structure proposed in the embodiment of the present application is a combination of cladding and spiral grooves. The structure diagram of this method is as follows: Figure 4-5 As shown. Process spiral grooves on the surface of the cladding. Preferably, a combination of cladding and single spiral grooves, double spiral grooves and quadruple spiral grooves can be considered. The cladding structure 2 proposed in the embodiment of the present application is a combination of cladding and trapezoidal ribs. The structure diagram of this method is shown in FIG. Figure 6-7As shown. Trapezoidal ribs are machined onto the cladding surface. Preferably, a combination of cladding and single, double, or quadruple ribs can be considered. Both of these cladding structures can enhance fluid mixing and heat transfer without problems like shedding or localized overheating.

[0064] In one embodiment, the second pipe 28 between the storage tank 2 and the experimental section 4 is further provided with an electric heater 3, a second high-temperature electric hydraulic valve 19, and a sixth high-temperature electric hydraulic valve 23. The electric heater 3 is used to heat the lead and bismuth entering the experimental section 4.

[0065] Preferably, the second high-temperature electric liquid valve 19 and the sixth high-temperature electric liquid valve 23 are respectively arranged on both sides of the electric heater 3, wherein the second high-temperature electric liquid valve 19 is located on the side of the electric heater 3 close to the storage tank 2, and the sixth high-temperature electric liquid valve 23 is located on the side of the electric heater 3 close to the experimental section 4.

[0066] In one embodiment, the apparatus further comprises an electromagnetic pump 11. The electromagnetic pump 11 is disposed on the second pipe 28 between the glove box 12 and the experimental section 4. The electromagnetic pump 11 provides pressure head for the lead-bismuth circulation in the entire experimental apparatus.

[0067] In one embodiment, the device further comprises a flow meter 14. The flow meter 14 is provided on the second pipe 28 and is located between the glove box 12 and the electric heater 3. The flow meter 14 is used to measure the flow in the circuit.

[0068] In one embodiment, the apparatus further includes a filter 13 for filtering impurities from the experimental apparatus. Filter 13 is located on flow line 2 formed between the electromagnetic pump 11 and the flow meter 14 . Flow line 2 is connected in parallel with flow line 1 (flow line 1 refers to the line containing the glove box 12 and the third high-temperature electric hydraulic valve 20 ).

[0069] Preferably, a fourth high-temperature electric liquid valve 21 and a fifth high-temperature electric liquid valve 22 are respectively provided on the circulation pipeline 2 and at both ends of the inlet and outlet of the filter 13 .

[0070] In one embodiment, an oxygen control box 9 is provided on the second pipe 28 between the electromagnetic pump 11 and the experimental section 4. The oxygen control box 9 can control the oxygen concentration in the liquid lead bismuth in the loop, thereby forming an oxide film on the surface of the experimental device and reducing the corrosion of the liquid lead bismuth to the experimental device; at the same time, the oxygen control box 9 can also serve as an expansion box to accommodate the increased volume of the liquid lead bismuth due to thermal expansion caused by the increase in temperature.

[0071] Preferably, a liquid level meter 30 is provided on the oxygen control box 9 for detecting the liquid level of liquid lead and bismuth in the oxygen control box 9 .

[0072] In one embodiment, a heat exchanger 10 is further provided on the second pipe 28 between the electromagnetic pump 11 and the oxygen control box 9. The heat exchanger 10 cools down the high-temperature liquid lead and bismuth flowing out of the oxygen control box.

[0073] Preferably, the heat exchanger 10 is a shell-and-tube heat exchanger, wherein the flow medium on the tube side is liquid lead-bismuth, and the flow medium on the shell side is high-temperature heat transfer oil.

[0074] In one embodiment, the apparatus further comprises a melting tank 1. This melting tank 1 is used to dissolve the initially added solid lead-bismuth into liquid lead-bismuth. The melting tank 1 is typically positioned above the storage tank 2, and the melting tank 1 and storage tank 2 are connected via a first pipe 27 and a first high-temperature electric hydraulic valve 18. When the solid lead-bismuth melts into liquid lead-bismuth and reaches a suitable state, the liquid lead-bismuth is transferred via the first high-temperature electric hydraulic valve 18 and first pipe 27 into the storage tank 2 for storage.

[0075] In one embodiment, the apparatus further includes a high-pressure argon cylinder 15. The high-pressure argon cylinder 15 is connected to the storage tank 2, the oxygen control box 9, and the glove box 12, respectively, via a third conduit 29 (the third conduit 29 is a gas conduit). Specifically, the high-pressure argon cylinder 15 is connected to the oxygen control box 9 via a second electric valve 25. Simultaneously, the high-pressure argon cylinder 15 is connected to the storage tank 2 via a first electric valve 24. High-pressure argon is then introduced into the storage tank 2, thereby drawing liquid lead and bismuth from the storage tank 2 through the second, sixth, and third high-temperature electric liquid valves 23 and 20, filling the experimental apparatus until a signal is displayed on the liquid level gauge 30. The first, second, and first electric valves 18 and 24 are then closed. The high-pressure argon cylinder 15 is connected to the glove box 12 via a third electric gas valve 26. To maintain a slight positive pressure in the glove box 12, a gas line must be connected to the upper end of the glove box 12, and the glove box 12 should also be placed in a high position to prevent lead and bismuth from spilling out when the sealing cover of the glove box 12 is subsequently opened. The second high-temperature electric hydraulic valve 19 is located on the first pipeline 27, between the electric heater 3 and the storage tank 2. The sixth high-temperature electric hydraulic valve 23 is located on the second pipeline 28, between the electric heater 3 and the experimental section 4.

[0076] In one embodiment, the apparatus further includes a heating system 17, which is a device used to maintain the temperature of pipes, equipment, etc. In this embodiment, heating system 17 heats the liquid lead and bismuth in storage tank 2 to a specified temperature. The electric heating wires of heating system 17 are installed in all areas of the experimental apparatus through which the lead and bismuth flow.

[0077] In one embodiment, the apparatus further comprises a temperature-measuring thermocouple 31 and a temperature-controlling thermocouple 32. Preferably, the temperature-measuring thermocouple 31 and the temperature-controlling thermocouple 32 are disposed in all areas of the experimental apparatus through which lead and bismuth flow. The heating system 17 uses the temperature-measuring thermocouple 31 and the temperature-controlling thermocouple 32 to achieve zoned control of the temperature of the liquid lead and bismuth in different areas of the experimental apparatus. The electric heater 3 cooperates with the heating system 17 to heat the liquid lead and bismuth entering the experimental section 4. However, in specific implementations, the heating system 17 and the electric heater 3 are controlled by zones, with the heating system 17 monitoring the global temperature while the electric heater 3 only heats the liquid lead and bismuth at the entrance of the experimental section 4.

[0078] In one embodiment, the apparatus further comprises a vacuum pump 16 . The vacuum pump 16 is used to evacuate the pipelines involved in the experimental apparatus. Specifically, the vacuum pump 16 is connected to the oxygen control box 9 via a third pipe 29 .

[0079] The working principle and working process of the experimental device for corrosion product deposition of lead-bismuth fast reactor fuel assemblies proposed in the above embodiment of the present application are as follows:

[0080] After assembling the experimental apparatus for corrosion product deposition on lead-bismuth fast reactor fuel assemblies proposed in this embodiment according to the components and their connections as described in the aforementioned embodiments and preferred embodiments, the electromagnetic pump 11 was activated and the flow rate was adjusted. When the flow meter 14 reading reached the experimental requirements, the current in the electromagnetic pump 11 was maintained constant. The sealing flange connecting the glove box 12 to the experimental apparatus was opened, and particles from the glove box 12 platform were dropped into the experimental apparatus. The sealing flange was then closed. After a period of circulating flow, the particles were evenly mixed in the liquid lead-bismuth solution, and the corrosion product deposition experiment on the lead-bismuth fast reactor fuel assembly was conducted.

[0081] During the experiment, multiple particle delivery is performed through the glove box 12 to achieve the purpose of adjusting the particle concentration, thereby effectively shortening the experimental time of generating particles by lead-bismuth corrosion of structural materials.

[0082] After completing the designed test conditions, close the third high-temperature electric liquid valve 20, open the fourth high-temperature electric liquid valve 21 and the fifth high-temperature electric liquid valve 22, so that the liquid lead and bismuth in the experimental device flow to the pipeline where the filter 13 is located. After a period of time, close the electric heating simulated fuel assembly 5, the secondary side of the heat exchanger 10 and the electromagnetic pump 11 in turn, open the second high-temperature electric liquid valve 19, and discharge all the liquid lead and bismuth into the storage tank 2. Then open the second electric gas valve 25, use the high-pressure argon bottle 15 to purge impurities from the experimental device, and then turn on the vacuum pump 16 to evacuate. After the vacuuming work is completed, close the fourth high-temperature electric liquid valve 21, the fifth high-temperature electric liquid valve 22, the sixth high-temperature electric liquid valve 23, the second high-temperature electric liquid valve 19 and the second electric gas valve 25 in turn, and finally shut down the heating system 17.

[0083] In summary, compared with the existing technology, the present invention has the following beneficial effects:

[0084] This application proposes an experimental setup for corrosion product deposition on lead-bismuth fast reactor fuel assemblies. By adding a glove box to the experimental pipeline, this setup effectively shortens the experimental time for particle generation from lead-bismuth corrosion of structural materials and simulates surface fouling deposition on lead-bismuth fast reactor fuel. Compared to existing technologies, this experimental setup boasts a simpler structure, reducing both experimental costs and experimental time.

[0085] 2. The present application proposes an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, which is designed with two flow pipes. The pipe where the glove box is located can release and increase the particle concentration in the circulating liquid lead-bismuth in real time online through the glove box, and allow the particles to be evenly distributed in the liquid lead-bismuth, effectively shortening the experimental time for particles generated by lead-bismuth corrosion of structural materials and simulating the dirt deposition on the surface of lead-bismuth fast reactor fuel under different particle concentrations; and the pipe where the filter is located can filter impurities in the lead-bismuth after the experiment, facilitating experiments at other concentrations.

[0086] 3. The experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies proposed in this application can study the deposition phenomenon of different fuel assembly structures in lead-bismuth fast reactors by designing different cladding tube wall structures, and the experimental cost is low.

[0087] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An experimental device for the deposition of corrosion products in lead-bismuth fast reactor fuel assemblies, characterized in that: The experimental device includes: Storage tank (2), experimental section (4), and glove box (12); The experimental section (4) and the glove box (12) are connected end to end via a second pipe (28) to form a closed loop; An electrically heated simulated fuel assembly (5) including a cladding tube (7) is provided in the internal cavity of the experimental section (4); the storage tank (2) is connected to the second pipe (28) via a first pipe (27) and is located at the liquid inlet end of the experimental section (4); The glove box (12) is used to release particles into the liquid lead-bismuth in the experimental device to adjust the particle concentration in the liquid lead-bismuth, effectively shortening the experimental time of generating particles due to lead-bismuth corrosion of structural materials and simulating dirt deposition on the surface of lead-bismuth fast reactor fuel; The experimental device further comprises: an electromagnetic pump (11); the electromagnetic pump (11) is arranged on the second pipe (28) between the glove box (12) and the experimental section (4); The experimental device further comprises: an oxygen control box (9); the oxygen control box (9) is arranged on the second pipe (28) between the electromagnetic pump (11) and the experimental section (4), and is located at the liquid outlet end of the experimental section (4); the oxygen control box (9) controls the oxygen concentration in the liquid lead bismuth in the loop; The experimental device further comprises a heat exchanger (10), wherein the heat exchanger (10) is arranged on the second pipe (28) between the electromagnetic pump (11) and the oxygen control box (9).

2. The experimental device according to claim 1, characterized in that The electrically heated simulated fuel assembly (5) further comprises: an electrically heated rod (6) and a thermocouple (8); the electrically heated rod (6) is covered by the cladding tube (7), and an insulating material is used to uniformly fill the gap between the electrically heated rod (6) and the cladding tube (7); and the thermocouple (8) is arranged on the inner wall surface of the cladding tube (7).

3. The experimental device according to claim 2, characterized in that The experimental device further comprises an electric heater (3), wherein the electric heater (3) is arranged on the second pipe (28) between the storage tank (2) and the experimental section (4).

4. The experimental device according to claim 1, characterized in that The experimental device further includes a flow meter (14); the flow meter (14) is arranged on the second pipe (28) between the glove box (12) and the electric heater (3).

5. The experimental device according to claim 4, characterized in that The experimental device further includes: a filter (13), wherein the filter (13) is arranged on the flow pipeline between the electromagnetic pump (11) and the flow meter (14), and is connected in parallel with the glove box (12), and a fourth high-temperature electric liquid valve (21) and a fifth high-temperature electric liquid valve (22) are respectively arranged at both ends of the inlet and outlet of the filter (13).

6. The experimental device according to claim 4, characterized in that The experimental device further comprises: a liquid level meter (30); the liquid level meter (30) is used to detect the liquid level height of the liquid lead and bismuth in the oxygen control box (9).

7. The experimental device according to any one of claims 1 to 6, characterized in that: The structure of the cladding tube (7) comprises: processing different numbers of spiral grooves on the surface of the cladding tube (7), or processing different numbers of trapezoidal ribs on the surface of the cladding tube (7).

8. The experimental device according to claim 7, characterized in that The experimental device further comprises: a high-pressure argon gas cylinder (15); the high-pressure argon gas cylinder (15) is connected to the storage tank (2), the oxygen control box (9) and the glove box (12) respectively through a third pipe (29).

9. The experimental device according to claim 7, characterized in that The experimental device further comprises: a heating system (17), a temperature measuring thermocouple (31), and a temperature controlling thermocouple (32); wherein the heating system (17), the temperature measuring thermocouple (31), and the temperature controlling thermocouple (32) are arranged in all areas through which lead and bismuth flow in the experimental device.

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