An electrolysis apparatus

Abstract

The application relates to the technical field of spent fuel electrolytic reduction, and provides an electrolysis device, which comprises an operation chamber, a reaction container, an electrode assembly, a cooling device, a purification circulating device and an auxiliary device, the operation chamber is formed with an operation cavity and a visual window; the reaction container comprises a body and a cover, the body is formed with a reaction cavity and a mounting port, the reaction cavity is used for placing a molten salt electrolyte, the cover is arranged at the mounting port, and the part of the body, where the cover is arranged, is arranged in the operation cavity; the electrode assembly comprises an anode part and a cathode part, the anode part is used for placing a reducing agent, and the cathode part is used for placing oxide spent fuel; the cooling device is arranged at the connection between the body and the operation chamber and is located outside the operation cavity; the purification circulating device is communicated with the reaction cavity and is used for removing impurities from the molten salt electrolyte; and the auxiliary device comprises a heating assembly and a trapping assembly, the trapping assembly is used for collecting gaseous molten salt electrolyte, and the heating assembly is used for heating the reaction cavity. The electrolysis device provided by the application can safely treat oxide spent fuel through multiple passive safety designs.

Description

Technical Field

[0001] This application relates to the field of spent fuel electrolysis reduction technology, and more particularly to an electrolysis device. Background Technology

[0002] Molten salt electrolytic reduction technology is a highly efficient dry post-processing technique that can directly reduce metal oxides to metals in high-temperature molten salt. It offers advantages such as a short process and low waste volume, making it suitable for processing highly radioactive spent fuel. However, scaling up this technology from laboratory scale to engineering applications with a processing capacity of hundreds of kilograms presents several challenges, including the sealing of the operating space, leakage of radioactive materials, and the impact of gaseous molten salt electrolytes on operational visibility. Summary of the Invention

[0003] This application provides an electrolysis device that can safely process oxide spent fuel.

[0004] The technical solution of this application embodiment is implemented as follows: This application provides an electrolysis apparatus, including: The control room consists of an operating cavity and a viewing window; A reaction vessel includes a body and a cover. The body has a reaction chamber and an installation port communicating with the reaction chamber. The reaction chamber is used to place molten salt electrolyte. The cover is disposed at the installation port. The portion of the body to which the cover is mounted is disposed in the operating chamber. An electrode assembly includes an anode and a cathode, both of which are disposed in the reaction chamber. The anode is used to hold a reducing agent, and the cathode is used to hold spent oxide fuel. A cooling device is provided at the connection between the main body and the operating chamber, and is located outside the operating cavity; A purification and circulation device, connected to the reaction chamber, is used to remove impurities from the molten salt electrolyte; The auxiliary device includes a heating component and a collection component, wherein the collection component is used to collect the gaseous molten salt electrolyte, and the heating component is used to heat the reaction chamber.

[0005] In one embodiment, the anode has a first cavity with a bottom opening for placing the reducing agent, wherein the density of the reducing agent is lower than the density of the molten salt electrolyte.

[0006] In one embodiment, the cathode element forms a second cavity that is closed at the bottom and open at the periphery, the second cavity being used to hold the spent oxide fuel; and / or, The reaction vessel includes a partition disposed in the reaction chamber to define a cathode chamber, an anode chamber, and a flow channel. The flow channel connects the cathode chamber and the anode chamber. The anode element is located in the anode chamber, and the cathode element is located in the cathode chamber.

[0007] In one embodiment, the purification and circulation device includes a purification chamber, a first pipe, a second pipe, a first pump body, and a second pump body. The purification chamber is connected to the reaction chamber through the first pipe and the second pipe, respectively. The molten salt electrolyte can be purified by chemical precipitation in the purification chamber. The first pump body is located in the first pipe, and the first pipe can transport the molten salt electrolyte to the purification chamber under the drive of the first pump body. The second pump body is located in the second pipe, and the second pipe can transport the purified molten salt electrolyte to the reaction chamber under the drive of the second pump body.

[0008] In one embodiment, the heating assembly forms a heating chamber, the electrolysis device includes a protective liner disposed in the heating chamber, and the portion of the body located outside the operating chamber is disposed within the protective liner.

[0009] In one embodiment, the number of protective liners is multiple, and the multiple protective liners are nested together; and / or, The protective liner is removably installed in the heating chamber.

[0010] In one embodiment, the electrolysis equipment includes an isolator, with a circumferential gap between two adjacent protective liners and / or a circumferential gap between the body and the protective liners, the isolator being disposed in the circumferential gap.

[0011] In one embodiment, the auxiliary device includes a gas purifier connected to the operating chamber for transporting gas into the operating chamber; and / or, The auxiliary device includes a stirrer, the stirring end of which is located in the reaction chamber, and the stirrer is used to stir the molten salt electrolyte; and / or The auxiliary device includes a robotic arm disposed in the operating cavity, the robotic arm being configured to replace the electrode assembly.

[0012] In one embodiment, the electrolysis equipment includes a control device that is communicatively connected to the auxiliary device, the electrode assembly, the cooling device, and the purification circulation device, respectively, for adjusting the electrolysis parameters of the electrode assembly, the auxiliary parameters of the auxiliary device, the cooling parameters of the cooling device, and the purification parameters of the purification circulation device.

[0013] In one embodiment, the cover is formed with at least one sampling port, the sampling port being in communication with the reaction chamber; and / or, The cover has an interface that communicates with the reaction chamber, and the interface is used to connect a reference electrode.

[0014] The electrolysis equipment provided in this application allows operators to manipulate the reaction vessel within the operating chamber through a viewing window when handling hundreds of kilograms of spent oxide fuel. This includes actions such as opening the cover for sample addition and replacing electrode components. During electrolysis, the reaction chamber can be heated by a heating component to accelerate the reaction process. A collection component collects volatile molten salt electrolyte, effectively suppressing the diffusion and condensation of corrosive media such as gaseous molten salt electrolyte, significantly maintaining the visibility of the viewing window, ensuring a clear field of vision during operation, and improving operational safety. A cooling component is installed at the connection between the main body and the operating chamber outside the operating chamber, eliminating the need for cooling media in the operating and reaction chambers. This reduces the risk of cooling media contacting radioactive spent fuel due to internal pipe ruptures in the cooling component and keeps the temperature of the operating chamber (the part in contact with the operator) within a safe range, further enhancing operational safety. A purification and circulation device removes impurities from the molten salt electrolyte, allowing for its recycling and continuous electrolysis of spent oxide fuel, resulting in good economic efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the electrolysis equipment provided in the embodiments of this application; Figure 2 A schematic diagram of the structure of a reaction vessel, electrode assembly, cooling device, heating assembly, stirrer, robotic arm, protective liner, and separator provided for another embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electrolysis device provided in another embodiment of this application.

[0016] Explanation of reference numerals in the attached figures 100. Electrolysis equipment; 100a. Roller; 1. Operating chamber; 1a. Operating cavity; 2. Reaction vessel; 21. Body; 21a. Reaction cavity; 21a1. Anode cavity; 21a2. Cathode cavity; 21a3. Flow channel; 22. Cover; 23. Baffle; 3. Electrode assembly; 31. Anode component; 31a. First cavity; 32. Cathode component; 32a. Second cavity; 4. Cooling device; 4a. Inlet; 4b. Outlet; 5. 51. Purification and circulation device; 52. Purification chamber; 52. First pipeline; 521. Input section; 522. Extraction section; 53. Second pipeline; 54. First pump body; 55. Second pump body; 61. Heating assembly; 611. Furnace body; 611a. Heating chamber; 612. Heater; 62. Collection assembly; 63. Gas purifier; 64. Stirrer; 65. Robotic arm; 7. Protective liner; 8. Isolation component; 9. Control device. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] One embodiment of this application provides an electrolysis device 100, please refer to... Figures 1 to 3 The electrolysis equipment 100 includes an operating chamber 1, a reaction vessel 2, an electrode assembly 3, a cooling device 4, a purification and circulation device 5, and auxiliary devices. The operating chamber 1 has an operating cavity 1a and a viewing window. The reaction vessel 2 includes a body 21 and a cover 22. The body 21 has a reaction cavity 21a and an installation port communicating with the reaction cavity 21a. The reaction cavity 21a is used to hold molten salt electrolyte. The cover 22 is located at the installation port, and the portion of the body 21 with the cover 22 is located within the operating cavity 1a. The electrode assembly 3 includes an anode 31 and a cathode 32, both located within the reaction cavity 21a. The anode 31 holds a reducing agent, and the cathode 32 holds spent oxide fuel. The cooling device 4 is located at the connection between the body 21 and the operating chamber 1, and is located outside the operating cavity 1a. The purification and circulation device 5 communicates with the reaction cavity 21a and is used to remove impurities from the molten salt electrolyte. The auxiliary device includes a heating component 61 and a collection component 62. The collection component 62 is used to collect gaseous molten salt electrolyte, and the heating component 61 is used to heat the reaction chamber 21a.

[0019] The operating room 1 is a closed space used for operations such as adding samples, taking samples, and replacing electrode assembly 3. Operators can operate the relevant internal structures through a viewing window.

[0020] For example, the operating room 1 can be a glove box or a hot room.

[0021] Reaction vessel 2 refers to the container that provides a site for the electrolysis reaction. The shape of reaction vessel 2 is not limited; for example, it can be cylindrical.

[0022] Electrode assembly 3 refers to the component used for electrolyzing reducing agents and oxide spent fuel.

[0023] Oxide fuels can be mixtures of uranium oxide, plutonium oxide, cerium oxide, and other fission product oxides.

[0024] Cooling device 4 refers to a device used to cool the connection between reaction vessel 2 and body 21 in order to reduce the impact of heat on operating chamber 1.

[0025] For example, the cooling device 4 can be a ring structure, which is arranged around the part of the body 21 located outside the operating chamber 1a and in contact with the operating chamber 1, thereby reducing the heat conduction to the operating chamber 1a.

[0026] For example, the cooling device 4 has an inlet 4a and an outlet 4b with its internal space. The cooling medium can enter the cooling device 4 through the inlet 4a and flow out from the outlet 4b after heat exchange.

[0027] Purification and circulation device 5 refers to a device used to remove impurities from molten salt electrolyte.

[0028] For example, the ion to be removed is an oxygen ion.

[0029] Auxiliary devices refer to devices used to assist the electrolysis reaction. For example, the heating component 61 can be used to heat the reaction chamber 21a to accelerate the reaction rate, and the trapping component 62 can be used to capture the gaseous molten salt electrolyte that volatilizes into the operating chamber 1a to reduce the diffusion of corrosive media and improve the visibility of the operating chamber 1a.

[0030] For example, the location of the trapping assembly 62 is not limited; for instance, it can be installed on the cover 22 or on the top of the operating chamber 1. The trapping assembly 62 has a collection port through which gaseous molten salt electrolyte can enter the trapping assembly 62. The condensation and filtration structures inside the trapping assembly 62 can effectively absorb and collect the gaseous molten salt electrolyte to suppress the diffusion and condensation of molten salt vapor in the operating chamber 1a.

[0031] It should be noted that in reaction chamber 21a, the electrolysis reaction is divided into two steps. The cathode 32 undergoes a reduction reaction. Taking uranium oxide as an example: UO X +2xe→U+x0 2- Anodizing reaction, taking lithium metal as an example: Li-e → Li + That is, oxide spent fuel is reduced directly at the cathode.

[0032] The electrolysis equipment 100 provided in this application allows operators to manipulate a portion of the reaction vessel 2 located in the operating chamber 1a through a viewing window when handling hundreds of kilograms of spent oxide fuel. This includes actions such as opening the cover 22 for sample addition and replacing the electrode assembly 3. During the electrolysis reaction, the reaction chamber 21a can be heated by the heating assembly 61 to accelerate the reaction process. The collection assembly 62 collects the volatile molten salt electrolyte, effectively suppressing the diffusion and condensation of corrosive media such as gaseous molten salt electrolyte. This significantly maintains the visibility of the viewing window, ensuring a clear field of vision during operation and improving efficiency. Operational safety is ensured by installing a cooling assembly at the connection between the main body 21 outside the operating chamber 1a and the operating room 1, thus eliminating the need for cooling medium in both the operating chamber 1a and the reaction chamber 21a. This not only reduces the possibility of the cooling medium coming into contact with radioactive spent fuel due to internal pipe ruptures in the cooling assembly, but also keeps the temperature of the part in contact with the operator, i.e., the operating room 1, within a safe range, further enhancing operational safety. Furthermore, the purification and circulation device 5 removes impurities from the molten salt electrolyte, allowing for its recycling and enabling continuous electrolysis of the oxide spent fuel, resulting in good economic efficiency.

[0033] In some embodiments, the reaction vessel 2 can be made of a high-temperature corrosion-resistant nickel-based alloy or special stainless steel, with a designed operating temperature range of 500°C to 900°C, capable of meeting the electrolysis reaction requirements of different types of spent oxide fuels. The capacity design of the reaction chamber 21a can precisely match the processing needs of hundreds of kilograms of spent oxide fuel.

[0034] In one embodiment, please refer to Figure 2 The anode 31 has a first cavity 31a with a bottom opening. The first cavity 31a is used to place a reducing agent, wherein the density of the reducing agent is lower than the density of the molten salt electrolyte.

[0035] For example, the shape of the anode 31 is not limited; for example, it can be cylindrical, cubic, cuboid, or other irregular shapes.

[0036] Here, by forming a first cavity 31a with a bottom opening inside the anode 31, the first cavity 31a is used to place the reducing agent. When the anode 31 is placed in the molten salt electrolyte, since the density of the reducing agent is less than that of the molten salt electrolyte, the reducing agent will float on the surface of the molten salt electrolyte in the first cavity 31a. In this way, the conductivity of the molten salt can be ensured, and the loss of active material caused by the reducing agent flowing out from the bottom opening can be reduced.

[0037] In some embodiments, the reducing agent can be lithium metal. Here, using lithium metal instead of traditional precious metal anodes such as platinum can reduce material costs by more than 60%, and further reduce the processing costs of oxide spent fuel.

[0038] In some embodiments, the anode 31 is made of stainless steel or a nickel-based alloy, which can withstand long-term corrosion by highly corrosive molten salts such as LiCl-KCl or LiCl-Li2O.

[0039] In some embodiments, the design current density of the anode element 31 is not less than 1 A / cm². 2 .

[0040] In one embodiment, the cathode 32 is formed with a second cavity 32a that is closed at the bottom and open at the periphery, the second cavity 32a being used to hold spent oxide fuel.

[0041] For example, the shape of the cathode element 32 is not limited, and it can be a basket-type or frame-type structure.

[0042] Here, by forming a second cavity 32a in the cathode 32, it can be used to place the sheet or particles of oxide spent fuel. The bottom-closed and peripherally open configuration not only reduces the leakage of oxide spent fuel and its reducing agents from the bottom, making it easy to collect, but also ensures the conduction of molten salt through the peripheral openings.

[0043] In some embodiments, the anode 31 and cathode 32 can be modularly designed, that is, the anode 31 and cathode 32 have quick-release structures such as clamps, so that the operator can quickly disassemble and install the cathode 32 and anode 31 through the viewing window.

[0044] In some embodiments, hooks are formed on the top of the cathode 32 and the anode 31 to facilitate the hoisting mechanism to hoist the anode 31 and the cathode 32 using the hooks.

[0045] In one embodiment, please refer to Figure 1 and Figure 2 The reaction vessel 2 includes a partition 23, which is disposed in the reaction chamber 21a to define the reaction chamber 21a into a cathode chamber 21a2, an anode chamber 21a1, and a flow channel 21a3. The flow channel 21a3 connects the cathode chamber 21a2 and the anode chamber 21a1. The anode element 31 is located in the anode chamber 21a1, and the cathode element 32 is located in the cathode chamber 21a2.

[0046] For example, one end of the partition 23 can be connected to the top wall of the reaction chamber 21a, and the other end can extend downward and be spaced apart from the bottom wall of the reaction chamber 21a, so as to divide the reaction chamber 21a into an anode chamber 21a1, a cathode chamber 21a2 and a flow channel 21a3. The anode chamber 21a1 and the cathode chamber 21a2 are arranged opposite to each other, and the flow channel 21a3 is located below the partition 23.

[0047] Here, by setting a partition 23 in the reaction chamber 21a, the reaction chamber 21a is divided into an anode chamber 21a1, a cathode chamber 21a2, and a flow channel 21a3. This allows the anode element 31 to be placed in the anode chamber 21a1, the cathode element 32 to be placed in the cathode chamber 21a2, and the flow channel 21a3 to allow the molten salt electrolyte to flow between the anode chamber 21a1 and the cathode chamber 21a2. In this way, the partition 23 can physically isolate the cathode element 32 from the anode element 31, thereby effectively reducing the probability of short circuit and improving the service life of the anode element 31.

[0048] In one embodiment, please refer to Figure 3 The purification and circulation device 5 includes a purification chamber 51, a first pipe 52, a second pipe 53, a first pump body 54, and a second pump body 55. The purification chamber 51 is connected to the reaction chamber 21a through the first pipe 52 and the second pipe 53. Molten salt electrolyte can be purified by chemical precipitation in the purification chamber 51. The first pump body 54 is located in the first pipe 52. The first pipe 52 can transport the molten salt electrolyte into the purification chamber 51 under the drive of the first pump body 54. The second pump body 55 is located in the second pipe 53. The second pipe 53 can transport the purified molten salt electrolyte to the reaction chamber 21a under the drive of the second pump body 55.

[0049] For example, the shape of the cleanroom 51 is not limited; for example, it can be cylindrical, cuboid, or cube, etc.

[0050] For example, the ability of molten salt electrolyte to remove impurities through chemical precipitation in the cleanroom 51 means that impurities can be removed by adding a precipitant to the cleanroom 51 to react with impurities such as oxygen ions to generate a precipitate.

[0051] For example, the first pipe 52 includes an input section 521 and an extraction section 522. The input section 521 connects the purification chamber 51 and the reaction chamber 21a. The first pump body 54 can be connected to the purification chamber 51 through the extraction section 522. During operation, the purification chamber 51 can be evacuated to a negative pressure, allowing the molten salt electrolyte to flow into the purification chamber 51 through the input section 521. The second pipe 53 can be connected to the upper middle part of the purification chamber 51, and can pump the molten salt electrolyte located above the precipitate to the reaction chamber 21a through the second pump body 55.

[0052] Here, when it is necessary to remove impurities from the molten salt electrolyte, the molten salt electrolyte in the reaction chamber 21a can be pumped to the purification chamber through the first pipe 52 and the first pump body 54 for chemical precipitation to remove impurities. Then, the molten salt electrolyte that has been purified and restored to activity is pumped back to the reaction chamber 21a through the second pipe 53 and the second pump body 55. This cycle is repeated to achieve online purification and impurity removal of the molten salt electrolyte, thereby improving the utilization rate of the molten salt electrolyte and achieving good economic efficiency.

[0053] In some embodiments, impurities can also be removed by electrochemical purification, distillation, or other methods.

[0054] In some embodiments, the first pump body 54 may be a vacuum siphon pump. The first pump body 54 may be a corrosion-resistant pump.

[0055] In some embodiments, the precipitant can be MgCl2, which can not only effectively remove accumulated oxygen ions, but also reduce the introduction of impurity ions.

[0056] In some embodiments, the purification chamber 51 is equipped with a solid-liquid separation unit, which can remove precipitates generated by sedimentation, filtration and other methods.

[0057] In one embodiment, please refer to Figure 2 The heating component 61 forms a heating chamber 611a, and the electrolysis equipment 100 includes a protective liner 7, which is disposed in the heating chamber 611a. The portion of the body 21 located outside the operating chamber 1a is disposed inside the protective liner 7.

[0058] For example, the shape of the heating cavity 611a is not limited; for example, it can be cylindrical, cuboid, or cube, etc.

[0059] For example, the shape of the protective liner 7 is not limited, for example, it can be cylindrical, cuboid or cube, etc., as long as it can accommodate the part of the body 21 located outside the operating cavity 1a.

[0060] For example, the heating assembly 61 includes a furnace body 611 and a heater 612. The furnace body 611 forms a heating chamber 611a, and the heater 612 can be disposed in the cavity wall of the heating chamber 611a for heating the heating chamber 611a. The heater 612 can be a high-performance resistance heater 612, such as a silicon molybdenum rod or an iron-chromium-aluminum alloy heater 612, so that its maximum operating temperature can reach above 1000°C to meet the reaction temperatures of different types.

[0061] The protective liner 7 refers to a structure that can protect the body 21 to reduce the impact of molten salt electrolyte penetrating into the heating chamber 611a on the heater 612 and the external environment.

[0062] It should be noted that the material of the protective lining 7 is capable of withstanding long-term erosion by highly corrosive molten salts such as LiCl-KCl or LiCl-Li2O.

[0063] Here, by providing a protective liner 7 between the body 21 and the heating chamber 611a, the ability of the electrolysis equipment 100 to resist molten salt penetration can be enhanced, thereby further improving the safety of operation.

[0064] In some embodiments, the heater 612 is arranged circumferentially around the cavity wall of the heating chamber 611a to uniformly heat the reaction chamber 21a.

[0065] In one embodiment, please refer to Figure 2 The number of protective liners 7 is multiple, and multiple protective liners 7 are nested together.

[0066] For example, there can be two protective liners 7, which are nested together, with the body 21 located in the innermost protective liner 7.

[0067] Here, by setting multiple protective liners 7, the ability of the electrolysis equipment 100 to prevent molten salt penetration can be further improved.

[0068] In one embodiment, the protective liner 7 is detachably disposed in the heating chamber 611a. This facilitates the replacement and maintenance of the protective liner 7.

[0069] In one embodiment, please refer to Figure 2 The electrolysis equipment 100 includes an isolation element 8, with a circumferential gap between two adjacent protective liners 7 and / or a circumferential gap between the body 21 and the protective liners 7, and the isolation element 8 is disposed in the circumferential gap.

[0070] For example, there is a circumferential gap between two adjacent protective liners 7, or there is a circumferential gap between the body 21 and the protective liners 7, or there are circumferential gaps between two adjacent protective liners 7 and between the body 21 and the protective liners 7.

[0071] Here, the circumferential gap and the support of the isolation element 8 can provide independent displacement space for the body 21 or the protective liner 7 when the thermal expansion stress difference causes deformation. In addition, the heat flow generated by the heater 612 can achieve convective heat transfer through the circumferential gap to uniformly heat the reaction chamber 21a. In this way, the problem of uneven thermal expansion stress and thermal resistance at high temperature can be effectively solved.

[0072] In one embodiment, please refer to Figure 1 and Figure 3 The auxiliary device includes a gas purifier 63, which is connected to the operating chamber 1a and is used to transport gas to the operating chamber 1a.

[0073] For example, the gas purifier 63 includes a gas source, a pump body, and a delivery pipeline. The pump body can deliver the gas from the gas source to the operating chamber 1a through the delivery pipeline to maintain the operating chamber 1a with a high-purity inert gas (such as argon, requiring an oxygen content of less than 100 ppm and a water content of less than 100 ppm). It can also deliver the gas in the operating chamber 1a to the gas source through the delivery pipeline to achieve functions such as vacuuming and circulating purification of the operating chamber 1a.

[0074] For example, the gas source can be a gas cylinder.

[0075] Here, by setting up a gas purifier 63, multiple functions such as vacuuming, maintaining an inert atmosphere, and gas purification can be achieved by transporting gas to the operating chamber 1a, thereby improving the versatility of the electrolysis equipment 100.

[0076] In one embodiment, please refer to Figure 1 and Figure 2 The auxiliary device includes a stirrer 64, the stirring end of which is located in the reaction chamber 21a. The stirrer 64 is used to stir the molten salt electrolyte.

[0077] For example, the stirring end of the stirrer 64 may be provided with blades, which can stir the molten salt electrolyte in the reaction chamber 21a.

[0078] For example, the blades can be made of a special corrosion-resistant alloy.

[0079] Here, by setting up a stirrer 64, the molten salt electrolyte can be stirred to enhance the mass transfer process, optimize the microenvironment on the electrode surface, eliminate local inhomogeneities in the reaction system, and accelerate the reaction rate.

[0080] In one embodiment, please refer to Figure 1 and Figure 2 The auxiliary device includes a robotic arm 65, which is disposed in the operating chamber 1a and is configured to replace the electrode assembly 3.

[0081] For example, the top wall of the operating cavity 1a is integrated with a track, and the robotic arm 65 is movably mounted on the track.

[0082] Here, by setting up a robotic arm 65, the robotic arm 65 can be remotely operated to perform relevant actions in the operating chamber 1a, such as the installation, removal and positioning of motor components, the addition and sampling of reducing agent and spent fuel, etc., so as to improve the safety of operation.

[0083] In some embodiments, the robotic arm 65 has multiple degrees of freedom, which can support remote operation and accurately complete complex tasks such as positioning, adding, and taking samples of the electrode assembly 3.

[0084] In one embodiment, please refer to Figure 1 The electrolysis equipment 100 includes a control device 9, which is communicatively connected to the auxiliary device, the electrode assembly 3, the cooling device 4, and the purification circulation device 5, respectively, and is used to adjust the electrolysis parameters of the electrode assembly 3, the auxiliary parameters of the auxiliary device, the cooling parameters of the cooling device 4, and the purification parameters of the purification circulation device 5.

[0085] For example, the communication connection can be WIFI, Bluetooth, Ethernet cable, etc.

[0086] For example, the control device 9 can be communicatively connected to the heating component 61, the collection component 62, the gas purifier 63, the stirrer 64, and the robotic arm 65 of the auxiliary device. Its auxiliary parameters may include the opening and closing of the heater 612, the heating power (steady-state deviation not greater than ±1%), the heating time and heating rate (e.g., 0.1 ℃ / min-20 ℃ / min), the opening and closing of the collection component 62, the condensation temperature, etc.; the opening and closing of the gas purifier 63, the gas delivery volume, the gas source, etc.; the opening and closing of the stirrer 64, the stirring time, the rotation speed (control accuracy ±1 rpm), etc.; the opening and closing of the robotic arm 65, the lifting speed when gripping the electrode component 3 (e.g., 0.1 mm / s-5 mm / s), the gripped object, etc.

[0087] The electrolysis parameters of electrode assembly 3 may include the power supply of electrode assembly 3 being turned on, as well as the output voltage and output current.

[0088] The cooling parameters of the cooling device 4 may include the opening and closing of the cooling device 4, the cooling temperature, the cooling time, and the cooling rate.

[0089] The purification parameters of the purification circulation device 5 may include the input amount and input volume of molten salt electrolyte.

[0090] Here, by setting up control device 9, the parameters of auxiliary device, electrode assembly 3, cooling device 4 and purification circulation device 5 can be adjusted remotely to improve the automation level of electrolysis equipment 100, reduce radiation damage to operators, and ensure good safety.

[0091] In some embodiments, the control device 9 integrates a highly reliable PLC (Programmable Logic Controller) or DCS (Distributed Control System) architecture, and may also integrate a human-machine interface (HMI) and remote monitoring functions.

[0092] In some embodiments, temperature sensors are provided in the reaction areas of the reaction vessel 2, such as the reaction chamber 21a, the molten salt, and the electrodes. The temperature sensors are communicatively connected to the control device 9. The control device 9 can control the heating parameters of the heating component 61 based on the temperature monitored by the temperature sensors to ensure that the temperature difference in the entire reaction area is less than a preset value, such as 15°C.

[0093] The temperature sensor can be a thermocouple, such as type K or type S.

[0094] In some embodiments, the control device 9 also integrates a safety interlock module. When the control device 9 detects faults such as over-temperature, over-pressure, abnormal current or voltage, cooling failure, excessive atmosphere purity, or sealing failure, it can automatically trigger an emergency shutdown procedure and alarm to ensure the safety of the electrolysis equipment 100 and the operators.

[0095] In some embodiments, the control device 9 also has an operation terminal, which adopts a graphical touch screen design and can dynamically visualize the operating status, trend curves and alarm information of each device.

[0096] In some embodiments, the control device 9 integrates a data recording system, which has the functions of real-time acquisition, storage, query and export of key process parameters such as temperature, pressure, current, voltage and gas composition, providing complete data support for process optimization, quality traceability and safety audit.

[0097] In one embodiment, the cover 22 is formed with at least one sampling port, which is connected to the reaction chamber 21a.

[0098] In this way, molten salt electrolyte can be extracted periodically through the sampling port for analysis.

[0099] In one embodiment, the cover 22 is formed with an interface communicating with the reaction chamber 21a, the interface being used to connect a reference electrode.

[0100] Here, by inserting a reference electrode into the reaction chamber 21a through the interface, the potential of the cathode 32 and the cathode 32 can be monitored and controlled.

[0101] In some embodiments, the overall structural layout of the electrolysis equipment 100 needs to fully consider the space constraints and maintenance passage of the operating room 1. The part of the main body 21 located outside the operating chamber 1a, the heating component 61, and part of the purification and circulation device 5 are located in the main process area. The control device 9, the power supply of the electrolysis equipment 100, the cooling device 4, etc. are placed in the auxiliary area or equipment room and connected by through-wall kits.

[0102] In some embodiments, please refer to Figure 1 and Figure 2 Each electrolysis device 100 is equipped with rollers 100a at its bottom, which allows the electrolysis device 100 to be moved, improving its convenience.

[0103] It should be noted that both the operating room 1 and the clean room 51 mentioned above are solid structures, that is, they are built or constructed using relevant materials.

[0104] In some embodiments, based on the electrolysis equipment 100 described above, this application embodiment provides another aspect of a specific process for the electrolytic reduction of UO2: Approximately 100 kg of UO2 sheets or pressed products are loaded into the first cavity of the cathode 32. Approximately 20 kg of lithium metal granules are loaded into the second cavity 32a of the anode 31. The reaction vessel 2 is made of a high-temperature resistant nickel-based alloy, and the protective liner 7 is made of graphite or boron nitride. The molten salt electrolyte is pre-melted and dehydrated LiCl molten salt, and the heating temperature is set to 650°C. The control device 9 controls the heater 612 to program a temperature increase at a rate of 15°C / min, and maintains an argon protective atmosphere (O2 < 100 ppm, H2O < 100 ppm) in the operating cavity 1a throughout the process. The electrolysis process is controlled by a constant current, set to 200 A, and the stirrer 64 is set to 20 rpm. The O2 concentration in the molten salt electrolyte is periodically monitored through a sampling port. 2 The concentration (or indirectly determined by monitoring the voltage change of reaction vessel 2) is monitored. When the index exceeds the set value (e.g., equivalent to a Li2O concentration greater than 5 wt%), the purification circulation device 5 is activated, and an appropriate amount of anhydrous MgCl2 is added for precipitation treatment. The separated precipitate is collected and processed. After the electrolysis equipment 100 has been running continuously and stably for about 300 hours, electrolysis is stopped. The cathode 32 is transferred to a dedicated product collection device by the robotic arm 65, and the product on the cathode 32 is scraped or dissolved and peeled off. Analysis shows that the purity of metallic uranium in the product is higher than 98.5%, and the direct recovery rate of uranium metal reaches more than 96%, verifying the high efficiency and stability of the electrolysis equipment 100 in processing pure UO2.

[0105] In some embodiments, based on the electrolysis equipment 100 described above, this application provides another aspect of a specific process for the simulated electrolytic reduction of mixed oxide spent fuel: This embodiment simulates the processing of spent fuel containing a mixture of oxides with multiple actinide elements. The set temperature and heating rate are consistent with or similar to those of the electrode assembly 3, protective liner 7, and heater 612 in the previous embodiment. The cathode 32 is loaded with approximately 50 kg of a mixture consisting of UO2, a PuO2 simulant (such as CeO2), and other fission product oxides. The cathode 32 is still loaded with metallic lithium. The molten salt electrolyte is a LiCl-based molten salt, and the heating temperature is optimized to 680°C to better suit the reduction kinetics of the mixed oxides. The control device 9 sets the stirrer 64 to 10 rpm and employs a constant potential control strategy to preferentially reduce specific elements. The parameters of each device are flexibly adjusted via the remote control device 9's operating terminal. After approximately 150 hours of continuous operation, the cathode products are collected and analyzed in segments or as a whole. The results show that the recovery rates of uranium and plutonium (simulant cerium) reach approximately 95% and 90%, respectively, and different elements are separated to a certain extent, demonstrating that the electrolysis equipment 100 provided in this application possesses excellent processing capabilities and process adaptability for complex spent fuel systems.

[0106] In some embodiments, yet another embodiment of this application provides several safety precautions for the handling of highly radioactive oxide spent fuel: The reaction vessel 2 employs a double-layer protective liner 7. When processing extremely high-activity materials, the entire operating chamber 1a maintains a certain negative pressure (e.g., -0.1 kPa to -0.5 kPa), ensuring that even minor leaks are directed inwards, reducing the possibility of contaminant leakage. Temperature control employs a more refined gradient heating strategy, and the cathode potential is precisely controlled within the target range during the electrolysis stage to minimize unnecessary side reactions. The control device 9 monitors the temperature of key locations such as the main body 21, anode 31, cathode 32, and furnace body 611 in real time via PLC, ensuring that the temperature difference across the entire reaction zone is less than 15°C. During operation, the top-mounted trapping assembly 62 operates continuously or intermittently. After approximately 120 hours of safe processing, certain highly volatile radioactive fission nuclides in the produced metal products are effectively removed, and the total radioactivity of the products is significantly reduced. Simultaneously, the visibility of the viewing window remains above 85%, and remote operation is not significantly affected. These test results verify the excellent safety, stability, and reliability of the electrolysis equipment 100 provided in this application under extreme high-level radioactive environments.

[0107] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. An electrolysis device, characterized in that, include: The control room consists of an operating cavity and a viewing window; A reaction vessel includes a body and a cover. A reaction chamber and an installation port communicating with the reaction chamber are formed in the body. The reaction chamber is used to place molten salt electrolyte. The cover is disposed in the installation port. The part of the body on which the cover is installed is disposed in the operating chamber. An electrode assembly includes an anode and a cathode, both of which are disposed in the reaction chamber. The anode is used to hold a reducing agent, and the cathode is used to hold spent oxide fuel. A cooling device is provided at the connection between the main body and the operating chamber, and is located outside the operating cavity; A purification and circulation device, connected to the reaction chamber, is used to remove impurities from the molten salt electrolyte; The auxiliary device includes a heating component and a collection component, wherein the collection component is used to collect the gaseous molten salt electrolyte, and the heating component is used to heat the reaction chamber.

2. The electrolysis equipment according to claim 1, characterized in that, The anode has a first cavity with a bottom opening for placing the reducing agent, wherein the density of the reducing agent is lower than the density of the molten salt electrolyte.

3. The electrolysis equipment according to claim 1, characterized in that, The cathode element has a second cavity that is closed at the bottom and open at the periphery, the second cavity being used to hold the spent oxide fuel; and / or The reaction vessel includes a partition disposed in the reaction chamber to define a cathode chamber, an anode chamber, and a flow channel. The flow channel connects the cathode chamber and the anode chamber. The anode element is located in the anode chamber, and the cathode element is located in the cathode chamber.

4. The electrolysis equipment according to claim 1, characterized in that, The purification and circulation device includes a purification chamber, a first pipe, a second pipe, a first pump body, and a second pump body. The purification chamber is connected to the reaction chamber through the first pipe and the second pipe, respectively. The molten salt electrolyte can be purified by chemical precipitation in the purification chamber. The first pump body is located in the first pipe, and the first pipe can transport the molten salt electrolyte to the purification chamber under the drive of the first pump body. The second pump body is located in the second pipe, and the second pipe can transport the purified molten salt electrolyte to the reaction chamber under the drive of the second pump body.

5. The electrolysis equipment according to claim 1, characterized in that, The heating assembly forms a heating chamber, the electrolysis equipment includes a protective liner, the protective liner is disposed in the heating chamber, and the portion of the body located outside the operating chamber is disposed inside the protective liner.

6. The electrolysis equipment according to claim 5, characterized in that, The protective liner is multiple, and the multiple protective liners are nested together; and / or, The protective liner is removably installed in the heating chamber.

7. The electrolysis equipment according to claim 6, characterized in that, The electrolysis equipment includes an isolator, and there is a circumferential gap between two adjacent protective liners and / or a circumferential gap between the body and the protective liners, with the isolator disposed in the circumferential gap.

8. The electrolysis equipment according to claim 1, characterized in that, The auxiliary device includes a gas purifier, which is connected to the operating chamber and is used to transport gas into the operating chamber; and / or, The auxiliary device includes a stirrer, the stirring end of which is located in the reaction chamber, and the stirrer is used to stir the molten salt electrolyte; And / or, The auxiliary device includes a robotic arm disposed in the operating cavity, the robotic arm being configured to replace the electrode assembly.

9. The electrolysis equipment according to claim 1, characterized in that, The electrolysis equipment includes a control device, which is communicatively connected to the auxiliary device, the electrode assembly, the cooling device, and the purification circulation device, respectively, for adjusting the electrolysis parameters of the electrode assembly, the auxiliary parameters of the auxiliary device, the cooling parameters of the cooling device, and the purification parameters of the purification circulation device.

10. The electrolysis equipment according to claim 1, characterized in that, The cover has at least one sampling port, which is in communication with the reaction chamber; and / or, The cover has an interface that communicates with the reaction chamber, and the interface is used to connect a reference electrode.

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