Method and device for treating high-tritium-content water of high-temperature gas cooled reactor

Abstract

The invention discloses a high-tritium-content water treatment method and device for a high-temperature gas cooled reactor, and the method comprises the steps: collection and pretreatment of tritium-containing water: removing suspended particles in the tritium-containing water and adjusting the pH value of the water through a chemical reagent; performing liquid-phase water-hydrogen isotope catalytic exchange, namely realizing isotope exchange of hydrogen and tritium in the pretreated tritium-containing water at low temperature by adopting a palladium-based catalyst; water distillation: evaporating tritium-containing water after liquid-phase water-hydrogen isotope catalytic exchange under a vacuum low-temperature condition, and condensing water vapor; gas-phase water-hydrogen isotope catalytic exchange is carried out, and tritium gas is further separated in a gas phase through high-temperature catalytic exchange; and performing electrolysis and catalytic exchange on the tritium-containing water subjected to gas-phase water-hydrogen isotope catalytic exchange by combining electrolysis with liquid-phase catalytic exchange so as to deeply separate tritium. According to the invention, standard discharge of wastewater treatment can be ensured, tritium resources in the wastewater can be recovered, and effective utilization of the resources is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear energy and radioactive wastewater treatment, and particularly relates to a method and device for treating high-tritium-containing water in a high-temperature gas-cooled reactor. Background Art

[0002] During the operation of nuclear reactors, the mechanisms for generating tritium in different types of reactors vary significantly. In pressurized water reactors, tritium is mainly generated in nuclear triple fissions of fuel elements, control rods, burnable poison rods, and primary coolant, especially the tritium generated by nuclear fuel fission accounts for the main part. Since pressurized water reactors use light water as coolant, tritium mainly exists in the form of low-concentration and large-volume tritium-containing water.

[0003] In contrast, the generation mechanism of tritium in high-temperature gas-cooled reactors mainly focuses on systems such as nuclear fuel, reactor structural materials, and helium coolant. Tritium passes through the copper oxide bed in the reactor purification system to oxidize gaseous tritium into tritiated water (HTO), and after being treated by molecular sieve, high-concentration tritium-containing water is formed. Different from traditional pressurized water reactors, the tritium-containing water generated by high-temperature gas-cooled reactors has the characteristic of high concentration. Since its ecological toxicity is 10,000 times that of gaseous tritium, direct discharge will pose a serious threat to the environment and ecosystem.

[0004] Currently, pressurized water reactors usually meet environmental supervision requirements by discharging low-concentration tritium water. However, due to the relatively high concentration of tritium-containing water generated by high-temperature gas-cooled reactors, it is not suitable to adopt the same discharge treatment method. Therefore, in current high-temperature gas-cooled reactor projects, high-concentration tritium-containing water is collected in multiple special storage tanks for temporary storage. However, long-term storage of high-concentration tritium-containing water faces the penetration effect of liquid tritium on metal storage tanks, which may bring risks of corrosion and leakage of the storage tanks, affecting their long-term safety and reliability.

[0005] Tritium not only has the risk of radioactive pollution, but is also a resource with application value, especially the high-concentration tritium water generated in high-temperature gas-cooled reactors. Tritium can be used as a tracer, a calibration standard substance for analytical equipment, etc., and has broad industrial application prospects. Therefore, whether from the perspective of environmental protection or from the perspective of tritium resource recovery and utilization, the research on the treatment and recovery technology for high-concentration tritium-containing water has important practical significance.

[0006] Although there are already some tritium water treatment technologies that can be applied to nuclear power plants, these technologies usually use methods such as separation, adsorption, or electrolysis to remove and treat tritium. However, there are still certain limitations in the application of existing technologies in high-temperature gas-cooled reactors:

[0007] Low treatment efficiency: Traditional tritium water treatment technologies have low treatment efficiency when dealing with high-concentration tritium water, and it is difficult to quickly and safely separate and remove tritium, especially for the tritium water in high-temperature gas-cooled reactors with a large treatment volume.

[0008] High energy consumption: Existing tritium water treatment technologies usually require high energy consumption, especially those based on electrolysis, evaporation and other technologies, which may lead to an increase in the operating cost of nuclear power plants and are difficult to achieve cost-effective treatment.

[0009] Poor adaptability: Most of the existing technologies are treatment schemes designed for pressurized water reactors. In high-temperature gas-cooled reactors, due to the different characteristics of tritium water (such as higher tritium concentration and differences in the physical and chemical properties of tritium water), traditional treatment processes cannot fully meet the treatment requirements of high-temperature gas-cooled reactors, and the treatment effect is poor.

[0010] Lack of resource recovery scheme: Existing tritium treatment methods often only focus on the removal of tritium in wastewater, but fail to effectively recover tritium, wasting its potential as a valuable resource such as an industrial standard substance and a tracer. The technology for recovering tritium is still in its infancy and has limited industrial applications.

[0011] Therefore, the existing technologies have obvious deficiencies in dealing with the treatment and recovery of high-concentration tritium-containing water. There is an urgent need to develop efficient and safe treatment and recovery technologies to address the challenges in tritium water management in high-temperature gas-cooled reactors. Summary of the Invention

[0012] The object of the present invention is to provide a method and device for treating high-tritium-containing water in a high-temperature gas-cooled reactor, which is used to effectively treat and recover high-concentration tritium-containing wastewater generated in a high-temperature gas-cooled reactor, ensure that the wastewater treatment meets the discharge standards, and recover the tritium resources therein to achieve the effective utilization of resources.

[0013] In order to achieve the above object, the present invention adopts the following technical solutions:

[0014] A method for treating high-tritium-containing water in a high-temperature gas-cooled reactor, comprising:

[0015] Collection and pretreatment of tritium-containing water, including removing suspended particulate matter in the tritium-containing water and adjusting the pH value of the water through chemical reagents;

[0016] Liquid-phase water-hydrogen isotope catalytic exchange, using a palladium-based catalyst to achieve isotope exchange of hydrogen and tritium in the pretreated tritium-containing water at low temperature;

[0017] Water distillation, evaporating the tritium-containing water after liquid-phase water-hydrogen isotope catalytic exchange and condensing the water vapor under vacuum and low-temperature conditions;

[0018] Gas-phase water-hydrogen isotope catalytic exchange, further separating tritium gas through high-temperature catalytic exchange in the gas phase;

[0019] Electrolysis combined with liquid-phase catalytic exchange, electrolyzing and catalytically exchanging the tritium-containing water after gas-phase water-hydrogen isotope catalytic exchange to deeply separate tritium.

[0020] A further improvement of the present invention is that it further includes: electrolysis of water and final recovery of tritium, condensing the tritium gas after deep separation into liquid state and storing it.

[0021] A further improvement of the present invention is that in the step of collecting and pre-treating the tritium-containing water, it includes using a mechanical filtration device to remove suspended particulate matter and adjusting the pH value of the water through chemical reagents.

[0022] A further improvement of the present invention is that in the liquid-phase water-hydrogen isotope catalytic exchange step, the palladium-based catalyst used is filled in a reaction tower, the diameter of the catalyst particles is 50 microns, and the reaction temperature of the catalytic reaction tower is controlled at 25 - 30 °C.

[0023] A further improvement of the present invention is that the catalyst for gas-phase water-hydrogen isotope catalytic exchange is a palladium-based catalyst, and the tritium gas is separated through a selective permeation membrane, and the purity of the tritium gas reaches more than 99%.

[0024] A further improvement of the present invention is that for the electrolysis combined with liquid-phase catalytic exchange, titanium electrodes are used, the electrolysis voltage is controlled at 1.8 - 2.2 V, and during the electrolysis process, the isotope exchange of hydrogen and tritium is promoted through the catalyst.

[0025] A further improvement of the present invention is that the electrolysis voltage during the electrolysis combined with liquid-phase catalytic exchange is controlled at 1.8 - 2.2 V, and the tritium gas generated during the electrolysis of water is condensed to -5 to -10 °C through a condenser.

[0026] A high-tritium water treatment device for a high-temperature gas-cooled reactor includes:

[0027] A collection and pre-treatment unit for tritium-containing water, which removes suspended particulate matter in the tritium-containing water and adjusts the pH value of the water through chemical reagents;

[0028] A liquid-phase water-hydrogen isotope catalytic exchange unit, which uses a palladium-based catalyst to achieve the isotope exchange of hydrogen and tritium in the pre-treated tritium-containing water at low temperature;

[0029] A water distillation unit, which evaporates the tritium-containing water after liquid-phase water-hydrogen isotope catalytic exchange under vacuum and low-temperature conditions and condenses the water vapor;

[0030] A gas-phase water-hydrogen isotope catalytic exchange unit, which further separates tritium gas through high-temperature catalytic exchange in the gas phase;

[0031] An electrolysis combined with liquid-phase catalytic exchange unit, which electrolyzes and catalytically exchanges the tritium-containing water after gas-phase water-hydrogen isotope catalytic exchange to deeply separate tritium.

[0032] A further improvement of the present invention is that it further includes: an electrolysis of water and final recovery unit for tritium, which condenses the deeply separated tritium gas into liquid state and stores it.

[0033] A further improvement of the present invention lies in that in the tritiated water collection and pretreatment unit, a mechanical filtration device is used to remove suspended particulate matter and the pH value of water is adjusted by chemical reagents.

[0034] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0035] A method and device for treating high-tritium-containing water in a high-temperature gas-cooled reactor provided by the present invention form an efficient tritium water treatment technology of multi-stage separation and recovery by integrating liquid-phase water-hydrogen isotope catalytic exchange (LPCE), gas-phase water-hydrogen isotope catalytic exchange (VPCE), electrolysis combined with liquid-phase catalytic exchange (CECE), water distillation (WD) and water electrolysis technologies and combining the advantages of each process. Through this technology, not only can tritium resources be efficiently separated and recovered, but also the treated wastewater can meet the discharge standards, with the advantages of low energy consumption, high recovery efficiency and strong safety.

[0036] In the application of treating high-tritium-containing water in a high-temperature gas-cooled reactor, the present invention can effectively solve the deficiencies of the prior art in terms of treatment efficiency, resource recovery, energy consumption, etc., and ensure the long-term safe operation of nuclear power plants and the achievement of environmental protection requirements. Description of the Drawings

[0037] Figure 1 It is a flowchart of a method for treating high-tritium-containing water in a high-temperature gas-cooled reactor of the present invention.

[0038] Figure 2 It is a structural block diagram of a device for treating high-tritium-containing water in a high-temperature gas-cooled reactor of the present invention. Detailed Embodiments

[0039] In the following text, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0040] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0041] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0042] It should be further understood that the term "and / or" used in the specification and appended claims of the present invention refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0043] Various structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0044] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0045] Embodiment 1

[0046] A method for treating high-tritium-containing water in a high-temperature gas-cooled reactor provided by the present invention includes:

[0047] Collection and pretreatment of tritium-containing water, including removing suspended particulate matter in the tritium-containing water and adjusting the pH value of the water through chemical reagents;

[0048] Liquid-phase water-hydrogen isotope catalytic exchange, using a palladium-based catalyst to achieve isotope exchange of hydrogen and tritium in the pretreated tritium-containing water at low temperature;

[0049] Water distillation, evaporating the tritium-containing water after liquid-phase water-hydrogen isotope catalytic exchange under vacuum and low temperature conditions and condensing the water vapor;

[0050] Gas-phase water-hydrogen isotope catalytic exchange, further separating tritium gas through high-temperature catalytic exchange in the gas phase;

[0051] Electrolysis combined with liquid-phase catalytic exchange, electrolyzing and catalytically exchanging the tritium-containing water after gas-phase water-hydrogen isotope catalytic exchange to deeply separate tritium.

[0052] In this embodiment, it further includes: electrolysis of water and final recovery of tritium, condensing the deeply separated tritium gas into a liquid state and storing it.

[0053] In the step of collection and pretreatment of tritium-containing water in this embodiment, it includes using a mechanical filtration device to remove suspended particulate matter and adjusting the pH value of the water through chemical reagents.

[0054] In the step of liquid-phase water-hydrogen isotope catalytic exchange in this embodiment, the palladium-based catalyst used is filled in a reaction tower, the diameter of the catalyst particles is 50 microns, and the reaction temperature of the catalytic reaction tower is controlled at 25 - 30 °C.

[0055] In this embodiment, the catalyst for the gas-phase water-hydrogen isotope catalytic exchange is a palladium-based catalyst, and tritium gas is separated by a selective permeation membrane, with the purity of tritium gas reaching over 99%.

[0056] In this embodiment, a titanium electrode is used for the combined electrolysis and liquid-phase catalytic exchange, and the electrolysis voltage is controlled at 1.8 - 2.2 V. During the electrolysis process, the catalyst promotes the isotope exchange of hydrogen and tritium.

[0057] In this embodiment, the electrolysis voltage during the combined electrolysis and liquid-phase catalytic exchange process is controlled at 1.8 - 2.2 V, and the tritium gas generated during the water electrolysis process is condensed to -5 to -10 °C by a condenser.

[0058] Example 2

[0059] A method for treating high-tritium-containing water in a high-temperature gas-cooled reactor provided by the present invention combines the advantages of several existing hydrogen isotope separation processes, including liquid-phase water-hydrogen isotope catalytic exchange (LPCE), vapor-phase water-hydrogen isotope catalytic exchange (VPCE), combined electrolysis catalytic exchange (CECE), water distillation (WD), and water electrolysis, etc. High-efficiency tritium separation, recovery, and wastewater purification are achieved through multi-stage treatment. The technical solutions and the technical means adopted in each step will be elaborated in detail below in combination with each process flow.

[0060] The first step: Collection and pretreatment of tritium-containing water

[0061] First, the tritium-containing water (HTO) in the high-temperature gas-cooled reactor is oxidized and collected into the tritium-containing water collection system through the helium purification system of the nuclear reactor. At this stage, the tritium-containing water may contain solid suspended matters and other impurities, which may affect the subsequent treatment steps, so pretreatment is required.

[0062] Mechanical filtration: The tritium-containing water first passes through a mechanical filter to remove suspended particles and other impurities, ensuring pure water quality and reducing the load of subsequent processes.

[0063] Chemical pretreatment: In order to stabilize the chemical properties of the tritium-containing water and avoid poisoning or failure of the catalyst in subsequent processes, an appropriate amount of chemical reagent can be added to adjust the pH value or remove other interfering components. Through pretreatment, it is ensured that the tritium-containing water is suitable for subsequent efficient separation and recovery steps.

[0064] After pretreatment, the tritiated water enters the Liquid Phase Catalytic Exchange (LPCE) system. The LPCE process promotes the isotope exchange reaction between tritium and hydrogen using a catalyst under low-temperature conditions, and is suitable for treating tritiated water in the liquid phase.

[0065] Catalyst selection: This process uses a specially designed palladium catalyst, which has the characteristics of high selectivity and high activity, and can effectively promote the exchange reaction between hydrogen isotopes.

[0066] Low-temperature operation: The reaction is carried out at a relatively low temperature (about 25 °C), which can not only ensure a high reaction efficiency but also reduce energy consumption.

[0067] The purpose of this step is to preliminarily separate tritium in the liquid phase, reduce the concentration of tritium in water through catalytic exchange, and at the same time improve the separation efficiency of tritium.

[0068] After the initial catalytic exchange is completed, the tritium content in the water is still relatively high. At this time, the tritiated water is further separated by Water Distillation (WD) technology. Water distillation separates and concentrates tritium in water through evaporation and condensation.

[0069] Evaporator design: This system uses a low-temperature vacuum evaporation device, which can evaporate water while reducing the boiling point, reduce the volatilization loss of tritium, and ensure safe operation.

[0070] Condensation system: The steam after water distillation is cooled to liquid water by a condenser, and the concentrated tritium is retained during the distillation process, further improving the separation efficiency of tritium.

[0071] The role of the water distillation process in tritium water treatment is to further reduce the tritium content in water by physical means, make the water meet the discharge standards, and at the same time improve the concentration efficiency of tritium.

[0072] The gaseous components generated during the distillation process are introduced into the Vapor Phase Catalytic Exchange (VPCE) system, and tritium in the gas phase is further separated through this technology. The VPCE technology is based on the hydrogen isotope exchange reaction at high temperature and is especially suitable for the gas purification process in high-temperature gas-cooled reactors.

[0073] Catalytic reaction tower: The gaseous components pass through the catalytic reaction tower, which is filled with a specially designed catalyst and can achieve efficient separation of tritium at a relatively high temperature (about 300 °C).

[0074] Tritium gas separation: Tritium gas and other gaseous components are further separated through a selective adsorption membrane to ensure that the separated tritium gas meets the high-purity standard.

[0075] The VPCE process can efficiently separate tritium in tritium-containing gases and is suitable for the purification and recovery of tritium in the gas phase.

[0076] Combined Electrolysis and Catalytic Exchange in Liquid Phase (CECE)

[0077] For the liquid-phase water still containing a small amount of tritium after VPCE treatment, the present invention adopts the combined electrolysis and catalytic exchange in liquid phase (CECE) technology. This technology separates tritium from water through the electrolysis process and combines catalytic exchange technology to improve the tritium recovery efficiency.

[0078] Electrolytic cell design: A multi-stage electrolytic cell design is adopted, which can achieve the electrolysis of water at a lower voltage and optimize the electrolysis efficiency by controlling the current and voltage.

[0079] Catalyst-assisted electrolysis: During the electrolysis process, the catalyst promotes the exchange reaction of hydrogen isotopes, further improving the separation and recovery efficiency of tritium.

[0080] Through the CECE process, the present invention can further reduce the tritium content in water, achieve deep recovery of tritium, and ensure the final purification effect of water.

[0081] Water electrolysis and final recovery of tritium

[0082] During the electrolysis process, a small amount of tritium is contained in the generated gaseous hydrogen, and the final tritium gas recovery is carried out through the water electrolysis technology. The electrolysis process can separate hydrogen gas and tritium gas, and through further condensation and storage, the purification and recovery of tritium are achieved.

[0083] Tritium condensation and storage: The recovered tritium gas is converted into liquid tritium through a condensation device and stored in a specially designed corrosion-resistant storage tank to ensure long-term safe storage.

[0084] Through water electrolysis and the final recovery of tritium, the present invention can not only efficiently separate tritium, but also use the recovered tritium in fields such as industrial reference materials and tracers, further improving the utilization rate of tritium resources.

[0085] Further purification of the treated wastewater

[0086] After all separation and recovery processes are completed, the remaining wastewater may still contain a small amount of radionuclides and organic pollutants. At this time, the wastewater is further treated through a multi-stage filtration system and activated carbon adsorption technology to ensure that it meets the national discharge standard of GB8978-2002.

[0087] Multi-stage filtration system: Remove radionuclides and particulate pollutants in the wastewater through high-efficiency filters to ensure that the wastewater is clean and harmless.

[0088] Activated carbon adsorption: Use activated carbon to adsorb organic substances and trace pollutants in the wastewater to ensure that the water quality meets the standard.

[0089] The high-temperature gas-cooled reactor high-tritium water treatment and recovery technology of the present invention combines multiple hydrogen isotope separation technologies, enabling efficient treatment of high-concentration tritiated water and resource recovery of tritium. To achieve efficient treatment, multiple separation and purification processes are included in the specific implementation, and specific technical measures are taken in each process to ensure the treatment effect. The specific implementation of the present invention will be described in detail below with reference to the accompanying drawings.

[0090] During the operation of the high-temperature gas-cooled reactor, tritium is oxidized to tritiated water (HTO) through the helium purification system in the reactor. These tritiated waters are transported to the tritiated water collection system through dedicated pipelines. During this process, the water may contain some suspended particulate matter and chemical impurities, such as corrosion products, metal oxides, sediments, etc. Common impurities include rust (Fe2O3, Fe3O4), aluminum oxide (Al2O3), calcium and magnesium precipitates, etc., which mainly come from the corrosion products in the coolant system of the nuclear reactor or pipelines. To avoid the influence of impurities on subsequent treatment processes, the tritiated water is first filtered through a mechanical filtration device. A multi-layer stainless steel filter (pore size 5-10 microns) is used to effectively remove particulate matter and suspended matter in the water, ensuring pure water quality. The filtered tritiated water enters the next treatment process, ensuring that the solid particle content in the water is below 10 ppm.

[0091] According to the chemical composition of the tritiated water, the water contains substances such as chlorides, sulfates, carbonates, etc. These substances will affect the activity of subsequent catalysts or cause corrosion to equipment. The pH value of the tritiated water needs to be maintained within the range of 6.5-7.5, which can not only avoid acid-base poisoning of the catalyst but also ensure the corrosion resistance of the equipment. If the pH value is too high, a small amount of sulfuric acid (H2SO4) is added for neutralization; if the pH value is too low, sodium hydroxide (NaOH) is added to adjust it to the appropriate range. In addition, calcium hydroxide (Ca(OH)2) is added to the liquid to remove heavy metal ions (such as lead, cadmium, etc.) in the water to avoid affecting the life and activity of subsequent catalysts.

[0092] The pretreated tritium-containing water enters the liquid phase water-hydrogen isotope catalytic exchange system. The process realizes the isotope exchange reaction of tritium and hydrogen under low temperature conditions through a palladium-based catalyst. LPCE technology is to gradually separate tritium from water by reacting hydrogen and tritium in water. The catalyst uses a palladium-based catalyst (Pd / C), which has excellent selectivity and stability. The catalyst particle diameter is about 50 microns, and the thickness of the catalyst bed loaded in the reaction tower is 2 meters to ensure sufficient reaction contact time. The reaction temperature of the catalytic reaction tower is controlled at 25-30℃, and the pressure is controlled to operate at normal pressure. In the reaction tower, tritium is gradually separated from water through isotope exchange reaction with hydrogen. The flow rate of water is controlled at 1.5-2.0L / h to ensure sufficient reaction. The purpose of this stage is to gradually separate tritium from hydrogen through isotope exchange reaction, and the tritium content of water after the reaction is greatly reduced to 10-20Bq / L.

[0093] After the liquid-phase catalytic exchange treatment, the concentration of tritium has been significantly reduced, but there is still a certain amount of tritium in the water. At this time, further separation is carried out through water distillation (WD) technology. The purpose of water distillation is to further concentrate the tritium in the water by using the vaporization and condensation process of water. The evaporator is a multi-effect evaporation device. It reduces the boiling point of water to about 50°C through vacuum, evaporates the water at low temperature, reduces the volatilization loss of tritium, and reduces the energy consumption of the equipment. After the water vapor is collected, it is cooled to a liquid state through a condenser. The condensation system uses a titanium alloy condenser, which has good corrosion resistance and can condense the evaporated water vapor into liquid water under a vacuum environment. The tritium concentration of the condensed water is further reduced to 1-5Bq / L, meeting the emission standards. This step uses water distillation technology to further reduce the tritium content in the water, and at the same time collects water vapor through a condenser to ensure that the wastewater meets the discharge standards.

[0094] The gas phase produced during the distillation process contains some tritium. At this time, the gas is treated by gas phase water-hydrogen isotope catalytic exchange technology. VPCE technology is suitable for the separation of tritium in high-temperature gas phase. The catalytic reaction tower used in this stage is filled with a specially designed palladium-based catalyst and operates at a high temperature of 300°C. Gas phase water and hydrogen undergo isotope exchange reactions under the action of the catalyst to separate tritium from hydrogen in the gas phase. The gas at the outlet of the catalytic reaction tower enters the selective membrane separation device. The membrane has high selectivity for tritium gas and can effectively separate tritium gas from other gases, ensuring that the purity of the separated tritium gas reaches more than 99%. Through the VPCE process, tritium in the gas phase is efficiently separated and enters the next recovery process.

[0095] For the remaining tritium in the gas phase and liquid phase, the present invention conducts in-depth treatment through the combined electrolysis and liquid-phase catalytic exchange (CECE) process. This process combines electrolysis and catalytic exchange, enabling efficient separation of tritium in water. The electrolytic cell uses electrodes such as titanium electrodes to electrolyze tritiated water under a DC voltage of 1.8 - 2.2V, generating hydrogen and oxygen. During electrolysis, tritium in the water is released together with hydrogen and enters the catalytic exchange stage. The hydrogen generated during electrolysis undergoes a catalytic exchange reaction with tritium in the water, further improving the tritium separation efficiency. The temperature of the reaction tower is controlled at around 25°C. After the CECE process, the tritium content in the water can be reduced to below 1 Bq / L, meeting international standards.

[0096] The tritium gas separated through the CECE process undergoes a further water electrolysis process, and finally tritium is recovered and purified. The separated tritium gas is condensed into liquid tritium through a low-temperature condenser, and the condensation temperature is controlled at -5 to -10°C. The condensed tritium is stored in a specially made corrosion-resistant storage tank, and the material of the storage tank is 316L stainless steel to ensure the safe storage of tritium under low-temperature conditions. After being purified and stored through this step, tritium can be used in fields such as industrial tracers and reference materials, and has high value.

[0097] The treated wastewater may still contain trace amounts of radioactive substances and organic pollutants. At this time, a multi-stage microporous filter membrane (pore size 0.5 microns) is used for further filtration to remove trace radioactive substances and suspended particles in the water, ensuring that the water quality cleanliness reaches the discharge standard. In addition, high-efficiency activated carbon is used to adsorb organic pollutants and residual radioactive isotopes in the wastewater. Activated carbon has a large specific surface area and strong adsorption capacity, and can effectively remove trace pollutants, ensuring that the wastewater meets the "GB 8978 - 2002" standard before discharge. Through multi-stage filtration and activated carbon adsorption technology, the pollutant concentration in the wastewater can be reduced to the specified level of the national discharge standard (tritium content < 1 Bq / L), and finally safe discharge is achieved.

[0098] The technical effects of the present invention are as follows:

[0099] Through the above detailed multi-stage treatment process, the present invention realizes the efficient separation of high-concentration tritiated water generated by high-temperature gas-cooled reactors and the recovery of tritium. The specific technical means in each link, such as mechanical filtration, chemical pretreatment, catalytic exchange in the liquid phase and gas phase, water distillation, electrolysis, and water electrolysis processes, all combine the current most advanced separation and recovery technologies to ensure the high efficiency of tritium separation, the minimization of energy consumption, and the minimization of environmental impact.

[0100] In addition, the present invention also has a flexible process design, which can adjust the process parameters of each treatment link according to the different concentrations and specific conditions of tritiated water, ensuring that the technology can meet the treatment requirements of various tritium-containing wastewaters. The final tritium gas recovery process not only improves the environmental protection of wastewater treatment, but also enables the high-value industrial recycling of tritium.

[0101] This technical solution can be widely applied to the treatment of high-concentration tritium-containing wastewater in high-temperature gas-cooled reactors and other types of nuclear power plants, with good economic and social benefits, and can significantly improve the safety and recycling rate of wastewater treatment.

[0102] Example 3

[0103] As shown in Figure 2, a high-tritium water treatment device for a high-temperature gas-cooled reactor provided by the present invention includes:

[0104] A collection and pretreatment unit for tritiated water, which removes suspended particulate matter in the tritiated water and adjusts the pH value of the water through chemical reagents;

[0105] A liquid-phase water-hydrogen isotope catalytic exchange unit, which uses a palladium-based catalyst to achieve isotope exchange of hydrogen and tritium in the pretreated tritiated water at low temperature;

[0106] A water distillation unit, which evaporates the tritiated water after liquid-phase water-hydrogen isotope catalytic exchange under vacuum and low-temperature conditions and condenses the water vapor;

[0107] A gas-phase water-hydrogen isotope catalytic exchange unit, which further separates tritium gas through high-temperature catalytic exchange in the gas phase;

[0108] An electrolysis combined with liquid-phase catalytic exchange unit, which electrolyzes and catalytically exchanges the tritiated water after gas-phase water-hydrogen isotope catalytic exchange to deeply separate tritium.

[0109] In this embodiment, it also includes: a water electrolysis and final tritium recovery unit, which condenses the deeply separated tritium gas into a liquid state and stores it.

[0110] The above has shown and described the basic principles, main features and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0111] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention fall within the protection scope of the claims of the present invention.

Claims

1. A method for treating high-tritium-containing water in a high-temperature gas-cooled reactor, characterized in that, Including: Collection and pretreatment of tritiated water, including removing suspended particulate matter in the tritiated water and adjusting the pH value of the water with chemical reagents; Liquid-phase water-hydrogen isotope catalytic exchange, using a palladium-based catalyst to achieve isotope exchange of hydrogen and tritium in the pretreated tritiated water at low temperature; Water distillation, evaporating the tritiated water after liquid-phase water-hydrogen isotope catalytic exchange and condensing the water vapor under vacuum and low temperature conditions; Gas-phase water-hydrogen isotope catalytic exchange, further separating tritium gas through high-temperature catalytic exchange in the gas phase; Electrolysis combined with liquid-phase catalytic exchange, electrolyzing and catalytically exchanging the tritiated water after gas-phase water-hydrogen isotope catalytic exchange to deeply separate tritium.

2. A method for treating high-tritium-containing water in a high-temperature gas-cooled reactor according to claim 1, characterized in that, Also including: Water electrolysis and final recovery of tritium, condensing the deeply separated tritium gas into liquid and storing it.

3. A method for treating high-tritium-containing water in a high-temperature gas-cooled reactor according to claim 1, characterized in that, In the step of collection and pretreatment of tritiated water, it includes using a mechanical filtration device to remove suspended particulate matter and adjusting the pH value of the water with chemical reagents.

4. A method for treating high-tritium-containing water in a high-temperature gas-cooled reactor according to claim 1, characterized in that, In the step of liquid-phase water-hydrogen isotope catalytic exchange, the used palladium-based catalyst is loaded in a reaction tower, the diameter of the catalyst particles is 50 microns, and the reaction temperature of the catalytic reaction tower is controlled at 25-30°C.

5. A method for treating high-tritium-containing water in a high-temperature gas-cooled reactor according to claim 1, characterized in that, The catalyst for gas-phase water-hydrogen isotope catalytic exchange is a palladium-based catalyst, and tritium gas is separated through a selective permeation membrane, and the purity of tritium gas reaches over 99%.

6. The high-tritium water treatment method for a high-temperature gas-cooled reactor according to claim 1, wherein, Electrolysis combined with liquid-phase catalytic exchange uses titanium electrodes, the electrolysis voltage is controlled at 1.8-2.2V, and the isotope exchange of hydrogen and tritium is promoted by a catalyst during the electrolysis process.

7. A method for treating high - tritium - containing water in a high - temperature gas - cooled reactor according to claim 1, characterized in that, The electrolysis voltage during electrolysis combined with liquid-phase catalytic exchange is controlled at 1.8-2.2V, and the tritium gas generated during the water electrolysis process is condensed to -5 to -10°C by a condenser.

8. A high - tritium - containing water treatment device for a high - temperature gas - cooled reactor, characterized in that, Including: Collection and pretreatment unit of tritiated water, removing suspended particulate matter in the tritiated water and adjusting the pH value of the water with chemical reagents; Liquid-phase water-hydrogen isotope catalytic exchange unit, using a palladium-based catalyst to achieve isotope exchange of hydrogen and tritium in the pretreated tritiated water at low temperature; Water distillation unit, evaporating the tritiated water after liquid-phase water-hydrogen isotope catalytic exchange and condensing the water vapor under vacuum and low temperature conditions; Gas-phase water-hydrogen isotope catalytic exchange unit, further separating tritium gas through high-temperature catalytic exchange in the gas phase; Electrolysis combined with liquid-phase catalytic exchange unit, electrolyzing and catalytically exchanging the tritiated water after gas-phase water-hydrogen isotope catalytic exchange to deeply separate tritium.

9. The high-tritium water treatment device for a high-temperature gas-cooled reactor according to claim 8, wherein Also including: Water electrolysis and final recovery unit of tritium, condensing the deeply separated tritium gas into liquid and storing it.

10. The high-tritium water treatment device for a high-temperature gas-cooled reactor according to claim 8, wherein, In the collection and pretreatment unit of tritiated water, it includes using a mechanical filtration device to remove suspended particulate matter and adjusting the pH value of the water with chemical reagents.

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