Method and system for purifying nitric oxide in radioactive waste tail gas through plasma treatment

Abstract

The invention discloses a method and system for purifying nitric oxide in radioactive waste tail gas through plasma treatment, and relates to the technical field of radioactive waste treatment. Comprising the following steps that radioactive waste is fed into a plasma melting furnace to be subjected to heat treatment to generate combustible gas; combustible gas enters the plasma combustion furnace to generate tail gas; the tail gas sequentially enters the cooling deacidification system and the cooling adsorption system; in the cooling adsorption system, nitrogen oxides in the tail gas are adsorbed and desorbed through alternate use of a first adsorption and desorption tower and a second adsorption and desorption tower, and the desorbed high-concentration nitrogen oxides are fed into a plasma combustion furnace to inhibit generation of thermal nitrogen oxides in a hearth and are reduced into nitrogen at the same time; monitoring the adsorbed tail gas, and discharging the tail gas after the tail gas is qualified; the plasma torch heat source can be inhibited from generating high-concentration nitrogen oxide, and the emission concentration of the nitrogen oxide in the tail gas is effectively reduced to the unit digit level on the basis of not generating additional radioactive secondary waste.

Description

Technical Field

[0001] The invention relates to the technical field of radioactive waste treatment, and in particular to a method and system for purifying nitrogen oxides in tail gas of radioactive waste treated by plasma. Background Art

[0002] There are certain nitrogen oxides in the tail gas generated during the plasma high-temperature melting treatment of radioactive waste. At the same time, for plasma technology that uses nitrogen or air as the working gas of the plasma torch, a large amount of nitrogen oxides will be produced in the process of igniting the plasma torch to generate heat. The produced nitrogen oxides are mixed into the tail gas of the waste treatment, which greatly increases the content of nitrogen oxides in the tail gas. Therefore, when using plasma as a heat source for thermal treatment, more nitrogen oxides will be produced from the source.

[0003] In order to remove nitrogen oxides from exhaust gas, the traditional method is to set up a denitrification device and use reducing substances such as urea or ammonia to undergo redox reactions with nitrogen oxides in exhaust gas. However, this method consumes a lot of reagents, is costly, and produces additional secondary waste. Summary of the invention

[0004] The present invention is to solve the technical problem of high nitrogen oxide content in tail gas generated in the process of treating radioactive waste by plasma technology using nitrogen or air as the working gas of the plasma torch. The purpose is to provide a method and system for purifying nitrogen oxides in tail gas of radioactive waste treated by plasma, which can inhibit the generation of high-concentration nitrogen oxides by the heat source of the plasma torch, effectively reduce the concentration of nitrogen oxide emissions in the tail gas to single-digit level without generating additional radioactive secondary waste, reduce the use of traditional denitrification equipment, and reduce the cost of treating radioactive waste with plasma technology.

[0005] The present invention is achieved through the following technical solutions:

[0006] The first object of the present invention is to provide a method for purifying nitrogen oxides in tail gas of radioactive waste by plasma treatment, comprising the following steps:

[0007] The radioactive waste is fed into a plasma melting furnace for plasma heat treatment to produce combustible gas;

[0008] The combustible gas enters the plasma combustion furnace for further processing to produce tail gas;

[0009] The tail gas enters the cooling and deacidification system and the cooling adsorption system in sequence; in the cooling adsorption system, the nitrogen oxides in the tail gas are adsorbed and desorbed by alternating the first adsorption and desorption tower and the second adsorption and desorption tower, and the desorbed high-concentration nitrogen oxides are sent to the plasma combustion furnace to suppress the generation of thermal nitrogen oxides in the furnace. At the same time, the nitrogen oxides are reduced in the reducing atmosphere of the combustible gas to react and generate nitrogen;

[0010] The tail gas after adsorption by the cooling adsorption system is monitored and discharged after passing the monitoring.

[0011] Furthermore, the tail gas enters the cooling and deacidification system, and is subjected to rapid cooling spraying, wet deacidification and cooling heat exchange in sequence.

[0012] Furthermore, both the first adsorption and desorption tower and the second adsorption and desorption tower can monitor the nitrogen oxide concentration and the system temperature. When the nitrogen oxide concentration in one of the adsorption and desorption towers exceeds 8000 mg / m 3 And / or when the temperature exceeds 10°C, the tail gas is introduced into another adsorption-desorption tower, the original adsorption tower and desorption tower are purged with air, and the cooling is stopped to slowly release the nitrogen oxides.

[0013] The second object of the present invention is to provide a plasma treatment system for purifying nitrogen oxides in tail gas of radioactive waste, which is used in a method for purifying nitrogen oxides, comprising:

[0014] The plasma melting furnace has a sealed feeding device connected to the top to perform pyrolysis and melting treatment on the fed radioactive waste;

[0015] A plasma combustion furnace connected to the combustible gas outlet of the plasma melting furnace;

[0016] A cooling and acid removal system is connected to the exhaust port of the plasma combustion furnace;

[0017] A cooling adsorption system is used to alternately adsorb and desorb nitrogen oxides in the tail gas discharged from the cooling and deacidification system. The nitrogen oxide outlet of the cooling adsorption system is connected to the air inlet of the plasma combustion furnace through a nitrogen oxide reflux pipeline; and a tail gas emission system is connected to the tail gas emission outlet of the cooling adsorption system.

[0018] Furthermore, a melting furnace plasma torch is provided at the heat source inlet of the plasma melting furnace, and a combustion furnace plasma torch is provided at the heat source inlet of the plasma combustion furnace.

[0019] Furthermore, the air inlets of the plasma melting furnace and the plasma combustion furnace are both connected to blowers.

[0020] Furthermore, the cooling and deacidification system includes a quenching tower, an alkali washing tower and a cooler which are connected in sequence.

[0021] Furthermore, the condensate outlet of the cooler is connected to the inlet of the alkali washing tower through a condensate reflux pipeline.

[0022] Furthermore, the cooling adsorption system comprises a first adsorption-desorption tower and a second adsorption-desorption tower which are arranged in parallel, and the inlets of the first adsorption-desorption tower and the second adsorption-desorption tower are both connected to the gas outlet of the cooler.

[0023] Furthermore, the exhaust gas emission system includes an induced draft fan, an exhaust gas monitoring device and a chimney, the induced draft fan is connected to the cooling adsorption system and the chimney, and the exhaust gas monitoring device is arranged on the chimney.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] 1. The present invention can achieve NO in flue gas through low-temperature physical adsorption method x Deep removal of NO x Recycling technology will NO x Do harmless treatment. NO x The NO in the original adsorption unit is completely adsorbed by the adsorbent in the adsorption tower, and then the adsorption and desorption units are switched to x Desorption release, the released high concentration of NO x Return to the plasma combustion furnace. NO x After entering the plasma combustion furnace, high concentration NO x The addition of will inhibit the thermal NO x The generation of NO x Will be restored to N 2 The process design of the present invention is simple, and the process optimization of the purification of radioactive waste tail gas by plasma treatment is realized, and the problem of high-concentration nitrogen oxides generated by the heat source of the plasma torch is solved.

[0026] 2. The present invention utilizes NO x Due to its own redox characteristics, a cooling adsorption system and a nitrogen oxide reflux pipeline are set up. Through the adsorption, desorption and recycling cycle of nitrogen oxides, the collected high-concentration nitrogen oxides are recycled to suppress the thermal NO in the furnace. x is produced and reduced to N 2 , without generating additional radioactive secondary waste, it greatly improves the quality of nitrogen oxide emissions and effectively reduces the concentration of nitrogen oxide emissions in exhaust gas to single digit levels.

[0027] 3. The present invention forms a balanced cycle of nitrogen elements from the plasma combustion furnace to the adsorption unit section in the system. The principle is simple and effective, which reduces the traditional denitration device system set up to remove nitrogen oxides, reduces the use of denitration reagents, reduces the equipment that contacts with radioactive gases, reduces the accumulation of radioactive secondary wastes, reduces the processing cost, and improves the exhaust emission quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0029] Figure 1 It is a schematic diagram of the structure of the system of the present invention.

[0030] Marks and corresponding parts names in the attached drawings:

[0031] 1-melting furnace plasma torch, 2-combustion furnace plasma torch, 3-plasma melting furnace, 4-plasma combustion furnace, 5-blower, 6-sealed feeding device, 7-quenching tower, 8-alkali washing tower, 9-cooler, 10-first adsorption and desorption tower, 11-second adsorption and desorption tower, 12-condensate reflux pipeline, 13-nitrogen oxide reflux pipeline, 14-induced draft fan, 15-exhaust gas monitoring device, 16-chimney. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the technical solutions in the embodiments of the present invention are clearly and completely described below in combination with the embodiments and drawings. Obviously, the schematic implementation modes of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0033] The following is a detailed description of an embodiment of a plasma treatment method and system for purifying nitrogen oxides in radioactive waste tail gas according to the present invention with reference to the accompanying drawings as appropriate. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions and repeated descriptions of well-known matters are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art.

[0034] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0035] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0036] Unless otherwise specified, the terms "include" and "comprising" mentioned in this application may be open-ended or closed-ended. For example, the terms "include" and "comprising" may mean that other substances not listed may also be included or only the listed substances may be included.

[0037] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0038] The technical solution of the present invention is further described in detail below in conjunction with the embodiments. Take the plasma technology using nitrogen as the working gas of the plasma torch to treat radioactive waste from a nuclear power plant as an example.

[0039] Example 1

[0040] A method for purifying nitrogen oxides in tail gas of radioactive waste by plasma treatment, comprising the following steps:

[0041] (1) Radioactive waste is fed into the plasma melting furnace 3 through the sealed feeding device 6. The plasma torch 1 of the melting furnace is energized and discharged to generate a plasma torch flame. The radioactive waste containing organic components generates small molecular combustible gas during the plasma heat treatment process.

[0042] (2) The combustible gas enters the plasma combustion furnace 4 for further processing to produce tail gas.

[0043] During the treatment process, the furnaces of the plasma melting furnace 3 and the plasma combustion furnace 4 are in a slightly negative pressure environment, and the entire system is maintained in a negative pressure state through exhaust by the induced draft fan 14 to ensure that radioactive gases do not escape.

[0044] During the treatment process, there is a small amount of oxygen in the flames of the melting furnace plasma torch 1 and the combustion furnace plasma torch 2. Under the high temperature environment provided by the torch, oxygen and nitrogen produce thermal nitrogen oxides. These nitrogen oxides enter the plasma combustion furnace 4 together with the combustible gas produced by the pyrolysis and gasification of radioactive waste, or are directly produced at the flame of the combustion furnace plasma torch 2 in the plasma combustion furnace 4.

[0045] (3) The tail gas enters the cooling and deacidification system.

[0046] In the tail gas treatment system, the tail gas is firstly sprayed with quenching tower 7 to reduce the tail gas temperature to less than 200°C. The tail gas after cooling needs to be deacidified. After wet deacidification in alkali washing tower 8, the tail gas is further cooled. The saturated water vapor in the tail gas is removed through indirect cooling and heat exchange of cooler 9. At the same time, the condensed water condensed in cooler 9 will flow back to alkali washing tower 8 to participate in the alkali washing cycle and ensure that the equipment temperature in alkali washing tower 8 is kept at a low level. The relatively dry low-temperature tail gas after cooler 9 enters the cooling adsorption system again.

[0047] (4) The exhaust gas after cooling and deacidification enters the cooling adsorption system.

[0048] There is a low-temperature adsorption material in the cooling adsorption system, which adsorbs and removes nitrogen oxides. The exhaust gas passing through the cooling adsorption system can have acid gas content and nitrogen oxide gas content of only single digits, allowing safe discharge.

[0049] It should be noted that the present invention does not limit the low-temperature adsorption material, and can be a material that absorbs NO at low temperature. x Any adsorbent material with adsorption effect, for example, can be low-temperature activated carbon material, can also be molecular sieve material. When molecular sieve is used as adsorbent material, the amount used is 87g, and the total adsorption of NO x 12.2g, desorbed naturally for 12 hours without heating, the adsorbent material showed strong adsorption performance for high concentration nitrogen oxides at low temperature, and the adsorption capacity was as high as 3000mg / m 3 The penetration time of nitrogen oxides from 0 to 1 in flue gas is as long as 36 hours. The adsorbent material is heated in an air atmosphere at 300 and 500°C with stable performance. When heated in an air atmosphere at 1000°C for 2 hours, only the surface of individual particles melts.

[0050] In the cooling adsorption system, the nitrogen oxides in the exhaust gas are adsorbed and desorbed by alternating the first adsorption desorption tower 10 and the second adsorption desorption tower 11. The desorbed high-concentration nitrogen oxides are sent to the plasma combustion furnace 4 to suppress the generation of thermal nitrogen oxides in the furnace. At the same time, the nitrogen oxides are reduced in the reducing atmosphere of the combustible gas to react and generate nitrogen.

[0051] The high-concentration nitrogen oxides produced by desorption are sent into the plasma combustion furnace 4 through the nitrogen oxide reflux pipeline 13 to participate in the redox reaction in the combustion chamber. In the plasma combustion furnace 4, the small molecules of the combustible gas react with oxygen to generate carbon dioxide and water vapor, and the nitrogen oxides are reduced in the reducing atmosphere of the small molecules of the combustible gas to generate nitrogen. The gas that has fully reacted in the combustion chamber enters the exhaust gas purification system again, and is subjected to cooling, deacidification and cooling adsorption in turn.

[0052] By continuously feeding the desorbed high-concentration nitrogen oxides into the plasma combustion furnace 4, the generation of thermal nitrogen oxides in the furnace can be suppressed. At the same time, the nitrogen oxides are reduced to generate nitrogen in the reducing atmosphere of the combustible gas, forming a nitrogen oxide cycle balance.

[0053] Specifically, both the first adsorption and desorption tower 10 and the second adsorption and desorption tower 11 can monitor the nitrogen oxide concentration and the system temperature. For example, when the nitrogen oxide concentration in the first adsorption and desorption tower 10 exceeds 8000 mg / m 3 When the temperature exceeds 10°C, the system switching device is turned on to introduce the tail gas into the second adsorption and desorption tower 11, the first adsorption and desorption tower is purged with air, and the temperature is stopped to slowly release the nitrogen oxides and introduce them into the front plasma combustion furnace 4 together with the purging air. The first adsorption and desorption tower 10 and the second adsorption and desorption tower 11 are used alternately, and the adsorption and desorption functions are performed alternately.

[0054] (4) The exhaust gas adsorbed by the cooling adsorption system is introduced into the chimney 16 through the induced draft fan 14 and monitored. After being qualified, it is discharged.

[0055] The present invention can realize NO in flue gas through low temperature physical adsorption method. x Deep removal of NO x Recycling technology will NO x Do harmless treatment. NO x The NO in the original adsorption unit is completely adsorbed by the adsorbent in the adsorption tower, and then the adsorption and desorption units are switched to x Desorption release, the released high concentration of NO x Sent back to the plasma combustion furnace 4. NO x After entering the plasma combustion furnace 4, high concentration NO x The addition of will inhibit the thermal NO x The generation of NO x Will be restored to N 2 Therefore, after the circulation operation, the original NO x 、N 2 , and the NO of recycling x A new chemical equilibrium state will be reached. It will enter the tail gas treatment system through the combustion furnace outlet for circulation. During this process, the nitrogen oxides in the flue gas after adsorption will achieve extremely low emissions. The balanced nitrogen oxides flow will circulate in the front section and participate in the redox reaction.

[0056] The process design of the present invention is simple, realizes the process optimization of purification of tail gas of radioactive waste treated by plasma, and solves the problem of high-concentration nitrogen oxides generated by the heat source of the plasma torch.

[0057] It should be noted that during the process of treating low-level radioactive technical waste from nuclear power plants using plasma technology, corresponding radiation shielding and protection measures are installed at the external interfaces of the corresponding devices.

[0058] Example 2

[0059] A plasma treatment system for purifying nitrogen oxides in tail gas of radioactive waste is used in the nitrogen oxide purification method described in Example 1, comprising a plasma melting furnace 3, a plasma combustion furnace 4, a cooling and deacidification system, a cooling adsorption system and a tail gas emission system.

[0060] The top of the plasma melting furnace 3 is connected to a sealed feeding device 6 for pyrolysis and melting of the fed radioactive waste. A melting furnace plasma torch 1 is provided at the heat source inlet of the plasma melting furnace 3 , and the air inlet of the plasma melting furnace 3 is connected to a blower 5 .

[0061] The plasma combustion furnace 4 is connected to the combustible gas outlet of the plasma melting furnace 3 , a combustion furnace plasma torch 2 is provided at the heat source inlet of the plasma combustion furnace 4 , and an air inlet of the plasma combustion furnace 4 is connected to the air blower 5 .

[0062] The cooling and deacidification system is connected to the exhaust port of the plasma combustion furnace 4; specifically, the cooling and deacidification system includes a quenching tower 7, an alkali washing tower 8 and a cooler 9 which are connected in sequence, the inlet of the quenching tower 7 is connected to the exhaust port of the plasma combustion furnace 4, the outlet of the quenching tower 7 is connected to the gas inlet of the alkali washing tower 8, the gas outlet of the alkali washing tower 8 is connected to the gas inlet of the cooler 9, the gas outlet of the cooler 9 is connected to the inlet of the cooling adsorption system, and the condensate outlet of the cooler 9 is connected to the liquid inlet of the alkali washing tower 8 through the condensate reflux pipeline 12.

[0063] The cooling adsorption system comprises a first adsorption and desorption tower 10 and a second adsorption and desorption tower 11 arranged in parallel, and the inlets of the first adsorption and desorption tower 10 and the second adsorption and desorption tower 11 are both connected to the gas outlet of the cooler 9. In the cooling adsorption system, the nitrogen oxides in the tail gas discharged from the cooling and deacidification system are alternately adsorbed and desorbed, and the nitrogen oxide outlet of the cooling adsorption system is connected to the air inlet of the plasma combustion furnace 4 through the nitrogen oxide reflux pipeline 13.

[0064] The exhaust gas emission system includes an induced draft fan 14, an exhaust gas monitoring device 15 and a chimney 16. The induced draft fan 14 connects the exhaust gas emission port of the cooling adsorption system with the inlet of the chimney 16. The exhaust gas monitoring device 15 is arranged on the chimney 16 to detect the exhaust gas components.

[0065] In the nitrogen oxide purification system of the present invention, low-level radioactive waste enters the plasma melting furnace 3 from the top of the plasma melting furnace 3 through a feeding device. During the process of feeding into the plasma melting furnace 3, the radioactive waste with organic components forms small molecular combustible gas during the plasma heat treatment process and enters the plasma combustion furnace 4. During the treatment process, the plasma melting furnace 3 and the plasma combustion furnace 4 are both in a slightly negative pressure environment. The entire system is maintained in a negative pressure state through exhaust by the induced draft fan 14 to ensure that the radioactive gas does not escape.

[0066] The present invention utilizes NO x Due to its own redox characteristics, a cooling adsorption system and a nitrogen oxide reflux pipeline 13 are set up. Through the adsorption, desorption and reuse cycle of nitrogen oxides, the quality of nitrogen oxide emissions is greatly improved without generating additional radioactive secondary waste, and the concentration of nitrogen oxide emissions in the exhaust gas is effectively reduced to single-digit levels.

[0067] The present invention forms a balanced cycle of nitrogen elements from the plasma combustion furnace 4 to the adsorption unit section in the system. The principle is simple and effective, reducing the number of traditional denitration device systems set up to remove nitrogen oxides, reducing the use of denitration reagents, reducing equipment that contacts with radioactive gases, reducing the accumulation of radioactive secondary wastes, reducing treatment costs, and improving the quality of tail gas emissions.

[0068] Finally, it should be noted that the above specific embodiments are only used to explain in detail the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific implementation method of the present invention and is not used to limit the protection scope of the present invention. Although the present invention is described in detail with reference to the above specific embodiments, ordinary technicians in this field should understand that it is still possible to modify the technical solutions recorded in the above embodiments, or to replace or improve some or all of the technical features therein. These modifications, equivalent replacements and improvements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for purifying nitrogen oxides in tail gas of radioactive waste by plasma treatment, characterized in that: The following steps are involved: The radioactive waste is fed into a plasma melting furnace (3) to undergo plasma heat treatment to generate combustible gas; The combustible gas enters the plasma combustion furnace (4) for further processing to produce tail gas; The tail gas enters the cooling and deacidification system and the cooling adsorption system in sequence; in the cooling adsorption system, the nitrogen oxides in the tail gas are adsorbed and desorbed by alternately using the first adsorption and desorption tower (10) and the second adsorption and desorption tower (11); the desorbed high-concentration nitrogen oxides are sent to the plasma combustion furnace (4) to suppress the generation of thermal nitrogen oxides in the furnace; at the same time, the nitrogen oxides are reduced in the reducing atmosphere of the combustible gas to react and generate nitrogen; The tail gas after adsorption by the cooling adsorption system is monitored and discharged after passing the monitoring.

2. The method for purifying nitrogen oxides in tail gas of radioactive waste by plasma treatment according to claim 1, characterized in that: The tail gas enters the cooling and deacidification system, and undergoes rapid cooling spraying, wet deacidification and cooling heat exchange in sequence.

3. The method for purifying nitrogen oxides in tail gas of radioactive waste by plasma treatment according to claim 1, characterized in that: The first adsorption desorption tower (10) and the second adsorption desorption tower (11) can monitor the nitrogen oxide concentration and the system temperature. When the nitrogen oxide concentration in one of the adsorption desorption towers exceeds 8000 mg / m 3 When the temperature exceeds 10°C, the tail gas is introduced into another adsorption-desorption tower, and the original adsorption-desorption tower is purged with air to slowly release the nitrogen oxides.

4. A plasma treatment system for purifying nitrogen oxides in tail gas of radioactive waste, used in the purification method according to any one of claims 1 to 3, characterized in that: include: The plasma melting furnace (3) is connected to a sealed feeding device (6) at the top to perform pyrolysis and melting treatment on the fed radioactive waste; A plasma combustion furnace (4) connected to the combustible gas outlet of the plasma melting furnace (3); A cooling and deacidification system connected to the exhaust port of the plasma combustion furnace (4); A cooling adsorption system is used to alternately adsorb and desorb nitrogen oxides in the tail gas discharged from the cooling and deacidification system. The nitrogen oxide outlet of the cooling adsorption system is connected to the air inlet of the plasma combustion furnace (4) through a nitrogen oxide reflux pipeline (13); and the tail gas discharge port of the cooling adsorption system is connected to the tail gas discharge system.

5. A plasma treatment system for purifying nitrogen oxides in tail gas of radioactive waste according to claim 4, characterized in that: The heat source inlet of the plasma melting furnace (3) is provided with a melting furnace plasma torch (1), and the heat source inlet of the plasma combustion furnace (4) is provided with a combustion furnace plasma torch (2).

6. A plasma treatment system for purifying nitrogen oxides in tail gas of radioactive waste according to claim 4, characterized in that: Air inlets of the plasma melting furnace (3) and the plasma combustion furnace (4) are both connected to air blowers (5).

7. A plasma treatment system for purifying nitrogen oxides in tail gas of radioactive waste according to claim 4, characterized in that: The cooling and deacidification system comprises a quenching tower (7), an alkali washing tower (8) and a cooler (9) which are connected in sequence.

8. A plasma treatment system for purifying nitrogen oxides in tail gas of radioactive waste according to claim 7, characterized in that: The condensate outlet of the cooler (9) is connected to the inlet of the alkali washing tower (8) via a condensate reflux pipeline (12).

9. A plasma treatment system for purifying nitrogen oxides in tail gas of radioactive waste according to claim 7, characterized in that: The cooling adsorption system comprises a first adsorption-desorption tower (10) and a second adsorption-desorption tower (11) which are arranged in parallel, and the inlets of the first adsorption-desorption tower (10) and the second adsorption-desorption tower (11) are both connected to the gas outlet of the cooler (9).

10. A plasma treatment system for purifying nitrogen oxides in tail gas from radioactive waste according to any one of claims 4 to 9, characterized in that: The exhaust gas emission system comprises an induced draft fan (14), an exhaust gas monitoring device (15) and a chimney (16); the induced draft fan (14) is connected to the cooling adsorption system and the chimney (16); and the exhaust gas monitoring device (15) is arranged on the chimney (16).

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