Compatibility system for treating radioactive waste and treatment device and method

Abstract

The invention discloses a compatibility system for treating radioactive waste and a treatment device and method, and relates to the technical field of radioactive waste treatment devices.The compatibility system comprises a temporary storage room, a database management system, a sorting system, a crushing system and a packaging system; the temporary storage room is used for carrying out physical property identification and radioactivity identification on the waste; the basic data recognized by the temporary storage room enters a database management system, and a first compatibility scheme conforming to the basic data is called out from a database; performing primary selection in a sorting system according to the first compatibility scheme; self-adaptive adjustment is carried out according to the working condition in the furnace, and a second compatibility scheme is formed; a third compatibility scheme is formed according to the working condition of the tail gas, so that the conventional pollutant emission of the system reaches the standard; self-adaptive adjustment is carried out according to the radioactive emission working condition, and a fourth compatibility scheme is formed; after the compatibility is completed, entering a crushing system; and feeding into a packaging system after crushing. The radioactive waste treatment efficiency is improved, and the system safety and radioactive risks are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive waste treatment devices, and in particular to a radioactive waste treatment system, a treatment device and a method. Background Art

[0002] With the continuous development of nuclear power in my country, the total amount of radioactive waste generated by the operation and decommissioning of nuclear power plants in the future will continue to increase. The research and development of high-volume reduction and volume reduction treatment technologies for nuclear waste has become one of the main driving forces and challenges for nuclear safety. Compared with the incineration of conventional civilian household garbage or hazardous waste, the pyrolysis and gasification treatment of radioactive waste pays more attention to the interception of radioactive nuclides, the radiation safety of the incineration process, and the overall volume reduction effect of the waste. Compared with traditional treatment technologies, plasma incineration volume reduction and solidification technology has the advantages of a wide range of applications, fast reaction speed, low secondary pollution, small tail gas volume, and compact equipment. It can realize the decomposition and gasification combustion of radioactive waste, high-temperature melting of inorganic waste, and solidification of radioactive nuclides in one system, greatly reducing the volume of waste and obtaining a stable final waste body.

[0003] However, due to the high temperature and high enthalpy characteristics of plasma itself, the nitrogen oxides produced in the process of treating radioactive waste are very high (2000-4000 mg / m 3 ), so it will have a certain impact on environmental emissions.

[0004] In addition, the radioactive waste being treated contains a large amount of volatile radioactive nuclides, including Cs-137, I-131, etc. After these nuclides enter the furnace during the pre-treatment process, they will quickly evaporate into the flue gas during the pyrolysis and gasification process. The total amount of radioactive nuclides in the flue gas finally discharged from the chimney is subject to relevant requirements and must not exceed the standard. Therefore, it is necessary to adsorb the nuclides in the flue gas to control the total amount.

[0005] In terms of plasma gasification volume reduction and solidification technology, waste pretreatment and compatibility are key links. Compatibility refers to the process of analyzing the physical and chemical properties of various types of radioactive wastes with complex components and various forms collected, forming a waste matching plan based on the analysis results, and pre-disposing the materials in accordance with the plan in order to achieve the purpose of stable, controllable, uniform and balanced combustion of the waste components before entering the plasma furnace. Reasonable matching operation can stabilize combustion and promote the decomposition of harmful substances. At the same time, it can also save combustion-supporting fuel, protect refractory materials, extend the service life of incineration equipment, and reduce operating costs. For radioactive waste, more attention should be paid to the radiation dose index and type of nuclides contained in the waste to avoid the risk of radioactive enrichment. However, there is currently no relevant literature disclosing the matching system before radioactive waste treatment, which makes the treatment efficiency of radioactive waste low and poses great safety and radioactive risks. Summary of the invention

[0006] Based on the problems pointed out in the background technology that the current radioactive waste treatment efficiency is low and there are great safety risks and radioactive risks, the purpose of the present invention is to provide a compatibility system, a treatment device and a method for treating radioactive waste. The compatibility system performs effective measurement, monitoring and intelligent management among the radioactive waste temporarily stored in the warehouse, the pretreatment system, the plasma furnace system and the exhaust gas system, thereby improving the treatment efficiency of radioactive waste, reducing system safety and radioactive risks, and ultimately achieving the purpose of reducing the volume of radioactive waste and meeting radioactive emission standards.

[0007] The present invention is achieved through the following technical solutions:

[0008] In a first aspect, the present application provides a compatibility system for treating radioactive waste, including a temporary storage room, a database management system, a sorting system, a crushing system, and a packaging system;

[0009] The temporary storage room is used to identify the physical properties and radioactivity of the waste; the basic data after identification in the temporary storage room enters the database management system, and the first matching scheme that conforms to it is called out from the database; preliminary selection is carried out in the sorting system according to the first matching scheme; then according to the working conditions in the furnace, adaptive adjustment is made to form a second matching scheme that conforms to it; then according to the exhaust working conditions, a third matching scheme that conforms to it is formed to make the system conventional pollutant emissions meet the standards; then according to the radioactive emission working conditions, adaptive adjustment is made to form a fourth matching scheme that conforms to it; the materials after matching are entered into the crushing system; the crushed materials enter the packaging system.

[0010] Among them, the contents of physical property identification and radioactive identification in the temporary storage room mainly include: physical properties, industrial analysis, elemental analysis, harmful substance content, characteristic identification, reactivity, compatibility, water stability and radioactive analysis.

[0011] Among them, physical properties include: physical composition, bulk density, and particle size.

[0012] Among them, industrial analysis includes: fixed carbon, ash, volatile matter, moisture, ash melting point, and lower calorific value.

[0013] Among them, elemental analysis and harmful substance content, such as S, Cl, F, Br, I, P, Hg and alkali metals.

[0014] Among them, characteristic identification, such as corrosiveness, leaching toxicity, acute toxicity, flammability and explosiveness.

[0015] Radioactivity analysis includes: nuclide type analysis, such as Cs-137, Cs-134, Te-131, Zr-95, Sr-90, Co-60, Co-58, Mn-54, Ag-110m, Sb-124, I-131, I-132, and a small amount of Am-241, Pu-239, U-235, U-238. It also includes nuclide radioactivity graded analysis.

[0016] Taking Co-60 as an example, it is divided into two levels according to its radioactivity level:

[0017] Level I (low-level waste): specific activity less than or equal to 4×106Bq / kg.

[0018] Level II (intermediate level waste): specific activity greater than 4×106Bq / kg.

[0019] Among them, in the crushing system, most of the organic matter is crushed into centimeter-level fine materials.

[0020] Among them, the packaging system packs the crushed materials into bags, and the weight of each bag is controlled at about 500-1000g.

[0021] In a second aspect, the present application provides a treatment device for treating radioactive waste, comprising the above-mentioned compatibility system, and also comprising a plasma furnace and a secondary combustion chamber that are interconnected, wherein the rear end of the smoke exhaust port of the secondary combustion chamber is sequentially connected to a denitrification device, a heat exchanger, a quenching tower, a bag filter, a primary washing tower, and a secondary washing tower, and the rear end of the secondary washing tower is connected to a low-temperature deep-cold removal system;

[0022] The low-temperature deep-cold removal system includes a flue gas cooler, a gas-liquid separator, an adsorber, an electric heater, and an induced draft fan which are interconnected, and the flue gas cooler is connected to the secondary scrubbing tower;

[0023] The adsorber includes a No. 1 adsorber and a No. 2 adsorber connected in parallel, and the No. 1 adsorber and the No. 2 adsorber are both connected with a return furnace pipe, and the return furnace pipe has two branch pipes, and the two branch pipes are respectively connected to the annular air inlet of the plasma furnace body and the annular air inlet of the second combustion chamber.

[0024] Furthermore, the plasma furnace includes a vertical section and a horizontal section, arranged in an L shape; a No. 1 plasma torch is arranged directly above the horizontal section of the plasma furnace; a glass liquid overflow port is arranged above the side of the horizontal section of the plasma furnace, and a metal liquid drain port is arranged below.

[0025] Furthermore, after the material enters the vertical section of the plasma furnace from the feed port of the plasma furnace, a gasification and pyrolysis layer is formed, and an annular air inlet is arranged on the plasma furnace at the gasification and pyrolysis layer.

[0026] Furthermore, the plasma furnace uses high temperature resistant, corrosion resistant and refractory materials as the internal working layer.

[0027] Furthermore, an inclined section is provided on the right side of the furnace bottom of the plasma furnace.

[0028] Furthermore, a No. 1 plasma torch is arranged on the top of the secondary combustion chamber.

[0029] Furthermore, the bag dust collector adopts a redundant configuration, including a No. 1 bag dust collector and a No. 2 bag dust collector.

[0030] Furthermore, the plasma furnace body and the secondary combustion chamber are provided with a plurality of annular air inlets.

[0031] In a third aspect, the present application provides a method for treating radioactive waste, comprising the following steps:

[0032] The radioactive waste treated by the compatibility system is added into the plasma furnace to form a gasification and pyrolysis layer. In the gasification and pyrolysis layer, the organic matter is gasified and pyrolyzed into synthesis gas, and then this part of the gas is discharged from the plasma furnace exhaust pipe into the secondary combustion chamber;

[0033] After the flue gas is burned in the secondary combustion chamber, it is discharged from the secondary combustion chamber and enters the denitration device for denitration. After denitration, the flue gas enters the heat exchanger for cooling, and then enters the quenching tower for cooling. After quenching, the flue gas enters the bag filter for dust removal, and then enters the secondary washing tower, where alkali solution is sprayed for deacidification.

[0034] The flue gas after washing enters the cooler of the low-temperature deep-cold removal system for cooling, and then enters the gas-liquid separator to separate the water vapor generated in the washing tower to ensure that dry flue gas is generated;

[0035] After gas-liquid separation, the gas enters the adsorber for adsorption treatment. The exhaust gas NO x The concentration was kept below 1mg / Nm 3 , SO2 concentration is kept below 3mg / Nm 3 .

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] (1) The compatibility system of the present invention performs effective measurement, monitoring and intelligent management among radioactive waste temporarily stored in the warehouse, the pretreatment system, the plasma furnace system and the tail gas system, thereby improving the processing efficiency, reducing the system safety and radioactive risks, and ultimately achieving the effect of reducing the volume of radioactive waste and meeting the radioactive emission standards. A database is established for the current radioactive waste management, and programmed and data-based overall management is carried out.

[0038] (2) The present invention optimizes the compatibility scheme step by step through a database system and performs intelligent management, ultimately meeting the requirements of various subsystems such as a plasma furnace, an exhaust system, and a radioactive system, thereby meeting the requirements of the entire process.

[0039] (3) The present invention uses cloud computing to collect data from different nuclear power plants on a cloud server for comparison and optimization, and can perform remote online monitoring and cloud optimization functions for the compatibility system of the present invention.

[0040] (4) The compatibility system of the present invention can effectively ensure the stability of the system during the plasma technology treatment of radioactive waste, the conventional tail gas emission system meets the requirements of the national standard GB18484, the radioactive emission meets the standard, and the comprehensive volume reduction ratio of radioactive waste is less than 20.

[0041] (5) The plasma treatment device of the present invention adds a low-temperature deep-cold removal system to the tail gas treatment system to absorb high-concentration NO x After that, it returns to the plasma furnace and the secondary combustion chamber for reduction treatment, so as to ensure that the flue gas discharged from the chimney can reach near-zero emission, solving the problem of high nitrogen oxides and failure to achieve near-zero emission in the past. At the same time, the selection of suitable adsorption materials can strongly adsorb radionuclides, reduce the total radiation dose in the flue gas, and thus make the radioactive emission meet the standard.

[0042] (6) The low-temperature deep-cold removal system of the plasma treatment device of the present invention reduces the flue gas temperature to below 0°C, the SO2 adsorption capacity increases exponentially, and the NO adsorption capacity increases exponentially. Low-temperature catalytic oxidation is the key mechanism to promote the substantial increase in NO adsorption capacity. In this way, the high-concentration flue gas coming out of the plasma furnace can be recycled through the process of low-temperature adsorption-heating desorption-return to the furnace, thereby reducing the concentration of nitrogen oxides emitted from the final chimney and solving some inherent problems of the plasma furnace.

[0043] (7) The low-temperature deep-cold removal system of the present invention can simultaneously remove pollutants such as SO2, HCl, and HF while treating nitrogen oxides; thus, the goal of "integrated removal" of pollutants can be achieved.

[0044] (8) The adsorption material of the present invention can strongly adsorb Cs-137, I-131, etc., reducing the total radiation dose in the flue gas, thereby ensuring that the radioactive emissions meet the standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] 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:

[0046] Figure 1 A treatment process flow chart of a compatibility system for treating radioactive waste in the present invention;

[0047] Figure 2 It is a schematic structural diagram of a plasma treatment device for radioactive waste in the present invention;

[0048] Figure 3 It is a schematic diagram of the structure of the plasma furnace in the present invention;

[0049] Figure 4 It is a structural schematic diagram of the secondary combustion chamber in the present invention;

[0050] Figure 5 It is a schematic diagram of the structure of the low-temperature deep-cold removal system of the present invention.

[0051] Reference numerals:

[0052] 1-plasma furnace, 2-feeding port, 3-refractory material, 4-plasma furnace exhaust pipe, 5-1-No. 1 plasma torch, 5-2-No. 1 plasma torch, 6-overflow outlet sealing chamber, 7-receiving hopper car, 8-1-right annular air inlet, 8-2-left annular air inlet, 9-gasification pyrolysis layer, 10-glass liquid layer, 11-metal liquid layer, 12-metal liquid emptying port, 13-glass liquid overflow port, 14-second combustion chamber ash discharge port, 15-second combustion chamber exhaust port, 16-1-No. 1 second combustion chamber horizontal annular air inlet, 16-2-No. 2 second combustion chamber horizontal annular air inlet , 17-secondary combustion chamber, 18-1-middle annular air inlet of No. 1 secondary combustion chamber, 18-2-middle annular air inlet of No. 2 secondary combustion chamber, 19-induced draft fan, 20-denitrification device, 21-heat exchanger, 22-quenching tower, 23-1-No. 1 bag dust collector, 23-2-No. 1 bag dust collector, 24-first-stage washing tower, 25-second-stage washing tower, 26-flue gas cooler, 27-gas-liquid separator, 28-1-No. 1 adsorber, 28-2-No. 2 adsorber, 29-electric heater, 30-temporary storage room, 31-sorting system, 32-crushing system, 33-packing system. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0054] The following detailed description specifically discloses the implementation methods of the compatibility system, treatment device and method for treating radioactive waste of the present application with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0055] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range.

[0056] In addition, the terms "number one" and "number two" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "number one" and "number two" may explicitly or implicitly include at least one of the features.

[0057] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0058] 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.

[0059] 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.

[0060] Example 1

[0061] like Figure 1 As shown, this embodiment provides a compatibility system for treating radioactive waste, including a temporary storage room 30, a database management system, a sorting system 31, a crushing system 32, and a packaging system 33;

[0062] The temporary storage room 30 is used to identify the physical properties and radioactivity of the waste; the basic data after identification in the temporary storage room 30 enters the database management system, and the first matching scheme that conforms to it is called out from the database; preliminary selection is carried out in the sorting system 31 according to the first matching scheme; then, according to the working conditions in the furnace, adaptive adjustment is made to form a second matching scheme that conforms to it; then, according to the exhaust gas working conditions, a third matching scheme that conforms to it is formed to make the conventional pollutant emissions of the system meet the standards; then, according to the radioactive emission working conditions, adaptive adjustment is made to form a fourth matching scheme that conforms to it; the materials after matching are entered into the crushing system 32; the crushed materials enter the packaging system 33.

[0063] The specific processing steps are as follows:

[0064] Step 1: Radioactive waste enters the temporary storage room, where physical and radioactive identification is performed on the waste, and basic data is entered into the database management system.

[0065] Specifically including the following: physical properties, industrial analysis, elemental analysis and harmful substance content, characteristic identification, reactivity, compatibility, stability with water and radioactivity analysis, etc.;

[0066] The physical properties include: physical composition, bulk density, and particle size;

[0067] Industrial analysis includes: fixed carbon, ash, volatile matter, moisture, ash melting point, lower heating value; elemental analysis and harmful substance content (such as S, Cl, F, Br, I, P, Hg and alkali metals, etc.); characteristic identification (corrosiveness, leaching toxicity, acute toxicity, flammability and explosiveness); reactivity; compatibility and stability with water.

[0068] Radioactive analysis includes: nuclide type analysis (Cs-137, Cs-134, Te-131, Zr-95, Sr-90, Co-60, Co-58, Mn-54, Ag-110m, Sb-124, I-131, I-132, and a small amount of Am-241, Pu-239, U-235, U-238), and nuclide radioactivity graded analysis;

[0069] Taking Cs-134 as an example, it is divided into three levels according to its radioactive specific activity level.

[0070] Level I (low-level waste): specific activity less than or equal to 4×106Bq / kg.

[0071] Level II (intermediate level waste): specific activity greater than 4×106Bq / kg and less than or equal to 4×1011Bq / kg, and heat release rate less than or equal to 2kW / m3.

[0072] Level III (high-level waste): heat release rate greater than 2kW / m3, or specific activity greater than 4×1011Bq / kg;

[0073] After all the above physical property identification and radioactivity identification are completed, the basic data will be entered into the database management system respectively.

[0074] Step 2: The compatibility system will retrieve the first matching scheme that meets these conditions from the historical database, and conduct a preliminary selection of radioactive waste exclusion based on the scheme.

[0075] 1. Materials with high water content (over 30%) and high metal content (over 20%) will be manually sorted out through the glove box and will not enter the incineration process. They will be re-pretreated and will only be considered for entry into this process after meeting the treatment requirements.

[0076] 2. For radioactive wastes with specific activity exceeding the medium-level standard, they will be sorted by robots and will not enter the incineration process, but will be directly disposed of in the cement solidification line. This process basically does not handle radioactive wastes above the medium-level standard.

[0077] 3. Wastes with Cl content exceeding 10% and alkali metal content exceeding 40% will be sorted by robots and will not enter the incineration process but will be disposed of separately in the cement curing line.

[0078] Step 3: According to the working conditions in the furnace, the matching system performs adaptive adjustment to form a second matching plan that meets the conditions.

[0079] 1. To ensure the stability of calorific value, the plasma furnace entry standard is >3500kcal / kg.

[0080] 2. According to the incineration requirements in the furnace, that is, the combustion rate of the incineration system is greater than 99.9%, and the thermal reduction rate of the incineration residue is less than 5%, the proportion of volatile matter, fixed carbon and ash in the source item is appropriately adjusted to meet the incineration requirements.

[0081] 3. According to the vitreous test data, including vitreous compressive strength>60Mpa; radionuclide leaching rate<1g / (m2·d), the content of silicon, calcium and aluminum in the vitreous in the furnace source item is controlled.

[0082] By selecting the second matching scheme mentioned above, the operating conditions of the plasma furnace can be met.

[0083] Step 4: According to the exhaust gas operating conditions (emissions of pollutants such as dioxins, nitrogen oxides, and dust), a third matching scheme that meets the conditions is formed to ensure that the system's conventional pollutant emissions meet the standards.

[0084] 1. According to the measured values ​​of NOx, SOx, HF and HCl in CEMS, feedback is provided to adjust the relevant proportions of Cl, F and S in the source items.

[0085] 2. According to the content of heavy metals and alkali metals (Hg, K, Na, Ca) in the washing waste liquid, feedback is used to adjust the relevant proportions of heavy metals and alkali metals in the source items.

[0086] 3. According to the feedback value of the dioxin detection equipment, determine whether it exceeds the standard, so as to adjust the Cl content in the source item to adapt to the final dioxin emission.

[0087] 4. Control the proportion of fly ash collected by the bag to not exceed 3%. If it exceeds this value, the database system will feed back to the pre-treatment link to reduce the proportion of ash and control the plasma furnace parameters (temperature, oxygen content, etc.) to improve the burnout rate.

[0088] According to the above principles, a third matching scheme can be formed to ensure that the system's conventional pollutant emissions meet the standards.

[0089] Step 5: The matching system performs adaptive adjustment according to the radioactive emission conditions (nuclide types and radiation doses) to form a fourth matching scheme that meets the conditions, so that the system's radioactive emissions meet the standards.

[0090] 1. Use radioactive detection equipment to detect whether the content of volatile nuclides such as Cs-134 and Sr-90 exceeds the set value. If there is a deviation, feedback is provided to adjust the relevant proportion of volatile nuclides in the source item.

[0091] 2. Measure the nuclides in bag fly ash and vitreous body, and detect whether the content of volatile nuclides such as Cs-134 and Sr-90 is less than the set value. If there is a deviation, feedback is provided to adjust the relevant proportion of volatile nuclides in the source item.

[0092] Step 6: Optimized application of cloud computing technology.

[0093] Based on cloud computing technology, the hazardous waste disposal centers of different nuclear power units are used as nodes to collect data in real time and upload it to the system cloud server. The data is backed up in a remote database to ensure data security. The in / out and processing flow of radioactive waste from nuclear power plants can be traced through the network, and real-time monitoring can be carried out to find the source of the problem. At the same time, waste data of different types and regions (including operation and warehouse storage data) are continuously added to the database in the form of successful matching solutions to improve system performance.

[0094] After system optimization through cloud computing technology, the output result of this intelligent compatibility database is finally obtained and passed to the process system for execution, and this process is completed.

[0095] Through the above-mentioned matching system, it can be effectively ensured that the system is stable during the plasma technology treatment of radioactive waste, the conventional exhaust emission system meets the requirements of the national standard GB18484, the radioactive emissions meet the standards, and the comprehensive volume reduction ratio of radioactive waste is not less than 20.

[0096] The following is an application example using the compatibility system in Example 1.

[0097] The temporary storage room received a batch of radioactive waste, including miscellaneous dry waste (fly ash, inorganic salts, PVC, rubber, cotton, PE, protective clothing, etc.), concentrate, oil-containing adsorbent materials, etc. The types are relatively complex and the components vary greatly. The steps of the present invention are as follows:

[0098] Step 1: Radioactive waste enters the temporary storage room, and the basic database for physical property identification and radioactivity identification of the waste is shown in Table 1.

[0099] Table 1

[0100]

[0101]

[0102] Step 2: The compatibility system will call out the first compatibility scheme that matches these conditions from the historical database, and preliminarily select the radioactive waste for exclusion according to the scheme; among the above radioactive wastes, the resin is found to be of medium level after testing, and the water content is too high, so it is excluded and not included in the scope of this compatibility. As shown in Table 2 below.

[0103] Table 2

[0104]

[0105] Step 3: According to the working conditions in the furnace, the formulation system is adaptively adjusted to form a second formulation that conforms to the furnace. The specific case analysis is as follows. It is found through testing that the residue reduction rate is higher than 5%, so the ash content ratio in the source item is adjusted (the paper clothing ratio is reduced) to obtain the formulation shown in Table 3 below.

[0106] Table 3

[0107]

[0108] The above compatibility ratio basically guarantees the stability of calorific value and moisture, while also ensuring compatibility and safety.

[0109] Step 4: According to the exhaust gas operating conditions (emissions of pollutants such as dioxins, nitrogen oxides, and dust), a third matching scheme that meets the conditions is formed to ensure that the system's conventional pollutant emissions meet the standards.

[0110] The specific case analysis is as follows: According to the data fed back by the exhaust system dioxin detection system, the dioxin data exceeds 0.1ng TEQ / Nm 3 Therefore, it is necessary to reduce the proportion of chlorine in the source term to avoid the production of dioxins, and obtain the following compatibility scheme as shown in Table 4:

[0111] Table 4

[0112]

[0113]

[0114] Step 5: The matching system performs adaptive adjustment according to the radioactive emission conditions (nuclide types and radiation doses) to form a fourth matching scheme that meets the conditions, so that the system's radioactive emissions meet the standards.

[0115] The specific case analysis is as follows: After radioactive testing, it was found that Cs-134 exceeded the standard, so it was necessary to reduce the proportion of Cs-134 in the source term, and the compatibility scheme shown in Table 5 was obtained:

[0116] Table 5

[0117]

[0118] Step 6: Optimized application of cloud computing technology

[0119] According to step five, after obtaining the optimized matching method, it is uploaded to the cloud server together with the operating data, and compared with the matching database information of other nuclear power plants. It is found that the matching methods are basically similar, so the output result of this intelligent matching database is finally obtained and passed to the process system for execution, and the matching is completed.

[0120] Example 2

[0121] like Figures 1 to 5 As shown, this embodiment provides a plasma processing device for radioactive waste, including a temporary storage room, a database management system, a sorting system, a crushing system, and a packaging system;

[0122] The temporary storage room is used to identify the physical properties and radioactivity of the waste; the basic data after identification in the temporary storage room enters the database management system, and the first matching scheme that matches it is called out from the database; the first matching scheme is used for preliminary selection in the sorting system; then, according to the working conditions in the furnace, adaptive adjustments are made to form a second matching scheme that matches it; then, according to the exhaust working conditions, a third matching scheme that matches it is formed to make the system's conventional pollutant emissions meet the standards; then, according to the radioactive emission working conditions, adaptive adjustments are made to form a fourth matching scheme that matches it; after matching, the materials enter the crushing system; the crushed materials enter the packaging system;

[0123] It also includes a plasma furnace 1 and a secondary combustion chamber 17 which are interconnected. The rear end of the smoke outlet of the secondary combustion chamber 17 is connected in sequence with a denitration device 20, a heat exchanger 21, a quenching tower 22, a bag filter, a primary washing tower 24, and a secondary washing tower 25. The rear end of the secondary washing tower 25 is connected to a low-temperature deep-cold removal system.

[0124] The low temperature deep cold removal system includes a flue gas cooler 26, a gas-liquid separator 27, an adsorber, an electric heater, and an induced draft fan 19 which are interconnected, and the flue gas cooler 26 is connected to a secondary scrubber 25;

[0125] The adsorber includes a No. 1 adsorber 28-1 and a No. 2 adsorber 28-2 connected in parallel. Both the No. 1 adsorber 28-1 and the No. 2 adsorber 28-2 are connected with a return furnace pipe. The return furnace pipe has two branch pipes, which are respectively connected to the annular air inlet of the plasma furnace body and the annular air inlet of the second combustion chamber 17.

[0126] Specifically, the plasma furnace 1 includes a vertical section (gasification section) and a horizontal section (melting section), which are arranged in an L shape; a No. 1 plasma torch 5-1 is arranged directly above the horizontal section of the plasma furnace 1; a glass liquid overflow port 13 is arranged above the side of the horizontal section of the plasma furnace 1, and a metal liquid drain port 12 is arranged below.

[0127] A plasma torch No. 1 5-1 is arranged above the melting section. During the operation of the plasma torch, a high-power DC power supply is required for power supply, and cooling water is passed through the plasma torch for cooling. The plasma torch uses nitrogen as the carrier wind. The arc generated by the plasma torch ionizes the nitrogen to form a high-temperature jet (adjustable at 1500-2000°C), which directly heats and melts the inorganic matter coming from the vertical section, and then forms a glass liquid layer 10.

[0128] Among them, the No. 1 plasma torch 5-1 can adopt a high current and low voltage operation mode, such as 150kw output power, 350A, 430V, and a high-temperature jet length of about 300mm. The purpose of this is to use a shorter arc length (smaller nitrogen consumption), increase the outlet temperature of the plasma jet, provide high-temperature energy to the treated material (slag and ash) and make it easier to melt into glass. At the same time, the active radicals (H + 、N +Charged particles such as radioactive particles (e.g., charged particles) also enter the vertical gasification section from the melting section of the plasma furnace 1 and enter the gasification pyrolysis layer 9. These active groups have a greater activation catalytic effect and a greater promoting effect on the pyrolysis reaction, which can accelerate the decomposition of organic matter in radioactive waste and the combustion of carbon. At the same time, in the oxidation area inside the gasification pyrolysis layer 9, the organic matter is pyrolyzed and gasified into synthesis gas (CO+H2). In the process of this part of the synthesis gas escaping upward from the oxidation area (1200°C), it also has to pass through the drying and pyrolysis areas. Since the synthesis gas itself carries a certain reducing atmosphere, the middle and upper parts of the gasification pyrolysis layer 9 belong to the reducing area.

[0129] In the glass liquid layer 10, the slag is melted into liquid by the high temperature generated by the No. 1 plasma torch 5-1, wherein components such as silicon and calcium form the glass liquid layer 10 here, and some metals such as iron, copper, and silver have a relatively high density and are deposited at the bottom to form a metal liquid layer 11. This is the stratification phenomenon inside the molten pool.

[0130] Among them, a glass liquid overflow port 13 is arranged on the left side of the molten pool, which is usually blocked and sealed by a plug. When the glass liquid layer 10 formed by the melting of the slag in the molten pool reaches a certain height and the molten pool liquid level exceeds the overflow port by a large amount, the plug is moved from the left side by the actuator to move it out of the overflow port. At this time, the overflow port is opened, and the glass liquid flows out from the glass liquid overflow port 13. This structure solves the problem that the discharge port of the same type of furnace is easily blocked, resulting in poor discharge.

[0131] The slag usually contains a small amount of metal (such as iron, copper, etc.). This part of the metal liquid cannot form a glass body and usually accumulates at the bottom of the molten pool. After waiting for a certain period of time (such as about a month), the metal liquid drain port 12 is opened to drain the metal liquid at the bottom.

[0132] After the vitreous liquid flows out from the glass liquid overflow port 13, it enters the overflow outlet sealing chamber 6; the overflow outlet sealing chamber 6 is a structure of an outer steel shell and an inner lining of refractory material, which can not only prevent the high temperature coming out of the overflow port, but also prevent the leakage of radioactive substances; a water-cooled gate valve is arranged at the bottom of the overflow outlet sealing chamber 6, and when the overflow port is not discharging material, the water-cooled gate valve is in a closed state; before the overflow port is discharged, the water-cooled gate valve is opened, and the lower part is prepared for the receiving hopper car 7, and a water pool is arranged at the bottom of the receiving hopper car 7. When the overflow port is opened, the glass liquid flows into the water pool at the bottom of the hopper car, and then undergoes a water quenching process and then cools to form a glass body.

[0133] After a certain period of time, the glass liquid at the overflow port has flowed out. At this time, the water-cooled gate valve is closed, and the plug is moved by the actuator to block the overflow port again. At the same time, the upper part of the receiving hopper car 7 performs an automatic sealing operation to ensure the airtightness of the hopper car. After completing the above operations, the overflow port, the outlet of the water-cooled gate valve, and the upper part of the receiving hopper car 7 are all in a sealed state to ensure that there is no radioactive leakage. There is a pulley at the bottom of the receiving hopper car 7, which is automatically transferred to the finished product warehouse next to it through the track and temporarily stored in accordance with radiation protection requirements.

[0134] Specifically, after the material enters the vertical section of the plasma furnace 1 from the feed port 2 of the plasma furnace 1 , a gasification and pyrolysis layer 9 is formed. An annular air inlet is provided on the plasma furnace 1 at the gasification and pyrolysis layer 9 .

[0135] Among them, the gasification pyrolysis layer 9 forms a drying layer, a pyrolysis layer, an oxidation layer, a slag layer and other cross-sections from top to bottom in the vertical direction, and its temperature ranges from 400°C to 1200°C from the upper surface to the high temperature section.

[0136] Among them, the gasification pyrolysis layer 9 is provided with a right annular air inlet 8-1 and a left annular air inlet 8-2 (only two air inlets are marked in the figure, and 4 to 6 annular air inlets can be provided as needed in actual engineering applications to supplement oxygen to the gasification pyrolysis layer 9). In the gasification pyrolysis layer 9, most of the organic matter is gasified and pyrolyzed into synthesis gas (CO+H2) at a temperature of about 400°C to 600°C, and then this part of the gas is discharged from the exhaust pipe 4 of the plasma furnace 1 to the secondary combustion chamber 17.

[0137] Among them, the inorganic matter (bottom slag and ash) remaining in the gasification and pyrolysis layer 9 falls to the bottom of the vertical section and then enters the horizontal melting section of the plasma furnace 1.

[0138] Specifically, the plasma furnace 1 uses a high temperature resistant, corrosion resistant, refractory material 3 as an internal working layer.

[0139] Among them, the refractory material 3 can be selected from silicon nitride, silicon carbide, zirconium chromium corundum and other related materials according to different positions, and the surface temperature of the furnace shell is controlled at about 80°C to 100°C.

[0140] Specifically, an inclined section is provided on the right side of the furnace bottom of the plasma furnace 1 .

[0141] This structure makes it easier for the glass liquid on the right to flow to the left under the action of gravity, making it easier to discharge.

[0142] Specifically, a No. 1 plasma torch 5 - 2 is disposed on the top of the second combustion chamber 17 .

[0143] A No. 1 plasma torch 5-2 is arranged above the top of the second combustion chamber 17; during the operation of the plasma torch, a high-power DC power supply is also used for power supply, and cooling water is passed through to cool it. Here, the plasma torch uses nitrogen as the carrier wind; the arc generated by the plasma torch ionizes the nitrogen to form a high-temperature jet (adjustable at 1500-2000°C), which directly burns the synthesis gas from the plasma furnace 1 and burns out its combustible components. During use, due to its high temperature and high enthalpy characteristics, the plasma technology produces a high NOx (about 2000-4000 mg / m3) under the condition of inert gas as a carrier.

[0144] No. 1 plasma torch 5-2 Here, we can adopt high voltage and low current operation mode, such as 150kw output power, 250A, 600V, and high-temperature jet length of about 500mm. The purpose is to adopt a longer arc length (larger nitrogen consumption) to increase the concentration and coverage of active groups generated by nitrogen plasma, thereby improving the high-temperature combustion effect.

[0145] Specifically, the bag dust collector adopts a redundant configuration, including a No. 1 bag dust collector 23-1 and a No. 2 bag dust collector 23-2.

[0146] Specifically, the plasma furnace body and the secondary combustion chamber 17 are provided with a plurality of annular air inlets.

[0147] Among them, a vertical hole is opened in the smoke exhaust pipe 4 near the secondary combustion chamber 17 pipe, and a horizontal annular air inlet 16-1 for the secondary combustion chamber No. 1 and a horizontal annular air inlet 16-2 for the secondary combustion chamber No. 2 are provided. The purpose is to supply air and oxygen to the upper part of the secondary combustion chamber 17 to promote the combustion of the synthesis gas inside the secondary combustion chamber 17.

[0148] Among them, we set the middle annular air inlet 18-1 of the No. 1 second combustion chamber and the middle annular air inlet 18-2 of the No. 2 second combustion chamber in the middle of the second combustion chamber 17. The air inlet is opened horizontally in the middle of the second combustion chamber 17 to increase the oxygen required for the combustion of the combustible components; similarly, only two air inlets are marked on the figure, and 4 to 6 annular air inlets can be set as needed in actual engineering use to improve the treatment effect; from the middle air inlet position to the outlet of the second combustion chamber 17, it belongs to the burnout area in the graded air distribution. This part has a low air volume and low oxygen content. In addition, there is unburned synthetic gas from the middle and upper parts, so this area belongs to a reducing atmosphere. As mentioned above, we have implemented a two-stage air distribution scheme in the secondary combustion chamber 17, that is, a first-stage air inlet is set at the inlet of the secondary combustion chamber 17 to form a main combustion zone of the synthesis gas in the upper part of the secondary combustion chamber 17; a second-stage air inlet is set in the middle part of the secondary combustion chamber 17 to form a burnout zone of the combustible atmosphere in the lower middle part of the secondary combustion chamber 17 to ensure that the combustible components are burned out in the secondary combustion chamber 17. At the same time, the strategy of graded air distribution can effectively reduce the concentration of nitrogen oxides and ensure that pollutant emissions meet the standards; graded air distribution and low-nitrogen combustion is a mature technology and will not be elaborated in this article.

[0149] Example 3

[0150] Based on Example 1, this example provides a method for treating radioactive waste, using the plasma treatment device in Example 1 to treat radioactive waste, and the method is carried out according to the following steps:

[0151] S1. First, the crushed and mixed radioactive waste (including waste resin, PE, clothing, etc.) enters the plasma furnace 1 from the feed port 2 at the top of the plasma furnace 1 through the feeding device.

[0152] S2. After the material falls from the feed port 2 into the vertical section of the plasma furnace 1, a gasification pyrolysis layer 9 is formed. From top to bottom, the layer forms a drying layer, a pyrolysis layer, an oxidation layer, a slag layer and other cross-sections in the vertical direction. The temperature varies from 400°C to 1200°C from the upper surface to the high temperature section.

[0153] S3. The organic matter inside the plasma furnace 1 is gasified and decomposed to mainly form synthesis gas (CO+H2), which enters the secondary combustion chamber 17 through the plasma furnace 1 exhaust pipe 4. The flue gas that is completely burned in the secondary combustion chamber 17 is discharged from the secondary combustion chamber exhaust port 15 to the downstream exhaust gas treatment system; a small amount of ash generated in the process is regularly discharged through the secondary combustion chamber ash discharge port 14 at the bottom.

[0154] S3. After the flue gas comes out of the secondary combustion chamber 17 (1100°C), it first passes through the denitration device, where denitration is carried out in the furnace, that is, ammonia water is sprayed from the inside to react with nitrogen oxides to produce nitrogen and water.

[0155] S4, the flue gas enters the heat exchanger 21 for cooling from 1100°C to 600°C, and then enters the quenching tower 22, where the high-temperature flue gas is cooled to 175°C in a relatively short time, avoiding the secondary production area of ​​dioxins.

[0156] S5. After rapid cooling, the flue gas then enters the bag filter for dust removal. Redundancy configuration is considered here, that is, bag filter No. 1 23-1 and bag filter No. 23-2 are configured; then the flue gas enters the secondary washing and is sprayed with sodium hydroxide solution for deacidification.

[0157] S6. After washing, the flue gas enters the low-temperature deep-cold removal system. When the flue gas temperature drops below 0°C, the SO2 adsorption capacity increases exponentially, and the NO adsorption capacity increases exponentially. Therefore, low-temperature catalytic oxidation is the key mechanism to promote the substantial increase in NO adsorption capacity. Therefore, after cooling the flue gas, high-performance low-temperature adsorption materials can be used to remove SO2 and NO. x Carry out low temperature adsorption removal.

[0158] S7. After washing, the flue gas enters the flue gas cooler 26, where a refrigerator is used for cooling the flue gas to a desired temperature (about -20°C to 0°C, depending on the removal situation) using a low-temperature refrigerant.

[0159] S8. After cooling, the flue gas enters the gas-liquid separator 27 to separate the water vapor generated in the scrubbing tower to ensure that dry flue gas is generated.

[0160] S9, after gas-liquid separation, enters the adsorber, where the adsorber adopts an alternating working mechanism, that is, the first adsorber 28-1 starts working, and the second adsorber 28-2 is not put into operation at this time. The adsorption material (alumina or copper particles) inside the first adsorber 28-1 is used to absorb SO2 and NO in the flue gas. x Low temperature adsorption removal, most of the SO2 and NO in the flue gas x After all are removed, after a period of adsorption, the adsorption capacity of adsorber No. 1 28-1 reaches saturation state, and then the switching valve can be used to switch to adsorber No. 2 28-2. At this time, adsorber No. 1 28-1 starts working and adsorber No. 2 28-2 stops working. x The concentration was kept below 1mg / Nm 3 , SO2 concentration is kept below 3mg / Nm 3 ; Basically meet the national near-zero emission requirements.

[0161] S10, during the adsorption operation of the No. 1 adsorber 28-1, the No. 1 adsorber 28-1 is heated, regenerated and NO xThe treatment process is as follows: a separate blower is used to supply air to the adsorber No. 1 28-1, and electric heating is used in the process. After the heated air passes through the adsorber No. 1 28-1 and is heated, the SO2 and NO originally adsorbed by the adsorbent material are x , and then enters the hot air after being heated. As the temperature rises and the time increases, the SO2 and NO contained in adsorber No. 1 28-1 itself x The amount is gradually decreasing, and most of it enters the hot air. At this time, the first adsorber 28-1 is ready for use after regeneration, waiting for the next time the first adsorber 28-1 and the second adsorber 28-2 are switched for use.

[0162] S11, absorbs a large amount of SO2 and NO x The hot air is operated in the circuit in the following two ways:

[0163] Loop operation route 1: Enter the horizontal annular air inlet of the secondary combustion chamber 17, enter the secondary combustion chamber 17 furnace from the entrance section of the secondary combustion chamber 17, and implement a two-level air distribution scheme in the secondary combustion chamber 17 as described above, that is, a main combustion zone with a primary air inlet is set at the inlet of the secondary combustion chamber 17 and a burnout zone formed by a secondary air inlet is set in the middle of the secondary combustion chamber 17; after the hot air returned to the furnace enters the secondary combustion chamber 17 furnace, it is partially reduced after passing through the reduction area of ​​the burnout zone.

[0164] Recycling operation path 2: Entering the annular air inlet of the vertical section of the plasma furnace body, this part belongs to the gasification pyrolysis layer 9. As described above, since the synthesis gas itself has a certain reducing atmosphere, the middle and upper parts of the gasification pyrolysis layer 9 belong to the reducing area. After entering the plasma furnace body, the recycled hot air passes through the middle and upper reducing area of ​​the gasification pyrolysis layer 9 and enters the secondary combustion chamber 17 and the tail gas treatment link.

[0165] S12, the hot air returned to the furnace is mixed with the hot flue gas originally generated in the furnace and enters the exhaust gas treatment link. Therefore, SO2 and NO in the flue gas are x In this process, it is adsorbed at low temperature, desorbed by heating, returned to the furnace, and then enters the exhaust system, forming a reciprocating cycle.

[0166] S13. After low-temperature adsorption in the adsorber, the flue gas reaching near-zero emission is heated by the electric heater 29 and then passes through the induced draft fan 19 to meet emission standards.

[0167] Among them, in the low-temperature adsorption process, selecting a suitable adsorption material (such as zeolite, etc.) can strongly adsorb Cs-137, I-131, etc., reduce the total radiation dose in the flue gas, and thus make the radioactive emission meet the standard. The adsorption material that has been adsorbed to the critical point for a long time will eventually enter the plasma furnace 1 again for the glass solidification process after relevant processing steps (crushing, compatibility, etc.), or directly enter the cement solidification line for solidification treatment.

[0168] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A system for treating radioactive waste, characterized in that: It includes a temporary storage room (30), a database management system, a sorting system (31), a crushing system (32), and a packaging system (33); The temporary storage room (30) is used to identify the physical properties and radioactivity of the waste; the basic data identified by the temporary storage room (30) enters into a database management system, and a first matching scheme that matches the waste is retrieved from the database; a preliminary selection is performed in the sorting system (31) according to the first matching scheme; then, according to the working conditions in the furnace, an adaptive adjustment is performed to form a second matching scheme that matches the waste; then, according to the working conditions of the tail gas, a third matching scheme that matches the waste is formed to make the conventional pollutant emissions of the system meet the standards; then, according to the working conditions of the radioactive emission, an adaptive adjustment is performed to form a fourth matching scheme that matches the waste; after the matching is completed, the materials enter into a crushing system (32); and the crushed materials enter into a packaging system (33).

2. A treatment device for treating radioactive waste, characterized in that: The invention comprises the compatibility system as claimed in claim 1, and also comprises a plasma furnace (1) and a secondary combustion chamber (17) which are interconnected, characterized in that the rear end of the smoke outlet of the secondary combustion chamber (17) is connected in sequence with a denitration device (20), a heat exchanger (21), a quenching tower (22), a bag filter, a primary washing tower (24), and a secondary washing tower (25), and the rear end of the secondary washing tower (25) is connected to a low-temperature deep-cold removal system; The low-temperature deep-cold removal system comprises a flue gas cooler (26), a gas-liquid separator (27), an adsorber, an electric heater (29), and an induced draft fan (19) which are interconnected, and the flue gas cooler (26) is connected to the secondary scrubbing tower (25); The adsorber comprises a No. 1 adsorber (28-1) and a No. 2 adsorber (28-2) connected in parallel, and the No. 1 adsorber (28-1) and the No. 2 adsorber (28-2) are both connected to a return furnace pipe, and the return furnace pipe has two branch pipes, and the two branch pipes are respectively connected to the annular air inlet of the plasma furnace (1) and the annular air inlet of the second combustion chamber (17).

3. The plasma treatment device for radioactive waste according to claim 2, characterized in that: The plasma furnace (1) comprises a vertical section and a horizontal section, arranged in an L shape; a No. 1 plasma torch (5-1) is arranged directly above the horizontal section of the plasma furnace (1); a glass liquid overflow port (13) is arranged above the side of the horizontal section of the plasma furnace (1), and a metal liquid drain port (12) is arranged below.

4. The plasma treatment device for radioactive waste according to claim 3, characterized in that: After the material enters the vertical section of the plasma furnace (1) from the feed port (2) of the plasma furnace (1), a gasification and pyrolysis layer (9) is formed. An annular air inlet is provided on the plasma furnace (1) at the gasification and pyrolysis layer (9).

5. The plasma treatment device for radioactive waste according to claim 2, characterized in that: The plasma furnace (1) uses high temperature resistant, corrosion resistant and fire resistant materials (3) as the internal working layer.

6. The plasma treatment device for radioactive waste according to claim 2, characterized in that: The right side of the furnace bottom of the plasma furnace (1) is provided with an inclined section.

7. The plasma treatment device for radioactive waste according to claim 2, characterized in that: A No. 1 plasma torch (5-2) is arranged on the top of the secondary combustion chamber (17).

8. The plasma treatment device for radioactive waste according to claim 2, characterized in that: The bag dust collector adopts a redundant configuration, including a No. 1 bag dust collector (23-1) and a No. 2 bag dust collector (23-2).

9. A method for treating radioactive waste, characterized in that: The process is carried out using the plasma processing apparatus according to any one of claims 2 to 8.

10. A method for treating radioactive waste according to claim 9, characterized in that: The following steps are involved: The radioactive waste treated by the compatibility system is added to a plasma furnace (1) to form a gasification and pyrolysis layer (9), in which organic matter is gasified and pyrolyzed into synthesis gas, and then the gas is discharged from the plasma furnace exhaust pipe (4) into a secondary combustion chamber (17); After the flue gas is burned in the secondary combustion chamber (17), it is discharged from the secondary combustion chamber (17) and enters the denitration device (20) for denitration. The flue gas after denitration enters the heat exchanger (21) for cooling, and then enters the quenching tower (22) for cooling. The flue gas after quenching and cooling then enters the bag filter for dust removal, and then enters the secondary washing tower (25) to be sprayed with alkali solution for deacidification. The flue gas after washing enters the cooler of the low temperature deep cold removal system for cooling, and after cooling enters the gas-liquid separator (27) to separate the water vapor generated in the washing tower to ensure that dry flue gas is generated; After gas-liquid separation, the gas enters the adsorber for adsorption treatment. The exhaust gas NO x The concentration was kept below 1mg / Nm 3 , SO2 concentration is kept below 3mg / Nm 3 .

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