A radioactive waste treatment process and equipment system

Abstract

The present invention discloses a radioactive waste treatment process and equipment system, comprising a waste feed system, a reactor system, and an exhaust gas treatment system. The radioactive waste, including waste resin, waste activated carbon, and waste oil, undergoes a reaction within the reactor system at a reaction temperature of 600°C to 950°C and a reaction pressure of -15 to 35 kPa G. This process completely oxidizes and vaporizes the organic matter in the radioactive waste, enriching and solidifying the inorganic matter, including the radioactive substances, on a dedicated bed material to form waste bed material. The exhaust gas is treated and purified by the exhaust gas treatment system before being discharged. The waste bed material generated by the reaction is collected and packaged as a volume reduction product. This application achieves thermal treatment of radioactive waste, volume reduction of the radioactive waste, and compliance with exhaust gas emission standards.

Description

Technical Field

[0001] The invention relates to a radioactive waste treatment process and equipment system. Background Art

[0002] The treatment of radioactive waste from nuclear power plants is a crucial component of their safe production. Long-term, isolated storage, the ultimate disposal method for radioactive waste from nuclear power plants, is costly. Therefore, volume reduction of radioactive waste generated by nuclear power plants has become a crucial step in the waste disposal process.

[0003] Radioactive waste generated during nuclear power plant operations is mostly hydrocarbon-based organic matter, such as waste resin, waste activated carbon, and waste oil. There are currently no effective methods for reducing the volume of these wastes in China. A steam reforming process, which uses high-temperature steam to decompose organic matter, can effectively reduce the volume of these wastes, but its application costs remain high. For example, the invention "Thermal Volume Reduction of Radioactive Waste" [Application Publication No. CN 110431639 A] disclosed by Atkins Energy Global Solutions, Inc. on November 8, 2019, is an improved steam reforming technology.

[0004] Some people in China have tried to use the "municipal waste incineration" method to reduce the volume of these wastes, but failed due to problems such as the difficulty in capturing radioactive nuclides.

[0005] my country's nuclear power industry is developing vigorously. In order to further reduce the auxiliary costs of nuclear power, the problem of reducing the volume of radioactive organic waste needs to be solved urgently. Summary of the Invention

[0006] The purpose of the present invention is to provide a radioactive waste treatment process and equipment system, which, based on the characteristics and treatment features of waste from my country's nuclear power plants, can treat existing waste at low cost and high efficiency, thus solving the shortcomings of the existing technology.

[0007] To achieve the above technical objectives, the present invention provides a process for treating radioactive waste, comprising: providing a waste feeding system, a reactor system, and an exhaust gas treatment system; placing radioactive waste in the waste feeding system, the radioactive waste comprising waste resin, waste activated carbon, and waste oil; transporting the radioactive waste to the reactor system through the waste feeding system for reaction treatment, wherein the reaction treatment is carried out at a reaction temperature of 600° C. to 950° C. and a reaction pressure of −15 to 35 kPa G, causing complete oxidation and gasification of organic matter in the radioactive waste, while simultaneously enriching and solidifying inorganic matter, including radioactive substances, in the radioactive waste on a dedicated bed material to form waste bed material; and exhaust gas generated by the reaction treatment is treated and purified by the exhaust gas treatment system and then discharged to air, and the waste bed material generated by the reaction treatment is collected and packaged as a volume reduction product.

[0008] As a further improvement, the waste feeding system includes: a waste resin feeding system and a waste oil feeding system. In the waste resin feeding system, the waste resin is fed alone, or the waste resin is mixed with the waste activated carbon and fed. In the waste oil feeding system, the waste oil is fed. In the waste resin feeding system, the waste oil is transported to the reactor system by hydraulic conveying.

[0009] As a further improvement, the reactor system includes: a fluidized bed reactor and a first waste bed material collection tank. The fluidized bed reactor includes a fast bed located at the bottom and a boiling bed located at the top, so as to optimize the height-to-diameter ratio and provide a good gas-solid fluidized state for the reaction process while also providing sufficient reaction time. The first waste bed material collection tank is connected to the bottom of the fast bed.

[0010] As a further improvement, the lower part of the fast bed also has a waste feeding section, the inlet of the waste feeding section is connected to the outlet of the waste resin feeding system, and while the waste resin feeding system is feeding, a dispersion gas is input at the inlet of the waste feeding section to disperse the feed of the waste resin feeding system before entering the reactor system.

[0011] As a further improvement, a mixture of air and water vapor is used as a gasifying agent and a fluidizing gas and is fed into the lower part of the fast bed.

[0012] As a further improvement, it also provides a bed material adding system, which includes: a bed material device for accommodating bed material and an additive device for accommodating additives. The bed material and the additive share a feed port and are fed into the lower part of the fast bed.

[0013] As a further improvement, the tail gas generated in the fluidized bed enters the tail gas treatment system after passing through a cyclone separator. At the same time, an external circulation pipe is set between the lower part of the fluidized bed and the lower part of the fast bed to control the operation quality of the fluidized bed.

[0014] As a further improvement, the exhaust gas treatment system includes a dust removal and denitrification system and a wet desulfurization system. The dust removal and denitrification system primarily comprises a high-temperature filter and a medium-temperature denitrification filter, with a denitrification temperature of 330-390°C and ammonia as the denitrification agent. The bed material fines, which contain radionuclides and are carried in the exhaust gas intercepted by the filters, are collected in a second waste collection tank and a third waste collection tank, respectively.

[0015] As a further improvement, the main equipment of the wet desulfurization system is a washing tower, the desulfurization agent is mainly sodium hydroxide and sodium bicarbonate, and the tail gas is cooled by direct mixing water spray cooling.

[0016] As a further improvement, the inorganic matter includes elements such as lithium, sodium, potassium, calcium, cesium, strontium, cobalt, boron, and sulfur; the gasifying agent is air, water vapor, or a mixture of air and water vapor; the gas is air, nitrogen, or a mixture of air and nitrogen; in the hydraulic conveying method, the hydraulic conveying feed nozzle adopts gas atomization and is provided with a jacket insulation measure, and the volume mixing ratio of the conveyed waste resin and water is approximately 1:1.

[0017] As a further improvement, the salty wastewater discharged from the washing tower is reused in the device, and the tail gas is discharged from the top of the washing tower after being treated and purified by the tail gas treatment system, with the discharge temperature being less than 100°C.

[0018] As a further improvement, for the waste resin raw materials with a higher boric acid content in the waste resin, a bed material separation system is further provided between the first waste bed material collecting tank and the lower part of the rapid bed, which is mainly composed of a bed material separator. The waste bed material separated by the bed material separator enters the first waste bed material collecting tank, and the usable bed material separated by the bed material separator is transported back to the boiling bed to selectively discharge particles with a higher boron oxide B2O3 content in the bed material, thereby further improving the volume reduction ratio.

[0019] As a further improvement, the bed material separator is an air separation separator, including a non-cyclone separator.

[0020] As a further improvement, the cyclone separator includes a built-in air separation separator and an external air separation separator.

[0021] As a further improvement, the bed material is a non-uniform particle made of microporous aluminosilicate microspheres as a base material, and is matched with calcium oxide, active metals, and rare earth elements, with a particle size range of 0 to 1000 μm. The bed material is both the basic bed material of the fluidized bed reactor and a carrier for enriching radioactive nuclides. The bed material has fluidization properties and radioactive nuclide accommodation properties, as well as desulfurization properties and carbon monoxide combustion-supporting properties.

[0022] Correspondingly, the present invention also provides a radioactive waste treatment equipment system, wherein the radioactive waste includes: waste resin, waste activated carbon and waste oil; the treatment equipment system includes: a waste resin feeding system, a waste oil feeding system, a bed material addition system, a fluidized bed reactor system, a bed material separation system, an exhaust gas dust removal and denitrification system and a wet desulfurization system; in the waste resin feeding system, the waste resin can be fed alone or mixed with the waste activated carbon, and the feeding of the waste resin and waste activated carbon is carried out by hydraulic conveying; in the waste oil feeding system, the waste oil is fed using an oil pump; the fluidized bed reactor includes a fast bed located at the bottom and a boiling bed located at the top, and a first waste bed material collection tank is arranged in communication with the lower part of the fast bed.

[0023] As a further improvement, a bed material separation system is provided between the first waste bed material collecting trough and the lower part of the rapid bed, which is mainly composed of a bed material separator. The waste bed material separated by the bed material separator enters the first waste bed material collecting trough, and the usable bed material separated by the bed material separator is transported back to the boiling bed.

[0024] As a further improvement, all components in the processing equipment system that come into contact with radioactive nuclides adopt a metal inner wall structure.

[0025] The radioactive waste treatment process and equipment system provided by this invention utilizes a fluidized bed reactor to thermally treat the radioactive waste, oxidizing and gasifying the organic matter in the waste and concentrating the radioactive elements and other impurities in a dedicated solid bed material, thereby reducing the volume of the waste. Simultaneously, the tail gas treatment system rigorously collects the radioactive bed material fines and treats small amounts of SOx, NOx, and other gases in the product gaseous streams to ensure emission standards. This invention provides an efficient and comprehensive solution for reducing the volume of radioactive waste in existing nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of a first embodiment of the present invention;

[0027] Figure 2 FIG. 1 is a schematic diagram of a second embodiment of the present invention.

[0028] Figure numerals: waste resin feeding system 1, waste oil feeding system 2, bed material adding system 3, fluidized bed reactor system 4, bed material separator system 5, dust removal and denitrification system 6, wet desulfurization system 7, waste resin mixing equipment 11, special bed material holding equipment 31, additive holding equipment 32, fast bed 41, boiling bed 42, waste feeding section 43, external circulation pipe 44, cyclone separator 45, first waste bed material collecting tank 46, bed material separator 51, high temperature filter 61, medium temperature denitrification filter 62, second waste bed material collecting tank 63, third waste bed material collecting tank 64, cooling and washing tower 71. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Of course, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] like Figures 1 to 2 As shown, the present invention provides a radioactive waste treatment process, which provides major systems such as a waste feeding system, a reactor system and an exhaust gas treatment system.

[0031] The radioactive waste includes: waste resin, waste activated carbon and waste oil; the waste feeding system transports the radioactive waste into the reactor system and performs reaction treatment, and the reaction treatment is carried out under the conditions of a reaction temperature of 600°C to 950°C and a reaction pressure of -15 to 35 kPa G, so that the organic matter in the radioactive waste is completely oxidized and gasified, and at the same time, all inorganic substances including radioactive substances in the radioactive waste are enriched and solidified on the bed material to form waste bed material; the tail gas generated by the reaction treatment is treated and purified by the tail gas treatment system and then discharged, and the waste bed material generated by the reaction treatment is completely collected and packaged as a volume reduction product.

[0032] The radioactive waste treatment process provided by the present invention has a waste treatment capacity selectable between 5L / hr and 200L / hr and is designed for use in conjunction with nuclear power plants. The present invention provides a complete solution for the volume reduction treatment of radioactive waste resin, waste activated carbon, waste oil, and the like in nuclear power plants. The radioactive waste treatment device of the present invention achieves fully enclosed operation of all materials and is environmentally friendly. In addition to the special bed material enriched with radioactive nuclides being "solid waste" (i.e., the product after volume reduction), the "waste gas" of the radioactive waste treatment device of the present invention is treated and discharged in compliance with standards; and the "wastewater" can be recycled and does not need to be discharged externally. For waste resin raw materials with a high boric acid content, a bed material separator can be optionally installed. Particles with a high B2O3 content in the bed material are selectively discharged to further improve the "volume reduction ratio."

[0033] The waste feeding system includes: a waste resin feeding system 1 and a waste oil feeding system 2. In the waste resin feeding system 1, the waste resin is fed alone, or the waste resin is mixed with the waste activated carbon and fed. In the waste oil feeding system 2, the waste oil is fed alone. The waste resin feeding system 1 is transported to the reactor system by hydraulic conveying.

[0034] The reactor system includes an ebullating bed reactor 41, a fast bed reactor 42, an external circulation pipe 44, a cyclone separator 45, and a first waste bed material collection tank 46. The optimized reactor height-to-diameter ratio and assembly ensure good gas-solid fluidization throughout the reaction process while also providing sufficient reaction time.

[0035] The lower part of the fast bed also has a waste feeding section 43, the inlet of which is connected to the outlet of the waste resin feeding system 1. While the waste resin feeding system 1 is feeding, gas is input at the inlet of the waste feeding section to perform gas dispersion and transportation on the feed of the waste resin feeding system 1.

[0036] It also provides a bed material adding system 3, which includes: a bed material device 31 for accommodating bed material and an additive device 32 for accommodating additives; the bed material and the additive share a feed port and are added to the lower part of the fast bed.

[0037] The exhaust gas treatment system includes a dust removal and denitrification unit 6 and a cooling and desulfurization unit 7. The dust removal and denitrification unit primarily consists of a high-temperature filter 61 and a medium-temperature filter 62 loaded with a denitrification catalyst. The cooling and desulfurization unit's primary equipment is a cooling scrubber 71. Denitrification (nitrogen oxides, NOx) is performed at a temperature of 330-390°C using ammonia as the auxiliary agent. Desulfurization (SOx) is performed at approximately 80°C using sodium hydroxide and sodium bicarbonate as the primary desulfurization agents.

[0038] The inorganic substances include lithium, sodium, potassium, calcium, cesium, strontium, cobalt, boron, and sulfur. The gas is air, nitrogen, or a mixture of air and nitrogen. In the hydraulic conveying method, the hydraulic conveying feed nozzle adopts gas atomization and is provided with a jacketed heat insulation device. The volume mixing ratio of the conveyed waste resin and water is 1:1. A certain amount of wastewater contaminated with radioactive nuclides can be injected into the waste resin feeding system 1.

[0039] As a further improvement (see Appendix Figure 2 ), in order to deal with the waste resin raw materials with high boric acid content in the waste resin, a bed material separator 51 is further arranged between the first waste bed material collecting tank 46 and the fast bed 41. The waste bed material separated by the bed material separator 51 enters the first waste bed material collecting tank 46, and the rest returns to the ebullating bed reactor 42, and the particles with high boron oxide B2O3 content in the bed material are selectively discharged to further improve the volume reduction ratio.

[0040] The bed material separator is mainly a cyclone separator, including a cyclone separator and a non-air separation separator.

[0041] The specialized bed material is based on microporous aluminosilicate microspheres and is mixed with non-uniform particles made of calcium oxide, active metals, and rare earth elements, with a particle size range of 0 to 1000 μm. This bed material serves as both the basic bed material for the fluidized bed reactor and a carrier for enriching radionuclides. It exhibits fluidization properties, radionuclide retention capabilities, desulfurization properties, and carbon monoxide combustion-supporting properties.

[0042] The present invention utilizes a fluidized bed reactor combining a fast bed and an ebullating bed, effectively addressing the height-to-diameter ratio issue of small-scale fluidized beds. This ensures excellent gas-solid fluidization and sufficient reaction time for the reaction process. The specially formulated bed material, based on microporous aluminosilicate microspheres and supplemented with a specific amount of calcium oxide and active metals, exhibits excellent fluidization and radionuclide retention, sufficient desulfurization performance, and carbon monoxide combustion-supporting properties, simplifying the overall treatment process. This specialized bed material serves as both the base material for the fluidized bed reactor and as a carrier for enriching radionuclides. The reactor utilizes fully oxidative gasification conditions, operating at a temperature of approximately 720°C. This eliminates the generation of hydrogen sulfide (H2S) and maintains carbon monoxide (CO) emissions within acceptable limits. The reactor utilizes hydraulic feed, directly accepting spent ion exchange resin (IER) and granular activated carbon (GAC) from nuclear power plants. It can also process a certain amount of radionuclide-contaminated wastewater. The tail gas generated during the reaction is treated with two-stage filtration for dust removal and medium-temperature denitrification. This effectively intercepts the radionuclides carried by the gas products, preventing the escape of radionuclides from the bed material fines, and effectively removes the NOx generated during the reaction. Both in-reactor desulfurization and tail gas desulfurization are employed. Alkaline washing is used for tail gas desulfurization to ensure that sulfur dioxide, SO2, and dust in the tail gas meet emission standards. Equipment that may come into contact with radionuclides utilizes metal interior walls to reduce the adhesion of radionuclides. This, in turn, reduces the operating, maintenance, and overhaul costs of the treatment unit.

[0043] Compared with the invention (an improved steam reforming method) of "Thermal Volume Reduction of Radioactive Waste" [Application Publication No. CN 110431639 A] disclosed by Atkins Energy Global Solutions, Inc. on November 8, 2019, the present invention has the following main differences:

[0044] 1. The present invention adopts hydraulic conveying feeding mode, and the waste resin and other raw materials do not need to be dehydrated and pre-treated, nor does it require a screw mechanism for feeding. The operation is simple and reliable.

[0045] 2. The present invention adopts special bed materials and additives, which have a large capacity for enriching nuclides and also have a desulfurization function.

[0046] 3. The present invention does not use oxygen as a gasifying agent, so the operation is safer and the cost is lower.

[0047] 4. This invention utilizes complete oxidation reaction conditions and the characteristics of a specialized bed material, eliminating the generation of hydrogen sulfide (H2S). Most of the sulfur in the waste resin is solidified in the specialized bed material, resulting in low CO production and eliminating the need for a CO incinerator (TOX). This further simplifies the process flow.

[0048] 5. The wastewater generated by the tail gas treatment system of the present invention can be reused, which can further control the risk of radionuclide escape.

[0049] 6. The radioactive waste treatment device provided by the present invention requires less equipment, has a simple process, and is easy to operate, maintain, and overhaul. The operating and maintenance costs are significantly reduced.

[0050] 7. The present invention does not yet have the capability to treat dry active waste (DAW).

[0051] The present invention also provides a radioactive waste treatment equipment system, wherein the radioactive waste includes: waste resin, waste activated carbon and waste oil, wherein: the treatment equipment system includes: a waste resin feeding system 1, a waste oil feeding system 2, a bed material addition system 3, a fluidized bed reactor system 4, a dust removal and denitrification part 6 and a cooling and desulfurization part 7; the waste resin is fed into the waste resin feeding system 1 alone, or the waste resin and the waste activated carbon are mixed and fed, the waste oil is fed into the waste oil feeding system 2, and the waste resin feeding system 1 adopts a hydraulic conveying method; the fluidized bed reactor system mainly includes a fast bed 41 located at the bottom and a boiling bed 42 located at the top, and a first waste bed material collection tank 46 is arranged at the bottom of the fast bed 41 and connected to each other; a second waste bed material collection tank 63 and a third waste bed material collection tank 64 are provided in the dust removal and denitrification part.

[0052] Figure 1 This is a schematic diagram of the main flow chart of the first embodiment of a radioactive waste treatment process and apparatus according to the present invention. It thermally treats organic nuclear and solid waste using a fluidized bed reactor and specialized bed material. Under specific reaction conditions, the organic matter in the radioactive waste is completely oxidized and vaporized. Simultaneously, inorganic substances with lower concentrations, including radioactive substances, such as lithium, sodium, potassium, calcium, cesium, strontium, cobalt, boron, and sulfur, are concentrated and solidified on the specialized bed material. The bed material enriched with radioactive substances and other inorganic substances, i.e., the spent bed material, is collected and packaged as a "volume reduction" product. The exhaust gas is then scrubbed and purified before being discharged. Figure 2 The main flow diagram of the second embodiment of a radioactive waste treatment process and apparatus of the present invention is mainly used to treat waste resin raw materials with high content of boric acid.

[0053] In the embodiment provided by the present invention, it is mainly used in medium and large-scale domestic nuclear power plants.

[0054] Processing object: A waste resin, 4x10 6 ~4x10 10 Radioactive waste resin with activity level of Bq / kg;

[0055] B waste oil, mainly composed of hydraulic oil and lubricating oil;

[0056] Waste resin processing capacity: ~25L / h;

[0057] Waste resin volume reduction ratio: for waste resin ≥6.0;

[0058] Waste oil treatment capacity: ~200L / month;

[0059] Nuclide inclusion rate: ≥99%;

[0060] Secondary waste (waste gas / waste liquid) emissions: Required to meet the requirements of relevant national environmental protection standards.

[0061] Table 1 Properties of raw materials:

[0062] This embodiment uses hydraulic conveying to feed the material. The properties of the mixed feed are as follows: 3 Waste resin is taken as the base number, and the particle size range of waste resin raw materials is: particle size <1.5mm, and the range of 0.1~1mm is greater than 95%.

[0063]

[0064] Table 2 Reactor material balance:

[0065] The material balance for the fluidized bed reactor system is shown in the following table. Note: Reaction temperature ~693°C, reaction pressure ~20 kPaG. Calculations are based on raw materials with lower pollutant levels.

[0066]

[0067] Table 3 Tail gas composition:

[0068] The exhaust gas composition after exhaust treatment is as shown in the following table. Note: exhaust gas temperature is ~81℃.

[0069]

[0070] Waste bed material (solid waste) and volume reduction ratio:

[0071] In this embodiment, the solid waste generated during the operation of the device is waste bed material and waste additives. The treatment of waste oil has almost no effect on the volume reduction ratio of the waste resin raw material.

[0072] Waste bed material and waste additives are primarily composed of aluminosilicates, with small amounts of mineralized substances such as sodium, potassium, calcium, lithium, boron, and sulfur, as well as trace amounts of radioactive elements such as cesium, strontium, and cobalt. This constitutes radioactive dust solid waste. It is also a "volume reduction" product after waste resin processing and is collected, sealed, and then professionally disposed of.

[0073] Based on the calculation of 30 days as one operation cycle and the assumption that the waste alkaline water generated by tail gas treatment is not discharged, the device can process waste resin ~18 m 3 At the same time, it processes waste oil ~860kg; consumes special bed materials and additives ~2260kg; generates solid waste (waste bed materials, specific gravity ~1000kg / m 3 ) 2980kg; achieving a volume reduction ratio of ~6.3.

[0074] As attached Figure 2 Example 2 shown. Compared with Example 1, this embodiment is mainly used to treat waste resin raw materials with high boron content (boric acid, etc.). In order to obtain an optimized volume reduction ratio, a bed material separator 51 is also arranged between the first waste bed material collecting tank 46 and the lower part of the fast bed 41. The addition of the bed material separator is conducive to the selective discharge of particles with high B2O3 content in the bed material, avoiding the technical problem of consuming more additives and correspondingly generating more solid waste due to the low melting point of B2O3 (325-500°C), further reducing the generation of solid waste, and optimizing the post-treatment volume reduction ratio of waste resin raw materials containing higher Li, B, S and other elements. Calculated based on raw materials with higher pollutant values, and considering that the waste alkaline water generated by tail gas treatment is not discharged, the device can process ~18m3 of waste resin within a 20-day operating cycle. 3 At the same time, it processes waste oil ~860kg; consumes special bed materials and additives ~1430kg; generates solid waste (waste bed materials, specific gravity ~1000kg / m 3 ) ~ 2180kg; achieving a volume reduction ratio of ~9.9.

[0075] In preferred applications of the present invention, the preferred reaction temperature is 660-750°C; the preferred reaction pressure is 15-30 kPa G; the preferred deNOx temperature is 330-390°C; the preferred deNOx auxiliary agent is ammonia water; the preferred wet deSOx agent is a sodium alkali aqueous solution; the preferred volume ratio of waste resin to water is 1:1; and the preferred high-temperature filter combination is a two-stage filter.

[0076] The present invention provides a radioactive waste treatment process and equipment system, including a complete radioactive organic waste volume reduction process and specialized bed material (carrier). The radioactive waste treatment apparatus comprises a waste feed system, a fluidized bed reactor system, a bed material separator, a high-temperature filter, and an exhaust gas treatment system. Radioactive waste includes spent ion exchange resin, spent granular activated carbon, and waste oil. The specialized bed material, composed of heterogeneous particles such as aluminosilicate, calcium oxide, and rare earth elements, has a particle size range of 0 to 1000 μm. It serves as both the base bed material for the fluidized bed reactor and a carrier for enriching radionuclides. The waste volume reduction process utilizes a fluidized bed reactor combining a fast bed and an ebullating bed, carrying out a complete oxidation reaction at a reaction temperature of 600°C to 950°C. Two or more stages of high-temperature filters are used to intercept the specialized carrier fines carried in the gaseous products, ensuring the capture of radionuclides. The treatment capacity for radioactive waste (calculated as spent resin) is 5 to 300 liters per hour. The waste feeding system includes hydraulic and gaseous conveying methods; waste resin can be fed alone or mixed with waste activated carbon. The reactor system uses cyclone separators, including external cyclone separators and internal cyclone separators. The fluidized bed reactor, cyclone separator, high-temperature filter and other equipment adopt a metal inner wall structure. The hydraulic feed nozzle uses gas atomization and is equipped with a jacket for thermal insulation. The high-temperature filter has a NOx removal function. The temperature of the exhaust gas discharged into the atmosphere by the exhaust gas treatment system is less than 100°C. The present invention provides an efficient and complete solution for the volume reduction treatment of radioactive waste in existing nuclear power plants.

[0077] It should be understood that the scope of the present invention is not limited to the non-limiting embodiments, and it should be understood that the non-limiting embodiments are only provided as examples. The substantial scope of protection required by this application is further reflected in the scope provided by the independent claims and their dependent claims.

Claims

1. A process for treating radioactive waste, characterized in that: It provides waste feed systems, reactor systems, and tail gas treatment systems; Placing radioactive waste into the waste feeding system, wherein the radioactive waste includes: waste resin, waste activated carbon and waste oil; The waste feeding system transports the radioactive waste into the reactor system for reaction treatment. The reaction treatment is carried out at a reaction temperature of 600° C. to 950° C. and a reaction pressure of -15 to 35 kPa G, so that the organic matter in the radioactive waste is completely oxidized and gasified, and at the same time, the inorganic matter including radioactive substances in the radioactive waste is completely enriched and solidified on the dedicated bed material to form a waste bed material. The tail gas generated by the reaction process is treated and purified by the tail gas treatment system and then discharged to air, and the waste bed material generated by the reaction process is collected and packaged as a volume reduction product; The reactor system includes: a fluidized bed reactor and a first waste bed material collecting tank (46), wherein the fluidized bed reactor includes a fast bed (41) located at the bottom and a boiling bed (42) located at the top, so as to optimize the height-to-diameter ratio and provide a good gas-solid fluidized state for the reaction process while also providing sufficient reaction time, and the first waste bed material collecting tank (46) is connected to the bottom of the fast bed (41).

2. The radioactive waste treatment process according to claim 1, characterized in that: The waste feeding system comprises: a waste resin feeding system (1) and a waste oil feeding system (2). In the waste resin feeding system (1), the waste resin is fed alone, or the waste resin and the waste activated carbon are mixed and fed. In the waste oil feeding system (2), the waste oil is fed. The waste resin feeding system (1) is transported to the reactor system by hydraulic transport.

3. The radioactive waste treatment process according to claim 2, characterized in that: The lower part of the fast bed also has a waste feeding section (43), the inlet of the waste feeding section is connected to the outlet of the waste resin feeding system (1), and while the waste resin feeding system (1) is feeding, a dispersion gas is input at the inlet of the waste feeding section to disperse the feed of the waste resin feeding system (1) before entering the reactor system.

4. A radioactive waste treatment process according to claim 3, characterized in that: A mixture of air and water vapor is used as a gasifying agent and a fluidizing gas and is fed into the lower part of the fast bed (41).

5. A radioactive waste treatment process according to claim 4, characterized in that: It also provides a bed material adding system (3), which includes: a bed material device (31) for accommodating bed material and an additive device (32) for accommodating additives; the bed material and the additive share a feed port and are fed into the lower part of the fast bed.

6. The radioactive waste treatment process according to claim 5, characterized in that: The tail gas generated in the fluidized bed (42) enters the tail gas treatment system after passing through the cyclone separator (45). At the same time, an external circulation pipe (44) is provided between the lower part of the fluidized bed (42) and the lower part of the fast bed (41) to control the operation quality of the fluidized bed.

7. The radioactive waste treatment process according to claim 6, characterized in that: The tail gas treatment system includes: a dust removal and denitrification system (6) and a wet desulfurization system (7). The dust removal and denitrification system (6) is mainly composed of a high-temperature filter (61) and a medium-temperature denitrification filter (62). The denitrification temperature is 330-390°C. The denitrification agent is ammonia water. The bed material fine powder containing radionuclides carried in the tail gas intercepted by the filter is collected by the second waste collection tank (63) and the third waste collection tank (64).

8. The radioactive waste treatment process according to claim 7, characterized in that: The main equipment of the wet desulfurization system (7) is a washing tower (71), the desulfurization agent is mainly sodium hydroxide and sodium bicarbonate, and the cooling of the tail gas adopts direct mixing water spray cooling.

9. The radioactive waste treatment process according to claim 4, characterized in that: The inorganic matter includes: lithium, sodium, potassium, calcium, cesium, strontium, cobalt, boron, and sulfur elements; the gasifying agent is: air, water vapor, or a mixture of air and water vapor; the gas is: air, nitrogen, or a mixture of air and nitrogen; in the hydraulic conveying method, the hydraulic conveying feed nozzle adopts gas atomization and is provided with a jacket insulation measure, and the volume mixing ratio of the conveyed waste resin and water is 1:

1.

10. The radioactive waste treatment process according to claim 8, characterized in that: The salty wastewater discharged from the washing tower (71) is reused in the device, and the tail gas is discharged from the top of the washing tower (71) after being treated and purified by the tail gas treatment system, with the discharge temperature being less than 100°C.

11. The radioactive waste treatment process according to claim 1, characterized in that: For the waste resin raw material with a high boric acid content in the waste resin, a bed material separation system (5) is further provided between the first waste bed material collecting tank (46) and the lower part of the fast bed (41), which is mainly composed of a bed material separator (51). The waste bed material separated by the bed material separator (51) enters the first waste bed material collecting tank (46), and the usable bed material separated by the bed material separator (51) is transported back to the boiling bed (42) to selectively discharge particles with a high boron oxide B2O3 content in the bed material, thereby further improving the volume reduction ratio.

12. A radioactive waste treatment process according to claim 11, characterized in that: The bed material separator (51) is an air separation separator, including a non-cyclone separator.

13. The radioactive waste treatment process according to claim 6, characterized in that: The cyclone separator (45) comprises a built-in air separation separator and an external air separation separator.

14. The radioactive waste treatment process according to claim 5, characterized in that: The bed material is a non-uniform particle made of microporous aluminosilicate microspheres as a base material, and is matched with calcium oxide, active metals, and rare earth elements. The particle size range is 0 to 1000 μm. The bed material is both the basic bed material of the fluidized bed reactor and the carrier for enriching radioactive nuclides. The bed material has fluidization properties and radioactive nuclide accommodation properties, as well as desulfurization properties and carbon monoxide combustion-supporting properties.

15. The radioactive waste treatment process according to claim 14, characterized in that: The tail gas is subjected to dry desulfurization in the reactor system (4), and the tail gas is subjected to wet desulfurization in the tail gas treatment system.

16. A radioactive waste treatment equipment system, the radioactive waste comprising: Waste resin, waste activated carbon and waste oil, characterized by: The treatment equipment system comprises: a waste resin feeding system (1), a waste oil feeding system (2), a bed material adding system (3), a reactor system (4), a bed material separation system (5), a dust removal and denitrification system (6) and a wet desulfurization system (7); In the waste resin feeding system (1), the waste resin is fed alone or mixed with the waste activated carbon, and the waste resin and waste activated carbon are fed by hydraulic conveying; in the waste oil feeding system (2), the waste oil is fed by an oil pump; The reactor system comprises: a fluidized bed reactor and a first waste bed material collecting tank (46); the fluidized bed reactor comprises a fast bed (41) located at the bottom and a boiling bed (42) located at the top; the first waste bed material collecting tank (46) is arranged in communication with the lower part of the fast bed (41).

17. The radioactive waste treatment equipment system according to claim 16, characterized in that: A bed material separation system (5) is also provided between the first waste bed material collecting trough (46) and the lower part of the fast bed (41), mainly consisting of a bed material separator (51). The waste bed material separated by the bed material separator (51) enters the first waste bed material collecting trough (46), and the usable bed material separated by the bed material separator (51) is transported back to the fluidized bed (42).

18. The radioactive waste treatment equipment system according to claim 17, characterized in that: The components in the processing equipment system that come into contact with radioactive nuclides all adopt a metal inner wall structure.

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