Drying and salifying system and method for liquid radioactive waste of isotope test reactor

Abstract

A drying and salifying system for liquid radioactive waste of an isotope test reactor, comprising a buffer tank (10), a drying tank (20) and a covering mechanism (30). An inlet of the buffer tank (10) leads to a liquid waste source, the buffer tank (10) being provided with an acidity / basicity adjusting mechanism and a salt component adjusting mechanism; an opening of the drying tank (20) leads to an outlet of the buffer tank (10), and the drying tank (20) is provided with a drying mechanism, the drying mechanism being used for heating the drying tank (20), so that liquid waste in the drying tank (20) evaporates to form a salt; the covering mechanism (30) is used for covering the drying tank (20) so as to seal the drying tank (20).

Description

A system and method for drying and salting radioactive waste liquid from an isotope test reactor Technical Field

[0001] The present invention relates to the technical field of radioactive wastewater treatment, and in particular to a system and method for drying and salting radioactive waste liquid from an isotope test reactor. Background Art

[0002] As a new experimental reactor, the Medical Isotope Test Reactor (MITR) generates wastewater source terms characterized by complex salt composition, the presence of water-soluble volatile substances, a wide variety of radionuclides, high radioactivity, and a large treatment volume. This complexity and uniqueness of the source term impact the operational efficiency of the device, the target quality of the treated wastewater, and the economic and safety of production operations.

[0003] Currently, radioactive waste liquid is usually solidified by cement technology, but this technology will produce at least 60m 3 The radioactive solid waste generated during the temporary storage of the cement solidified body also generates maintenance costs, resulting in a large amount of manpower and material resources being consumed, and it is impossible to achieve effective treatment of radioactive waste liquid.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to provide an isotope test reactor radioactive waste liquid drying and salting system to solve the problem of high cost and unsatisfactory treatment effect when using cement solidification method to treat radioactive waste liquid.

[0006] The present invention is achieved through the following technical solutions:

[0007] An isotope test reactor radioactive waste liquid drying and salting system comprises: a buffer tank, the inlet of the buffer tank being connected to a waste liquid source, the buffer tank being provided with a pH adjustment mechanism and a salt composition adjustment mechanism; a drying tank, the tank port of the drying tank being connected to the outlet of the buffer tank, the drying tank being provided with a drying mechanism, the drying mechanism being used to heat the drying tank so that the waste liquid in the drying tank evaporates and forms salt; and a sealing mechanism being used to seal the drying tank.

[0008] Optionally, it further includes: a demister, the input end of the demister is connected to the drying tank through a steam pipe; a condenser cooler, the input end of the condenser cooler is connected to the output end of the demister; and a condensate tank, the inlet of the condensate tank is connected to the output end of the condensate cooler.

[0009] Optionally, the system further comprises: a filter, wherein the inlet of the filter is connected to the drying tank through the exhaust pipe, and the outlet of the filter is connected to the external environment.

[0010] Optionally, the sealing mechanism can be detachably engaged with the tank opening of the drying tank in a sealed manner, and the outlet of the buffer tank is connected to the drying tank through the sealing mechanism.

[0011] Optionally, the outlet of the buffer tank, the steam pipe and the exhaust pipe are all connected to the drying tank through the sealing mechanism.

[0012] Optionally, the output end of the demister is connected to the buffer tank through a first reflux pipe; the outlet of the condensate tank is connected to the buffer tank through a second reflux pipe.

[0013] Optionally, the system further comprises: a conveyor path for conveying the drying can in one direction, the capping mechanism being arranged directly above the starting end of the conveyor path; a lifting mechanism being provided at the starting end of the conveyor path for lifting the drying can so that the can opening at the top of the drying can contacts and is sealed with the capping mechanism.

[0014] Optionally, a surface dose detection mechanism is provided at the terminal end of the conveying path, and the surface dose detection mechanism is used to detect the surface quality of the drying can.

[0015] A method for drying and salifying radioactive waste liquid from an isotope test reactor is carried out using the above-mentioned system for drying and salifying radioactive waste liquid from an isotope test reactor, comprising the following steps:

[0016] Placing the drying can at the beginning of the conveying path, and using the lifting mechanism to lift the drying can until it contacts and seals the capping mechanism;

[0017] Passing the waste liquid source into the buffer tank, adjusting the pH and salt composition of the waste liquid source by the pH adjustment mechanism and the salt composition adjustment mechanism to obtain a treated liquid;

[0018] Passing the treated liquid into the drying tank, heating the treated liquid through the drying mechanism to obtain salt in the drying tank, steam in the steam pipe, and exhaust gas in the exhaust pipe;

[0019] Passing the steam into the demister to obtain mist in the demister, passing the mist into the condenser cooler for condensation to obtain condensate, and passing the condensate into the condensate tank for storage;

[0020] Passing the exhaust gas into the filter for filtration, and then emptying the exhaust gas after filtration;

[0021] The drying tank containing salt is capped by the capping mechanism, the capped drying tank is lowered to the conveying path by the lifting mechanism, and is conveyed to the terminal along the conveying path, and the surface quality of the drying tank is detected by the surface dosage detection mechanism.

[0022] Optionally, the pH value of the treatment liquid is neutral; the drying temperature of the drying mechanism is 145-155°C; the droplet diameter of the mist is ≥3μm; and the temperature of the condensate is 30-40°C.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] The present invention provides an isotope test reactor radioactive waste liquid drying and salting system. The system adopts the technical concept of drying and salting to replace the existing cement solidification method to treat radioactive waste liquid, effectively reducing the footprint of the treated product and effectively improving the safety of the process. Specifically, by providing a buffer tank, a pH adjustment mechanism, and a salt composition adjustment mechanism, the pH and salt composition of the waste liquid are pre-adjusted in the buffer tank to make the waste liquid suitable for the drying and salting operation. On this basis, by providing a drying tank and a drying mechanism, the adjusted waste liquid is passed into the drying tank and heated by the drying mechanism to evaporate the waste liquid and form salt. A sealing mechanism is provided on the drying tank to effectively seal the drying tank to prevent radioactive substances carried in the salt from contaminating the surrounding environment, allowing the salt to be transported together with the drying tank. Through the interaction of the above-mentioned features, the isotope test reactor radioactive waste liquid drying and salting system can effectively solve the problems of high cost and unsatisfactory treatment effect when treating radioactive waste liquid by the cement solidification method. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0026] FIG1 is a schematic diagram of an isotope test reactor radioactive waste liquid drying and salting system provided by an embodiment of the present invention;

[0027] FIG2 is a flow chart of a method for drying and salifying radioactive waste liquid from an isotope test reactor provided by an embodiment of the present invention.

[0028] The markings and corresponding component names in the accompanying drawings are: 10-buffer tank; 20-drying tank; 21-steam pipe; 22-exhaust pipe; 30-capping mechanism; 40-demister; 41-first reflux pipe; 50-condensation cooler; 60-condensate tank; 61-second reflux pipe; 70-filter; 80-transmission channel; 81-lifting mechanism; 82-surface dose detection mechanism. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0030] Example

[0031] Referring to Figure 1, an embodiment of the present invention provides an isotope test reactor radioactive waste liquid drying and salting system, comprising a buffer tank 10, the inlet of which is connected to a waste liquid source, and the buffer tank is provided with a pH adjustment mechanism and a salt composition adjustment mechanism; a second system comprises a drying tank 20, the tank port of which is connected to the outlet of the buffer tank 10, and the drying tank 20 is provided with a drying mechanism for heating the drying tank 20 to evaporate the waste liquid in the drying tank 20 and form salt; and a third system comprises a sealing mechanism 30, which is used to seal the drying tank 20 to seal the drying tank 21.

[0032] The isotope test reactor radioactive waste liquid drying and salting system provided in this embodiment utilizes the technical concept of drying and salting to treat radioactive waste liquid instead of the existing cement solidification method, effectively reducing the footprint of the treated product and effectively improving process safety. Specifically, by providing a buffer tank 10, a pH adjustment mechanism (not shown), and a salt composition adjustment mechanism (not shown), the pH and salt composition of the waste liquid are pre-adjusted within the buffer tank 10 to make the waste liquid suitable for drying and salting. Furthermore, by providing a drying tank 20 and a drying mechanism (not shown), the adjusted waste liquid is passed into the drying tank 20 and heated by the drying mechanism to evaporate the waste liquid and form salt. A sealing mechanism 30 is provided on the drying tank 20 to effectively seal the drying tank 20, preventing radioactive substances carried in the salt from contaminating the surrounding environment and allowing the salt to be transported together with the drying tank 20. The interaction of the aforementioned features enables the isotope test reactor radioactive waste liquid drying and salting system to effectively address the high cost and unsatisfactory treatment effects of cement solidification methods for treating radioactive waste liquid.

[0033] It should be noted that the above-mentioned pH adjustment mechanism can be implemented by any one of the existing technologies, such as a liquid supply tank containing acid and a liquid supply tank containing alkali, and acid or alkali is introduced according to the pH of the waste liquid to adjust the pH.

[0034] It should be noted that the above-mentioned salt component adjustment mechanism can be implemented by any one of the existing technologies, such as a material supply tank group, wherein each material supply tank contains materials with different components, so as to adaptively adjust the components of the waste liquid. The adjustment can be determined according to actual needs.

[0035] It should be noted that the above-mentioned drying mechanism can adopt any heating mechanism in the prior art, such as a heating coil, an electric heating rod, etc.

[0036] In order to effectively treat the steam generated during the drying and salting process, the above-mentioned isotope test reactor radioactive waste liquid drying and salting system also includes: a demister 40, the input end of which is connected to the drying tank 20 through a steam pipe 21; a condenser cooler 50, the input end of which is connected to the output end of the demister 40; and a condensate tank 60, the inlet of which is connected to the output end of the condensate cooler 50.

[0037] Through the above arrangement, the steam generated during the drying and salting process enters the demister 40 through the steam pipe 21. The demister 40 separates the droplets in the steam mist. The separated droplets are passed into the condenser cooler 50 for condensation to form condensate. The formed condensate is then stored in the condensate tank 60 to prevent the radioactive substances therein from contaminating the environment.

[0038] In order to effectively treat the waste gas generated during the salt formation process, the above-mentioned isotope test reactor radioactive waste liquid drying and salt formation system also includes: a filter 70, the inlet of the filter 70 is connected to the drying tank 20 through the waste gas pipe 22, and the outlet of the filter 70 is connected to the external environment.

[0039] In order to prevent radioactive substances contained in the waste liquid from polluting the environment during the salt formation process, the sealing mechanism 30 can be detachably matched with the tank opening of the drying tank 20, and the outlet of the buffer tank 10 is connected to the drying tank 20 through the sealing mechanism 30.

[0040] With the above arrangement, the lidding mechanism 30 is used to seal the opening of the drying tank 20 to prevent radioactive substances contained in the waste liquid in the drying tank 20 from contaminating the environment. Furthermore, by providing a connection between the outlet of the buffer tank 10 and the drying tank 20 via the lidding mechanism 30, the drying tank 20 can be independently separated from the lidding mechanism 30 while maintaining connectivity, for subsequent transportation.

[0041] Similarly, the outlet of the buffer tank 10 , the steam pipe 21 , and the exhaust pipe 22 are all connected to the drying tank 20 through the sealing mechanism 30 .

[0042] In order to further effectively utilize the condensate stored in the condensate tank 60 , the output end of the demister 40 is connected to the buffer tank 10 through a first reflux pipe 41 ; the outlet of the condensate tank 60 is connected to the buffer tank 10 through a second reflux pipe 61 .

[0043] In order to effectively transport the drying canister 20, the above-mentioned isotope test reactor radioactive waste liquid drying and salting system also includes: a conveying path 80, which is used to transport the drying canister 20 in one direction, and the sealing mechanism 30 is arranged directly above the starting end of the conveying path 80; a lifting mechanism 81 is provided at the starting end of the conveying path 80, and the lifting mechanism 81 is used to lift the drying canister 20 so that the canister opening at the top of the drying canister 20 contacts and is sealed with the sealing mechanism 30.

[0044] It should be noted that the jacking mechanism 81 may adopt any lifting structure in the prior art, such as a scissor lift or a hydraulic lift.

[0045] In order to detect the surface condition of the sealed drying tank 20 after salt formation and confirm the radiation residue on the tank surface, a surface dose detection mechanism 84 is provided at the terminal of the conveying path 80 to detect the surface quality of the drying tank 20.

[0046] This embodiment also provides a method for drying and salting radioactive waste liquid from an isotope test reactor, comprising the following steps:

[0047] S1, placing the drying can 20 at the beginning of the conveying path 80, and using the lifting mechanism 81 to lift the drying can 20 until it contacts and seals the capping mechanism 30;

[0048] S2, passing the waste liquid source into the buffer tank 10, adjusting the pH and salt composition of the waste liquid source by the pH adjustment mechanism and the salt composition adjustment mechanism to obtain a treated liquid;

[0049] S3, passing the treated liquid into the drying tank 20, and heating the treated liquid by the drying mechanism to obtain salt in the drying tank 20, steam in the steam pipe 21, and exhaust gas in the exhaust pipe 22;

[0050] S4.1. Passing the steam into the demister 40 to generate mist in the demister 40 , passing the mist into the condenser cooler 50 for condensation to generate condensate, and passing the condensate into the condensate tank 60 for storage;

[0051] S4.2, passing the exhaust gas into the filter 70 for filtration, and then emptying the exhaust gas after filtration;

[0052] S4.3. The drying tank 20 containing salt is capped by the capping mechanism 30 , and the capped drying tank 20 is lowered to the conveying path 80 by the lifting mechanism 81 . The drying tank 20 is conveyed to the terminal along the conveying path 80 , and the surface quality of the drying tank 20 is inspected by the surface dose inspection mechanism 84 .

[0053] The pH value of the treatment liquid is neutral; the drying temperature of the drying mechanism is 145-155° C.; the droplet diameter of the mist is ≥3 μm; and the temperature of the condensate is 30-40° C.

[0054] The reason for limiting the temperature of the condensate is that the content of volatile nuclides can be reduced at this temperature.

[0055] 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. An isotope test reactor radioactive waste liquid drying and salting system, It is characterized in that include: A buffer tank (10), the inlet of which is connected to a waste liquid source, and the buffer tank is provided with a pH adjustment mechanism and a salt component adjustment mechanism; a drying tank (20), wherein the tank opening of the drying tank (20) is connected to the outlet of the buffer tank (10), and the drying tank (20) is provided with a drying mechanism, wherein the drying mechanism is used to heat the drying tank (20) so that the waste liquid in the drying tank (20) evaporates and forms salt; A capping mechanism (30) is used to cap the drying tank (20) so as to seal the drying tank (21).

2. The isotope test reactor radioactive waste liquid drying and salting system according to claim 1, It is characterized in that Also includes: a demister (40), wherein an input end of the demister (40) is connected to the drying tank (20) via a steam pipe (21); A condenser cooler (50), wherein an input end of the condenser cooler (50) is connected to an output end of the demister (40); A condensate tank (60), wherein the inlet of the condensate tank (60) is connected to the output end of the condensate cooler (50).

3. The isotope test reactor radioactive waste liquid drying and salting system according to claim 2, It is characterized in that Also includes: A filter (70), wherein the inlet of the filter (70) is connected to the drying tank (20) through the exhaust pipe (22), and the outlet of the filter (70) is connected to the external environment.

4. The isotope test reactor radioactive waste liquid drying and salting system according to claim 3, It is characterized in that The sealing mechanism (30) can be detachably matched with the tank opening of the drying tank (20) in a sealed manner, and the outlet of the buffer tank (10) is connected to the drying tank (20) through the sealing mechanism (30).

5. The isotope test reactor radioactive waste liquid drying and salting system according to claim 4, It is characterized in that The outlet of the buffer tank (10), the steam pipe (21) and the exhaust pipe (22) are all connected to the drying tank (20) through the sealing mechanism (30).

6. The isotope test reactor radioactive waste liquid drying and salting system according to claim 5, It is characterized in that The output end of the demister (40) is in communication with the buffer tank (10) via a first reflux pipe (41); The outlet of the condensate tank (60) is connected to the buffer tank (10) via a second reflux pipe (61).

7. The isotope test reactor radioactive waste liquid drying and salting system according to claim 5, It is characterized in that Also includes: A conveying path (80), the conveying path (80) is used for unidirectionally conveying the drying can (20), and the capping mechanism (30) is arranged just above the starting end of the conveying path (80); A lifting mechanism (81) is provided at the beginning of the conveying path (80), and the lifting mechanism (81) is used to lift the drying tank (20) so that the tank opening at the top of the drying tank (20) contacts and is sealed with the capping mechanism (30).

8. The isotope test reactor radioactive waste liquid drying and salting system according to claim 7, It is characterized in that A surface dose detection mechanism (82) is provided at the terminal of the conveying path (80), and the surface dose detection mechanism (84) is used to detect the surface quality of the drying tank (20).

9. A method for drying and salting radioactive waste liquid from an isotope test reactor, It is characterized in that The isotope test reactor radioactive waste liquid drying and salting system according to claim 8 is used, comprising the following steps: Placing the drying tank (20) at the beginning of the conveying path (80), and lifting the drying tank (20) by the lifting mechanism (81) until the drying tank (20) contacts and seals the sealing mechanism (30); The waste liquid source is introduced into the buffer tank (10), and the waste liquid is adjusted by the pH adjustment mechanism and the salt component adjustment mechanism. Adjusting the pH and salt components of the waste liquid source to obtain a treated liquid; Passing the treated liquid into the drying tank (20), heating the treated liquid through the drying mechanism, so as to obtain salt in the drying tank (20), obtain steam in the steam pipe (21), and obtain exhaust gas in the exhaust pipe (22); Passing the steam into the demister (40) to obtain mist in the demister (40), passing the mist into the condenser cooler (50) for condensation to obtain condensate, and passing the condensate into the condensate tank (60) for storage; Passing the exhaust gas into the filter (70) for filtration and then discharging the exhaust gas after filtration; The drying tank (20) containing salt is capped by the capping mechanism (30), the capped drying tank (20) is lowered to the conveying path (80) by the lifting mechanism (81), and is conveyed to a terminal along the conveying path (80), and the surface quality of the drying tank (20) is detected by the surface dosage detection mechanism (82).

10. The method for drying and salting radioactive waste liquid from an isotope test reactor according to claim 9, Features: The pH value of the treatment liquid is neutral; The drying temperature of the drying mechanism is 145-155°C; The droplet diameter of the mist is ≥3 μm; The temperature of the condensate is 30-40°C.

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