Device for transferring and collecting radioactive special gas

Abstract

The invention relates to a device for transferring and collecting radioactive special gas. The device comprises a bracket and a collecting column arranged on the bracket, the collecting column comprises a vacuum cover and a collecting column, wherein a vacuum cavity is formed in the vacuum cover; the high-vacuum gate valve is arranged on the vacuum cover and divides the vacuum cavity into an upper vacuum cavity and a lower vacuum cavity; a secondary cold head of the GM refrigerator is arranged in the lower vacuum cavity; the flexible corrugated pipe is arranged above the high-vacuum gate valve; and the product tank is arranged on the periphery of the flexible corrugated pipe. The temperature of the product tank can be reduced to-260 DEG C by using the G-M refrigerator, high-purity radioactive special gas is effectively condensed, and then the gas is collected through pressure generated by temperature difference; according to the innovative design suitable for combination of the flexible corrugated pipe and the gate valve, the product tank can be lifted by introducing helium so as to be taken out, meanwhile, the vacuum cavity can be protected by introducing the helium, and air is prevented from entering the vacuum cavity to cause frosting of the second-stage cold head.

Description

Technical Field

[0001] The invention relates to the technical field of spent fuel treatment in nuclear power plants, and in particular to a device for transferring and collecting radioactive special gases. Background Art

[0002] Spent fuel, also known as irradiated nuclear fuel, is used nuclear fuel that has been exposed to radiation, usually produced by nuclear reactors in nuclear power plants. The process tail gas discharged during the post-processing of spent fuel or the operation of nuclear power plants contains a variety of radioactive gas nuclides, such as Kr-85, Xe-133, etc.

[0003] In order to extract radioactive special gases with practical value, the process tail gas is subjected to multiple process flows such as pretreatment, adsorption and purification to obtain a mixture of radioactive special gases and carrier gases. In order to separate the radioactive special gases with higher purity from the mixed gas, a low-temperature freezing method is used to condense the special gases and separate them from other gases. Subsequently, the condensed radioactive special gases need to be heated back to room temperature or gas close to room temperature, and then transferred and collected into special containers. Considering the importance of this process, it is necessary to develop a device specifically for transferring and collecting high-purity radioactive special gases. Such a device can ensure the safety and efficiency of the special gases during the transfer and collection process. Summary of the invention

[0004] The purpose of the present invention is to provide a device for transferring and collecting radioactive special gases in order to overcome at least one of the defects of the above-mentioned prior art, which can realize the transfer and collection of radioactive special gases after freezing and separation.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A device for transferring and collecting radioactive special gases, comprising a bracket and a collecting column arranged on the bracket;

[0007] The collection column comprises:

[0008] A vacuum cover, wherein a vacuum chamber is provided in the vacuum cover;

[0009] A high vacuum gate valve, which is arranged on the vacuum cover to divide the vacuum chamber into an upper vacuum chamber and a lower vacuum chamber;

[0010] A GM refrigerator, wherein a secondary cold head of the GM refrigerator is arranged in the lower vacuum chamber;

[0011] A flexible bellows, wherein the flexible bellows is arranged above the high vacuum gate valve;

[0012] A product tank is arranged outside the flexible bellows.

[0013] Furthermore, the device also includes a first lead shell component; the first lead shell component is arranged on the periphery of the flexible bellows, and the flexible bellows partially extends into the upper vacuum chamber.

[0014] Furthermore, the device also includes a second lead shell component; the second lead shell component is arranged on the periphery of the vacuum cover to wrap the lower vacuum chamber.

[0015] Furthermore, the device is also provided with an upper flange plate and a lower flange plate; the lower flange plate is installed on the upper end surface of the second lead shell assembly, and the four corners of the lower flange plate are provided with limiting guide rods; the four corners of the upper flange plate penetrate the limiting guide rods.

[0016] Furthermore, a handle is provided between the upper flange plate and the product tank for connecting the two.

[0017] Furthermore, a clamp is sleeved on the flexible bellows, and the flexible bellows and the product tank are connected into one body through the clamp, and the clamp is preferably a KF clamp.

[0018] Furthermore, the lower vacuum chamber is provided with a vacuum port, and a vacuum gauge arranged on the vacuum port.

[0019] Furthermore, the device is also provided with a cooling component, which includes a water chiller and a helium compressor; a water pipe is connected between the water chiller and the helium compressor; and a helium pipeline is connected between the helium compressor and the GM refrigerator.

[0020] Furthermore, the device is also provided with a measurement and control system, which includes vacuum degree measurement of the vacuum chamber, target point temperature measurement, pneumatic valve motion control, and pressure measurement. A vacuum gauge is installed in the lower chamber for vacuum degree measurement of the vacuum chamber. Low temperature sensors are arranged at the secondary cold heads. A pneumatic valve is installed in each of the main air intake line and the branch line, and a pressure transmitter is installed in the main air intake line.

[0021] Furthermore, the collecting column is installed on a bracket, the temperature display is integrated in a control cabinet, and the helium compressor and the chiller are placed separately.

[0022] Furthermore, the product tank is closed by a valve.

[0023] Furthermore, a shielding cover is provided on the periphery of the secondary cold head.

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

[0025] (1) The GM refrigerator can reduce the temperature of the specially designed product tank to as low as -260°C, which can effectively condense high-purity radioactive special gases and then collect the gases through the pressure generated by the temperature difference.

[0026] (2) The combination of GM refrigerator and heater can accurately enhance the stability of temperature control and operating efficiency.

[0027] (3) The innovative design of the flexible bellows combined with the gate valve can lift the product tank by introducing helium to remove the product tank. At the same time, the helium can protect the vacuum chamber and prevent air from entering and causing frost on the secondary cold head.

[0028] During the collection process, the product tank is fixed with a clamp, and the vacuum is drawn to compress the flexible bellows, driving the product tank to fall, so that the bottom of the product tank fits tightly with the secondary cold head. After the collection is completed, helium is introduced into the vacuum chamber under the collection column. Under the action of air pressure, the flexible bellows is lifted up, driving the product tank to separate from the secondary cold head, stopping the refrigeration, and then opening the gate valve to isolate the upper vacuum chamber from the lower vacuum chamber to prevent air from entering the lower vacuum chamber and frosting on the surface of the secondary cold head at ultra-low temperature. Finally, the clamp is removed to take out the product tank.

[0029] (4) It can complete the transfer and collection of special gases after freezing, ensure sealing, have radiation protection function, and can stably operate to obtain quantitative product tanks, that is, ensure the safety and efficiency of special gases during the transfer and collection process.

[0030] (5) The device can be automatically controlled and remotely controlled by using pneumatic valves, pressure transmitters, SMD heaters and DC power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a device for transferring and collecting radioactive special gases in an embodiment;

[0032] Figure 2 To collect the column structure diagram in the embodiment;

[0033] Figure 3 To collect column profiles in the examples;

[0034] Figure 4 This is one of the installation schematic diagrams of the product tank in the embodiment;

[0035] Figure 5 This is the second installation diagram of the product tank in the embodiment;

[0036] Figure 6 It is a schematic diagram of the process flow in the embodiment;

[0037] As shown in the figure: 1-collection column; 2-bracket; 3-upper flange plate; 4-limit guide rod; 5-lower flange plate; 6-high vacuum plug valve; 7-GM refrigerator; 8-handle; 9-first lead shell assembly; 10-second lead shell assembly; 11-vacuum cover; 12-vacuum reserved hole and vacuum valve; 13-clamp; 14-flexible bellows; 15-product tank; 16-shielding cover; 17-secondary cold head; 18-helium compressor; 19-chiller; 20-temperature display; 21-pressure transmitter; 22-molecular pump; 23-vacuum valve; 24-manual ball valve; 1A, 1B-pneumatic valve. DETAILED DESCRIPTION

[0038] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0039] Example

[0040] During the reprocessing of spent fuel, the process tail gas produced during shear dissolution contains a variety of radioactive gas nuclides, such as Kr-85, Xe-133, and Xe-135. After collecting the process tail gas and undergoing a series of process treatments, krypton gas containing a mixture of radioactive isotope Kr-85 and helium carrier gas can be obtained. The krypton gas is separated from the helium gas by cryogenic freezing. The frozen krypton needs to be transferred and collected in a specific container.

[0041] Based on the above application, this embodiment proposes a device for transferring and collecting radioactive special gases, which can realize krypton gas transfer and collection. The specific structure is shown in Figure 1-5 .

[0042] The device comprises a support 2 and a collecting column 1 arranged on the support 2;

[0043] The collecting column 1 comprises: a vacuum cover 11, wherein the vacuum cover 11 has a vacuum chamber; a high vacuum gate valve 6, wherein the high vacuum gate valve 6 is arranged on the vacuum cover 11 to divide the vacuum chamber into an upper vacuum chamber and a lower vacuum chamber; a GM refrigerator 7, wherein a secondary cold head 17 of the GM refrigerator 7 is arranged in the lower vacuum chamber; a flexible bellows 14, wherein the flexible bellows 14 is arranged above the high vacuum gate valve 6; and a product tank 10, wherein the product tank 10 is arranged on the periphery of the flexible bellows 14.

[0044] In this embodiment, the device further includes a first lead shell component 9; the first lead shell component 9 is arranged on the periphery of the flexible bellows 14, and the flexible bellows 14 partially extends into the upper vacuum chamber.

[0045] In this embodiment, the device further includes a second lead shell component 10; the second lead shell component 10 is arranged on the periphery of the vacuum cover 11 to wrap the lower vacuum chamber.

[0046] In this embodiment, the device is further provided with an upper flange plate 3 and a lower flange plate 5; the lower flange plate 5 is installed on the upper end surface of the second lead shell assembly 10, and the four corners of the lower flange plate 5 are provided with limiting guide rods 4; the four corners of the upper flange plate 3 penetrate the limiting guide rods 4, that is, the flexible bellows 14 is installed on the upper part of the high vacuum gate valve 6, which can ensure the up and down movement of the product tank 10 within a certain stroke, and the upper flange of the flexible bellows 14 is limited by four limiting guide rods to ensure that the movement direction is basically vertical.

[0047] In this embodiment, a handle 8 is provided between the upper flange plate 3 and the product tank 10 for connecting the two.

[0048] In this embodiment, a clamp 13 , preferably a KF clamp, is sleeved on the flexible bellows 14 , and the flexible bellows 14 and the product tank 10 are connected as one through the clamp 13 .

[0049] In this embodiment, the lower vacuum chamber is provided with a vacuum port and a vacuum gauge provided on the vacuum port. Specifically, the lower vacuum chamber is mainly used to form a vacuum for the GM refrigerator 7. The GM refrigerator 7 is installed in an inverted manner, directly installed on the flange plate, located at the bottom of the freezing column, and a vacuum port and a vacuum gauge are installed on the lower cavity.

[0050] In this embodiment, the device is also provided with a cooling component, which includes a water chiller and a helium compressor; a water pipe is connected between the water chiller and the helium compressor; a helium pipeline is connected between the helium compressor and the GM refrigerator 7.

[0051] In this embodiment, the product tank 10 is closed by a valve.

[0052] In this embodiment, a shielding cover 16 is disposed on the periphery of the secondary cold head 17 .

[0053] See also Figure 4-6 The device workflow of this embodiment is specifically as follows:

[0054] The flexible bellows 14 is in the retracted position. The high vacuum gate valve 6 is fully opened to penetrate the upper vacuum chamber and the lower vacuum chamber. The product tank is fixed with the clamp 13, and then the vacuum chamber of the collection column is evacuated to compress the flexible bellows 14, driving the product tank 15 to be close to the secondary cold head 17.

[0055] Open the pneumatic valve 1B on the inlet pipeline and open the manual ball valve 24 on the inlet of the product tank 15.

[0056] After the product tank 15 is evacuated using the molecular pump 22 , the pneumatic valve 1B and the manual ball valve 24 are closed.

[0057] Open the pneumatic valve 1A and the vacuum valve 23;

[0058] After the vacuum chamber is evacuated using the molecular pump 22, the vacuum valve 23 and the pneumatic valve 1A are closed.

[0059] The water chiller 18 and the helium compressor 19 are turned on to cool to a certain temperature.

[0060] Heat the frozen krypton, open the pneumatic valve 1B and the manual ball valve 24, transfer the krypton gas to the product tank 15, and after the transfer is completed, close the manual ball valve 24 at the inlet of the product tank 15.

[0061] A certain amount of helium is introduced into the vacuum chamber, and the flexible bellows 14 begins to rise under the action of air pressure, and is manually assisted to rise. After rising to the highest position, the introduction of helium is stopped, and the vacuum valve 23 and the pneumatic valve 1A are closed.

[0062] Close the high vacuum gate valve 6, open the clamp 13 on the product tank 15, and take out the product tank 15.

[0063] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A device for transferring and collecting radioactive special gases, comprising a support (2), characterized in that: It also includes a collection column (1) arranged on a support (2); The collection column (1) comprises: A vacuum cover (11), wherein the vacuum cover (11) has a vacuum chamber; A high vacuum gate valve (6), wherein the high vacuum gate valve (6) is arranged on the vacuum cover (11) to divide the vacuum chamber into an upper vacuum chamber and a lower vacuum chamber; A GM refrigerator (7), wherein a secondary cold head (17) of the GM refrigerator (7) is arranged in the lower vacuum chamber; a flexible bellows (14), wherein the flexible bellows (14) is arranged above the high vacuum gate valve (6); A product tank (10), wherein the product tank (10) is arranged outside the flexible bellows (14).

2. The device for transferring and collecting radioactive special gases according to claim 1, characterized in that: The device also includes a first lead shell component (9); The first lead shell component (9) is arranged on the periphery of the flexible bellows (14), and a portion of the flexible bellows (14) extends into the upper vacuum chamber.

3. The device for transferring and collecting radioactive special gases according to claim 1, characterized in that: The device also includes a second lead shell assembly (10); The second lead shell component (10) is arranged on the periphery of the vacuum cover (11) and wraps the lower vacuum chamber.

4. The device for transferring and collecting radioactive special gases according to claim 3, characterized in that: The device is also provided with an upper flange plate (3) and a lower flange plate (5); The lower flange plate (5) is mounted on the upper end surface of the second lead shell assembly (10), and limiting guide rods (4) are arranged at the four corners of the lower flange plate (5); the limiting guide rods (4) are passed through the four corners of the upper flange plate (3).

5. The device for transferring and collecting radioactive special gases according to claim 4, characterized in that: A handle (8) is provided between the upper flange plate (3) and the product tank (10) for connecting the two.

6. The device for transferring and collecting radioactive special gases according to claim 1, characterized in that: The flexible bellows (14) is sleeved with a clamp (13), and the flexible bellows (14) and the product tank (10) are connected into one body via the clamp (13).

7. The device for transferring and collecting radioactive special gases according to claim 1, characterized in that: The lower vacuum chamber is provided with a vacuum extraction port and a vacuum gauge arranged on the vacuum extraction port.

8. The device for transferring and collecting radioactive special gases according to claim 1, characterized in that: The device is also provided with a cooling component, which includes a water chiller and a helium compressor; A water pipe is connected between the water chiller and the helium compressor; and a helium pipeline is connected between the helium compressor and the GM refrigerator (7).

9. The device for transferring and collecting radioactive special gases according to claim 1, characterized in that: The product tank (10) is closed by a valve.

10. The device for transferring and collecting radioactive special gases according to claim 1, characterized in that: A shielding cover (16) is arranged on the periphery of the secondary cold head (17).

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