A uranium hexafluoride secondary sampling quantitative device and sampling method thereof

Abstract

The present invention belongs to the technical field of physical and chemical testing in uranium enrichment plants, and particularly relates to a uranium hexafluoride secondary sampling and quantitative device and a sampling method thereof. The device comprises: a sampling bottle, a sample storage container joint, a sample injection volume control valve, a sample injection volume tube, a monitoring port, a valve, a pressure gauge joint, a pressure gauge, a quantitative container and a system joint; one end of the sample storage container joint is connected to the sampling bottle, and the other end of the sample storage container joint is connected to the sample injection volume control valve; the sample injection volume control valve and one end of the sample injection volume tube are threadedly connected via a pipe sleeve joint, and the other end of the sample injection volume tube is welded to the quantitative container; one end of the monitoring port and one end of the valve are sealed via a threaded interface; the other end of the valve is connected to a pressure gauge joint and a pressure gauge; the other end of the monitoring port is welded to the quantitative container; and one end of the system joint is welded to the quantitative container.

Description

Technical Field

[0001] The invention belongs to the technical field of physical and chemical detection in uranium enrichment plants, and particularly relates to a uranium hexafluoride secondary sampling and quantitative device and a sampling method thereof. Background Art

[0002] Uranium enrichment plants typically use a specialized sampling bottle to collect a portion of product or raw material before transferring it to the laboratory for analysis. Prior art techniques, during the physical and chemical testing process, operators connect the sampling bottle to an evacuated manifold to divert the uranium hexafluoride (UF6) into specialized smaller containers required for laboratory analysis. This process is known as "secondary sampling." The amount of UF6 sampled during secondary sampling directly impacts the success of subsequent physical and chemical testing. Therefore, to ensure more accurate UF6 quantitative secondary sampling, a dedicated UF6 secondary sampling device and sampling method were designed. This device, integrated into the sampling system, allows for more precise control of the sample size and improves efficiency. Summary of the Invention

[0003] The present invention aims to design a uranium hexafluoride secondary sampling quantitative device and sampling method to address the above-mentioned deficiencies in the existing technology, so as to solve the technical problems of the difficulty in controlling the sampling amount and the inability to quantify and standardize the operation during the secondary sampling process of uranium enrichment plants.

[0004] The technical solution of the present invention is:

[0005] A uranium hexafluoride secondary sampling and quantitative device comprises: a sampling bottle, a sample storage container joint 1, a sample injection volume control valve 2, a sample injection volume tube 3, a monitoring port 4, a valve 5, a pressure gauge joint 6, a pressure gauge 7, a quantitative container 8 and a system joint 9; one end of the sample storage container joint 1 is connected to the sampling bottle, and the other end of the sample storage container joint 1 is connected to the sample injection volume control valve 2; the sample injection volume control valve 2 and one end of the sample injection volume tube 3 are threadedly connected via a pipe sleeve joint, and the other end of the sample injection volume tube 3 is welded to the quantitative container 8; one end of the monitoring port 4 and one end of the valve 5 are sealed via a threaded interface; the other end of the valve 5 is connected to the pressure gauge joint 6 and the pressure gauge 7; the other end of the monitoring port 4 is welded to the quantitative container 8; and one end of the system joint 9 is welded to the quantitative container 8.

[0006] As described above, the sample storage container connector 1 includes: an upper connector 11 of the sample storage container connector and a lower interface 12 of the sample storage container connector; the upper connector 11 of the sample storage container connector is welded to the lower interface 12 of the sample storage container connector; the lower interface 12 of the sample storage container connector is cylindrical as a whole and has an external thread on the outer wall for fixing the loading container threaded connection; the lower interface 12 of the sample storage container connector is also provided with an internal through hole 13 of the sample storage container connector and a sample storage container connector connection port 14.

[0007] As described above, the injection volume tube 3 includes: an outer tube 31 of the injection volume tube, an injection volume tube connector 32, an injection volume tube connector sealing cap 33 and an injection volume tube inner tube 34; the injection volume tube inner tube 34 is arranged inside the outer tube 31 of the injection volume tube, and the injection volume tube inner tube 34 is welded to the injection volume tube connector 32, and the injection volume tube connector 32 is provided with an injection volume tube connector sealing cap 33.

[0008] As described above, the pressure gauge joint 6 includes: an upper connection end 61 of the pressure gauge joint and a lower connection end 63 of the pressure gauge joint; the upper connection end 61 of the pressure gauge joint is welded to the lower connection end 63 of the pressure gauge joint; a pressure gauge joint internal through tube 62 is provided inside the upper connection end 61 of the pressure gauge joint, and a pressure gauge joint sealing interface 64 is provided inside the lower connection end 63 of the pressure gauge joint; the pressure gauge joint sealing interface 64 is communicated with the pressure gauge joint internal through tube 62.

[0009] As mentioned above, a raw tape is provided between the pressure gauge 7 and the pressure gauge joint sealing interface 64; the pressure gauge joint sealing interface 64 is a cylindrical groove as a whole, and an internal thread is provided on the inner wall.

[0010] As described above, the system connector 9 includes: a sample guide tube 91, a sample outlet connector 92 and a sample outlet sealing cap 93; the sample guide tube 91 is welded with the sample outlet connector 92; the sample outlet connector 92 is threadedly connected to the sample outlet sealing cap 93; the sample guide tube 91 is used to guide the sample in the sample quantification device to the sample sealing system.

[0011] As mentioned above, the quantitative container 8 is located between the sampling bottle and the sample manifold as a buffer container and a quantitative control device after the sample is injected. The quantitative container 8 ensures that the temperature in the system is constant during the experiment, and the temperature of the quantitative container 8 is controlled not to exceed 60°C. The pressure in the quantitative container 8 does not exceed 0.1 MPa. The diffusion of gaseous uranium hexafluoride in the sample separation system satisfies the ideal gas state equation P·V=n·R·T…………(1)

[0012] Where: R is a constant, P represents the pressure of uranium hexafluoride; V represents the effective volume of the quantitative device, n represents the amount of uranium hexafluoride, and T represents the temperature of uranium hexafluoride;

[0013] therefore According to the physical properties of uranium hexafluoride, the temperature T in formula (2) is proportional to the saturated vapor pressure P. When the temperature is constant, the pressure of uranium hexafluoride in the system is stable. The sample volume requirement of the special loading container is 8g to 10g. After removing the sample loss during the sampling process, the quantitative design is based on a sample volume of 10g. After the corresponding relationship between the temperature and saturated vapor pressure of uranium hexafluoride is known, the n value is calculated based on 10g of uranium hexafluoride, and the change in the volume of the quantitative container 8 at different temperatures can be obtained. The quantitative container 8 is designed to be a cylindrical structure according to the internal volume of the constant temperature box, and the radius is selected as 40mm. The corresponding size value of the height of the cylindrical quantitative container 8 is calculated.

[0014] The sampling method of the uranium hexafluoride secondary sampling and quantitative device as described above comprises the following steps:

[0015] Step 1: Connect the quantitative container 8 to the sampling system and perform a pressure test with compressed air. No leakage is found under a pressure of 0.85 MPa. After the mechanical pump is turned on and the system is evacuated, the ultimate vacuum value is less than 10 Pa. A helium mass spectrometer is used for leak detection. The static leakage rate of the system is less than 1×10- 8 Pa·L / s; then the system is passivated;

[0016] Step 2: After the passivation work is completed, a sampling volume test is carried out. A total of 10 tests are carried out. Each time, the quantitative control device controls the pressure to increase by 50mbar; the sampling volume under the corresponding pressure is counted respectively; after multiple tests and assessments, the control error of the sampled weight is less than 0.5g.

[0017] The present invention has the following beneficial effects:

[0018] 1) The uranium hexafluoride secondary sampling and quantitative device designed in this invention can accurately control the weight of the sample package. This improves the sampling volume control accuracy, reduces sample consumption during the preparation process, improves work efficiency, and reduces production labor intensity.

[0019] 2) The uranium hexafluoride secondary sampling and quantitative device designed in the present invention controls the pressure of uranium hexafluoride within the device by controlling its temperature, so that uranium hexafluoride is always evenly distributed in the device in a gaseous state. The amount of subsample collected in the collection container can be accurately controlled, and the weight error of the subsamples taken by the device of the present invention is controlled to less than 0.5g. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a uranium hexafluoride secondary sampling and quantitative device designed by the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of the sample storage container joint in the uranium hexafluoride secondary sampling and quantitative device designed by the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the sample injection tube in the uranium hexafluoride secondary sampling and quantitative device designed by the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of the pressure gauge joint in the uranium hexafluoride secondary sampling and quantitative device designed by the present invention;

[0024] Figure 5 This is a schematic diagram of the system connector structure in the uranium hexafluoride secondary sampling and quantitative device designed by the present invention;

[0025] Among them, 1 is the sample storage container connector, 2 is the injection volume control valve, 3 is the injection volume tube, 4 is the monitoring port, 5 is the valve, 6 is the pressure gauge connector, 7 is the pressure gauge, 8 is the quantitative container, and 9 is the external connection connector;

[0026] 11 is the upper connector of the sample storage container connector; 12 is the lower interface of the sample storage container connector; 13 is the internal through hole of the sample storage container connector; 14 is the connection port of the sample storage container connector; 31 is the outer tube of the sample injection tube; 32 is the sample injection tube connector; 33 is the sealing cap of the sample injection tube connector; 34 is the internal tube of the sample injection tube; 61 is the upper connection end of the pressure gauge connector; 62 is the internal tube of the pressure gauge connector; 63 is the lower connection end of the pressure gauge connector; 64 is the sealing interface of the pressure gauge connector; 91 is the sample diversion tube; 92 is the sample outlet connector; 93 is the sample outlet sealing cap DETAILED DESCRIPTION

[0027] The following further describes a uranium hexafluoride secondary sampling quantitative device and a sampling method thereof of the present invention:

[0028] like Figures 1 to 5 As shown, a secondary sampling and quantitative device for uranium hexafluoride includes: a sampling bottle, a sample storage container connector 1, a sample injection volume control valve 2, a sample injection volume tube 3, a monitoring port 4, a valve 5, a pressure gauge connector 6, a pressure gauge 7, a quantitative container 8, and a system connector 9; one end of the sample storage container connector 1 is connected to the sampling bottle, and the other end of the sample storage container connector 1 is connected to the sample injection volume control valve 2; the sample injection volume control valve 2 and one end of the sample injection volume tube 3 are threadedly connected via a pipe sleeve connector, and the other end of the sample injection volume tube 3 is welded to the quantitative container 8; one end of the monitoring port 4 and one end of the valve 5 are sealed via a threaded interface; the other end of the valve 5 is connected to the pressure gauge connector 6 and the pressure gauge 7; the other end of the monitoring port 4 is welded to the quantitative container 8; and one end of the system connector 9 is welded to the quantitative container 8.

[0029] As described above, the sample storage container connector 1 includes: an upper connector 11 of the sample storage container connector and a lower interface 12 of the sample storage container connector; the upper connector 11 of the sample storage container connector is welded to the lower interface 12 of the sample storage container connector; the lower interface 12 of the sample storage container connector is cylindrical as a whole and has an external thread on the outer wall for fixing the loading container threaded connection; the lower interface 12 of the sample storage container connector is also provided with an internal through hole 13 of the sample storage container connector and a sample storage container connector connection port 14.

[0030] As described above, the injection volume tube 3 includes: an outer tube 31 of the injection volume tube, an injection volume tube connector 32, an injection volume tube connector sealing cap 33 and an injection volume tube inner tube 34; the injection volume tube inner tube 34 is arranged inside the outer tube 31 of the injection volume tube, and the injection volume tube inner tube 34 is welded to the injection volume tube connector 32, and the injection volume tube connector 32 is provided with an injection volume tube connector sealing cap 33.

[0031] As described above, the pressure gauge joint 6 includes: an upper connection end 61 of the pressure gauge joint and a lower connection end 63 of the pressure gauge joint; the upper connection end 61 of the pressure gauge joint is welded to the lower connection end 63 of the pressure gauge joint; a pressure gauge joint internal through tube 62 is provided inside the upper connection end 61 of the pressure gauge joint, and a pressure gauge joint sealing interface 64 is provided inside the lower connection end 63 of the pressure gauge joint; the pressure gauge joint sealing interface 64 is communicated with the pressure gauge joint internal through tube 62.

[0032] As mentioned above, a raw tape is provided between the pressure gauge 7 and the pressure gauge joint sealing interface 64; the pressure gauge joint sealing interface 64 is a cylindrical groove as a whole, and an internal thread is provided on the inner wall.

[0033] As described above, the system connector 9 includes: a sample guide tube 91, a sample outlet connector 92 and a sample outlet sealing cap 93; the sample guide tube 91 is welded with the sample outlet connector 92; the sample outlet connector 92 is threadedly connected to the sample outlet sealing cap 93; the sample guide tube 91 is used to guide the sample in the sample quantification device to the sample sealing system.

[0034] As mentioned above, the quantitative container 8 is located between the sampling bottle and the sample manifold as a buffer container and a quantitative control device after the sample is injected. The quantitative container 8 ensures that the temperature in the system is constant during the experiment, and the temperature of the quantitative container 8 is controlled not to exceed 60°C. The pressure in the quantitative container 8 does not exceed 0.1 MPa. The diffusion of gaseous uranium hexafluoride in the sample separation system satisfies the ideal gas state equation P·V=nR·T…………(1)

[0035] Where: R is a constant, P represents the pressure of uranium hexafluoride; V represents the effective volume of the quantitative device, n represents the amount of uranium hexafluoride, and T represents the temperature of uranium hexafluoride;

[0036] therefore According to the physical properties of uranium hexafluoride, the temperature T in formula (2) is proportional to the saturated vapor pressure P. When the temperature is constant, the pressure of uranium hexafluoride in the system is stable. The sample volume requirement for the dedicated loading container is 8g to 10g. After eliminating sample loss during the extraction process, the quantitative design is based on a sample volume of 10g. After knowing the corresponding relationship between the temperature and saturated vapor pressure of uranium hexafluoride, the value of n is calculated based on 10g of uranium hexafluoride, and the change in the volume of the quantitative container 8 at different temperatures can be obtained. The quantitative container 8 is designed to be a cylindrical structure based on the internal volume of the constant temperature chamber, with a radius of 40mm. The corresponding height value of the cylindrical quantitative container 8 is calculated. Uranium hexafluoride is selected as the volume parameter of the device at 55°C.

[0037] The sampling method of the uranium hexafluoride secondary sampling and quantitative device as described above comprises the following steps:

[0038] Step 1: Connect the quantitative container 8 to the sampling system and perform a pressure test with compressed air. No leakage is found under a pressure of 0.85 MPa. After the mechanical pump is turned on and the system is evacuated, the ultimate vacuum value is less than 10 Pa. A helium mass spectrometer is used for leak detection. The static leakage rate of the system is less than 1×10 -8 Pa·L / s; then the system is passivated;

[0039] Step 2: After the passivation work is completed, a sampling volume test is carried out. A total of 10 tests are carried out. Each time, the quantitative control device controls the pressure to increase by 50mbar; the sampling volume under the corresponding pressure is counted respectively; after multiple tests and assessments, the control error of the sampled weight is less than 0.5g.

[0040] Example:

[0041] Experiments have shown that the diffusion of gaseous uranium hexafluoride within the sample distribution system satisfies the ideal gas state equation. The temperature of uranium hexafluoride is directly proportional to its saturated vapor pressure, and the pressure of uranium hexafluoride within the system remains stable when the temperature is constant. The device of the present invention controls the pressure of uranium hexafluoride within the system by controlling its temperature, ensuring that the uranium hexafluoride is uniformly distributed within the device in a gaseous state. To accurately control the amount of subsample collected in the collection container, a quantitative container 8 is designed into the device of the present invention.

[0042] Connect the quantitative container 8 to the sampling system and perform a pressure test using compressed air. No leakage is observed at a pressure of 0.85 MPa. After the mechanical pump is turned on to evacuate the system, the ultimate vacuum value is less than 10 Pa. A helium mass spectrometer leak detector is used for testing, and the static leak rate of the system is less than 1×10 -8Pa·L / s. The system was then passivated. Following this, sampling volume tests were conducted according to the design plan. Ten tests were conducted, with the dosing device increasing the pressure by 50 mbar each time. The sample volume at each corresponding pressure was calculated. The system was passivated successfully. After multiple tests, the sample weight control error was less than 0.5g. Finally, a standard operating method for precise sampling volume control was developed.

[0043] By using the device of the present invention to perform sample separation, accurate control of the sample amount is achieved, the consumption of uranium hexafluoride in the secondary sampling process is reduced, the work efficiency is improved, and the operating labor intensity is effectively reduced.

[0044] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the embodiments described above. Various modifications can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Any content not described in detail in the present invention may be adapted from existing technologies.

Claims

1. A secondary sampling and quantitative device for uranium hexafluoride, characterized by: include: A sampling bottle, a sample storage container connector (1), a sample injection volume control valve (2), a sample injection volume tube (3), a monitoring port (4), a valve (5), a pressure gauge connector (6), a pressure gauge (7), a quantitative container (8) and a system connector (9); one end of the sample storage container connector (1) is connected to the sampling bottle, and the other end of the sample storage container connector (1) is connected to the sample injection volume control valve (2); the sample injection volume control valve (2) and one end of the sample injection volume tube (3) are threadedly connected through a pipe sleeve connector, and the other end of the sample injection volume tube (3) is welded to the quantitative container (8); one end of the monitoring port (4) and one end of the valve (5) are sealed through a threaded interface; the other end of the valve (5) is connected to the pressure gauge connector (6) and the pressure gauge (7); the other end of the monitoring port (4) is welded to the quantitative container (8); one end of the system connector (9) is welded to the quantitative container (8); The quantitative container (8) is located between the sampling bottle and the sample separation manifold as a buffer container and a quantitative control device after the sample is injected; the quantitative container (8) ensures that the temperature in the system is constant during the experiment, and controls the temperature of the quantitative container (8) not to exceed 60°C, the pressure in the quantitative container (8) not to exceed 0.1MPa, and the diffusion of gaseous uranium hexafluoride in the sample separation system satisfies the ideal gas state equation of PV=n RT…………(1) Where: R is a constant, P represents the pressure of uranium hexafluoride; V represents the effective volume of the quantitative device, n represents the amount of uranium hexafluoride, and T represents the temperature of uranium hexafluoride; therefore According to the physical properties of uranium hexafluoride, the temperature (T) in formula (2) is proportional to the saturated vapor pressure (P), and the pressure of uranium hexafluoride in the system is stable after the temperature is constant; the special loading container requires a sample volume of 8g to 10g, and after removing the sample loss during the sampling process, the quantitative design is performed based on a sample volume of 10g; after the corresponding relationship between the temperature and saturated vapor pressure of uranium hexafluoride is known, the n value is calculated based on 10g of uranium hexafluoride, and the change in the volume of the quantitative container (8) at different temperatures can be obtained; and according to the internal volume of the constant temperature box, the quantitative container (8) is designed to be a cylindrical structure, and the radius is selected as 40mm, and the corresponding size value of the height of the cylindrical quantitative container (8) is calculated.

2. The uranium hexafluoride secondary sampling and quantitative device according to claim 1, characterized in that: The sample storage container connector (1) comprises: an upper connector (11) of the sample storage container connector and a lower interface (12) of the sample storage container connector; the upper connector (11) of the sample storage container connector and the lower interface (12) of the sample storage container connector are welded; the lower interface (12) of the sample storage container connector is cylindrical in shape and has an outer thread on its outer wall for fixing a loading container for threaded connection; the lower interface (12) of the sample storage container connector is also provided with an internal through hole (13) of the sample storage container connector and a connection port (14) of the sample storage container connector.

3. The uranium hexafluoride secondary sampling and quantitative device according to claim 2, characterized in that: The injection volume tube (3) comprises: an outer tube (31) of the injection volume tube, an injection volume tube connector (32), an injection volume tube connector sealing cap (33) and an injection volume tube inner tube (34); the injection volume tube inner tube (34) is provided inside the outer tube (31) of the injection volume tube, the injection volume tube inner tube (34) is welded to the injection volume tube connector (32), and the injection volume tube connector sealing cap (33) is provided on the injection volume tube connector (32).

4. The uranium hexafluoride secondary sampling and quantitative device according to claim 3, characterized in that: The pressure gauge joint (6) comprises: an upper connection end (61) of the pressure gauge joint and a lower connection end (63) of the pressure gauge joint; the upper connection end (61) of the pressure gauge joint is welded to the lower connection end (63); a pressure gauge joint internal through-tube (62) is provided inside the upper connection end (61) of the pressure gauge joint, and a pressure gauge joint sealing interface (64) is provided inside the lower connection end (63); the pressure gauge joint sealing interface (64) and the pressure gauge joint internal through-tube (62) are in communication.

5. A uranium hexafluoride secondary sampling and quantitative device as claimed in claim 4, characterized in that: A raw tape is provided between the pressure gauge (7) and the pressure gauge joint sealing interface (64); the pressure gauge joint sealing interface (64) is a cylindrical groove as a whole, and an internal thread is provided on the inner wall.

6. The uranium hexafluoride secondary sampling and quantitative device according to claim 5 is characterized in that: The system connector (9) comprises: a sample guide tube (91), a sample outlet connector (92) and a sample outlet sealing cap (93); the sample guide tube (91) is welded with the sample outlet connector (92); the sample outlet connector (92) is threadedly connected to the sample outlet sealing cap (93); the sample guide tube (91) is used to guide the sample in the sample quantification device to the sample sealing system.

7. The sampling method of the uranium hexafluoride secondary sampling and quantitative device according to any one of claims 1 to 6, characterized in that The steps include: Step 1: Connect the quantitative container (8) to the sampling system and perform a pressure test using compressed air. No leakage is found under a pressure of 0.85 MPa. After the mechanical pump is turned on and the system is evacuated, the ultimate vacuum value is less than 10 Pa. A helium mass spectrometer is used for leak detection. The static leakage rate of the system is less than 1×10 -8 Pa·L / s; then the system is passivated; Step 2: After the passivation work is completed, a sampling volume test is carried out. A total of 10 tests are carried out. Each time, the quantitative control device controls the pressure to increase by 50mbar; the sampling volume under the corresponding pressure is counted respectively; after multiple tests and assessments, the control error of the sampled weight is less than 0.5g.

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