A method and device for rapidly preparing xenon or krypton gas source for nuclear data measurement

Abstract

The application discloses a kind of fast preparation method and device of xenon or krypton gas source for nuclear data measurement, to solve the problem that prior art cannot carry out fast enrichment purification preparation source to low concentration xenon (Xe) or krypton (Kr) in component complex raw gas.Its method specifically includes: step 1, at 10-30 ℃ temperature, using pretreatment adsorption column to pretreat raw gas, remove H2O, part CO2 and organic gas in raw gas;Step 2, using enrichment purification adsorption column to adsorb and intercept Xe or Kr in pretreated gas, adsorption interception time is determined according to the sample amount of raw gas;Step 3, using heating and carrier gas purging combination desorption separation method to purify Xe or Kr adsorbed and intercepted on the enrichment purification adsorption column;Step 4, enrichment purification adsorption column is pumped to negative pressure 5-15kPa, and it is heated to 160-200 ℃, and temperature is kept for a predetermined period of time, generally 5-15min, so that Xe or Kr is desorbed from the enrichment purification adsorption column, and Xe or Kr gas source is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to a nuclear data measurement method and device, in particular to a fast preparation method and device of a xenon or krypton gas source for nuclear data measurement. BACKGROUND

[0002] Nuclear data is of great value to nuclear basic research and nuclear technology application, and accurate measurement of xenon (Xe) and krypton (Kr) gas isotopes is of great significance to nuclear data evaluation. Generally, the concentration of Xe and Kr gas isotopes is low, and the existence of Xe gas isotopes will affect the radioactivity measurement of Kr gas isotopes, and the existence of Kr gas isotopes will also affect the radioactivity measurement of Xe gas isotopes. Therefore, it is necessary to enrich and purify low-concentration Xe and Kr gas isotopes to improve the accuracy of Xe and Kr gas isotope radioactivity measurement.

[0003] Low-temperature rectification is a mature method for separating and preparing Xe and Kr, and in the Chinese patent with the publication number CN1920455, a method for obtaining Xe and / or Kr by low-temperature separation of air is disclosed. This method is energy-consuming, high-cost, and complex, and is only suitable for large-scale factory production. Adsorption separation based on adsorbents has been widely used in the separation and purification of various gas mixtures due to its low energy consumption and small investment cost. In the Chinese patent with the publication number CN101985081A, a method for separating radon (Rn) and Xe gas by using carbon molecular sieve is disclosed. The Xe standard gas with a concentration of 20-200 ppm and the Rn gas with an activity of 40×10 4 ~80×10 4 Bq / m 3 After removing water by 13X molecular sieve, the Xe standard gas and the Rn gas are adsorbed in the carbon molecular sieve adsorption bed, and then flow through the 13X molecular sieve adsorption bed again after being heated and desorbed, so that Xe and Rn are adsorbed in the serially connected carbon molecular sieve adsorption beds, and the separation of Xe and Rn is realized. This method can only separate Xe and Rn standard gas, and cannot process original gas containing Xe and Kr with complex components. In addition, the five-stage adsorption bed provided by this method increases the complexity of the device, and cannot prepare a small-volume gas measurement source. SUMMARY

[0004] The present application aims to provide a fast preparation method and device of a xenon or krypton gas source for nuclear data measurement, so as to solve the technical problem that the prior art cannot quickly enrich and purify low-concentration xenon (Xe) or krypton (Kr) isotopes in original gas with complex components to improve the accuracy of Xe or Kr gas isotope radioactivity measurement.

[0005] In order to achieve the above-mentioned purpose, the present application provides a fast preparation method of a xenon or krypton gas source for nuclear data measurement, which is characterized by comprising the following steps:

[0006] Step 1, raw gas pretreatment;

[0007] The raw gas is pretreated by using a pretreatment adsorption column at a temperature of 10-30℃ to remove H2O, part of CO2 and organic gas in the raw gas;

[0008] Step 2, Xe or Kr enrichment;

[0009] The Xe or Kr in the pretreated gas is adsorbed and intercepted by using an enrichment and purification adsorption column, and the adsorption and interception time is determined according to the sample amount of the raw gas;

[0010] Step 3, Xe or Kr purification;

[0011] The Xe or Kr adsorbed and intercepted in the enrichment and purification adsorption column is purified by using a desorption separation method combining heating and carrier gas purging;

[0012] Step 4, Xe or Kr source preparation;

[0013] The enrichment and purification adsorption column is pumped to a negative pressure of 5-15kPa and heated to 160-200℃, and the Xe or Kr is desorbed from the enrichment and purification adsorption column to obtain a Xe or Kr gas source.

[0014] Further, step 4 further comprises:

[0015] The desorbed Xe or Kr gas source is temporarily stored in a buffer tank, and carrier gas is supplemented into the enrichment and purification adsorption column and the buffer tank according to the required gas amount of the buffer tank; the gas source in the buffer tank is back mixed with the gas source in the enrichment and purification adsorption column for 3-5 times, and then the gas in the enrichment and purification adsorption column is pressurized and transferred to the buffer tank to obtain a uniform Xe or Kr gas source.

[0016] Further, in step 1, when preparing a Xe gas source, the pretreatment adsorption column is filled with 13X molecular sieve, and the enrichment and purification adsorption column is filled with coconut activated carbon;

[0017] When preparing a Kr gas source, the pretreatment adsorption column is filled with 13X molecular sieve and coconut activated carbon, and the enrichment and purification adsorption column is filled with coconut activated carbon.

[0018] Further, in step 2, when preparing a Xe gas source, the adsorption and interception temperature of the enrichment and purification adsorption column is-10-30℃; when preparing a Kr gas source, the adsorption and interception temperature of the enrichment and purification adsorption column is-80--60℃.

[0019] Further, in step 3, when preparing the Xe gas source, the purification time of the Xe gas is determined according to the desorption curve of Xe and Kr enriched in the purification adsorption column; and when preparing the Kr gas source, the purification time of the Kr gas is determined according to the pressure at which the enrichment purification adsorption column is located and the desorption curve of Kr.

[0020] Further, in step 4, the preset time period is 5-15 min; the carrier gas is helium or nitrogen, and the pressure in the buffer tank is 300-450 kPa.

[0021] Meanwhile, the application also provides a device for rapidly preparing a xenon or krypton gas source for nuclear data measurement, which is characterized in that it comprises an original gas pretreatment unit, an enrichment purification unit and a source preparation unit.

[0022] The original gas pretreatment unit comprises a first booster pump, a first high-low temperature box and a pretreatment adsorption column; the first booster pump is used for extracting the original gas, and the outlet end thereof is communicated with the inlet end of the pretreatment adsorption column; the outlet end of the pretreatment adsorption column is connected with a first vacuum system; and the pretreatment adsorption column is placed in the first high-low temperature box.

[0023] The enrichment purification unit comprises an enrichment purification adsorption column, a carrier gas assembly and a second high-low temperature box; the inlet end of the enrichment purification adsorption column is communicated with the outlet end of the pretreatment adsorption column, the first vacuum system and the carrier gas assembly, respectively; the outlet end of the enrichment purification adsorption column is connected with a second vacuum system and also connected with a waste gas system; and the enrichment purification adsorption column is placed in the second high-low temperature box.

[0024] The source preparation unit comprises a second booster pump and a source box assembly; the inlet end of the second booster pump is communicated with the outlet end of the enrichment purification adsorption column, the second vacuum system and the waste gas system, respectively; the outlet end of the second booster pump is communicated with the source box assembly and connected with a third vacuum system; and the source box assembly is used for collecting the Xe or Kr gas source.

[0025] Further, the original gas pretreatment unit further comprises a first mass flow controller, a first electromagnetic valve, a first pressure sensor, a first filter and a second electromagnetic valve.

[0026] The first mass flow controller is arranged on the pipeline through which the first booster pump communicates with the original gas.

[0027] The first electromagnetic valve is arranged on the pipeline at the outlet end of the first booster pump.

[0028] The first pressure sensor is connected to the pipeline between the first electromagnetic valve and the pretreatment adsorption column through a first tee.

[0029] The first filter is arranged at the outlet end of the pretreatment adsorption column.

[0030] The second electromagnetic valve is arranged on a pipeline between the pretreatment adsorption column and the first vacuum system.

[0031] Further, the enrichment and purification unit further comprises a third electromagnetic valve, a second pressure sensor, a second filter, a fourth electromagnetic valve, a fifth electromagnetic valve, a first check valve and a gas chromatograph.

[0032] The inlet end of the third electromagnetic valve is communicated with the inlet end of the second electromagnetic valve and the outlet end of the pretreatment adsorption column through a second three-way joint, and the outlet end of the third electromagnetic valve is communicated with the second pressure sensor, the carrier gas assembly and the inlet end of the enrichment and purification adsorption column through a first four-way joint.

[0033] The outlet end of the enrichment and purification adsorption column is communicated with the second vacuum system, the waste gas system and the second booster pump through a second four-way joint.

[0034] The second filter is arranged at the outlet end of the enrichment and purification adsorption column.

[0035] The fourth electromagnetic valve is arranged on a pipeline between the second four-way joint and the second vacuum system.

[0036] The fifth electromagnetic valve is arranged on a pipeline between the second four-way joint and the waste gas system.

[0037] The inlet end of the first check valve is communicated with the outlet end of the fifth electromagnetic valve, and the outlet end of the first check valve is communicated with the waste gas system through the gas chromatograph.

[0038] Further, the source preparation unit further comprises a sixth electromagnetic valve, a seventh electromagnetic valve, an eighth electromagnetic valve, a buffer tank, a third pressure sensor, a ninth electromagnetic valve and a tenth electromagnetic valve.

[0039] The sixth electromagnetic valve is arranged on a pipeline between the second four-way joint and the second booster pump.

[0040] The inlet end of the seventh electromagnetic valve is communicated with the outlet end of the sixth electromagnetic valve and the inlet end of the second booster pump through a third three-way joint, and the outlet end of the seventh electromagnetic valve is communicated with the outlet end of the second booster pump and the inlet end of the buffer tank through a fourth three-way joint.

[0041] The eighth electromagnetic valve is arranged on a pipeline between the fourth three-way joint and the buffer tank.

[0042] The outlet end of the buffer tank is communicated with the third pressure sensor, the source box assembly and the third vacuum system through a third four-way joint.

[0043] The ninth electromagnetic valve is arranged on a pipeline between the third four-way joint and the third vacuum system.

[0044] The tenth electromagnetic valve is arranged on a pipeline between the third four-way joint and the source box assembly.

[0045] Further, the carrier gas assembly comprises a second mass flow controller, a second check valve, an eleventh electromagnetic valve;

[0046] The outlet end of the eleventh electromagnetic valve is communicated with the first four-way valve, and the inlet end is communicated with the outlet end of the second check valve;

[0047] The inlet end of the second check valve is communicated with the carrier gas through the second mass flow controller.

[0048] Further, the source box assembly comprises a twelfth electromagnetic valve, a thirteenth electromagnetic valve, a chromatographic measurement source box and a radioactive measurement source box;

[0049] The tenth electromagnetic valve is communicated with the chromatographic measurement source box and the radioactive measurement source box through a fifth three-way valve respectively;

[0050] The twelfth electromagnetic valve is arranged on the pipeline between the fifth three-way valve and the chromatographic measurement source box;

[0051] The thirteenth electromagnetic valve is arranged on the pipeline between the fifth three-way valve and the radioactive measurement source box.

[0052] Further, when preparing a Xe gas source, the pre-treatment adsorption column is filled with 13X molecular sieve with a particle size of 2-4 mm; when preparing a Kr gas source, the pre-treatment adsorption column is filled with 13X molecular sieve with a particle size of 2-4 mm and coconut shell activated carbon with a mesh of 26-30 and a main peak of pore size distribution at 0.55 nm and 1.13 nm, the length of the 13X molecular sieve is 1 / 10-3 / 10 of the column length, and the length of the coconut shell activated carbon is 7 / 10-9 / 10 of the column length;

[0053] The enrichment and purification adsorption column is filled with coconut shell activated carbon with a mesh of 26-30 and a main peak of pore size distribution at 0.55 nm and 1.13 nm.

[0054] Further, the column body of the pre-treatment adsorption column is made of a stainless steel pipe with a diameter of 12-25 mm, a length of 400 mm and a wall thickness of 1-3 mm;

[0055] The column body of the enrichment and purification adsorption column is made of a stainless steel pipe with a diameter of 25-35 mm, a length of 400 mm and a wall thickness of 1-3 mm;

[0056] The buffer tank is made of stainless steel, has a volume of 100-150 ml and a wall thickness of 1-3 mm;

[0057] The chromatographic measurement source box and the radioactive measurement source box are both made of stainless steel, have a volume of 4-50 ml and a wall thickness of 0.5-3 mm.

[0058] Further, define the tenth solenoid valve to the fifth three-way pipe as a sample pipe; the length of the sample pipe is 3-5m.

[0059] The beneficial effects of the present application are:

[0060] 1. The present application uses a pretreatment adsorption column to pretreat the original gas. When preparing a Xe gas source, the 13X molecular sieve in the pretreatment adsorption column removes H2O in the original gas, partially removes CO2 and organic gas in the original gas, and reduces the adverse effects of H2O, CO2 and organic gas on the adsorption of Xe by the activated carbon in the enrichment and purification adsorption column. When preparing a Kr gas source, the 13X molecular sieve column layer in the pretreatment adsorption column removes H2O in the original gas, partially removes CO2 and organic gas in the original gas; the activated carbon column layer adsorbs and retains Xe in the original gas, realizes the adsorption separation of Xe and Kr, and avoids the contamination of Xe in the Kr measurement source caused by the desorption of Xe in the subsequent Kr source preparation process. The accuracy of Xe or Kr gas isotope radiometric measurement is improved.

[0061] 2. The present application can complete the enrichment and purification of Xe or Kr on the same enrichment and purification adsorption column, and reduces the complexity of the preparation process and preparation device of the Xe or Kr gas source for nuclear data measurement.

[0062] 3. In the preparation of the Kr gas source, the present application judges the desorption of impurity gas on the enrichment and purification adsorption column by the change of the pressure of the enrichment and purification adsorption column during the Kr purification process, which is simple and easy to operate; at the same time, the time to stop Kr purification is selected combined with the desorption curve of Kr, and the enrichment and purification adsorption column is pumped to a negative pressure of 5-15kPa, which can reduce the amount of impurity gas desorption in the high-temperature desorption process, and is beneficial to the recovery of Kr.

[0063] 4. The Xe or Kr gas source prepared by the present application has the characteristics of high specific activity, high decontamination and good uniformity; the original gas treatment capacity is 10-50L, the Xe recovery rate is greater than 70%, the Kr decontamination factor is greater than 3×10 5 ; the Kr recovery rate is greater than 55%, and the Xe decontamination factor is greater than 3×10 5 ; the preparation process takes no more than 1 hour, which meets the requirements of nuclear data testing.

[0064] 5. The present application adopts a long sample pipe of 3-5m, which facilitates the radiation shielding of the preparation device, avoids the irradiation damage of the original gas and high-dose-rate gas in the buffer tank to the operator and the measuring equipment, and can realize the preparation and measurement of remote online Xe or Kr gas source.

[0065] 6、The preparation method can treat original gas with complex components, for example, the components (concentration) in the original gas can be Xe (0.08-400ppm), Kr (1.0-100ppm), H2O (0.01-3%), CO2 (0.04-10%), CH4, C2H2, C2H4 and C2H6 (0.4-6%), Ar (0.01-3%), O2 and N2 (balance).

[0066] 7、The method can be used not only for preparing Xe or Kr gas source for nuclear data measurement, but also for purifying and separating Xe and Kr in waste gas of nuclear facilities. BRIEF DESCRIPTION OF DRAWINGS

[0067] Figure 1 is a flow chart of a fast preparation method of a xenon or krypton gas source for nuclear data measurement according to the present application;

[0068] Figure 2 is a structural schematic diagram of a fast preparation device of a xenon or krypton gas source for nuclear data measurement according to the present application;

[0069] Figure 3 is a pore size distribution diagram of 26-30 mesh coconut shell activated carbon in the embodiment of the present application;

[0070] In the diagram, the main peak of the pore size distribution of the 26-30 mesh coconut shell activated carbon is at 0.55 and 1.13nm, there are medium-intensity pore size distribution peaks at 0.75, 1.41 and 1.77nm, and there is a weak pore size distribution peak at 3.89nm;

[0071] Figure 4 is a breakthrough curve diagram of Xe and Kr in tail gas of a pretreatment adsorption column on an enrichment and purification adsorption column in the embodiment of the present application;

[0072] In the diagram, under the conditions that the adsorption temperatures of the pretreatment adsorption column and the enrichment and purification adsorption column are 25℃ and 0℃ respectively and the sampling flow rate is 3L / min, Kr has completely penetrated the enrichment and purification adsorption column when the total sampling flow rate is 5L, Xe starts to penetrate the enrichment and purification adsorption column when the total sampling flow rate is 50L, and Xe completely penetrates the enrichment and purification adsorption column when the total sampling flow rate is 100L; it can be seen that Xe and Kr in the tail gas of the pretreatment adsorption column can be adsorbed and separated by the enrichment and purification adsorption column, and Xe in the original gas can be enriched and preliminarily purified;

[0073] Figure 5 is a breakthrough curve diagram of Kr in tail gas of a pretreatment adsorption column on an enrichment and purification adsorption column in the embodiment of the present application;

[0074] In the figure, under the conditions that the adsorption temperatures of the pretreatment adsorption column and the enrichment and purification adsorption column are 25℃ and -70℃ respectively, the sample injection flow rate is 3L / min, and the total sample injection flow rate is 60L, Kr starts to penetrate the enrichment and purification adsorption column; when the total sample injection flow rate is not more than 60L, the enrichment and purification adsorption column effectively intercepts Kr in the tail gas of the pretreatment adsorption column, so as to enrich Kr in the original gas;

[0075] Figure 6 is the desorption curve of Xe and Kr on the enrichment and purification adsorption column in the heating and carrier gas purging process in the embodiment of the application;

[0076] In the figure, under the conditions that the second high-low temperature box temperature program is 0℃ (15min)→80℃ (10min)→80℃ (25min)→200℃ (stop), and the nitrogen purging flow rate is 100mL / min, the peak position spacing between the Kr desorption peak and the Xe desorption peak is large; the heating and carrier gas purging combination mode can realize the desorption and separation of Xe and Kr adsorbed on the enrichment and purification adsorption column after adsorption separation, further purify Xe, and improve the Kr decontamination factor;

[0077] Figure 7 is the pressure change of the enrichment and purification adsorption column and the Kr desorption curve in the heating and carrier gas purging process in the embodiment of the application

[0078] In the figure, under the conditions that the second high-low temperature box temperature program is -70℃ (30min)→100℃ (45min)→100℃ (stop), and the nitrogen purging flow rate is 50mL / min, the pressure of the enrichment and purification adsorption column first increases and then decreases, and finally stabilizes to 98kPa, and Kr starts to flow out from the enrichment and purification adsorption column after 25min of heating and carrier gas purging; it can be seen that the heating and carrier gas purging combination mode can separate most of the impurity gases from Kr on the enrichment and purification adsorption column, reduce the amount of impurity gases desorbed in the high-temperature desorption process, and is beneficial to the recovery of Kr.

[0079] Reference Signs:

[0080] 1 - first mass flow controller, 2 - first booster pump, 3 - first electromagnetic valve, 4 - first pressure sensor, 5 - first high-low temperature box, 6 - pretreatment adsorption column, 7 - first filter, 8 - second electromagnetic valve, 9 - third electromagnetic valve, 10 - second pressure sensor, 11 - second high-low temperature box, 12 - enrichment and purification adsorption column, 13 - second filter, 14 - fourth electromagnetic valve, 15 - fifth electromagnetic valve, 16 - first one-way valve, 17 - gas chromatograph, 18 - second mass flow controller, 19 - second one-way valve, 20 - eleventh electromagnetic valve, 21 - sixth electromagnetic valve, 22 - second booster pump, 23 - seventh electromagnetic valve, 24 - eighth electromagnetic valve, 25 - buffer tank, 26 - ninth electromagnetic valve, 27 - third pressure sensor, 28 - tenth electromagnetic valve, 29 - twelfth electromagnetic valve, 30 - chromatographic measurement source box, 31 - thirteenth electromagnetic valve, 32 - radioactive measurement source box. DETAILED DESCRIPTION

[0081] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0082] The present application provides a method for rapidly preparing a xenon or krypton gas source for nuclear data measurement, as shown in the formula (I): Figure 1 The method comprises the following steps:

[0083] (1) The original gas is pretreated at room temperature (10-30°C) using a pretreatment adsorption column. When preparing a Xe gas source, the pretreatment adsorption column is filled with 13X molecular sieve. When preparing a Kr gas source, the pretreatment adsorption column is filled with 13X molecular sieve and coconut activated carbon.

[0084] (2) The Xe or Kr in the tail gas of the pretreatment adsorption column is adsorbed and intercepted using an enrichment and purification adsorption column, and the time for stopping Xe or Kr enrichment is determined according to the sample amount. The enrichment and purification adsorption column is filled with coconut activated carbon. When preparing a Xe gas source, the adsorption temperature of the enrichment and purification adsorption column is shallow low temperature to room temperature (-10-30°C). When preparing a Kr gas source, the adsorption temperature of the enrichment and purification adsorption column is low temperature (-80-60°C).

[0085] (3) The Xe or Kr adsorbed on the enrichment and purification adsorption column is purified using a desorption separation method combining heating and carrier gas purging. When preparing a Xe gas source, the appropriate Xe purification stop time is selected according to the desorption curve of Xe and Kr on the enrichment and purification adsorption column. When preparing a Kr gas source, the appropriate Kr purification stop time is selected according to the pressure of the enrichment and purification adsorption column and the desorption curve of Kr.

[0086] (4) After the enrichment and purification adsorption column is drawn to negative pressure (5-15 kPa), it is kept at high temperature (160-200℃) for a certain period of time (5-15 min).

[0087] (5) After the enrichment and purification adsorption column is kept warm, add an appropriate amount of carrier gas to the enrichment and purification adsorption column and the buffer tank according to the amount of gas required by the buffer tank.

[0088] (6) Use a diaphragm booster pump and a bypass valve connected in parallel to it to backmix the gas in the buffer tank and the enrichment and purification adsorption column 3 to 5 times.

[0089] (7) Use a diaphragm booster pump to transfer the backmixed gas in the enrichment and purification adsorption column to a buffer tank (300-450 kPa).

[0090] (8) The gas in the buffer container is sampled into the chromatographic measurement source box and the radiometric measurement source box.

[0091] Based on the above methods, this embodiment provides the following rapid preparation apparatus for xenon or krypton gas sources for nuclear data measurement, such as... Figure 2 As shown, it includes:

[0092] Raw gas pretreatment unit: The raw gas passes through the first mass flow controller 1 and the first booster pump 2 (diaphragm booster pump) and is then connected to the inlet of the first solenoid valve 3. The outlet of the first solenoid valve 3 is connected to the inlet of the first pressure sensor 4 and the pretreatment adsorption column 6 via the first three-way valve. The outlet of the pretreatment adsorption column 6 passes through the first filter 7 and is then connected to the inlets of the second solenoid valve 8 and the third solenoid valve 9 via the second three-way valve. The pretreatment adsorption column 6 is placed in the first high and low temperature chamber 5. The outlet of the second solenoid valve 8 is connected to the first vacuum system. When preparing Xe gas source, the pretreatment adsorption column 6 is filled with 13X molecular sieve with a particle size of 2-4 mm. When preparing Kr gas source, the pretreatment adsorption column 6 is filled with 13X molecular sieve with a particle size of 2-4 mm and coconut shell activated carbon of 26-30 mesh with major pore size peaks at 0.55 and 1.13 nm. The 13X molecular sieve is filled to a length of 1 / 10 to 3 / 10 of the column length, and the coconut shell activated carbon is filled to a length of 7 / 10 to 9 / 10 of the column length. The pretreatment adsorption column 6 is selected from... A stainless steel tube with a wall thickness of 1–3 mm is used. When preparing the Xe gas source, the original gas is pretreated using a pretreatment adsorption column 6 at room temperature (10–30℃). A 13X molecular sieve removes H2O from the original gas and partially removes CO2 and organic gases. When preparing the Kr gas source, the original gas is pretreated using a pretreatment adsorption column 6 at room temperature (10–30℃). A 13X molecular sieve column removes H2O from the original gas and partially removes CO2 and organic gases. A coconut shell activated carbon column adsorbs and retains Xe from the original gas, achieving adsorption separation of Xe and Kr.

[0093] Enrichment and purification unit: The outlet of the third solenoid valve 9 is connected to the outlet of the second pressure sensor 10, the eleventh solenoid valve 20, and the inlet of the enrichment and purification adsorption column 12 via the first four-way valve. The carrier gas, after passing through the second mass flow controller 18 and the second one-way valve 19, is connected to the inlet of the eleventh solenoid valve 20. The outlet of the enrichment and purification adsorption column 12, after passing through the second filter 13, is connected to the inlet of the fourth solenoid valve 14, the fifth solenoid valve 15, and the sixth solenoid valve 21 via the second four-way valve. The enrichment and purification adsorption column 12 is placed in the second high and low temperature chamber 11. The outlet of the fourth solenoid valve 14 is connected to the second vacuum system. The outlet of the fifth solenoid valve 15, after passing through the first one-way valve 16 and the gas chromatograph 17, is connected to the waste gas system. The enrichment and purification adsorption column 12 is packed with 26-30 mesh coconut shell activated carbon with the main peaks of pore size distribution at 0.55 and 1.13 nm. The enrichment and purification adsorption column 12 uses... A stainless steel tube with a wall thickness of 1–3 mm is used. The concentrations of Xe and Kr in the tail gas of the enrichment and purification adsorption column 12 during the Xe or Kr enrichment and purification process are detected at 3–6 min intervals using a gas chromatograph 17. The temperature and pressure of the enrichment and purification adsorption column 12 during the Xe or Kr purification process are also monitored at 1–6 min intervals. When preparing the Xe gas source, the Xe in the tail gas of the pretreatment adsorption column 6 is adsorbed and retained using the enrichment and purification adsorption column 12 at a low to normal temperature (-10–30 °C). The Xe adsorbed on the enrichment and purification adsorption column 12 is purified using a desorption separation method combining heating and carrier gas purging. An appropriate Xe purification stop time is selected based on the Xe and Kr desorption curves. When preparing the Kr gas source, the Kr in the tail gas of the pretreatment adsorption column 6 is adsorbed and retained using an enrichment and purification adsorption column 12 at a low temperature (-80 to -60℃). The Kr adsorbed on the enrichment and purification adsorption column 12 is then purified using a desorption separation method combining heating and carrier gas purging. An appropriate Kr purification stop time is selected based on the pressure of the enrichment and purification adsorption column 12 and the Kr desorption curve. The enrichment and purification of Xe or Kr can be completed on the same enrichment and purification adsorption column 12.

[0094] The outlet of the sixth electromagnetic valve 21 is connected to the inlet of the second booster pump 22 (a diaphragm booster pump) through a third three-way joint, the outlet of the seventh electromagnetic valve 23 is connected to the outlet of the diaphragm booster pump 22 and the inlet of the eighth electromagnetic valve 24 through a fourth three-way joint, the outlet of the eighth electromagnetic valve 24 is connected to the inlet of the third pressure sensor 27, the ninth electromagnetic valve 26 and the tenth electromagnetic valve 28 through a third four-way joint via the buffer tank 25, the outlet of the ninth electromagnetic valve 26 is connected to the third vacuum system, the outlet of the tenth electromagnetic valve 28 is connected to the inlet of the twelfth electromagnetic valve 29 and the thirteenth electromagnetic valve 31 through a fifth three-way joint, and the outlets of the twelfth electromagnetic valve 29 and the thirteenth electromagnetic valve 31 are connected to the colorimetric measurement source box 30 and the radioactive measurement source box 32 respectively. The buffer tank 25 has a volume of 100-150 ml and a wall thickness of 1-3 mm, and the colorimetric measurement source box 30 and the radioactive measurement source box 32 have a volume of 4-50 ml, a wall thickness of 0.5-3 mm and are made of stainless steel. The carrier gas is helium or nitrogen. After the enrichment and purification of Xe or Kr is completed, the enrichment and purification adsorption column 12 is extracted to a pressure of 5-15 kPa, the enrichment and purification adsorption column 12 is kept at a temperature of 160-200 ℃ for 5-15 min, the gas in the enrichment and purification adsorption column 12 and the buffer tank 25 is mixed, and the mixed gas in the enrichment and purification adsorption column 12 is transferred to the buffer tank 25 at a pressure of 300-450 kPa. During the preparation of the source, the enrichment and purification adsorption column 12 and the buffer tank 25 are supplemented with an appropriate amount of carrier gas according to the required amount of gas in the buffer tank 25, the gas in the enrichment and purification adsorption column 12 is pressurized and transferred to the buffer tank 25 using the second booster pump 22, the gas in the buffer tank 25 is returned to the enrichment and purification adsorption column 12 using the seventh electromagnetic valve 23 connected in parallel with the second booster pump 22, and the gas in the enrichment and purification adsorption column 12 and the buffer tank 25 is mixed. The gas is mixed for 3-5 times to make the gas in the enrichment and purification adsorption column 12 and the buffer tank 25 uniform.

[0095] The Xe or Kr measurement source prepared by the preparation method and the preparation device has the characteristics of high specific activity, high decontamination and good uniformity, the raw gas treatment capacity is 10-50 L, the recovery rate of Xe is greater than 70%, the Kr decontamination factor is greater than 3×10 5 , the recovery rate of Kr is greater than 55%, and the Xe decontamination factor is greater than 3×10 5 . The preparation of the measurement source takes no more than 1 hour.

[0096] The use of the above preparation device is described below based on the preparation of Xe or Kr gas source:

[0097] I. Preparation of Xe gas source.

[0098] According to the connection relationship shown in Figure 2 , the rapid preparation device for xenon gas source is established.

[0099] Among them, the pretreatment adsorption column 6 is selected from Stainless steel tube with wall thickness of 1 mm, filled with 13X molecular sieve with particle size of 3 mm; the enrichment and purification adsorption column 12 is selected Stainless steel tube with wall thickness of 2 mm, filled with coconut shell activated carbon with mesh size of 26-30 and pore size distribution with main peak at 0.55 nm and 1.13 nm; the pore size distribution of the coconut shell activated carbon with mesh size of 26-30 is shown in Figure 3 The pretreatment adsorption column 6 and the enrichment and purification adsorption column 12 are temperature-controlled by the first high-low temperature box 5 and the second high-low temperature box 11, and the temperature-control range of the first high-low temperature box 5 and the second high-low temperature box 11 is -10-300 ℃. The standard gas prepared by Xe and Kr stable isotopes is selected as the simulation gas of the original gas, and the components (concentrations) thereof are as follows: Xe (50 ppm), Kr (50 ppm), H2O (1%), CO2 (7%), CH4, C2H2, C2H4 and C2H6 (4%), Ar (1%), O2 and N2 (balance). Nitrogen is selected as the carrier gas. The volume of the buffer tank 25 is 100 mL, the volume of the chromatographic measurement source box 30 is 50 mL, and the volume of the radioactive measurement source box 32 is 4 mL, and the wall thicknesses of the buffer tank 25 and the two source boxes are all 1 mm. The length of the sample splitting pipeline is 5 m, and the pipeline is selected from Stainless steel tube with wall thickness of 1 mm, filled with 13X molecular sieve with particle size of 3 mm; the enrichment and purification adsorption column 12 is selected Stainless steel tube with wall thickness of 2 mm, filled with coconut shell activated carbon with mesh size of 26-30 and pore size distribution with main peak at 0.55 nm and 1.13 nm; the pore size distribution of the coconut shell activated carbon with mesh size of 26-30 is shown in

[0100] As shown in Figure 1 , the operation steps are as follows:

[0101] (1) Preliminary preparation;

[0102] Before use, the buffer tank 25, the chromatographic measurement source box 30 and the radioactive measurement source box 32 and the corresponding pipelines need to be vacuumized, and the pretreatment adsorption column 6 and the enrichment and purification adsorption column 12 need to be vacuum activated at 200 DEG C for 30 min. The specific operation is as follows: open the first electromagnetic valve 3, the second electromagnetic valve 8, the fourth electromagnetic valve 14, the seventh electromagnetic valve 23, the eighth electromagnetic valve 24, the ninth electromagnetic valve 26, the tenth electromagnetic valve 28, the twelfth electromagnetic valve 29 and the thirteenth electromagnetic valve 31, vacuumize the pretreatment adsorption column 6, the enrichment and purification adsorption column 12, the buffer tank 25, the chromatographic measurement source box 30 and the radioactive measurement source box 32 and the corresponding pipelines; set the temperature program of the first high-low temperature box 5 and the second high-low temperature box 11 as follows: room temperature (30 min) -> 200 DEG C (30 min) -> 200 DEG C (stop), start the temperature program of the first high-low temperature box 5 and the second high-low temperature box 11, keep the pretreatment adsorption column 6 and the enrichment and purification adsorption column 12 at 200 DEG C for 30 min, then stop heating, and stop vacuumizing after falling to room temperature, and close all valves. The vacuum degree of the pretreatment adsorption column 6, the enrichment and purification adsorption column 12, the buffer tank 25, the chromatographic measurement source box 30 and the radioactive measurement source box 32 and the corresponding pipelines is better than 0.1 kPa, that is, the values of the first pressure sensor 4, the second pressure sensor 10 and the third pressure sensor 27 are all less than 0.1 kPa.

[0103] The first high-low temperature box 5 and the second high-low temperature box 11 are used to maintain the pretreatment adsorption column 6 and the enrichment and purification adsorption column 12 at the respective required adsorption temperatures in advance. The pretreatment adsorption column 6 is used to pretreat the raw gas at an adsorption temperature of 25 DEG C, and the temperature program of the first high-low temperature box 5 is as follows: room temperature (5 min) -> 25 DEG C (20 min) -> 25 DEG C (stop); the enrichment and purification adsorption column 12 is used to adsorb and intercept Xe in the tail gas of the pretreatment adsorption column 6 at an adsorption temperature of 0 DEG C, and the temperature program of the second high-low temperature box 11 is as follows: room temperature (15 min) -> 0 DEG C (10 min) -> 0 DEG C (stop).

[0104] (2) Pretreatment of raw gas and Xe enrichment;

[0105] Set the flow rate of the first mass flow controller 1 to 3 L / min, and open the first mass flow controller 1, the first booster pump 2 (diaphragm booster pump), the first electromagnetic valve 3, the third electromagnetic valve 9 and the fifth electromagnetic valve 15. Stop sampling when the total sampling flow rate is 30 L, and close the first mass flow controller 1, the first booster pump 2, the first electromagnetic valve 3, the third electromagnetic valve 9 and the fifth electromagnetic valve 15. The sampling flow rate is controlled by the first mass flow controller 1. Figure 4It can be seen that when the total sample flow rate is 30 L / min, Kr has completely penetrated the enrichment and purification adsorption column 12, while Xe has not penetrated the enrichment and purification adsorption column 12, at which time the enrichment and purification adsorption column 12 completes the adsorption separation of Xe and Kr in the tail gas of the pretreatment adsorption column 6, and a clean mass transfer zone of Xe remains on the enrichment and purification adsorption column 12 for subsequent desorption separation of Xe and Kr.

[0106] (3) Xe purification;

[0107] After the sample injection is completed, the temperature program of the second high-low temperature box 11 is set as: 0°C (15 min)→80°C (10 min)→80°C (5 min)→200°C (15 min)→200°C (stop), the flow rate of the second mass flow controller 18 is set as 100 mL / min, the temperature program of the second high-low temperature box 11 is started, and the second mass flow controller 18, the eleventh electromagnetic valve 20 and the fifth electromagnetic valve 15 are opened. The tail gas of the enrichment and purification adsorption column 12 is discharged by the second mass flow controller 18, and the tail gas of the enrichment and purification adsorption column 12 is analyzed by the gas chromatograph 17. Figure 6 It can be seen that after heating and carrier gas purging for 25 min, the Kr concentration in the tail gas of the enrichment and purification adsorption column 12 is reduced to 0.01 ppm (the detection lower limit of the gas chromatograph 17), and the enrichment and purification adsorption column 12 can realize the desorption separation of Xe and Kr. Therefore, the purging can be stopped after heating and carrier gas purging of the enrichment and purification adsorption column 12 for 25 min: the second mass flow controller 18, the eleventh electromagnetic valve 20 and the fifth electromagnetic valve 15 are closed. The enrichment and purification adsorption column 12 is pumped to negative pressure: the fourth electromagnetic valve 14 is opened, and the fourth electromagnetic valve 14 is closed when the value of the second pressure sensor 10 is reduced to 10 kPa.

[0108] (4) Xe measurement source preparation;

[0109] When the enrichment and purification adsorption column 12 is kept at 200℃ for 10 min, nitrogen is supplemented to the enrichment and purification adsorption column 12 and the buffer tank 25, the flow rate of the second mass flow controller 18 is set to 500 mL / min, the second mass flow controller 18, the eleventh electromagnetic valve 20, the sixth electromagnetic valve 21 and the eighth electromagnetic valve 24 are turned on, when the value of the third pressure sensor 27 rises to 190 kPa, the second mass flow controller 18 and the eleventh electromagnetic valve 20 are turned off. The gas in the enrichment and purification adsorption column 12 and the buffer tank 25 is back mixed: the second booster pump 22 (a diaphragm booster pump) is turned on, when the value of the second pressure sensor 10 drops to 10 kPa, the second booster pump 22 is turned off, the seventh electromagnetic valve 23 is turned on, when the value of the third pressure sensor 27 stabilizes, the seventh electromagnetic valve 23 is turned off, and the process is repeated for 3 times. After the back mixing is completed, the gas in the enrichment and purification adsorption column 12 is pressurized and transferred to the buffer tank 25: the second booster pump 22 is turned on, when the value of the second pressure sensor 10 drops to 2 kPa, the sixth electromagnetic valve 21, the second booster pump 22 and the eighth electromagnetic valve 24 are turned off, and the value of the third pressure sensor 27 rises to 427 kPa. The Xe gas source is sampled: the tenth electromagnetic valve 28, the twelfth electromagnetic valve 29 and the thirteenth electromagnetic valve 31 are turned on, when the value of the third pressure sensor 27 stabilizes, the tenth electromagnetic valve 28, the twelfth electromagnetic valve 29 and the thirteenth electromagnetic valve 31 are turned off.

[0110] (5) Xe measurement source uniformity, recovery rate and decontamination factor;

[0111] The concentrations of Xe and Kr in the chromatographic measurement source box 30 and the radioactive measurement source box 32 are measured by a gas chromatograph, the Xe concentration in the chromatographic measurement source box 30 is 2856 ppm, and the Kr concentration is 0.01 ppm (the detection lower limit of the gas chromatograph, the same below), the Xe concentration in the radioactive measurement source box 32 is 2853 ppm, and the Kr concentration is 0.01 ppm; the sample uniformity in the chromatographic measurement source box 30 and the radioactive measurement source box 32 is good, and the difference in Xe concentration is less than 0.2%; the Xe recovery rate and the Kr decontamination factor are calculated according to the volume and pressure of the buffer tank 25, the total sampling flow rate and the concentrations of Xe and Kr in the simulated gas, the Xe recovery rate is 73%, and the Kr decontamination factor is 3.2×10 5 ; without considering the time used for the preparation of the measurement source, the preparation of the Xe measurement source takes no more than 1 hour.

[0112] II. Preparation of Kr gas source

[0113] According to the connection relationship shown in Figure 2 , a rapid preparation device for krypton gas source is established.

[0114] Among them: the pretreatment adsorption column 6 selects A stainless steel tube with a wall thickness of 2 mm, 13X molecular sieve with a particle size of 3 mm is packed in 1 / 5 of the length of the pre-treatment adsorption column 6, and the remaining part of the pre-treatment adsorption column 6 is packed with coconut shell activated carbon with a mesh size of 26-30 and a pore size distribution with a main peak at 0.55 nm and 1.13 nm. The pore size distribution of the coconut shell activated carbon with a mesh size of 26-30 is shown in Fig. 1. Figure 3 The enrichment and purification adsorption column 12 is selected from A stainless steel tube with a wall thickness of 2 mm, packed with coconut shell activated carbon with a mesh size of 26-30 and a pore size distribution with a main peak at 0.55 nm and 1.13 nm. The pre-treatment adsorption column 6 and the enrichment and purification adsorption column 12 are temperature-controlled by the first high-low temperature box 5 and the second high-low temperature box 11, and the temperature control range of the first high-low temperature box 5 and the second high-low temperature box 11 is -100-300°C. The standard gas prepared by using Xe and Kr stable isotopes is selected as the simulation gas of the original gas, and the components (concentrations) thereof are as follows: Xe (50 ppm), Kr (50 ppm), H2O (1%), CO2 (7%), CH4, C2H2, C2H4 and C2H6 (4%), Ar (1%), O2 and N2 (balance). The carrier gas is selected to be nitrogen. The buffer tank 25 has a volume of 100 mL, the chromatographic measurement source box 30 has a volume of 50 mL, and the radioactive measurement source box 32 has a volume of 4 mL. The wall thicknesses of the buffer tank 25 and the two source boxes are all 1 mm. The total length of the sample splitting pipeline is 5 m, and the pipeline is selected to be an inch stainless steel tube. The remaining pipelines in the device are selected to be an inch stainless steel tube.

[0115] The operation steps are as follows:

[0116] (1) Preliminary preparation;

[0117] Before use, the buffer tank 25, the chromatographic measurement source box 30 and the radioactive measurement source box 32 and the corresponding pipelines need to be vacuumized, and the pretreatment adsorption column 6 and the enrichment and purification adsorption column 12 need to be vacuum activated at 200 DEG C for 30 min. The specific operation is as follows: the first electromagnetic valve 3, the second electromagnetic valve 8, the fourth electromagnetic valve 14, the ninth electromagnetic valve 26, the seventh electromagnetic valve 23, the eighth electromagnetic valve 24, the tenth electromagnetic valve 28, the twelfth electromagnetic valve 29 and the thirteenth electromagnetic valve 31 are opened, and the pretreatment adsorption column 6, the enrichment and purification adsorption column 12, the buffer tank 25, the chromatographic measurement source box 30 and the radioactive measurement source box 32 and the corresponding pipelines are vacuumized; the temperature program of the first high-low temperature box 5 and the second high-low temperature box 11 is set as: room temperature (30 min) -> 200 DEG C (30 min) -> 200 DEG C (stop), the temperature program of the first high-low temperature box 5 and the second high-low temperature box 11 is started, the pretreatment adsorption column 6 and the enrichment and purification adsorption column 12 are kept at 200 DEG C for 30 min, then heating is stopped, and the vacuum is stopped after the temperature drops to room temperature, and all the valves are closed. The vacuum degree of the pretreatment adsorption column 6, the enrichment and purification adsorption column 12, the buffer tank 25, the chromatographic measurement source box 30 and the radioactive measurement source box 32 and the corresponding pipelines is better than 0.1 kPa, that is, the value of the first pressure sensor 4, the second pressure sensor 10 and the third pressure sensor 27 is less than 0.1 kPa.

[0118] The pretreatment adsorption column 6 and the enrichment and purification adsorption column 12 are maintained at the respective required adsorption temperatures in advance by using the first high-low temperature box 5 and the second high-low temperature box 11. The pretreatment adsorption column 6 is used for pretreating the raw gas at an adsorption temperature of 25 DEG C, and the temperature program of the first high-low temperature box 5 is: room temperature (5 min) -> 25 DEG C (35 min) -> 25 DEG C (stop); the enrichment and purification adsorption column 12 is used for adsorbing and intercepting Kr in the tail gas of the pretreatment adsorption column 6 at an adsorption temperature of -70 DEG C, and the temperature program of the second high-low temperature box 11 is: room temperature (30 min) -> -70 DEG C (10 min) -> -70 DEG C (stop).

[0119] (2) Pretreatment of raw gas and Kr enrichment;

[0120] The flow rate of the first mass flow controller 1 is set as 3 L / min, and the first mass flow controller 1, the first booster pump 2, the first electromagnetic valve 3, the third electromagnetic valve 9 and the fifth electromagnetic valve 15 are opened. The raw gas flows into the enrichment and purification adsorption column 12 through the pretreatment adsorption column 6. When the total sample flow rate is 30 L, the sample injection is stopped, and the first mass flow controller 1, the first booster pump 2, the first electromagnetic valve 3, the third electromagnetic valve 9 and the fifth electromagnetic valve 15 are closed. The sample gas is enriched and purified by the enrichment and purification adsorption column 12, and the enriched and purified sample gas is collected in the buffer tank 25. Figure 5It can be seen that when the total sample flow is 30 L, Kr has not penetrated the enrichment and purification adsorption column 12, at this time the enrichment and purification adsorption column 12 has completed the adsorption and retention of Kr in the tail gas of the pretreatment adsorption column 6, and a clean mass transfer zone of Kr is left on the enrichment and purification adsorption column 12 for subsequent desorption and separation of impurity gas and Kr.

[0121] (3) Kr purification

[0122] After the sample is injected, the temperature program of the second high-low temperature box 11 is set as: -70℃ (22min)→50℃ (3min) 50℃ (5min)→180℃ (15min)→180℃ (stop), the flow rate of the second mass flow controller 18 is set as 50mL / min, the temperature program of the second high-low temperature box 11 is started, and the second mass flow controller 18, the eleventh electromagnetic valve 20 and the fifth electromagnetic valve 15 are opened. The pressure of the enrichment and purification adsorption column 12 is detected by the second pressure sensor 10, and the Kr content in the tail gas of the enrichment and purification adsorption column 12 is detected by the second GC 17. Figure 7 It can be seen that when the temperature of the second high-low temperature box 11 rises to 50℃, the pressure of the enrichment and purification adsorption column 12 drops to 100kPa and no Kr is detected in the tail gas, which shows that the enrichment and purification adsorption column 12 can realize the desorption and separation of most impurity gas and Kr. Therefore, the carrier gas can be stopped to purge the enrichment and purification adsorption column 12 after the temperature of the second high-low temperature box 11 rises to 50℃: the second mass flow controller 18, the eleventh electromagnetic valve 20 and the fifth electromagnetic valve 15 are turned off. The enrichment and purification adsorption column 12 is pumped to negative pressure: the fourth electromagnetic valve 14 is opened, and when the value of the second pressure sensor 10 drops to 10kPa, the fourth electromagnetic valve 14 is turned off.

[0123] (4) Preparation of Kr measurement source

[0124] After the enrichment and purification adsorption column 12 was kept at 180℃ for 10 min, nitrogen was supplied to the enrichment and purification adsorption column 12 and the buffer tank 25: the flow rate of the second mass flow controller 18 was set to 500 mL / min, the second mass flow controller 18, the eleventh electromagnetic valve 20, the sixth electromagnetic valve 21 and the eighth electromagnetic valve 24 were opened, and when the value of the third pressure sensor 27 rose to 130 kPa, the second mass flow controller 18 and the eleventh electromagnetic valve 20 were closed. The gas in the enrichment and purification adsorption column 12 and the buffer tank 25 was backmixed: the second booster pump 22 was opened, and when the value of the second pressure sensor 10 fell to 10 kPa, the second diaphragm booster pump 22 was closed, the seventh electromagnetic valve 23 was opened, and when the value of the third pressure sensor 27 stabilized, the seventh electromagnetic valve 23 was closed, and this process was repeated three times. After the backmixing was completed, the gas in the enrichment and purification adsorption column 12 was pressurized and transferred to the buffer tank 25: the second booster pump 22 was opened, and when the value of the second pressure sensor 10 fell to 2 kPa, the sixth electromagnetic valve 21, the second booster pump 22 and the eighth electromagnetic valve 24 were closed, and the value of the third pressure sensor 27 rose to 415 kPa. The Kr gas source was sampled: the tenth electromagnetic valve 28, the twelfth electromagnetic valve 29 and the thirteenth electromagnetic valve 31 were opened, and when the value of the third pressure sensor 27 stabilized, the tenth electromagnetic valve 28, the twelfth electromagnetic valve 29 and the thirteenth electromagnetic valve 31 were closed.

[0125] (5) Kr measurement source uniformity, recovery rate and decontamination factor

[0126] The concentrations of Xe and Kr in the chromatographic measurement source box 30 and the radioactive measurement source box 32 were measured by a gas chromatograph, the Xe concentration in the chromatographic measurement source box 30 was 0.01 ppm (the lower limit of detection of the gas chromatograph, the same below), the Kr concentration was 2289 ppm, the Xe concentration in the radioactive measurement source box 32 was 0.01 ppm, and the Kr concentration was 2293 ppm; the sample uniformity in the chromatographic measurement source box 30 and the radioactive measurement source box 32 was good, and the difference in the Kr concentration was less than 0.2%; the Kr recovery rate and the Xe decontamination factor were calculated according to the volume and pressure of the buffer tank 25, the total sampling flow rate and the concentrations of Xe and Kr in the simulated gas, the Kr recovery rate was 57%, and the Xe decontamination factor was 3.3 x 10 5 ; without considering the time used for the preparation of the measurement source, the preparation of the Kr measurement source took no more than 1 hour.

[0127] The method and device based on the present application have been applied to nuclear data measurement experiments for many times, and provide Xe or Kr measurement sources with high specific activity, high decontamination and good uniformity for nuclear data measurement.

[0128] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any change or replacement within the technical scope disclosed by the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for rapidly preparing a xenon or krypton gas source for nuclear data measurement, characterized in that, Includes the following steps: Step 1: Pretreatment of raw gas; At a temperature of 10–30°C, the original gas was pretreated using a pretreatment adsorption column to remove H2O, some CO2, and organic gases from the original gas. Step 2, Xe or Kr enrichment; An enrichment and purification adsorption column was used to adsorb and retain Xe or Kr in the pretreated gas. The adsorption and retention time was determined based on the amount of original gas injected. Step 3: Purify with Xe or Kr; The adsorption and separation method combining heating and carrier gas purging is used to purify the Xe or Kr adsorbed and retained on the enrichment and purification adsorption column; Step 4, Xe or Kr source; The enrichment and purification adsorption column is evacuated to a negative pressure of 5-15 kPa and heated to 160-200°C for a preset time period, allowing Xe or Kr to desorb from the column. The desorbed Xe or Kr gas source is temporarily stored in a buffer tank, and carrier gas is added to the enrichment and purification adsorption column and the buffer tank according to the required gas volume. The gas in the buffer tank is remixed with the gas in the enrichment and purification adsorption column 3-5 times. Then, the gas in the enrichment and purification adsorption column is pressurized and transferred to the buffer tank to obtain a uniform Xe or Kr gas source.

2. The rapid preparation method of xenon or krypton gas source for nuclear data measurement according to claim 1, characterized in that: In step 1, when preparing the Xe gas source, the pretreatment adsorption column is filled with 13X molecular sieve, and the enrichment and purification adsorption column is filled with coconut shell activated carbon. When preparing the Kr gas source, the pretreatment adsorption column is filled with 13X molecular sieve and coconut shell activated carbon, and the enrichment and purification adsorption column is filled with coconut shell activated carbon.

3. The rapid preparation method of xenon or krypton gas source for nuclear data measurement according to claim 2, characterized in that: In step 2, when preparing the Xe gas source, the adsorption cutoff temperature of the enrichment and purification adsorption column is -10 to 30°C; when preparing the Kr gas source, the adsorption cutoff temperature of the enrichment and purification adsorption column is -80 to -60°C.

4. The rapid preparation method of xenon or krypton gas source for nuclear data measurement according to claim 3, characterized in that: In step 3, when preparing the Xe gas source, the purification time of Xe gas is determined based on the desorption curves of Xe and Kr on the enrichment and purification adsorption column; when preparing the Kr gas source, the purification time of Kr gas is determined based on the pressure of the enrichment and purification adsorption column and the desorption curve of Kr.

5. The rapid preparation method of xenon or krypton gas source for nuclear data measurement according to claim 4, characterized in that: In step 4, the preset time period is 5-15 minutes; the carrier gas is helium or nitrogen; and the pressure inside the buffer tank is 300-450 kPa.

6. A rapid preparation apparatus for a xenon or krypton gas source for nuclear data measurement, used in the rapid preparation method for a xenon or krypton gas source for nuclear data measurement according to any one of claims 1-5, characterized in that: It includes a raw gas pretreatment unit, an enrichment and purification unit, and a source preparation unit; The raw gas pretreatment unit includes a first booster pump (2), a first high and low temperature chamber (5), and a pretreatment adsorption column (6); the first booster pump (2) is used to extract raw gas, and its outlet end is connected to the inlet end of the pretreatment adsorption column (6); the outlet end of the pretreatment adsorption column (6) is connected to a first vacuum system; the pretreatment adsorption column (6) is placed in the first high and low temperature chamber (5); The enrichment and purification unit includes an enrichment and purification adsorption column (12), a carrier gas assembly, and a second high and low temperature chamber (11); the inlet end of the enrichment and purification adsorption column (12) is connected to the outlet end of the pretreatment adsorption column (6), the first vacuum system, and the carrier gas assembly; the outlet end of the enrichment and purification adsorption column (12) is connected to the second vacuum system and also to the waste gas system; the enrichment and purification adsorption column (12) is placed in the second high and low temperature chamber (11); The source generation unit includes a second booster pump (22) and a source box assembly; the inlet end of the second booster pump (22) is connected to the outlet end of the enrichment and purification adsorption column (12), the second vacuum system and the waste gas system respectively, and the outlet end of the second booster pump (22) is connected to the source box assembly and connected to the third vacuum system; the source box assembly is used to collect Xe or Kr gas sources; the source generation unit also includes a buffer tank (25) and a third pressure sensor (27); the outlet end of the buffer tank (25) is connected to the third pressure sensor (27), the source box assembly and the third vacuum system respectively through a third four-way valve.

7. The apparatus for rapid preparation of xenon or krypton gas source for nuclear data measurement according to claim 6, characterized in that: The raw gas pretreatment unit also includes a first mass flow controller (1), a first solenoid valve (3), a first pressure sensor (4), a first filter (7), and a second solenoid valve (8); The first mass flow controller (1) is installed on the pipeline connecting the first booster pump (2) to the original gas; The first solenoid valve (3) is installed on the pipeline at the outlet end of the first booster pump (2); The first pressure sensor (4) is connected to the pipeline between the first solenoid valve (3) and the pretreatment adsorption column (6) via a first tee. The first filter (7) is located at the outlet end of the pretreatment adsorption column (6); The second solenoid valve (8) is located on the pipeline between the pretreatment adsorption column (6) and the first vacuum system.

8. The apparatus for rapid preparation of xenon or krypton gas source for nuclear data measurement according to claim 7, characterized in that: The enrichment and purification unit also includes a third solenoid valve (9), a second pressure sensor (10), a second filter (13), a fourth solenoid valve (14), a fifth solenoid valve (15), a first one-way valve (16), and a gas chromatograph (17). The inlet of the third solenoid valve (9) is connected to the inlet of the second solenoid valve (8) and the outlet of the pretreatment adsorption column (6) through the second three-way valve. The outlet of the third solenoid valve (9) is connected to the second pressure sensor (10), the carrier gas assembly and the inlet of the enrichment and purification adsorption column (12) through the first four-way valve. The outlet end of the enrichment and purification adsorption column (12) is connected to the second vacuum system, the waste gas system and the second booster pump (22) respectively through the second four-way valve; The second filter (13) is located at the outlet of the enrichment and purification adsorption column (12); The fourth solenoid valve (14) is installed on the pipeline between the second four-way valve and the second vacuum system; The fifth solenoid valve (15) is installed on the pipeline between the second four-way valve and the exhaust gas system; The inlet end of the first check valve (16) is connected to the outlet end of the fifth solenoid valve (15), and the outlet end of the first check valve (16) is connected to the exhaust gas system after passing through the gas chromatograph (17).

9. The apparatus for rapid preparation of xenon or krypton gas source for nuclear data measurement according to claim 8, characterized in that: The source control unit also includes a sixth solenoid valve (21), a seventh solenoid valve (23), an eighth solenoid valve (24), a ninth solenoid valve (26), and a tenth solenoid valve (28); The sixth solenoid valve (21) is installed on the pipeline between the second four-way valve and the second booster pump (22); The inlet end of the seventh solenoid valve (23) is connected to the outlet end of the sixth solenoid valve (21) and the inlet end of the second booster pump (22) via the third three-way valve, and its outlet end is connected to the outlet end of the second booster pump (22) and the inlet end of the buffer tank (25) via the fourth three-way valve. The eighth solenoid valve (24) is installed on the pipeline between the fourth three-way valve and the buffer tank (25); The ninth solenoid valve (26) is installed on the pipeline between the third four-way valve and the third vacuum system; The tenth solenoid valve (28) is located on the pipeline between the third four-way valve and the source box assembly.

10. The apparatus for rapid preparation of xenon or krypton gas source for nuclear data measurement according to claim 9, characterized in that: The carrier gas assembly includes a second mass flow controller (18), a second check valve (19), and an eleventh solenoid valve (20); The outlet end of the eleventh solenoid valve (20) is connected to the first four-way valve, and the inlet end is connected to the outlet end of the second one-way valve (19). The inlet end of the second check valve (19) is connected to the carrier gas via the second mass flow controller (18).

11. The apparatus for rapid preparation of xenon or krypton gas source for nuclear data measurement according to claim 10, characterized in that: The source box assembly includes a twelfth solenoid valve (29), a thirteenth solenoid valve (31), a chromatographic measurement source box (30), and a radiometric measurement source box (32); The tenth solenoid valve (28) is connected to the chromatography measurement source box (30) and the radioactivity measurement source box (32) respectively through the fifth three-way valve; The twelfth solenoid valve (29) is located on the pipeline between the fifth three-way valve and the chromatographic measurement source box (30); The thirteenth solenoid valve (31) is located on the pipeline between the fifth tee and the radiometric measurement source box (32).

12. The apparatus for rapid preparation of xenon or krypton gas source for nuclear data measurement according to claim 11, characterized in that: When preparing Xe gas source, the pretreatment adsorption column (6) is filled with 13X molecular sieve with a particle size of 2-4 mm; when preparing Kr gas source, the pretreatment adsorption column (6) is filled with 13X molecular sieve with a particle size of 2-4 mm and coconut shell activated carbon with a pore size of 26-30 mesh and a pore size distribution with the main peaks at 0.55 nm and 1.13 nm. The filling length of 13X molecular sieve is 1 / 10 to 3 / 10 of the column length, and the filling length of coconut shell activated carbon is 7 / 10 to 9 / 10 of the column length. The enrichment and purification adsorption column (12) is filled with coconut shell activated carbon of 26-30 mesh with the main peaks of pore size distribution at 0.55 nm and 1.13 nm.

13. The apparatus for rapid preparation of xenon or krypton gas source for nuclear data measurement according to claim 12, characterized in that: The column of the pretreatment adsorption column (6) is made of stainless steel tube with a diameter of 12-25 mm, a length of 400 mm, and a wall thickness of 1-3 mm. The enrichment and purification adsorption column (12) is made of stainless steel tube with a diameter of 25-35 mm, a length of 400 mm, and a wall thickness of 1-3 mm. The buffer container (25) is made of stainless steel and has a volume of 100-150ml and a wall thickness of 1-3mm. Both the chromatographic measurement source box (30) and the radiometric measurement source box (32) are made of stainless steel, with a volume of 4-50 ml and a wall thickness of 0.5-3 mm.

14. The apparatus for rapid preparation of xenon or krypton gas source for nuclear data measurement according to claim 13, characterized in that: The pipeline between the tenth solenoid valve (28) and the fifth tee is defined as the sample distribution pipeline; the length of the sample distribution pipeline is 3 to 5 m.

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