Device and method for separating mother and child nuclides of americium and neptunium

Abstract

The invention relates to an americium-neptunium mother and daughter nuclide separation device and a separation method, belongs to the technical field of actinide isotope separation and preparation, and solves the technical problems of long period and low recovery rate of americium-neptunium mother and daughter nuclide separation. The separation device comprises a radiation shielding body, a temperature controller, a liquid storage tank unit, a color layer separation unit, a waste liquid collector, a product collection unit, a valve and a delivery pump. Liquid in the liquid storage tank unit enters the color layer separation unit through the conveying pump, and liquid flowing out of the color layer separation unit enters the waste liquid collector or the product collection unit. The separation method comprises the following steps: preparing feed liquid, washing liquid, leacheate and a chromatographic layer adsorption column before separation; and adsorbing, washing and leaching americium and neptunium. The method is used for separating mother and child nuclides of americium neptunium

Description

Technical Field

[0001] The invention belongs to the technical field of separation and preparation of actinide isotopes, and in particular relates to a device and a method for separating americium-neptunium parent-daughter nuclides. Background Art

[0002] Many isotopes of americium (Am) and neptunium (Np) are parent-daughter nuclide pairs, such as the decay daughter of Am-241 is Np-237, the decay daughter of Am-242m is Np-238, the decay daughter of Am-243 is Np-239, etc. Their decay relationships are as follows:

[0003]

[0004] Among them, between Am-241 and Np-237, the daughter half-life is much longer than the parent half-life, and the decay of the mother and daughter is not balanced. The decay relationship between the mother and daughter can be used to separate the parent nucleus and daughter nucleus for analysis and determination, so as to diagnose the age of the americium material. In the mother and daughter of Am-242m and Np-238, Am-243 and Np-239, the daughter nuclides are all short-lived nuclides, and the parent half-life is much longer than the daughter. Therefore, after a certain daughter half-life, the activities of the parent and daughter reach a long-term equilibrium. The daughter nuclides can be extracted and prepared by the "cow milking" method and used as tracers for the recovery rate of the chemical process in neptunium analysis. However, these tracers cannot be prepared once and used for a long time due to their short half-life. Therefore, they need to be prepared by frequent "milking" periodically, such as once a week, to meet the needs of routine Np-237 analysis in samples. Therefore, establishing a simple and efficient separation technology for americium-neptunium parent and daughter nuclides is of great significance for applications such as nuclear material chronology, nuclear decay data measurement, and high-purity tracer preparation.

[0005] Most reports on the separation of americium and neptunium parent and daughter nuclides use extraction chromatography. 239 Np from 243 Am. J Radioanal Nucl Chem. 2005, 266 (1): 71-74) reported the separation of tetravalent neptunium and trivalent americium using Aliquat-336 silica gel column based on the principle of ferrous aminosulfonate reduction. etc. The preparation of 239 Nptracer from 243Am and the purification of the stock solution. J Radioanal Nucl Chem (2013) 298: 1179-1183) et al. reported the separation of tetravalent neptunium and trivalent americium by TEVA resin chromatography column based on the principle of ferrous reduction. 239 Np tracerbased on a second-milking process.J Radioanal NuclChem.2016,307:1215-1219) reported that no redox agent was used for valence adjustment, and HDEHP resin was used to extract neptunium and separate trivalent americium. The above method has the following shortcomings: (1) The recovered Am parent solution contains impurities such as Fe ions introduced during the redox process and organic acid is used for desorption, which requires additional steps to remove; or the medium of the recovered Am parent solution is inconsistent with the medium required for the next Np daughter preparation column, and a lengthy step is required to transfer the system, which inevitably causes the loss of Am parent; (2) Without the use of a redox agent, pentavalent Np will disproportionate to tetravalent and hexavalent, resulting in a reduced or unstable recovery rate of Np-239; (3) The purity of the Np daughter is not high enough, and there is contamination of the Am parent. It can be seen that the shortcomings of the existing americium-neptunium parent-daughter nuclide separation technology are difficult to meet the needs of various applications. Summary of the invention

[0006] In order to overcome the shortcomings of long cycle and low recovery rate in the separation of americium-neptunium parent and daughter nuclides, the present invention provides an americium-neptunium parent and daughter nuclides separation device and separation method.

[0007] The technical solution adopted by the present invention to solve the technical problem is:

[0008] A method for separating americium and neptunium parent and daughter nuclides comprises the following steps:

[0009] Step 1: Preparation before separation

[0010] Add 100 mg of sodium nitrite to the radioactive solution containing americium and neptunium, keep the temperature at 70-100 degrees for 15 minutes, and cool to form a feed solution before separation;

[0011] Dissolving the acid in water respectively to form an aqueous washing solution and an aqueous eluent;

[0012] TRU or RE, P 204 or LN or P 507 The resins are respectively loaded into chromatography columns;

[0013] Step 2: Adsorption of Americium and Neptunium

[0014] The aqueous radioactive solution containing americium and neptunium prepared in step 1 is passed through a TRU or RE chromatography adsorption column to adsorb americium and neptunium, and the effluent is collected as waste liquid;

[0015] Step 3: Washing

[0016] The washing liquid is washed through a TRU or RE chromatography adsorption column, and the effluent is collected as waste liquid;

[0017] Step 4: Rinse

[0018] The first-stage eluent passes through the TRU or RE chromatography adsorption column and P 204 or LN or P 507 The chromatographic adsorption column performs desorption of americium and neptunium and re-adsorption of americium, and the effluent, i.e. the radioactive solution of neptunium, is collected in a neptunium product collector;

[0019] The first stage eluent is again directly passed through P 204 or LN or P 507 The chromatographic adsorption column is used to further wash and recover neptunium, and the effluent is collected in a neptunium product collector;

[0020] Washing liquid passes through P 204 or LN or P 507 The chromatographic adsorption column desorbs americium, and the effluent, i.e., the radioactive solution of americium, is collected in an americium product collector or a storage tank for the radioactive solution of americium and neptunium;

[0021] Step 5: Regeneration

[0022] The second-stage eluent passes through the TRU or RE chromatography adsorption column, and the effluent is collected as waste liquid;

[0023] The first stage eluent passes through P 204 or LN or P 507 The pipeline between the chromatography adsorption column and the TRU or RE chromatography adsorption column, the effluent is collected as waste liquid;

[0024] The first stage eluent passes through P 204 or LN or P 507 Chromatographic adsorption column, the effluent is collected as waste liquid;

[0025] The washing liquid passes through the TRU or RE chromatography adsorption column, and the effluent is collected as waste liquid;

[0026] Step 6: Recycling

[0027] After the americium product solution in the americium-neptunium radioactive solution storage tank is left for a certain period of time, the required amount of neptunium daughters or a new group of americium-neptunium radioactive solutions that need to be separated are generated, and steps one to five are repeated to enter the next separation and preparation process, in this way, the isotopes of neptunium and americium are cyclically separated and prepared.

[0028] The radioactive solution of americium-neptunium is a solution composed of Am-243, Am-242m, or Am-241 and its decay daughter Np-239, Np-238, or Np-237, which is rich in sodium nitrite.

[0029] The acid in step 1 is nitric acid, hydrochloric acid, hydrofluoric acid or a combination of the above acids, and the concentration of the acid is 0.01 to 8.0 mol / L.

[0030] The radioactive solution containing americium and neptunium is 3-8 mol / L HNO3; the aqueous washing solution is 3-8 mol / L HNO3 solution; the first-stage eluent is 0.01-0.3 mol / L HNO3 solution; the second-stage eluent is 0.05-0.3 mol / L HCl solution containing 0.05-0.5 mol / L HF.

[0031] The above TRU or RE chromatographic column and P 204 or LN or P 507 The chromatographic column can be automatically regenerated and used for the next separation or preparation process.

[0032] After the first separation or preparation of neptunium isotopes, the recovered radioactive americium solution is completely consistent with the acid composition and concentration of the americium-neptunium radioactive solution required before the preparation, and directly meets the conditions for the next separation or preparation.

[0033] The above separation or cyclic preparation is repeated at least 10 times before the chromatographic adsorption column needs to be replaced.

[0034] The americium recovered by the above separation is stored in a liquid storage tank or an americium product collector instead of being stored on a chromatography column.

[0035] The americium-neptunium radioactive solution storage tank is provided with a shielding body outside.

[0036] The above separation process is carried out at room temperature.

[0037] The americium mentioned above is various americium isotopes such as americium-243, americium-242m and americium-241, and the neptunium is various neptunium isotopes such as neptunium-239, neptunium-238 and neptunium-237.

[0038] The beneficial effects of the present invention are:

[0039] A device for separating mother and daughter nuclides of americium and neptunium effectively utilizes the characteristics of two chromatographic columns for adsorbing americium and neptunium, and skillfully connects the output and input solution media between the two columns, so that the TRU or RE chromatographic adsorption column can separate americium and neptunium from impurity ions. 204 or LN or P 507 The chromatographic adsorption column is used to prepare high-purity neptunium and americium and simultaneously convert the americium solution as the starting liquid medium, laying the foundation for the automated control and cyclic preparation of the process.

[0040] A device for separating americium and neptunium from their parent and daughter nuclides. The recovered americium is automatically stored in a liquid storage tank with radiation shielding instead of being retained on a chromatographic separation column, thereby avoiding radiation degradation of organic adsorption materials, providing effective protection for multiple recycling uses of the chromatographic separation column, and ensuring the radiation safety of personnel.

[0041] A method for separating americium and neptunium parent and daughter nuclides, wherein each separation unit has a clear function, a simple process, and is easy to control and adjust. The separation, purification, preparation, medium conversion, regeneration and other processes are integrated in design. The entire process can be completed within 1.5 hours, and the separation of americium and neptunium parent and daughter nuclides can be achieved ten times.

[0042] Compared with the existing methods, a method for separating the parent and daughter nuclides of americium and neptunium has realized the automatic separation of americium and neptunium under program control; the recovery rates of neptunium and americium are better than 95% and 99%, and the decontamination factor of americium to neptunium is 10 4 The decontamination factor of neptunium to americium is 10 5 . BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of a device for separating americium and neptunium parent and daughter nuclides according to an embodiment of the present invention;

[0044] Figure 2 The γ-radioactivity spectrum of the original solution of Am-243 and Np-239 mother and daughter used in Example 1 of the present invention;

[0045] Figure 3 This is the gamma radiation energy spectrum of daughter Np-239 obtained in Example 1 of the present invention;

[0046] Figure 4 This is the γ-radiation energy spectrum of the parent Am-243 after separation in Example 1 of the present invention.

[0047] Reference numerals: 1. Feed liquid reservoir, 2. Washing liquid reservoir, 3. First stage eluent reservoir, 4. Second stage eluent reservoir, 5. Waste liquid collector, 6. Neptunium product collector, 7. TRU or RE chromatography adsorption column, 8. P 204 or LN or P 507 Chromatographic adsorption column, 9. valve, 10. delivery pump, 11. temperature controller, 12. radiation shielding body, 13. americium product collector. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] like Figure 1 As shown, the device for separating the parent and daughter nuclides of americium and neptunium of the present invention comprises a radiation shield 12, a temperature controller 11, a liquid storage tank unit, a chromatographic separation unit, a waste liquid collector 5, and a product collection unit. The above units and devices are connected by pipelines. Preferably, the pipeline adopts a silicone tube; and corresponding valves 9 and a delivery pump 10 are configured in the pipeline. In this way, the electromagnetic valve and the peristaltic pump can be controlled by a microcomputer to realize automatic control of the separation process, reduce the impact of radioactive nuclides radiation on the human body during separation, and reduce the labor intensity of personnel. The peristaltic pump uses a hose extrusion method to deliver the separation liquid, and the flow rate and flow velocity of the liquid are controlled by the rotation speed of the peristaltic pump.

[0050] The above-mentioned liquid storage tank unit includes a liquid storage tank 1 containing americium-neptunium radioactive solution, a washing liquid storage tank 2, a first-stage eluent storage tank 3, and a second-stage eluent storage tank 4. Each liquid storage tank is connected to a corresponding chromatographic adsorption column through a valve and a pump, and realizes different functions.

[0051] The above-mentioned chromatography separation unit includes a TRU or RE chromatography adsorption column 7, P 204 or LN or P 507 Chromatographic adsorption column 8.

[0052] The connection relationship between the above-mentioned storage tanks and the chromatography adsorption column is as follows: the storage tank 1 containing the radioactive solution of americium and neptunium is placed at the lower end, and its inner bottom end is connected to the inlet of the delivery pump through a pipeline and a valve; the washing liquid storage tank 2, the first-stage eluent storage tank 3 and the second-stage eluent storage tank 4 are placed in parallel at the upper end, and their outlets are connected to the inlet of the delivery pump 10 through a valve 9; the outlet of the delivery pump 10 is connected to the TRU or RE chromatography adsorption column 7 and the P through the valve 9. 204 or LN or P 507 The discharge port of the TRU or RE chromatographic adsorption column 7 is connected to the waste liquid collector 5 and P through valve 9 respectively. 204 or LN or P 507 The material inlet of the chromatographic adsorption column 8 is connected; P 204 or LN or P 507 The discharge port of the chromatographic adsorption column 8 is connected to the storage tank 1 containing the radioactive solution of americium and neptunium or the americium product collector 13, the neptunium product collector 6 and the waste liquid collector 5 respectively through the valve 9.

[0053] The separation step of the present invention is:

[0054] Step 1: Preparation before separation

[0055] Add 100 mg of sodium nitrite to the radioactive solution containing americium and neptunium, keep the temperature at 70-100 degrees for 15 minutes, and cool to form a feed solution before separation; dissolve the acid in water to form an aqueous washing solution and an aqueous eluent; the acid used is nitric acid and hydrochloric acid, hydrofluoric acid or a combination of the above acids, and the concentration of the acid is 0.01 to 8.0 mol / L; place a TRU or RE chromatography adsorption column, P 204 or LN or P 507 The resins are loaded into chromatography columns respectively.

[0056] TRU or RE chromatography column is used to separate Np, Am and constant Na; 204 or LN or P 507 The chromatographic column is used to separate americium from neptunium, and to convert the acid system for eluting and recovering Am into the acid composition and concentration required before the americium-neptunium radioactive solution is separated on the column, so that it can be directly used for the next separation and preparation of americium-neptunium.

[0057] Step 2: using a peristaltic pump to deliver and a solenoid valve to select, the radioactive solution containing americium and neptunium is passed through a TRU or RE chromatography adsorption column 7 to adsorb americium and neptunium, and the effluent is collected as waste liquid;

[0058] Step 3: Use a peristaltic pump to deliver and a solenoid valve to select, so that the washing liquid passes through the TRU or RE chromatography adsorption column for washing, and the effluent is collected as waste liquid;

[0059] Step 4: Use the peristaltic pump to deliver and the solenoid valve to select, so that the first-stage eluent passes through the TRU or RE chromatography adsorption column 7 and P in turn. 204 or LN or P 507 The chromatographic adsorption column 8 performs desorption of americium and neptunium and re-adsorption of americium, and the effluent, i.e. the radioactive solution of neptunium, is collected in the neptunium product collector 6;

[0060] Step 5: Use the peristaltic pump to deliver and the solenoid valve to select, so that the first-stage eluent passes directly through P again 204 or LN or P 507 The chromatographic adsorption column 8 is used for further washing and recovery of neptunium, and the effluent is collected in the neptunium product collector 6;

[0061] Step 6: Use the peristaltic pump to deliver and the solenoid valve to select, so that the washing liquid passes through P 204 or LN or P 507 The chromatographic adsorption column 8 desorbs americium, and the effluent, i.e., the radioactive solution of americium, is collected in the americium product collector 13 or the storage tank 1 for the radioactive solution of americium and neptunium;

[0062] Step 7: Use a peristaltic pump to deliver and a solenoid valve to select, so that the second-stage eluent passes through the TRU or RE chromatography adsorption column 7, and the effluent is collected as waste liquid;

[0063] Step 8: Use the peristaltic pump to deliver and the solenoid valve to select, so that the first-stage eluent passes through P 204 or LN or P 507 The pipeline between the chromatography adsorption column 8 and the TRU or RE chromatography adsorption column 7, the effluent is collected as waste liquid;

[0064] Step 9: Use the peristaltic pump to deliver and the solenoid valve to select. The first stage eluent passes through P 204 or LN or P 507 Chromatographic adsorption column 8, the effluent is collected as waste liquid;

[0065] Step 10: Use a peristaltic pump to deliver and a solenoid valve to select, so that the washing liquid passes through the TRU or RE chromatography adsorption column 7, and the effluent is collected as waste liquid;

[0066] Step 11: After the americium product solution in the americium-neptunium radioactive solution storage tank is left for a certain period of time, the required amount of neptunium daughters or a new group of americium-neptunium radioactive solutions that need to be separated are generated, and steps 1 to 10 are repeated to enter the next separation and preparation process. In this way, neptunium and americium isotopes are cyclically separated and prepared.

[0067] In the above method, the radioactive solution of americium-neptunium is a solution composed of Am-243, Am-242m, or Am-241 and its decay daughter Np-239, Np-238, or Np-237, which is rich in sodium nitrite.

[0068] The specific embodiments are as follows:

[0069] Example 1

[0070] Add 100 mg of sodium nitrite to 15 mL of 4 mol / L HNO3 americium-neptunium radioactive solution in the liquid storage tank 1, and maintain the temperature at 80 degrees for 15 minutes and cool to form a feed solution before separation. Its γ radioactivity spectrum is as follows: Figure 2 shown.

[0071] The flow rate of the americium-neptunium feed solution is controlled at 1.5 mL / min, and the americium-neptunium solution is separated by a TRU chromatographic adsorption column. The TRU chromatographic adsorption column is A TRU chromatography column is used to separate americium and neptunium from the major element Na, and the effluent is collected in the waste liquid collector 5.

[0072] Use 15 mL of 4 mol / L HNO3 solution in the washing liquid reservoir 2 to wash through the TRU chromatography adsorption column at a flow rate of 2 mL / min, and collect the effluent in the waste liquid collector 5.

[0073] Use 30mL 0.05mol / L HNO3 solution in the first-stage eluent reservoir 3, control the flow rate at 1.5mL / min, and pass it through the TRU chromatography adsorption column and P 204 The chromatographic adsorption column is used to desorb americium and neptunium and re-adsorb americium, wherein P 204 The chromatographic column is P 204 The effluent, i.e. the radioactive solution of neptunium, is collected in the neptunium product collector 6.

[0074] Use 10mL 0.05mol / L HNO3 solution in the first-stage eluent reservoir 3, control the flow rate to 1.5mL / min, and pass it directly through P again. 204 The chromatographic adsorption column is further washed and recovered for neptunium, and the effluent is collected in the neptunium product collector 6. Its γ-radioactivity spectrum is as follows: Figure 3 shown.

[0075] Use 15mL 4mol / L HNO3 solution in the washing liquid reservoir 2, control the flow rate to 1.5mL / min, and pass through P 204 The chromatographic adsorption column 81 desorbs americium, and the effluent, i.e., the radioactive solution of americium, is collected in the americium product collector 13 or the storage tank 1 of the radioactive solution of americium and neptunium. The gamma radioactivity spectrum thereof is as follows: Figure 4 shown.

[0076] Use 10 mL of 0.1 mol / L HCl-0.2 mol / L HF solution in the second-stage eluent reservoir 4, control the flow rate to 1.5 mL / min, pass through the TRU chromatography adsorption column, and collect the effluent as waste liquid.

[0077] Use 5mL 0.05mol / L HNO3 solution in the first-stage eluent reservoir 3, control the flow rate to 2mL / min, and pass through P 204 The pipeline between the chromatography adsorption column and the TRU chromatography adsorption column, the effluent is collected as waste liquid.

[0078] Use 15mL 0.05mol / L HNO3 solution in the first-stage eluent reservoir 3, control the flow rate to 2mL / min, and pass through P 204 The effluent was collected as waste liquid.

[0079] Use 15mL 4mol / L HNO3 solution in the washing liquid reservoir 2, control the flow rate to 2mL / min, pass through the TRU chromatography adsorption column, and collect the effluent as waste liquid.

[0080] The recoveries of americium and neptunium were 99.7% and 95.6%, respectively, and the separation process took 88 minutes. The neptunium product solution was left for one month until Np-239 decayed completely, and the decontamination factor of neptunium to americium was determined to be 1.2×10 5The Np-239 decontamination experiment determined that the decontamination factor of americium to neptunium is 1.1×10 4 .

[0081] Example 2

[0082] The TRU chromatography adsorption column in Example 1 is replaced by an RE chromatography adsorption column, P 204 The chromatographic adsorption column was replaced with an LN chromatographic adsorption column, and the separation process of Example 1 was repeated to obtain Np-239 and Am-243 solutions. The recovery rate of neptunium was measured to be 95.1%, and the decontamination factor of neptunium to americium was 1.4×10 5 , the recovery rate of americium is 99.2%.

[0083] Example 3

[0084] After the Am-243 solution in the americium-neptunium radioactive solution storage tank in Example 1 was left for 8 days, the separation process of Example 1 was repeated to obtain neptunium and an americium solution for the next cycle. The recovery rates of neptunium and americium were measured to be 95.5% and 99.6%, respectively. The decontamination factor of neptunium to americium was 1.1×10 5 .

Claims

1. A device for separating mother and daughter nuclides of americium and neptunium, characterized in that: The device comprises the following components: a radiation shield (12), a temperature controller (11), a liquid storage tank unit, a chromatography separation unit, a waste liquid collector (5), a product collection unit, a valve (9) and a delivery pump (10); The liquid in the liquid storage tank unit enters the chromatographic separation unit through a delivery pump (10), and the liquid flowing out of the chromatographic separation unit enters a waste liquid collector (5) or a product collection unit; the components through which the liquid in the liquid storage tank unit flows are connected by pipelines, and valves (9) are provided on the pipelines through which the liquid flows through each component; The liquid storage tank unit comprises a feed liquid storage tank (1), a washing liquid storage tank (2), a first-stage eluent storage tank (3), and a second-stage eluent storage tank (4), and each storage tank is connected to the chromatographic separation unit via a valve (9) and a delivery pump (10); The liquid storage tank (1) is located inside the temperature controller (11), and a radiation shielding body (12) is arranged outside the temperature controller (11); The chromatographic separation unit comprises a TRU or RE chromatographic adsorption column (7), a P 204 or LN or P 507 Chromatographic adsorption column (8); The TRU or RE chromatographic adsorption column (7) may be a TRU chromatographic adsorption column or a RE chromatographic adsorption column; P 204 or LN or P 507 The chromatographic adsorption column (8) may be P 204 Chromatographic adsorption column, can also be LN chromatographic adsorption column, can also be P 507 Chromatographic adsorption column; The product collecting unit comprises an americium product collector (13) and a neptunium product collector (6); The liquid storage tank unit is connected to the chromatographic separation unit through a valve (9) and a delivery pump (10), and the connection relationship is as follows: the feed liquid storage tank (1) is placed at the lower end, and its inner bottom end is connected to the inlet of the delivery pump (10) through the valve (9); the washing liquid storage tank (2), the first-stage eluent storage tank (3) and the second-stage eluent storage tank (4) are placed in parallel at the upper end, and their outlets are connected to the inlet of the delivery pump (10) through the valve (9); the outlet of the delivery pump (10) is connected to the TRU or RE chromatographic adsorption column (7) and the P through the valve (9). 204 or LN or P 507 The discharge port of the TRU or RE chromatographic adsorption column (7) is connected to the waste liquid collector (5) and P through a valve (9). 204 or LN or P 507 The material inlet of the chromatographic adsorption column (8) is connected; 204 or LN or P 507 The discharge port of the chromatographic adsorption column (8) is connected to a liquid storage tank (1) containing a radioactive solution of americium and neptunium or an americium product collector (13), a neptunium product collector (6) and a waste liquid collector (5) respectively through a valve (9).

2. The americium-neptunium parent-daughter nuclide separation device according to claim 1, characterized in that: The pipeline is a silicone tube.

3. The americium-neptunium parent-daughter nuclide separation device according to claim 1, characterized in that: It also includes a microcomputer, which is used to control the valve (9) and the delivery pump (10); The valve (9) is a solenoid valve, and the delivery pump (10) is a peristaltic pump; the rotation speed of the peristaltic pump controls the flow rate and flow velocity of the liquid.

4. A method for separating americium and neptunium parent and daughter nuclides, characterized in that: The following steps are involved: Step 1, preparation before separation: Placing the radioactive solution of americium and neptunium to be separated into a feed liquid storage tank (1), adding sodium nitrite, controlling the temperature of the feed liquid storage tank (1) to be 70° to 100° by a temperature controller (11), keeping the temperature for a certain period of time, and cooling to room temperature to obtain a feed liquid containing americium and neptunium; Dissolve nitric acid and hydrochloric acid, hydrofluoric acid or a combination of the above acids at a concentration of 0.01 mol / L to 8.0 mol / L in water respectively. A washing liquid and an eluent are formed, and both the washing liquid and the eluent are aqueous; TRU, RE, P 204 , LN, P 507 The resins are respectively loaded into chromatographic columns to obtain corresponding chromatographic adsorption columns; Step 2, adsorption of americium and neptunium: The feed liquid in the feed liquid storage tank (1) passes through a TRU or RE chromatographic adsorption column (7), so that americium and neptunium are adsorbed in the TRU or RE chromatographic adsorption column (7), and the effluent of the TRU or RE chromatographic adsorption column (7) is collected in a waste liquid collector (5); Step 3: Washing The washing liquid in the washing liquid storage tank (2) passes through a TRU or RE chromatographic adsorption column (7) for washing, and the effluent of the TRU or RE chromatographic adsorption column (7) is collected in a waste liquid collector (5); Step 4: Rinse: First, the first-stage eluent in the first-stage eluent storage tank (3) passes through a TRU or RE chromatography adsorption column (7), a P 204 or LN or P 507 Chromatographic adsorption column (8), elution, on TRU or RE chromatographic adsorption column (7), P 204 or LN or P 507 The desorption of americium and neptunium and the re-adsorption of americium are carried out in the chromatographic adsorption column (8), and P 204 or LN or P 507 The effluent from the chromatography adsorption column (8) is collected in a neptunium product collector (6) to obtain a neptunium radioactive solution; Secondly, the first-stage eluent in the first-stage eluent storage tank (3) is directly passed through P 204 or LN or P 507 Chromatographic adsorption column (8) for further washing and recovery of neptunium. 204 or LN or P 507 The effluent from the chromatography adsorption column (8) is collected in a neptunium product collector (6) to obtain a neptunium radioactive solution; Again, the washing liquid in the washing liquid storage tank (2) passes through P 204 or LN or P 507 Chromatographic adsorption column (8) to desorb americium and convert P 204 or LN or P 507 The effluent from the chromatography adsorption column (8) is collected in an americium product collector (13) to obtain an americium radioactive solution.

5. The method for separating americium and neptunium parent and daughter nuclides according to claim 4, characterized in that: The method further comprises step 5, regeneration; first, the second-stage eluent in the second-stage eluent storage tank (4) passes through a TRU or RE chromatographic adsorption column (7), and the effluent of the TRU or RE chromatographic adsorption column (7) is collected into a waste liquid collector (5); Secondly, the first-stage eluent in the first-stage eluent storage tank (3) is passed through P 204 or LN or P 507 The pipeline between the chromatography adsorption column (8) and the TRU or RE chromatography adsorption column (7) flows into the waste liquid collector (5); again, the first-stage eluent in the first-stage eluent storage tank (3) passes through the P 204 or LN or P 507 Chromatographic adsorption column (8), P 204 or LN or P 507 The effluent from the chromatographic adsorption column (8) is collected in a waste liquid collector (5); finally, the washing liquid in the washing liquid storage tank (2) passes through a TRU or RE chromatographic adsorption column (7), and the effluent from the TRU or RE chromatographic adsorption column (7) is collected in a waste liquid collector (5).

6. The method for separating americium and neptunium parent and daughter nuclides according to claim 4, characterized in that: The concentration of HNO3 in the americium-neptunium solution is 3 mol / L to 8 mol / L.

7. The method for separating americium and neptunium parent and daughter nuclides according to claim 4, characterized in that: In the step 1, in the preparation before separation, A 3 mol / L to 8 mol / L HNO3 solution is used as a washing liquid, and the washing liquid is placed in a washing liquid storage tank (2); a 0.01 mol / L to 0.3 mol / L HNO3 solution is used as a first-stage eluent, and the first-stage eluent is placed in a first-stage eluent storage tank (3); A solution containing 0.05 mol / L to 0.5 mol / L HF and 0.05 mol / L to 0.3 mol / L HCl is used as the second-stage eluent, and the second-stage eluent is placed in a second-stage eluent storage tank (4).

8. The method for separating americium and neptunium parent and daughter nuclides according to claim 4, characterized in that: In the step 1, in the preparation before separation, the radioactive americium-neptunium solution to be separated is 15 mL of a radioactive americium-neptunium solution containing 4 mol / L HNO3, 100 mg of sodium nitrite is added, and the temperature of the feed liquid storage tank (1) is controlled by a temperature controller (11) to be 80°, and the temperature is kept for 15 minutes; In the step 2, in the adsorption of americium and neptunium, the flow rate of the feed liquid is 1.5 mL / min, and the feed liquid passes through the TRU chromatographic adsorption column. The TRU chromatographic adsorption column is In the step 3, in the washing, the washing liquid is 15 mL of 4 mol / L HNO3 solution, the flow rate is 2 mL / min, and the washing liquid passes through the TRU chromatography adsorption column; In the first step of step 4, the first-stage eluent is 30 mL of 0.05 mol / L HNO3 solution at a flow rate of 1.5 mL / min, which passes through the TRU chromatography adsorption column and P 204 Chromatographic adsorption column, P 204 The chromatographic column is In the second process of step 4, the first-stage eluent is 10mL 0.05mol / L HNO3 solution, and the flow rate is 1.5mL / min, directly through P 204 Chromatographic adsorption column; During the step 4, the washing liquid was 15 mL of 4 mol / L HNO3 solution at a flow rate of 1.5 mL / min. 204 The americium was desorbed using a chromatography column.

9. The method for separating americium and neptunium parent and daughter nuclides according to claim 5, characterized in that: In the first process of step 5, the second-stage eluent is 10 mL of 0.1 mol / L HCl-0.2 mol / L HF solution, and the flow rate is 1.5 mL / min, passing through the TRU chromatography adsorption column; In the second process of step 5, the first-stage eluent is 5 mL of 0.05 mol / L HNO3 solution, the flow rate is 2 mL / min, and the 204 The pipeline between the chromatography adsorption column and the TRU chromatography adsorption column; In the process of step 5, the first-stage eluent is 15mL 0.05mol / L HNO3 solution, the flow rate is 2mL / min, and the first-stage eluent passes through P 204 Chromatographic adsorption column; In the final process of step 5, the washing liquid is 15 mL of 4 mol / L HNO3 solution, the flow rate is 2 mL / min, and the washing liquid passes through the TRU chromatography adsorption column.

10. The method for separating americium and neptunium parent and daughter nuclides according to claim 4, characterized in that: The radioactive solution of americium and neptunium to be separated is a solution composed of Am-243, Am-242m, or Am-241 and its decay daughter Np-239, Np-238, or Np-237, which is rich in sodium nitrite.

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