Americium-neptunium parent-daughter nuclide separation device and separation method

Abstract

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

Description

Technical Field

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

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

[0003]

[0004] In the case of Am-241 and Np-237, the daughter half-life is much longer than the parent half-life, resulting in disequilibrium between the parent and daughter nuclei. This decay relationship can be exploited to separate the parent and daughter nuclei for analysis and determination, thereby diagnosing the age of americium materials. In the Am-242m and Np-238, and Am-243 and Np-239 parent-daughter pairs, the daughter nuclides are all short-lived, while the parent half-life is much longer than the daughter. Therefore, after a certain period of daughter half-life, the activities of the parent and daughter nuclides reach long-term equilibrium. These daughter nuclides can be extracted and prepared using a "cow milking" method and used as tracers for chemical process recovery in neptunium analysis. However, due to their short half-lives, these tracers cannot be prepared in a single batch for long-term use. Therefore, they require frequent "milking" (e.g., weekly) 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 that based on the principle of ferrous sulfamate reduction, tetravalent neptunium and trivalent americium were separated by extraction using Aliquat-336 silica gel column. etc. The preparation of the 239 Nptracer from 243Am and the purification ofthe stock solution.J Radioanal NuclChem(2013)298:1179-1183) reported the separation of tetravalent neptunium from trivalent americium based on the principle of ferrous reduction using TEVA resin column chromatography. Literature 3 (Yanmei Shi et al. An efficient method for preparing high-purity 239 Np tracerbased on a second-milking process.J Radioanal NuclChem.2016,307:1215-1219) reported the separation of neptunium from trivalent americium using HDEHP resin extraction without using redox reagents for valence adjustment. The above methods have the following disadvantages: (1) The recovered Am parent solution contains impurities such as Fe ions introduced by the oxidation-reduction process and desorption using organic acids, 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, which requires lengthy steps to convert the system, which inevitably causes loss of Am parent; (2) In the absence of redox reagents, pentavalent Np will be reduced to tetravalent and hexavalent, resulting in reduced or unstable recovery of Np-239; (3) The purity of Np daughter is not high enough, and there is contamination of Am parent. As can be seen, the deficiencies of the existing americium-neptunium parent-daughter nuclide separation technology cannot well meet the needs of various applications. SUMMARY

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

[0007] The technical scheme adopted by the present application to solve its technical problems is:

[0008] An americium-neptunium parent-daughter nuclide separation method, comprising the following steps:

[0009] Step one: preparation before separation

[0010] 100 mg of sodium nitrite is added to the radioactive solution containing americium and neptunium, and the solution is cooled at a constant temperature of 70-100 degrees for 15 minutes to form a solution before separation;

[0011] The acid is dissolved in water to form an aqueous washing solution and an aqueous elution solution;

[0012] TRU or RE, P 204 or LN or P 507 resin is packed into a chromatographic column;

[0013] Step two: Adsorption of americium and neptunium

[0014] The aqueous americium and neptunium containing radioactive solution prepared in step one is passed through the TRU or RE chromatographic adsorption column for adsorption of americium and neptunium, and the effluent is collected as waste liquid;

[0015] Step three: Washing

[0016] The washing liquid is passed through the TRU or RE chromatographic adsorption column for washing, and the effluent is collected as waste liquid;

[0017] Step four: Elution

[0018] The first stage elution liquid is passed through the TRU or RE chromatographic adsorption column and the P 204 or LN or P 507 chromatographic adsorption column in turn for desorption of americium and neptunium and re-adsorption of americium, and the effluent, i.e. the neptunium radioactive solution, is collected in the neptunium product collector;

[0019] The first stage elution liquid is passed through the P 204 or LN or P 507 chromatographic adsorption column again for further washing and recovery of neptunium, and the effluent is collected in the neptunium product collector;

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

[0021] Step five: Regeneration

[0022] The second stage elution liquid is passed through the TRU or RE chromatographic adsorption column, and the effluent is collected as waste liquid;

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

[0024] The first stage elution liquid is passed through the P 204 or LN or P 507 chromatographic adsorption column, and the effluent is collected as waste liquid;

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

[0026] Step six: Recycle

[0027] The Am-Np radioactive solution is a solution of Am-243 or Am-242m or Am-241 and its daughter Np-239 or Np-238 or Np-237, which is rich in sodium nitrite.

[0028] The acid in step 1 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.

[0029] The Am-Np radioactive solution is a solution of Am-243 or Am-242m or Am-241 and its daughter Np-239 or Np-238 or Np-237, which is rich in sodium nitrite.

[0030] The Am-Np radioactive solution 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; and the second-stage eluent is 0.05-0.3 mol / L HCl solution containing 0.05-0.5 mol / L HF.

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

[0032] The recovered Am radioactive solution after the first separation or preparation of Np isotopes is directly used for the next separation or preparation process, as the acid composition and concentration of the Am-Np radioactive solution required before preparation are completely consistent.

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

[0034] The recovered Am is stored in a storage tank or an Am product collector, rather than being stored on the chromatographic column.

[0035] The Am-Np radioactive solution storage tank is provided with a shielding body.

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

[0037] The Am is Am-243, Am-242m and Am-241, and the Np is Np-239, Np-238 and Np-237.

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

[0039] The application discloses an americium-neptunium parent-daughter nuclide separation device. 204 or LN or P 507 The color layer adsorption column is used for preparing high-purity neptunium and americium and simultaneously converting americium solution into a starting material medium, thereby laying a foundation for automatic control and cyclic preparation of the process.

[0040] The application discloses an americium-neptunium parent-daughter nuclide separation device.

[0041] The application discloses an americium-neptunium parent-daughter nuclide separation method.

[0042] Compared with the prior art, the americium-neptunium parent-daughter nuclide separation method realizes automatic separation of americium and neptunium through program control. 4 The recovery rate of neptunium and americium is higher than 95% and 99%, respectively. 5 . BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 Fig. 1 is a schematic diagram of an americium-neptunium parent-daughter nuclide separation device according to an embodiment of the application.

[0044] Figure 2 Fig. 2 is a gamma radiation performance spectrum diagram of an Am-243 and Np-239 parent-daughter original solution used in Embodiment 1 of the application.

[0045] Figure 3 Fig. 3 is a gamma radiation performance spectrum diagram of a daughter Np-239 obtained in Embodiment 1 of the application.

[0046] Figure 4 Fig. 4 is a gamma radiation performance spectrum diagram of a parent Am-243 after separation in Embodiment 1 of the application.

[0047] Fig. 1 is a schematic diagram of an americium-neptunium parent-daughter nuclide separation device according to an embodiment of the application. 204 or LN or P 507 Fig. 1 is a schematic diagram of an americium-neptunium parent-daughter nuclide separation device according to an embodiment of the application. DETAILED DESCRIPTION

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

[0049] like Figure 1 As shown, the apparatus for separating parent and daughter nuclides of americium and neptunium according to the present invention comprises a radiation shield 12, a temperature controller 11, a liquid reservoir unit, a chromatography separation unit, a waste liquid collector 5, and a product collection unit. These units and components are connected by pipelines, preferably silicone tubes. Appropriate valves 9 and a delivery pump 10 are also provided within the pipelines. This allows the solenoid valves and peristaltic pump to be controlled by a microcomputer, enabling automated control of the separation process, minimizing the impact of radioactive nuclides on the human body during separation and reducing labor intensity. The peristaltic pump uses a hose to squeeze the liquid for separation, and the flow rate and velocity of the liquid are controlled by the peristaltic pump's rotational speed.

[0050] The above-mentioned reservoir unit includes a reservoir 1 containing a radioactive solution of americium and neptunium, a washing solution reservoir 2, a first-stage eluent reservoir 3, and a second-stage eluent reservoir 4. Each reservoir is connected to a corresponding chromatography 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 Chromatography adsorption column 8.

[0052] The connection relationship between the above-mentioned reservoirs and the chromatography adsorption column is as follows: the reservoir 1 containing the radioactive solution of americium and neptunium is placed at the lower end, and its internal bottom end is connected to the inlet of the delivery pump through a pipeline and a valve; the washing liquid reservoir 2, the first-stage eluent reservoir 3 and the second-stage eluent reservoir 4 are placed side by side 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 TRU or RE chromatographic adsorption column 7 through the outlet valve 9 and the waste liquid collector 5 and P 204 or LN or P 507 Chromatographic adsorption column 8 feed port connection; P 204 or LN or P 507 The discharge port of the chromatography 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 a valve 9.

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

[0054] Step 1: Preparation before separation

[0055] The radioactive solution containing Am and Np is added with 100 mg of sodium nitrite, and then heated at a constant temperature of 70-100 °C for 15 min, and cooled to form the feed solution before separation; the acids are dissolved in water to form the aqueous washing solution and the aqueous elution solution; the acids used are nitric acid and hydrochloric acid, hydrofluoric acid, or a combination of the above acids, and the concentration of the acids is 0.01-8.0 mol / L; the TRU or RE chromatographic column, P 204 or LN or P 507 The resins are filled into the chromatographic columns respectively.

[0056] The TRU or RE chromatographic column is used to separate Np and Am from the constant Na; P 204 or LN or P 507 The chromatographic column is used to separate Am from Np, and the acid system for eluting and recovering Am is converted into the acid composition and concentration required for the separation of Am and Np before the column separation of the radioactive solution containing Am and Np, so as to be directly used for the separation and preparation of Am and Np in the next cycle.

[0057] In the second step, the radioactive solution containing Am and Np is pumped by a peristaltic pump and gated by a solenoid valve, so as to pass through the TRU or RE chromatographic column 7 for the adsorption of Am and Np, and the effluent is collected as waste liquid;

[0058] In the third step, the washing solution is pumped by a peristaltic pump and gated by a solenoid valve, so as to pass through the TRU or RE chromatographic column for washing, and the effluent is collected as waste liquid;

[0059] In the fourth step, the first-stage elution solution is pumped by a peristaltic pump and gated by a solenoid valve, so as to pass through the TRU or RE chromatographic column 7 and P 204 or LN or P 507 chromatographic column 8 in sequence for the desorption of Am and Np and the re-adsorption of Am, and the effluent, i.e. the radioactive solution of Np, is collected in the Np product collector 6;

[0060] In the fifth step, the first-stage elution solution is pumped by a peristaltic pump and gated by a solenoid valve, so as to pass through the P 204 or LN or P 507 chromatographic column 8 again for further washing and recovery of Np, and the effluent is collected in the Np product collector 6;

[0061] In the sixth step, the washing solution is pumped by a peristaltic pump and gated by a solenoid valve, so as to pass through the P 204 or LN or P 507 chromatographic column 8 for the desorption of Am, and the effluent, i.e. the radioactive solution of Am, is collected in the Am product collector 13 or the storage tank 1 of the radioactive solution containing Am and Np;

[0062] In the seventh step, the second-stage elution solution is pumped by a peristaltic pump and gated by a solenoid valve, so as to pass through the TRU or RE chromatographic column 7, and the effluent is collected as waste liquid;

[0063] Eighth step: using peristaltic pump delivery and solenoid valve gating, the first stage eluent through P 204 or LN or P 507 The pipeline between the color adsorption column 8 and the TRU or RE color adsorption column 7, the effluent is collected as waste liquid;

[0064] Ninth step: using peristaltic pump delivery and solenoid valve gating, the first stage eluent through P 204 or LN or P 507 The color adsorption column 8, the effluent is collected as waste liquid;

[0065] Tenth step: using peristaltic pump delivery and solenoid valve gating, the washing liquid through the TRU or RE color adsorption column 7, the effluent is collected as waste liquid;

[0066] Eleventh step: after the americium-neptunium radioactive solution in the storage tank is placed for a period of time, the required amount of neptunium daughter is generated, or a new group of americium-neptunium radioactive solutions that need to be separated, steps one to ten are repeated, and the next separation and preparation process is entered, in this way, the isotopes of neptunium and americium are cyclically separated and prepared.

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

[0068] The specific implementation is as follows:

[0069] Example 1

[0070] 100 mg of sodium nitrite is added to 15 mL of 4 mol / L HNO3 americium-neptunium radioactive solution placed in the storage tank 1, and the temperature controller is controlled at 80 degrees for 15 minutes, and then cooled to form the feed solution before separation, and the gamma radiation spectrum is as shown in Figure 2 .

[0071] The flow rate of the americium-neptunium-containing feed solution is controlled at 1.5 mL / min, and the americium-neptunium-containing solution is separated through the TRU color adsorption column, and the TRU color adsorption column is a TRU color column with , americium-neptunium and constant element Na are separated, and the effluent is collected in the waste liquid collector 5.

[0072] 15 mL of 4 mol / L HNO3 solution in the washing liquid storage tank 2 is used to control the flow rate of 2 mL / min through the TRU color adsorption column for washing, and the effluent is collected in the waste liquid collector 5.

[0073] Use 30mL of 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 Chromatographic adsorption column is P 204 The effluent, i.e. the radioactive solution of neptunium, is collected in the neptunium product collector 6.

[0074] Use 10mL of 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, and the effluent is collected in the neptunium product collector 6. Its γ-radioactivity spectrum is as follows: Figure 3 shown.

[0075] Use 15mL4mol / 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 γ-radiation spectrum 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 at 1.5 mL / min, pass it through the TRU chromatography adsorption column, and collect the effluent as waste liquid.

[0077] Use 5mL of 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 from the pipe between the chromatography adsorption column and the TRU chromatography adsorption column 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 of 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 for americium was determined to be 1.2×10 5The decontamination factor of americium from neptunium was 1.1 x 10 4 .

[0081] Example 2

[0082] The TRU chromatographic column in Example 1 was replaced by a RE chromatographic column, and the separation process of Example 1 was repeated to obtain a solution of Np-239 and Am-243. The recovery of neptunium was 95.1%, and the decontamination factor of neptunium from americium was 1.4 x 10 204 The TRU chromatographic column in Example 1 was replaced by a LN chromatographic column, and the separation process of Example 1 was repeated to obtain a solution of Np-239 and Am-243. The recovery of neptunium was 95.1%, and the decontamination factor of neptunium from americium was 1.4 x 10 5 The recovery of americium was 99.2%.

[0083] Example 3

[0084] The solution of Am-243 in the americium-neptunium radioactive solution storage tank in Example 1 was left to stand for 8 days, and the separation process of Example 1 was repeated to obtain a solution of neptunium and a solution of americium for the next cycle. The recovery of neptunium and americium was 95.5% and 99.6%, respectively. The decontamination factor of neptunium from americium was 1.1 x 10 5 .

Claims

1. A device for separating americium and neptunium parent and daughter nuclides, 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 chromatography separation unit via a valve (9) and a delivery pump (10); The liquid storage tank (1) is located inside a temperature controller (11), and a radiation shielding body (12) is provided outside the temperature controller (11); The chromatographic separation unit includes a TRU or RE chromatographic adsorption column (7), a P 204 or LN or P 507 Chromatographic adsorption column (8); The TRU or RE chromatography adsorption column (7) can be a TRU chromatography adsorption column or a RE chromatography adsorption column; P 204 or LN or P 507 The chromatographic adsorption column (8) can 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 includes an americium product collector (13) and a neptunium product collector (6); The liquid storage tank unit is connected to the chromatography 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 chromatography adsorption column (7) and the P 204 or LN or P 507 The inlet of the chromatography adsorption column (8) is connected; the outlet of the TRU or RE chromatography adsorption column (7) is connected to the waste liquid collector (5) and P through the valve (9). 204 or LN or P 507 The inlet of the chromatography adsorption column (8) is connected; 204 or LN or P 507 The discharge port of the chromatography 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: The radioactive solution of americium and neptunium to be separated is placed in a liquid storage tank (1), sodium nitrite is added, the temperature of the liquid storage tank (1) is controlled by a temperature controller (11) to be 70° to 100°, the temperature is kept for a certain period of time, and the solution is cooled to room temperature to obtain a liquid containing americium and neptunium; Dissolve nitric acid, hydrochloric acid, hydrofluoric acid or a combination of these acids with a concentration of 0.01 mol / L to 8.0 mol / L in water respectively. A washing liquid and an eluent are formed, both of which are aqueous; TRU, RE, P 204 , LN, P 507 The resins are respectively filled 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: Wash The washing liquid in the washing liquid storage tank (2) passes through a TRU or RE chromatography adsorption column (7) for washing, and the effluent of the TRU or RE chromatography adsorption column (7) is collected into a waste liquid collector (5); Step 4: Rinse: First, the first-stage eluent in the first-stage eluent storage tank (3) passes through the TRU or RE chromatography adsorption column (7), 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 into a neptunium product collector (6) to obtain a neptunium radioactive solution; Secondly, the first-stage eluent in the first-stage eluent reservoir (3) is directly passed through the 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 into a neptunium product collector (6) to obtain a neptunium radioactive solution; Again, the washing liquid in the washing liquid storage tank (2) is passed through P 204 or LN or P 507 Chromatographic adsorption column (8) to desorb americium and 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 parent and daughter nuclides of americium and neptunium according to claim 4, characterized in that: The method further includes step five, 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 chromatography adsorption column (8) is collected in a waste liquid collector (5); finally, the washing liquid in the washing liquid storage tank (2) passes through the TRU or RE chromatography adsorption column (7), and the effluent from the TRU or RE chromatography adsorption column (7) is collected in a waste liquid collector (5).

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

7. The method for separating parent and daughter nuclides of americium and neptunium according to claim 4, characterized in that: Said 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 0.05mol / L to 0.5mol / L HF and 0.05mol / L to 0.3mol / 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 parent and daughter nuclides of americium and neptunium 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 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 is passed through the TRU chromatography adsorption column and P 204 Chromatographic adsorption column, P 204 Chromatographic adsorption column is In the second process of step 4, the first-stage eluent is 10 mL of 0.05 mol / L HNO3 solution, and the flow rate is 1.5mL / min, directly through P 204 Chromatographic adsorption column; During the process of step 4 again, the washing liquid is 15mL 4mol / L HNO3 solution, the flow rate is 1.5mL / min, and the washing liquid is 15mL 4mol / L HNO3 solution. 204 Americium was desorbed using a chromatography column.

9. The method for separating parent and daughter nuclides of americium and neptunium 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 at a flow rate of 1.5 mL / min, passing through a 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 at a flow rate of 2 mL / min. 204 The pipeline between the chromatography adsorption column and the TRU chromatography adsorption column; During 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 step of step 5, the washing solution is 15 mL of 4 mol / L HNO3 solution, and the flow rate is 2 mL / min, and the washing solution passes through the TRU chromatography adsorption column.

10. The method for separating parent and daughter nuclides of americium and neptunium 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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