System for extracting and separating 228Th after reactor irradiation of 226Ra and treatment method

Abstract

The invention relates to the technical field of radioactive isotopes, and provides a system for extracting and separating 228Th after reactor irradiation of 226Ra and a treatment method, in order to solve the problems that the process of extracting 228Th after reactor irradiation of 226Ra is relatively strict and has potential safety hazards, the system comprises a shielding system and a liquid inlet system arranged outside the shielding system; the shielding system comprises a shielding work box, a target material dissolving device, a separating column and a collecting device; the inlet end of the separation column is connected with the target material dissolving device; the outlet end of the separation column is communicated with the collection device; the inlet end of the separation column is also communicated with a liquid inlet system; the treatment method comprises the following steps: dissolving an irradiated 226Ra target material into a target material dissolving solution, adsorbing the target material dissolving solution in a separation column, and leaching and eluting the separation column by adopting an acid leacheate to obtain a thorium-containing nuclide eluent; the device can be remotely and automatically operated, is good in sealing performance and high in efficiency, and reduces the irradiation dose of personnel operation.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive isotopes, and in particular to a reactor irradiation method. 226 Ra post-extraction and separation 228 Systems and processing methods for Th. Background Art

[0002] Radioactive isotopes have been successfully used in the medical field over the past few decades and have shown great advantages in cancer treatment. 224 Ra is a typical alpha radionuclide suitable for nuclear medicine treatment. It has a half-life of 3.6 days and only emits high-energy alpha particles. It can release high-energy doses within a few millimeters, effectively killing tumor cells without harming surrounding healthy tissues. 224 Ra is an ideal medical alpha radionuclide for targeted treatment of tumors and has gradually attracted people's attention in recent years. 224 Ra has a short half-life and is not suitable for long-term storage. 228 Made of 228 Th- 224 Ra generator, obtained by periodic elution 224 Ra. Therefore, 228 Th is prepared 224 Necessary nuclide raw material for Ra. Usually 228 There are two ways to obtain Th: (1) through natural radionuclides 232 Extraction of Th progeny: 232 Th is generated by α decay 228 Ra, 228 Ra is generated by β decay 228 Ac, 228 Ac is generated by β 228 Th. was separated and extracted by this method 228 Th, each extraction 1Ci 228 Th requires about 14.8t 232 Th salts have complicated process flow and difficult engineering preparation, and are only suitable for small-scale laboratory research. In addition, the extraction process requires the use of 30 years of storage. 228 Th, making the entire cycle extremely long; (2) through reactor irradiation 226 Ra post-extraction: 226 Ra is generated in the reactor through the (n,γ) reaction 227 Ra, 227 Ra is generated by β decay 227 Ac, 227 Ac is generated by (n,γ) reaction 228 Ac, 228 Ac is generated by β 228According to theoretical calculation, under the best irradiation conditions, each extraction of 1Ci of Th 228 Th only needs 300mg 226 In addition, in each irradiation process, only 1% of the target material is consumed for each irradiation section. 226 Ra raw material, 226 Ra can be reused after recycling. 232 Extraction of Th 228 Th, this method can greatly increase 228 The extraction efficiency of Th is expected to be engineered 228 Preparation of Th.

[0003] In the prior art, when irradiating from a reactor 226 Ra post-extraction 228 The Th process is complicated due to the complicated operation, high radiation dose for personnel, and many types of isotope impurities that are difficult to separate. In addition, the separation process involves a large number of α radionuclides, which need to be carried out under sealed conditions to avoid leakage risks. Therefore, the extraction and separation process is relatively harsh and has major safety issues, making it unsuitable for industrial production. Summary of the invention

[0004] The present invention aims to provide a reactor irradiation 226 Ra post-extraction and separation 228 The Th system and processing method can be remotely and automatically operated, have good sealing performance, high efficiency, and reduce the radiation dose of personnel operating.

[0005] The embodiments of the present invention are achieved through the following technical solutions:

[0006] A reactor irradiation 226 Ra post-extraction and separation 228 Th system, comprising: a shielding system and a liquid inlet system arranged outside the shielding system;

[0007] The shielding system comprises a shielding working box and a target material dissolving device, a separation column and a collecting device arranged in the shielding working box;

[0008] The inlet end of the separation column is connected to the target material dissolving device; the outlet end of the separation column is connected to the collecting device;

[0009] The inlet end of the separation column is also connected to the liquid inlet system.

[0010] Furthermore, the shielding system also includes a cutting device and a cover opening device arranged in the shielding working box; the cutting device is used to cut the 226The outer layer inner target tube of the Ra target material is cut; and the cover opening device is used for opening the cover of the inner layer inner target tube.

[0011] Furthermore, the collecting device comprises a first collecting bottle and a second collecting bottle, the first collecting bottle and the second collecting bottle are connected to the outlet end of the separation column through a pipeline, and a multi-way valve is provided on the pipeline.

[0012] Furthermore, the first collecting bottle is connected to a drying device via a pipeline.

[0013] Furthermore, the liquid inlet system includes a plurality of elution bottles for eluting the separation column, and a solution bottle for rinsing the components in the target material dissolution device.

[0014] Furthermore, it also includes an external control system, which is arranged outside the shielding work box and remotely controls the power pump, cutting device, lid opening device, dissolving device, and evaporation device through remote control.

[0015] A method for extracting and separating using the above device comprises the following steps:

[0016] After irradiation 226 The Ra target material is dissolved into a target material solution, which is adsorbed in a separation column filled with a separation material capable of separating Th from Ra and Ac, and then the separation column is rinsed with a first acid elution liquid and then eluted with a second acid elution liquid to obtain an eluent containing thorium nuclides.

[0017] Furthermore, the first acid washing liquid is hydrochloric acid or nitric acid with a concentration of 5 mol / L to 10 mol / L, and the second acid washing liquid is hydrochloric acid or nitric acid with a concentration of 0.5 mol / L to 1 mol / L.

[0018] Furthermore, the obtained thorium nuclide eluate comprises 227 Th and 228 Th, after 180 days of placement, 227 Th decays completely, yielding pure 228 Th solution.

[0019] Furthermore, the pure 228 The Th solution was evaporated to dryness to obtain thorium nitrate ( 228 Th) solid.

[0020] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0021] The separation system and separation process of the present invention can be used to simply and continuously irradiate the reactor 226 Ra post-extraction and separation 228Th, and has high separation efficiency, few separation steps, and can effectively reduce the radiation dose of operators, and can achieve reactor irradiation safely, continuously and stably 226 After Ra 228 Efficient preparation of Th. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A flow chart of an extraction and separation system provided in Example 1 of the present invention;

[0024] Icons: 1-first elution bottle, 2-second elution bottle, 3-solution bottle, 4-three-way valve A, 5-first power pump, 6-fourth power pump, 7-cutting device, 8-opening device, 9-dissolving device, 10-second power pump, 11-three-way valve B, 12-separation column, 13-third power pump, 14-evaporation device, 15-three-way valve C, 16-first collecting bottle, 17-second collecting bottle, 18-control system, 19-shielding working box. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0026] The following is a reactor irradiation method provided by an embodiment of the present invention. 226 Ra post-extraction and separation 228 Th's system and method are described in detail.

[0027] Example 1

[0028] A reactor irradiation 226 Ra post-extraction and separation 228 Th system, comprising: a shielding system and a liquid inlet system arranged outside the shielding system;

[0029] The shielding system includes a shielding working box 19 and a cutting device 7, a cover opening device 8, a dissolving device 9, a separation column 12, a collecting device and a drying device 14 arranged in the shielding working box 19;

[0030] Wherein, the separation column 12 is filled with Dowex 1×8 anion exchange resin, AG 1×8 anion exchange resin, AG MP1 anion exchange resin, and Dowex 1×8 anion exchange resin is preferably selected;

[0031] The inlet end of the separation column 12 is connected to the dissolving device 9 through the first delivery main pipe. Specifically, the dissolving device 9 is connected to the first delivery main pipe through a delivery branch pipe, and a three-way valve B11 is provided at the junction of the delivery branch pipe and the first delivery main pipe.

[0032] The outlet end of the separation column 12 is connected to the collection device through the second delivery main pipe; specifically, the collection device includes a first collection bottle 16 and a second collection bottle 17, and the first collection bottle 16 and the second collection bottle 17 are respectively connected to the second delivery main pipe through an infusion branch pipe, and then connected to the outlet end of the separation column 12 by the second delivery main pipe; it should be noted that a three-way valve C15 is provided at the junction of the two infusion branches and the second delivery main pipe; the second collection bottle 17 is connected to the evaporation device 14 through a delivery pipeline, and the delivery pipeline is provided with a third power pump 13;

[0033] The inlet end of the separation column 12 is also connected to the liquid inlet system; the liquid inlet system includes a plurality of elution bottles for eluting the separation column 12, and a solution bottle 3 for rinsing the components in the dissolution device 9; specifically, in the present invention, there are two elution bottles, namely a first elution bottle 1 and a second elution bottle 2, the first elution bottle 1 is filled with hydrochloric acid or nitric acid with a concentration of 5mol / L to 10mol / L, and the second elution bottle 2 is filled with hydrochloric acid or nitric acid with a concentration of 0.5mol / L to 1mol / L. The first elution bottle 1 and the second elution bottle 2 are respectively connected to the first delivery main pipe through an infusion tube, and then connected to the inlet end of the separation column 12 by the first delivery main pipe; it should be noted that a three-way valve A4 is provided at the confluence of the two infusion tubes and the first delivery main pipe, and a first power pump 5 is provided on the first delivery main pipe; and the solution bottle 3 is connected to the dissolution device 9 through a delivery pipeline, and a fourth power pump 6 is provided on the delivery pipeline;

[0034] When the present invention is used, firstly, the aluminum inner target tube containing the radium-226 target material after irradiation is clamped into the target cutting device 7 by a manipulator to complete the cutting of the aluminum inner target tube, thereby obtaining the quartz inner target tube containing the radium-226 target material; then, the quartz inner target tube is transferred to the uncapping device 8 by the auxiliary operation of the manipulator to complete the uncapping; the uncapped quartz inner target tube is transferred to the dissolving device 9, and then 2 mol / L nitric acid or hydrochloric acid is introduced into the dissolving device 9 through the conveying pipeline by using the external solution bottle 3 to rinse the quartz inner target tube, and then the rinse solution obtained after rinsing is transferred into a round-bottom flask with a heating module, and the heating is turned on until a clear and transparent target material dissolved solution is obtained;

[0035] Then, the second power pump 10 provides power to transfer the target material solution to the separation column 12, and the separation column 12 is eluted by multiple elution bottles (such as the first elution bottle 1 and the second elution bottle 2) outside the shielding working box 19. It should be noted that the multiple elution bottles are respectively filled with elution liquids of different gradient concentrations. Specifically, the elution liquid is 0.5mol / L to 10mol / L hydrochloric acid or nitric acid. Specifically in this embodiment, two elution bottles are provided, namely the first elution bottle 1 and the second elution bottle 2. The first elution bottle 1 is filled with hydrochloric acid or nitric acid with a concentration of 5mol / L to 10mol / L, and the second elution bottle 2 is filled with hydrochloric acid or nitric acid with a concentration of 0.5mol / L to 1mol / L.

[0036] When in use, firstly use high concentration hydrochloric acid or nitric acid of 5 mol / L to 10 mol / L in the first elution bottle 1 to elute the separation column 12. 228 Th, 227 The Th nuclide will be retained in the separation column 12. Adjust the three-way valve C15 to transfer Ac( 228 Ac, 228 Ac)、Ra( 223 Ra, 224 Ra, 226 Ra, 228 Then, when the elution volume is greater than 50 mL, no more actinium and radium nuclides flow out. At this time, the separation column 12 is eluted with a lower concentration of acid (i.e., 0.5 mol / L to 1 mol / L hydrochloric acid or nitric acid in the second elution bottle 2) outside the shielding working box 19, and the three-way valve C15 is adjusted to 228 Th, 227 The Th nuclide eluent is collected in the second collection bottle 17; after being placed for a period of time, 227 After the Th nuclide decays completely, pure 228 Th solution; at this time, the third power pump 13 provides power to 228 The Th solution is transferred to the evaporation device 14, and the solution is evaporated to dryness to obtain thorium nitrate ( 228 Th) solid.

[0037] Furthermore, the solution bottle 3 can store the solution, and the material can be quartz glass, which is resistant to high temperature and corrosion, has a scale, and is placed outside the shielding working box 19, with a capacity ranging from 50mL to 2L; specifically, the solution bottle 3 of suitable capacity or material can be adaptively selected according to the use requirements, and the present invention does not limit it.

[0038] Furthermore, each of the power pumps (such as the first power pump 5, the second power pump 10, the third power pump 13, and the fourth power pump 6) provides power for the system, and some of them are located outside the shielding working box 19 (the first power pump 5 and the fourth power pump 6), and some of them are located inside the shielding working box 19 (the second power pump 10 and the third power pump 13); each of the power pumps can be any one of a peristaltic pump, a syringe pump, a constant current pump, etc., and can accurately control the volume and flow rate of the required solution to ensure faster and more stable injection into the system.

[0039] Furthermore, the separation column 12 can be made of Peek material or quartz glass material, which is corrosion-resistant. The upper and lower ends of the separation column 12 are connected to the pipeline through a quick interface, which can achieve retention and elution of different nuclides.

[0040] Furthermore, each of the three-way valves (three-way valve A4, three-way valve B11, three-way valve C15) can be conveniently operated by a manipulator, and the solution inlet and outlet routes can be controlled by valve steering to guide the solution to different branches.

[0041] Furthermore, the target cutting device 7 is used for fixing and chip-free cutting of the aluminum inner target tube, and the material inside the tube can be taken out with the assistance of a manipulator; its specific structure can adopt an existing laser cutting machine, or it can adopt an irradiation target cutting device 7 as disclosed in the existing patent CN105414671A; the present invention does not impose any restrictions on this, and those skilled in the art can select a suitable device for cutting the target according to their needs.

[0042] Furthermore, the cover opening device 8 is mainly used for opening the cover of the quartz inner target tube; its specific structure can adopt the existing device for opening the cover of the inner target tube; in addition, it can also include the following components, such as: a fixing frame for placing the inner target tube and a servo rotating electric clamp for clamping the quartz inner target tube plug and automatically screwing it; the present invention does not limit this, and those skilled in the art can select a suitable device for opening the cover of the inner target tube according to their needs.

[0043] Furthermore, the dissolving device 9 is used to add liquid, rinse and dissolve the quartz inner target tube after the cover is opened; its specific structure can adopt the existing device for dissolving; in addition, it can also include the following components, such as: an inner target tube fixing frame, an injection pump, and an injection tube; the inner target tube is fixed by the inner target tube fixing frame, and liquid is passed into the injection tube by the injection pump, so that liquid (such as acid) is added to the inner target tube for rinsing; the present invention does not limit this, and technical personnel in this field can select a suitable device for dissolving the inner target tube cover according to needs.

[0044] Furthermore, the evaporation device 14 is used to separate the eluate ( 228Th) is completely evaporated to dryness and converted into solid nitrate; its specific structure can adopt the existing evaporation device 14; or a concentrated evaporation device or a round-bottom flask, etc.; the present invention is not limited to this, and those skilled in the art can select a suitable device for evaporation according to needs.

[0045] Furthermore, the shielding work box 19 is used for shielding the radioactive dose during the operation, and the size can be designed according to the needs. In the present invention, the shielding work box 19 has a size of 2*1.5*1.5m, and is mainly composed of lead, lead glass and stainless steel.

[0046] Furthermore, the control system 18 is arranged outside the shielding working box 19 and adopts remote control to remotely control various power pumps, three-way valves, cutting devices 7, lid opening devices 8, dissolving devices 9, evaporation devices 14 and other devices or components that need to be regulated; the above-mentioned components are connected to the control system 18 by signal.

[0047] Example 2

[0048] A reactor irradiation 226 Ra post-extraction and separation 228 The method of Th comprises the following steps:

[0049] The irradiated aluminum inner target tube containing 20 mg of 226Ra quartz inner target tube is clamped and fixed in the target cutting device 7, and the target cutting device 7 is opened by the control system 18 to complete the target cutting (i.e., the outer aluminum inner target tube is cut); the quartz inner target tube containing 226Ra target material is clamped in the cover opening device 8, and the cover opening device 8 is opened by the control system 18, and the quartz inner target tube is opened by using a manipulator and a servo rotating electric clamp; then the quartz inner target tube is clamped in the fixing frame for placing the inner target tube of the dissolving device 9, the fourth power pump 6 is turned on, and 20 mL of 2 mol / L nitric acid in the solution bottle 3 is added to the dissolving device 9 through the conveying pipeline, the quartz inner target tube is rinsed, and the target material is rinsed into the round-bottom flask, and the heating module is turned on to heat and dissolve the target material rinsing liquid in the round-bottom flask to obtain 20 mL of target material dissolved liquid.

[0050] Then, the second power pump 10 provides power to transfer the target material solution to the separation column 12, in which Dowex 1×8 anion exchange resin is installed, and the first power pump 5 is turned on, and the separation column 12 is eluted with 8 mol / L nitric acid in the first elution bottle 1 outside the shielding work box 19, and the three-way valve C15 is adjusted to collect the elution liquid of the nuclides such as Ra and Ac into the first collection bottle 16, and the Th nuclides are retained in the separation column 12. After eluting 50 mL, the three-way valve is adjusted so that the 0.8 mol / L nitric acid in the second elution bottle 2 is used to elute the separation column 12, and the Th nuclides are completely eluted. At the same time, the elution liquid is collected into the second collection bottle 17.

[0051] The third power pump 13 is started to transfer the solution in the first collecting bottle 16 to the evaporation device 14 for evaporation to obtain thorium nitrate (228Th) solid.

[0052] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A reactor irradiation 226 Ra post-extraction and separation 228 Th system, characterized in that include: A shielding system and a liquid inlet system arranged outside the shielding system; The shielding system comprises a shielding working box and a target material dissolving device, a separation column and a collecting device arranged in the shielding working box; The inlet end of the separation column is connected to the target material dissolving device; the outlet end of the separation column is connected to the collecting device; The inlet end of the separation column is also connected to the liquid inlet system.

2. Reactor irradiation according to claim 1 226 Ra post-extraction and separation 228 Th system, characterized in that The shielding system also includes a cutting device and a cover opening device arranged in the shielding working box; the cutting device is used to cut the 226 The outer layer inner target tube of the Ra target material is cut; and the cover opening device is used for opening the cover of the inner layer inner target tube.

3. Reactor irradiation according to claim 1 226 Ra post-extraction and separation 228 Th system, characterized in that The collecting device comprises a first collecting bottle and a second collecting bottle, the first collecting bottle and the second collecting bottle are connected with the outlet end of the separation column through a pipeline, and a multi-way valve is arranged on the pipeline.

4. Reactor irradiation according to claim 3 226 Ra post-extraction and separation 228 Th system, characterized in that The first collecting bottle is connected to a drying device via a pipeline.

5. The reactor irradiation according to claim 1 226 Ra post-extraction and separation 228 Th system, characterized in that The liquid inlet system comprises a plurality of elution bottles for eluting the separation column and a solution bottle for rinsing the components in the target material dissolving device.

6. Reactor irradiation according to claim 1 226 Ra post-extraction and separation 228 Th system, characterized in that It also includes an external control system, which is arranged outside the shielding work box and remotely controls the power pump, cutting device, cover opening device, dissolving device and evaporation device through remote control.

7. A reactor irradiation 226 Ra post-extraction and separation 228 The method of Th, characterized in that The following steps are involved: Using the system according to any one of claims 1 to 6 to irradiate a reactor 226 Extraction and separation after Ra 228 Th, the irradiated 226 The Ra target material is dissolved into a target material solution, which is adsorbed in a separation column filled with a separation material capable of separating Th from Ra and Ac, and then the separation column is rinsed with a first acid elution liquid and then eluted with a second acid elution liquid to obtain an eluent containing thorium nuclides.

8. Reactor irradiation according to claim 7 226 Ra post-extraction and separation 228 The method of Th, characterized in that The first acid washing liquid is hydrochloric acid or nitric acid with a concentration of 5 mol / L to 10 mol / L, and the second acid washing liquid is hydrochloric acid or nitric acid with a concentration of 0.5 mol / L to 1 mol / L.

9. Reactor irradiation according to claim 7 226 Ra post-extraction and separation 228 The method of Th, characterized in that The obtained thorium nuclide eluate contains 227 Th and 228 Th, after 180 days of placement, 227 Th decays completely, yielding pure 228 Th solution.

10. Reactor irradiation according to claim 9. 226 Ra post-extraction and separation 228 The method of Th, characterized in that For the pure 228 The Th solution is evaporated to dryness to obtain thorium nitrate solid.

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